KR101275450B1 - Improved thin-film coatings, electro-optic elements and assemblies incorporating these elements - Google Patents

Abstract

Electro-optical elements are becoming common in many vehicle and building applications. Various electro-optic element configurations provide variable transmittance and / or variable reflectance for windows and mirrors. The present invention relates to various thin film coatings, electro-optical elements, and assemblies comprising these elements.

Description

IMPROVED THIN-FILM COATINGS, ELECTRO-OPTIC ELEMENTS AND ASSEMBLIES INCORPORATING THESE ELEMENTS}

The present invention relates to various thin film coatings, electro-optical elements, and assemblies comprising these elements.

Cross-reference to related application

This application is based on U.S. Patent Act Article 119 (e) the following U.S. Provisional Patent applications, such as Tonar et al., Filed March 3, 2006, filed 60 / 779,369, filed June 5, 2006. 60 / 810,921 to Tonar et al., 60 / 873,474 to Tonar et al., Filed Dec. 7, 2006, and inventions filed to February 7, 2007 are entitled "ELECTRO-OPTIC ELEMENT WITH IMPROVED TRANSPARENT CONDUCTOR." (Electro-Optical Element with Improved Transparent Conductor) is claimed by Neuman (Agent Document No. GEN10PP-514), which is hereby incorporated by reference in its entirety.

This application is filed under the following U.S. patent application, namely, "ELECTRO-OPTICAL ELEMENT INCLUDING IMI COATINGS" (Representative Document No. GEN10-P517) and another application ( Representative Document No. GEN10 P518, both of which are filed concurrently with the present application, which are hereby incorporated by reference in their entirety.

Electro-optical elements are becoming common in many vehicle and building applications. Various electro-optical element configurations provide variable transmittance and / or variable reflectance for windows and mirrors.

1 shows a plane with a variable transmittance window.
2A and 2B show bus and train carriages, respectively, with variable transmittance windows.
3 shows a building with variable transmittance and / or variable reflectance windows.
4 is an illustration of a vehicle with a variable transmittance window and a variable reflectance rearview mirror.
5A-5E are various views of the outer rearview mirror assembly and associated variable reflectance elements.
6A-6D are various views of the inner rearview mirror assembly and associated variable reflectance elements.
7 shows a profile of a cross section of a variable reflectance element.
8A-8D show profiles of cross sections of various elements.
9A-9J illustrate various electrical contacts of various elements.
10 is an electrical control schematic for a number of elements.
11A-11C are various electrical control schematics.
FIG. 12 is a graph of element warp versus oxygen flow for various argon process gas pressures used in the urea manufacturing process.
FIG. 13 is a graph of thin film bulk resistance versus coral flow for various process gas pressures used in the urea manufacturing process.
14 is a graph of thin film thickness versus oxygen flow for various process gas pressures used in the urea manufacturing process.
FIG. 15 is a graph of thin film sheet resistance versus argon flow for various process gas pressures used in the urea manufacturing process.
FIG. 16 is a graph of thin film bulk resistance versus argon flow for various process gas pressures used in the urea manufacturing process.
FIG. 17 is a graph of thin film absorption versus oxygen flow for various process gas pressures used in the urea manufacturing process.
FIG. 18 is a plot of urea warp versus oxygen flow for various process gas pressures used in urea manufacturing processes.
FIG. 19 is a graph of urea warp versus thin film absorption for various process gas pressures used in urea manufacturing processes.
FIG. 20 is a graph of urea warp versus thin film transmission for various process gas pressures used in urea manufacturing processes.
21 to 32 are views illustrating various thin film surface shapes.
33A and 33B illustrate thin film peak-peak surface roughness.
FIG. 34 is a graph of sputtering yield versus ion energy for various thin film materials. FIG.
FIG. 35 is a graph of sputtering yield versus sputter gas mass / target mass. FIG.
36 and 37 are enlarged views of the results of ion-milling.
FIG. 38 is a graph showing the inverse of thin film surface roughness versus line speed. FIG.
39 shows a graph of thin film reflectance versus ion beam current.
40 is a graph showing the inverse of the thin film reflectance versus the linear velocity.
Fig. 41 is a graph showing the inverse of thin film b * versus linear velocity.
FIG. 42 is a graph of thin film reflectance versus ion beam residence time. FIG.
43 is a graph of thin film reflectance versus thickness.
FIG. 44 is a graph of thin film reflectance versus wavelength. FIG.
45 is a graph showing thin film transmittance versus wavelength.
46 shows a graph of thin film reflectance versus thickness.
47 is a graph showing thin film transmittance vs. reflectance.
48A-53 illustrate various graphs of thin film reflectance and / or transmittance versus wavelength.
54-62 illustrate various embodiments of elements having a graded thin-film coating.
Figure 63 shows an embodiment of a mirror element according to the prior art for the present invention.

1, 2A and 2B show multi-passenger vehicles 102, 202a, 202b using variable transmittance windows 110, 210a, 210b. Multi-passenger vehicles using variable transmittance windows 110, 210a and 210b are, for example, airplanes 102, buses 202a and trains 202b. It will be appreciated that other multi-passenger vehicles, some of which are described in detail elsewhere herein, may utilize variable transmittance windows 110, 210a, 210b. The multi-passenger vehicle, outlined in FIGS. 1, 2A and 2B, is also a window control system (not shown in FIGS. 1-2B, but shown and described with reference to FIG. ) Is also included. US Patent Application No. 60 / 804,378, co-assigned US Patent No. 6,567,708 and filed June 9, 2006, entitled " Variable Transmission Window Systems " The details are set forth and these are hereby incorporated by reference in their entirety.

Another application of the variable transmittance window is shown in FIG. 3. It may be advantageous if the windows 302 of the building 301 include a variable transmission function. It will be appreciated that these variable transmissive windows can be included in residential, commercial and industrial facilities.

4 illustrates a controlled vehicle 400 that includes various variable transmittance and variable reflectance elements. As an example, an interior rearview mirror assembly 415 is shown, and in at least one embodiment, the assembly 415 includes a variable reflectance mirror element and an automatic vehicle exterior light control system. vehicle exterior light control system. Detailed description of such an automatic vehicle exterior light control system is disclosed in commonly assigned US Patent Nos. 5,837,994, 5,990,469, 6,008,486, 6,130,448, 6,130,421, 6,049,171, 6,465,963, 6,403,942, 6,587,573, 6,611,610, 6,621,616, and 6,631,316, and US Patent Applications 10 / 208,142, 09 / 799,310, 60 / 404,879, 60 / 394,583, 10 / 235,476, 10 / 783,431, 10 / 777,468, and 09 / 800,460, which are incorporated herein by reference in their entirety. The control vehicle also includes an exterior rearview mirror assembly 410a on the driver's side, an exterior rearview mirror assembly 410b on the passenger side, a center high mounted stop light (CHMSL) 445, and an A-pillar (A). -pillar 450a, 450b, B-pillar 455a, 455b, and C-pillar 460a, 460b. It will be appreciated that any of these locations may provide an alternative location for image sensors, image sensors, or related processing and / or control components. It will be appreciated that any or all of the rearview mirrors may be an automatic dimming electro-optic mirror (ie, a variable reflectance mirror element). In at least one embodiment, the control vehicle may include variable transmittance windows 401, 402. The control vehicle includes headlights 420a and 42Ob, fog weather lights 430a and 430b, front turn indicator / hazard lights 435a and 435b and tail lights. 425a, 425b, rear turn indicators 426a, 426b, rear warning lights 427a, 427b, and backup lights 440a, 440b. It will be appreciated that additional exterior light may be provided, such as separate low beam and high beam headlights, integrated light including multipurpose lighting. It will also be appreciated that any of the external lights may be equipped with a positioner (not shown) that adjusts the associated primary optical axis of a given external light. In at least one embodiment, the at least one outer mirror assembly has a pivoting mechanism that enables pivoting in directions 410a1, 410a2, 410b1, 410b2. The control vehicle of FIG. 4 is generally for illustration and suitable automatic dimming rearview mirrors such as those disclosed in patents and patent applications incorporated herein by reference are also incorporated herein by reference. It will be appreciated that it may be used with other features described in the disclosure.

Preferably, this control vehicle comprises an interior rearview mirror of unit magnification. A unit magnification mirror, as used herein, is directly at a distance where the angular height and width of the image of the object are equal, except for defects that do not exceed conventional manufacturing tolerances. By virtue it is meant a planar or flat mirror with a reflective surface such as the angular height and width of the object. A prismatic day-night adjustment rearview mirror in which at least one associated position provides equal magnification is considered herein to be an equal magnification mirror. Preferably, this mirror measures the horizontal angle of incidence measured from the projected eye point when the control vehicle is occupied with a specified occupant capacity (if less) based on the driver and four passengers or an average occupant weight 68 kg. The included horizontal angle is at least 20 degrees and provides a field of view with a vertical angle sufficient to provide a view of the flat road surface starting at a point no greater than 61 m to the rear of the control vehicle and extending to the horizon. It will be appreciated that the line of sight may be partially obscured by a seated occupant or by a head restraint. The position of the driver's eye reference point is preferably a nominal position that is compliant or appropriate for a 95% male driver. In at least one embodiment, the control vehicle comprises at least one outer mirror of equal magnification. Preferably, the outer mirror provides the driver of the control vehicle with a view of the flat road surface extending from the line perpendicular to the longitudinal plane facing the driver's side of the control vehicle to the horizon at its widest point, where the seat is the last. In the short position, it extends 2.4 m out of the contact plane at 10.7 m behind the driver's eyes. It will be appreciated that the line of sight may be partially obscured by the rear body or fender contour of the control vehicle. Preferably, the position of the driver's eye reference point is a nominal position that conforms to the regulations or is appropriate for a 95% male driver. Preferably, the passenger side mirror is not obscured by the corresponding unpolished portion of the windshield, and is preferably adjustable by tilting in both the horizontal and vertical directions from the driver's seating position. In at least one embodiment, the control vehicle comprises a convex mirror mounted on the passenger side. Preferably, this mirror is configured to adjust by tilting in both the horizontal and vertical directions. Preferably, each exterior mirror comprises a reflective surface no greater than 126 cm and is positioned to provide the driver with a rearward view along the associated side of the control vehicle. Preferably, the average reflectance of the mirror, determined according to SAE Recommended Practice J964, OCT84, is at least 35% (40% in many European countries). In an embodiment in which the mirror element can have multiple reflectance levels, as in the electro-optic mirror element according to the invention, the minimum reflectance level in the daytime mode is at least 35% (40% for use in Europe), The minimum reflectance level in night mode is at least 4%. It will be appreciated that various embodiments of the present invention are equally applicable to motorcycle windshields and rearview mirrors.

Referring now to FIGS. 5A and 5B, various components of the outer rearview mirror assemblies 510a and 510b are shown. As will be described in detail herein, the electro-optic mirror element may be secured to a second substrate (a fixed distance apart from the first substrate through a first seal 521b and a primary seal 523b). 522b), forming a chamber between both substrates. In at least one embodiment, there is a void in at least a portion of the primary seal to form at least one chamber fill port 523b1. An electro-optic medium is encased in the chamber and the charging port (s) are sealingly closed with plug material 523b2. Preferably, the plug material is a UV curable epoxy or acrylic material. In at least one embodiment, spectral filter materials 545a and 545b are located proximate the second surface of the first substrate near the periphery of the mirror element. Electrical connectors 525b1 and 525b2 are preferably secured to the element via first adhesive material 526b1 and 526b2 respectively. The mirror element is secured to carrier plate 575b through second adhesive material 570b. The electrical connection from the outer rearview mirror to the other parts of the control vehicle is preferably made via connector 585b. This carrier is attached to an associated housing mount 585b via a positioner 580b. Preferably, this housing mount is in engagement with the housings 515a and 515b and is secured through at least one fastener 534b4. Preferably, the housing mount includes a swivel portion configured to engage a swivel mount 533b. The swivel mount is preferably configured to engage the vehicle mount 530b via at least one fastener 531b. Additional details of these components, additional components, their interconnections, and operation are provided herein.

5A and 5B, the outer rearview mirror assembly 510b shows that the spectral filter material 524b is located between the viewer and the primary seal material 523b when looking at the first substrate 521b. It is oriented so that it may become. Blind spot indicator 550a, keyhole illuminator 555a, puddle light 560a, auxiliary direction signal 54Oa1 or 541a, light sensor 565a, all of these, Their subcombinations, or their combinations, may be included in the rearview mirror assembly such that they are located behind the element relative to the viewer. Preferably, as described herein and in the many cited references cited herein, the devices 550a, 555a, 560a, 540a, or 541a, 565a are comprised of a mirror element and a combination such that they are at least partially invisible. It is. Additional details of these components, additional components, their interrelationships, and operation are included herein.

Referring now to FIGS. 5C-5E, a description of additional features in accordance with the present invention is provided. 5C shows the rearview mirror element 500c where the spectral filter material 596c is between the viewer and the primary seal material 578c when viewed from the first substrate 502c. First separation area 540c is provided to substantially electrically insulate first conductive portion 508c from second conductive portion 530c. Perimeter material 560c is applied to the edge of the rearview mirror element. 5D shows the rearview mirror element 500d with the primary seal material 578d positioned between the viewer and the spectral filter material 596d when viewed from the second substrate 512d. A second isolation region 586d is provided to substantially electrically insulate the third conductive portion 518d from the fourth conductive portion 587d. Peripheral material 560d is applied to the edge of the rearview mirror element. 5E shows the rearview mirror element 500e as seen from the cutout line of FIGS. 5E-5E of either rearview mirror element of FIG. 5C or 5D. The first substrate 502e is shown fixedly spaced apart from the second substrate 512e through the primary sealing material 578e. A spectral filter material (referred to herein as "chrome ring" in one embodiment) 596e is located between the viewer and the primary seal material 578e. First and second electrical clips 563e and 584e are provided, respectively, to facilitate electrical connection to the rearview mirror element. Peripheral material 560e is applied to the edge of the rearview mirror element. It will be appreciated that the primary seal material may be applied by means commonly used in the LCD industry, such as silk-screening or dispensing. US Pat. No. 4,094,058 to Yasutake et al., Incorporated herein by reference in its entirety, describes an applicable method. Using these techniques, the primary seal material may be applied to an individually cut to shape substrate or as multiple primary seal shapes on a large substrate. Large substrates having multiple primary seals applied may then be laminated to other large substrates, and individual mirror shapes may be cut out of the laminate after at least partially curing the primary seal material. have. This multi-processing technique is a commonly used method of manufacturing LCDs and is sometimes referred to as an array process. The electro-optical device according to the invention can be manufactured using a similar process. In the case of transparent conductors, reflectors, spectral filters, and solid state electro-optical devices, all coatings such as electro-optical layers or layers can be applied and patterned on large substrates as needed. These coatings apply a coating through a mask, selectively apply a patterned soluble layer underneath the coating and remove the coating on top of the soluble layer and the soluble layer after coating application, laser ablation or etching. It can be patterned using a number of techniques, such as. These patterns can include registration marks or targets that are used to accurately align or position the substrate throughout the manufacturing process. This is usually done optically with the visual system using pattern recognition techniques, for example. The alignment mark or target may also be applied directly to the glass, if desired, by sand blasting, laser or diamond scribing. Spacing media that control the spacing between the laminated substrates may be placed in the primary seal material or applied to the substrate prior to lamination. A spacing medium or means can be applied to the area of the laminate that is cut out of the finished singulated mirror assembly. If the device is a solution phase electro-optic mirror element, the laminated array may be cut according to shape before or after filling with the electro-optic material and plugging the fill port. have.

Referring now to FIGS. 6A and 6B, when looking at the first substrates 622a, 622b, the spectral filter material 645a or bezel 645b is between the viewer and the primary seal material (not shown). Inner rear view mirror assemblies 6Oa and 610b are shown. The mirror element is located in movable housings 675a and 675b and optionally on a stationary housing on mounting structure 681a (with fixed housing or 681b with no fixed housing). 677a) is shown. The first indicator 686a, the second indicator 687a, the operator interfaces 691a and 691b and the first optical sensor 696a are located in the chin portion of the movable housing. First information displays 688a, 688b, second information display 689a, and second light sensor 697a are included in the rearview mirror assembly such that they are behind the mirror element for the viewer. As described in connection with the outer rearview mirror assembly, it is preferred that the devices 688a, 688b, 689a, 697a be at least partially invisible as described in detail herein. In at least one embodiment, the inner rearview mirror assembly comprises at least one illumination assembly 670b, at least one microphone, subcombinations thereof, combinations thereof, or devices described above on the printed circuit board 665b. It may include other combinations of and. It will be appreciated that aspects of the invention may be included in multiple combinations in an electro-optical window or mirror individually or in whole.

6C shows a top view of a second substrate 612c that includes a stack of materials on a third surface, a fourth surface, or both the third and fourth surfaces. In at least one embodiment, under the primary seal material, at least a portion 620d of the material stack or at least substantially opaque layers of the material stack are removed or masked. At least a portion 620c2 of at least one layer of the material stack extends substantially to the outer edge of the substrate or extends to an area that facilitates electrical contact between the third surface stack and the element drive circuit (not shown in FIG. 6C). have. Related embodiments relate to inspection of the seal from the rear of the mirror or window element and / or plug visual inspection and / or plug curing after element assembly. In at least one embodiment, at least a portion of the outer edge 620d of the stack of materials 620c is located between the inner edge 678c1 and the inner edge 678c2 of the primary seal material 678c. In at least one embodiment, a portion of the material stack 620c1 or at least substantially opaque layers of the material stack is removed or masked, approximately 2 mm to about 8 mm wide, preferably about 5 mm wide, below the primary seal material. . At least a portion 620c2 of at least one layer of the material stack extends substantially to the outer edge of the substrate or is approximately 0.5 mm to approximately 5 mm wide, preferably approximately 1 mm wide, with a third surface stack and element drive circuit (not shown) It extends to an area that facilitates electrical contact between them. It will be appreciated that any of the first, second, third, and fourth surface material layers or surface material stacks may be as disclosed in the references cited herein or elsewhere herein.

6D shows a top view of a second substrate 612d that includes a third surface material stack. In at least one embodiment, at least a portion of the outer edge 620d1 of the third surface material stack 620d is located between the outer edge 678d1 and the inner edge 678d2 of the primary seal material 678d. In at least one related embodiment, the conductive tab portion 682d extends inward of the outer edge 678d1 of the primary seal material 678d from the edge of the second substrate. In at least one related embodiment, the conductive tab portion 682d1 overlaps at least a portion of the third surface material stack below the primary seal material 678d. In at least one embodiment, a substantially transparent conductive layer (not individually shown) (conductive metal oxide, etc.) of the third surface material stack is shown in FIG. 8B to provide an external electrical connection to the third surface. As is, it extends beyond the outer edge 620d1 of the remaining third surface stack. It will be appreciated that the conductive tabs may be deposited along any of the regions around the substrate as shown in FIGS. 9C-9I. In at least one embodiment, the conductive tab portion comprises chromium. While the conductive tab portion enhances conductivity through the conductive electrode, it will be appreciated that the conductive tab portion is optional as long as the conductive electrode layer has sufficient conductivity. In at least one embodiment, the conductive electrode layer provides the desired color related properties of the corresponding reflected beam in addition to providing the desired conductivity. Thus, when the conductive electrode is omitted, the color properties are controlled through the underlayer material specification. It will be appreciated that any of the first, second, third and fourth surface material layers or surface material stacks may be as disclosed in the references cited herein or elsewhere herein.

FIG. 7 shows a rearview mirror element 700 which is an enlarged view of the element shown in FIG. 5E to provide more detail. Element 700 includes a first substrate 702 and a second substrate 706 having a first surface 704. The first conductive electrode portion 708 and the second conductive electrode portion 730 applied to the second surface 706 are substantially electrically insulated from each other through the first isolation region 740. As can be seen, in at least one embodiment, the separation region is also substantially electrically insulated from the spectral filter material 796 and the corresponding adhesion promotion material 793 so that the first and second spectral filter materials It is positioned to define portions 724 and 736 and also to define first and second adhesion promoting material portions 727 and 739 respectively. Portions of the first isolation regions 740, 540c, 64Od, 54Oe are shown extending in parallel within a portion of the primary seal material 778 located near its center. This portion of separation region 740 may be placed such that the viewer does not easily recognize a line in the spectral filter material, for example, a portion of the separation region may be substantially inboard edge of spectral filter material 596. It will be appreciated that it can be aligned with (797). As described in more detail elsewhere herein, electro-optical material coloring and / or clearing when any portion of isolation region 740 is located inside the primary seal material. It will be appreciated that discontinuities of) can be observed. These operating characteristics can be manipulated to derive subjective visually appealing elements.

With further reference to FIG. 7, element 700 is shown to include a second substrate 712 having a third surface 715 and a fourth surface 714. Note that the first substrate can be larger than the second substrate to create an offset along at least a portion of the periphery of the mirror. Third and fourth conductive electrode portions 718, 787 are shown near third surface 715, which is substantially electrically insulated through second isolation region 786, respectively. Portions of the second isolation regions 786, 586c, 586d, 586e are shown extending in parallel within a portion of the primary seal material 778 located near its center. To prevent the viewer from easily recognizing a line in the spectral filter material, for example, a portion of the separation region may be aligned substantially in line with the inner edge 797 of the spectral filter material 796. It will be appreciated that this part may lie. As further shown in FIG. 7, a reflective material 720 may be applied between the optional overcoat material 722 and the third conductive electrode portion 718. Jointly assigned US patents / patent applications 6,111,684, 6,166,848, 6,356,376, 6,441,943, 10 / 115,860, 5,825,527, 6,111,683, 6,193,378, 09 / 602,919, 10 Any of the materials disclosed in US / 260,741, 60 / 873,474 and 10 / 430,885, which are incorporated herein by reference in their entirety, may be hydrophilic coatings on the first surface, or the like. Unitary surface coatings, or composite coating composites of conductive electrode materials, spectral filter materials, adhesion promoter materials, reflective materials, overcoat materials, etc. applied to the first, second, third and fourth surfaces It will be appreciated that it can be used to define stack of coatings. It will also be appreciated that hydrophilic coatings, silicone containing coatings or specially textured surfaces such as fluorinated alkyl salines or polymers may be applied to the first surface. Hydrophilic or hydrophobic coatings change the contact angle of moisture impinging on the first surface for glass without such a coating to improve rear vision when moisture is present. It will be appreciated that both third and fourth surface reflector embodiments are within the scope of the present invention. In at least one embodiment, the material applied to the third and / or fourth surface is configured to provide partially reflective / partly transmissive properties to at least a portion of the corresponding surface stack. In at least one embodiment, the materials applied to the third surface are integrated to provide a combination of reflector / conductive electrodes. It will be appreciated that additional "third surface" materials may extend out of the primary seal, in which case the corresponding separation region extends through the additional materials. For example, as shown in FIG. 6C, making at least a portion of the primary seal visible from the fourth surface facilitates inspection of the plug material and UV curing. In at least one embodiment, at least a portion of the material stack 620c or at least substantially opaque layer of material stack below the primary seal material to provide inspection of at least 25% of the primary seal width near at least a portion of the perimeter. Are removed or masked. It is better to provide an inspection of 50% of the primary seal width near at least a portion of the periphery. It is best to provide an inspection of at least 75% of the primary seal width near at least a portion of the perimeter. Various embodiments of the present invention include portions of a particular surface having a coating or coating stack different from other portions, for example, a "window" in front of a light source, an information display, a light sensor, or a combination thereof. windwind " can be formed to selectively transmit a particular band of light wavelengths or specific bands of light wavelengths, as described in many of the cited references included herein.

6A, 6B, and 7, the first isolation region 740 cooperates with a portion of the primary seal material 775 to form the first conductive electrode portion 708, the first spectral filter material portion ( 724 and a second conductive electrode portion 730, a second spectral filter material portion 736 and a second adhesion promoting material portion 739 that are substantially electrically insulated from the first adhesion promoting material portion 727. . This configuration allows the first electrically clip 763 to electrically communicate with the third conductive electrode portion 718, the reflective material 720, the optional overcoat 722 and the electro-optical medium 710. Make it possible to deploy In particular in embodiments where the electrically conductive material 748 is applied to the mirror element prior to the placement of the first electrical clip 769, the electrically conductive material may at least partially separate the interfaces 757, 766, 772, 775. It is obvious. Preferably, the third conductive electrode portion 718, the first electrical clip 763, and the composite of the material or materials forming the electrically conductive material 748 provide durable electrical communication between the clip and the material leading to the electro-optical medium. Is selected to facilitate. The second isolation region 786 cooperates with a portion of the primary seal material 775 to form the third conductive electrode portion 718, the reflective layer 720, the optional overcoat material 722 and the electro-optical medium 710. And a fourth conductive electrode portion 787 that is substantially electrically insulated from. This configuration allows the second electrical clip 784 to be in electrical communication with the first adhesion promoting material portion 727, the first spectral filter material portion 724, the first conductive electrode portion 708, and the electro-optical medium 710. It is possible to arrange the electrically conductive material 790 to make. In particular in embodiments where the electrically conductive material 790 is applied to the mirror element prior to the placement of the first electrical clip 784, it is evident that the electrically conductive material can at least partially separate the interfaces 785, 788, and 789. Do. Preferably, the first conductive electrode portion 708, the first electrical clip 784, the adhesion promoting material 793, the spectral filter material 796 and the material forming the electrically conductive material 790 are composites of It is selected to facilitate durable electrical communication between the material, up to the clip and the electro-optic medium.

Occasionally, one or more optional flash overcoat layers (not on reflective layer 720) are placed over reflective layer 720 such that an optional flash over-coat layer 722 is in contact with an electrochromic medium. 722). This flash overcoat layer 722 must have stable behavior as an electrode, have a good shelf life, be well bonded to the reflective layer 720, and be bonded to a seal member 778 This junction must be maintained when If the optical properties from the underlayer (s) are visible at the cover layer, the cover layer does not completely block the reflectivity of the layer (s) 720 below it. This should be thin enough. According to another embodiment of the invention, when a very thin flash overcoat 722 is disposed on top of the highly reflective layer, the reflective layer 720 may be a silver metal or silver alloy, since the flash layer protects the reflective layer. Yet still allows the highly reflective layer 720 to contribute to the reflectivity of the mirror. In this case, a thin layer of rhodium, ruthenium, palladium, platinum, nickel, tungsten, molybdenum or their alloys (e.g., less than about 300 .ANG., More preferably less than about 100 .ANG.) It is deposited on the reflective layer 720. The thickness of the flash layer depends on the material selected. For example, 10 .ANG. Elements consisting of a third surface coating of silver / rhodium / ruthenium / chromium (the latter one below) coated with a flash layer of ruthenium to a small extent may be subjected to high temperature testing and formation of spot defects during processing. It showed improved resistance to the haze of the viewing area of the element when receiving it compared to the element without the flash layer. The initial reflectance of the element with the ruthenium flash layer was 70-72%. If the reflective layer 720 is silver, the flash layer 722 may also be a silver alloy or aluminum-doped zinc oxide. The flash layer or thicker cover layer may be a transparent conductor such as a transparent metal oxide. The cover layer (s) may be specifically selected to complement the remaining layers for factors such as barrier properties, beneficial interferential optics, balance of condensation or tensile stress, and the like. It will be appreciated that the flash layer described above may be used in other embodiments described elsewhere in this document.

Such cover layers are made of the above-listed metals or other metals / alloys / semi-metals found to be compatible with electrochromic systems, when the metals or semimetal layer (s) are thicker than 300 angstroms. However, it tends to tolerate little optical effects from the layers underneath. If it is thought to be more desirable than having a metal cover layer, it may be beneficial to use such a thicker cover layer. Certain descriptions of such laminations are provided in co-assigned European patent EP0728618A2 "Dimmable Rearview Mirror for Motor Vehicles", which is incorporated herein by reference in its entirety. When such thicker cover layer (s) and transparent conductive layers such as indium doped tin oxide, aluminum doped zinc oxide, or indium zinc oxide are used, which can be used in combination with the glue layer and the flash layer, silver, There is still a conductive advantage of having a base layer such as silver alloy, copper, copper alloy, aluminum or aluminum alloy. Layers commonly thought to be insulators, such as titanium dioxide, silicon dioxide, zinc sulfide, etc., may also be used in such cover layer stacks or interlayers, whose layer thicknesses may be sufficient from those with higher conductivity. The conductivity may not negate the benefit of the higher layer (s) as long as it is still intended to pass current.

It is well known in the art of electrochromic technology that mirrors or windows can be uniformly darkened when an electrical potential is applied to the element. Unevenly darkening results in a local potential difference across the solid state EC material and a fluid or gel in the EC element. The potential across the element depends on the sheet resistance of the electrode, the bus bar configuration, the conductivity of the EC medium, the concentration of the EC medium, the cell spacing or the distance between the electrodes, and the distance between the bus bars. A commonly proposed solution to this problem is to make the coating or layer constituting the electrode thicker, thereby reducing its sheet resistance and allowing elements to darken faster. As described below, a practical penalty is given to limit this simple way of solving this problem. In many cases, these disadvantages make the EC factor unsuitable for a given application. In at least one embodiment of the present invention, an improved electrode material, a method of making the electrode and a busbar configuration which solve the problems caused by simply thickening the electrode layer and obtain an EC element with faster and more uniform darkening properties Described.

In a conventional inner mirror, the busbars run parallel to the long dimension. This is done to minimize the potential drop across the portion between the electrodes. The mirror also typically consists of a high sheet resistance transparent electrode and a low sheet resistance reflector electrode. The mirror darkens most quickly near the busbar for high sheet resistance electrodes and slowest at some intermediate position between the two electrodes. For electrodes with low sheet resistance, the darkening speed near the busbar is between these two values. There is a variation in the effective electrical potential as it travels between the two busbars. If the two long parallel busbars have a relatively short distance from each other (the distance between the busbars is less than half the length of the busbars), the mirror is darkened in a "window shade" manner. This means that the mirror darkens faster near one busbar and this darkening appears to move progressively between the two busbars. Typically, the darkening speed is measured in the middle of this portion, and for mirrors in which the ratio of width to height is greater than two, the nonuniformity of the darkening speed is relatively minor.

As the size of the mirror increases, and as the distance between the busbars increases, the relative difference in the darkening speed across the parts also increases. This can be worse if the mirror is designed for external applications. Metals that can withstand the harshness of these environments typically have lower conductivity than metals such as silver or silver alloys, which are typically suitable for internal mirror applications and are commonly used. Metal electrodes for external applications can thus have sheet resistances up to 6Ω / sq, while the inner mirror can have sheet resistances of <0.5Ω / sq. In other external mirror applications, the transparent electrode can be limited in thickness for various optical requirements. Transparent electrodes, such as ITO, are often limited to half wave thickness in the most common applications. This limitation is due to the properties of the ITO described herein but also due to the costs associated with making the ITO coating thicker. In other applications, the coating is limited to 80% of the half wave thickness. Both of these thickness constraints limit the sheet resistance of the transparent electrode to values greater than about 12 Ω / sq for a half wave and up to 17-18 Ω / sq for a coating that is 80% of a half wave coating. Higher sheet resistances of metal and transparent electrodes result in mirrors that are slower and less uniformly darkened.

The darkening speed can be estimated from the analysis of the EC elements by the electrical circuit. The discussion below relates to coatings having uniform sheet resistance across the elements. The potential at any location between parallel electrodes is only a function of the sheet resistance of each electrode and the resistance of the EC medium. In the table below, the average potential across the element between the electrodes is provided along with the difference between the maximum potential and the minimum potential. This example is for an element with a 10 cm spacing between parallel busbars, a cell spacing of 180 micrometers, a drive voltage of 1.2 volts, and a fluid resistivity of 100,000 Ω * cm. Six combinations of upper and lower electrode sheet resistances are compared.

[Table 1]

The darkening speed is the fastest at the electrical contact to the electrode of the highest sheet resistance and is related to the effective potential at this position. The higher the effective potential near this electrical contact (or elsewhere), the faster the average darkening speed of the mirror. The overall darkening time is fastest when the dislocation is as high as possible over that part. This allows electrochemistry to darken at an accelerated rate. The sheet resistance of the coating on both the upper and lower substrates plays a role in determining the effective potential between the electrodes, but as can be seen from the table above, the high sheet resistance electrode plays a more important role. In past electrochromic techniques, the improvement was made almost entirely by lowering the sheet resistance of the low resistance electrode. This is because the use of materials such as silver provided significant advantages and was relatively easy to implement.

It is known that the overall speed can be increased as the driving potential is increased, but the trend is constant regardless of the driving voltage. It is also known that current draw at a given voltage affects the uniformity of darkening. Uniformity can be improved by adjustments to cell spacing, concentration, or selection of EC materials, but often the improvement of uniformity using these adjustments is dependent on the darkening rate, the clearing speed, or both the darkening and the clearing rate. It can have a negative impact. For example, increasing cell spacing and decreasing fluid concentration reduce current draw, thereby improving uniformity, but increasing clearing time. Therefore, the sheet resistance of the layer must be set properly to achieve both the speed of darkening and the uniformity of darkening. Preferably, the sheet resistance of the transparent electrode should be less than 11.5 Ω / sq, preferably less than 10.5 Ω / sq, more preferably less than 9.5 Ω / sq, and due to the optical requirements described below, In certain embodiments, the thickness of the transparent electrode should be less than about half wave optical thickness. The reflector electrode should be less than about 3 Ω / sq, preferably less than about 2 Ω / sq, and most preferably less than 1 Ω / sq. The mirror or EC element thus configured also has a difference in the darkening time between the fastest and the slowest darkening speeds of less than three times, preferably less than two times, and most preferably more than 1.5 times. It has a relatively uniform darkening to be small. A new high performance low cost material that enables such a fast and uniform darkening element is described below.

In other applications, it may be impractical to have two relatively parallel busbars. This may be due to the uneven shape that is commonly found in external mirrors. In other situations, it may be desirable to have point contacts at low resistance electrodes. Point contact may enable minimization or removal of laser deletion lines used in certain applications. The use of point contact simplifies or prioritizes certain aspects of the mirror structure, but makes it difficult to achieve a relatively uniform dislocation across that portion. The removal of the relatively long busbars along the low resistive reflector electrodes substantially increases the resistance of the electrodes. Therefore, new combinations of busbar and coating sheet resistance values are needed to achieve fast and uniform darkening.

As noted above, one of ordinary skill in the art would expect that extremely low sheet resistance values are required at the metal reflector electrode to enable a point-and-point approach. Unexpectedly, it has been found that it is necessary to have a low sheet resistance for the transparent electrode in order to improve uniformity. Table 2 shows the results of the uniformity experiment. In this test, solution phase EC elements were prepared that were approximately 8 inches wide by 6 inches high. The benefits of element design described herein relate primarily to large elements. The large element is defined as the minimum distance from the edge of any point on the edge of the field of view to the geometric center is greater than approximately 5 cm. The lack of uniform darkening is even more problematic when the distance is greater than approximately 7.5 cm, and even more problematic when the distance is greater than approximately 10 cm. The sheet resistance of the transparent electrode (ITO) and the metal reflector was changed as shown in Table 2. The contact with the metal electrode was performed by point contact. To provide electrical contact to the metal reflector along one of the shorter length sides of the mirror, a clip contact, such as a J-clip, with an Ag paste line approximately 1 "in length was used. Opposite the point contact Electrical contact was made to the transparent electrode through an Ag paste that continued along one side and down one third of its distance along both long sides of the mirror The darkening time (T5515) was measured at three locations on the mirror. Position 1 is near the point contact point, position 2 is at the edge of the transparent electrode busbar opposite the point contact, and position 3 is at the center of the mirror T5515 time (in seconds) is 15% at 55% reflectivity of the mirror The time it takes to get to the reflectance The maximum reflectance is the maximum reflectance of the mirror ΔT5515 is the time difference between point 1 and point 2 or between point 2 and point 3. This is the fastest on the mirror. It is a measure of the difference in the darkening speed between the other locations and the other two places, as the darkening becomes more uniform, these numbers get closer to each other.The timing factor is that the darkening time at a given location is the time at the earliest location. This represents the relative scaling of time between different places regardless of the absolute rate at any given place, as described above, where a timing factor of less than 3 is preferred. , Preferably less than 2, and more preferably less than 1.5. From Table 2, it is not possible to achieve a timing factor of 3 when the ITO sheet resistance is 14Ω / sq in this particular mirror configuration. Notice that all three examples with ITO with 9Ω / sq have a timing factor less than 3. The center of the mirror reading is Section showed that the best place to escape from the fast place. The statistical analysis was unexpectedly ITO sheet resistance is the only factor affecting the timing factor performed on data. When using a statistical model, in this embodiment an ITO sheet resistance of less than about 11.5 Ω / sq needs to have a timing time of 3.0 or less. Using the same statistical model, in this mirror configuration, the ITO must have a sheet resistance of less than 7Ω / sq for the timing factor to be less than 2.0. Although the timing factor is not affected by the sheet resistance of the third surface reflector, the overall darkening speed is affected. When the reflector's sheet resistance is less than or equal to 2Ω / sq and ITO is approximately 9Ω / sq, the darkening speed for this mirror is less than 8 seconds from the center. This value corresponds approximately to a mirror of similar size with a conventional busbar configuration. Therefore, by lowering the sheet resistance of ITO, point contact is possible in a relatively high sheet resistance reflector.

[Table 2]

The unexpected role of sheet resistance of ITO in the uniformity and speed of darkening was extended in another series of experiments. In these experiments, the length of the busbar contact to the electrode of higher sheet resistance in this example ITO extends further down the side of the mirror and in some cases even to the bottom edge of the mirror. Table 3 shows the effect on the uniformity according to the change of busbar length. In these tests, the element shapes and configurations are the same as for Table 2 except where noted. The percentage of contact is a percentage comparison of the busbar length of the ITO contact compared to the total length of the perimeter. The bus bar ratio is the length of the ITO contact for small reflector contacts of approximately 2 cm or less.

The data in Table 3 show that the uniformity increases significantly with increasing busbar length of the high sheet resistance electrode. For a 2Ω / sq reflector, increasing the length of the busbar contact from 40% to 85% improves the timing factor from 2.4 to 1.7. For 0.5Ω / sq reflectors, the same change in ITO bus length from 40% to 85% improves the timing factor from 3.2 to 1.2 and significantly improves the darkening speed. Note that although elements with low sheet resistance reflectors generally darken faster than comparable 2Ω / sq cases, the uniformity of 0.5Ω / sq cases with shorter ITO contacts is actually better, as indicated by the timing factor. It is bad. Increasing the busbar length for ITO is particularly helpful for elements with 0.5Ω / sq reflectors.

When the percentage of contact is increased, the positions of the earliest darkening and the slowest darking can also change. In this example, the high contact percentage significantly improves the darkening time at both positions 1 and 3 and the corresponding timing factor.

[Table 3]

These experiments are beneficial when using short busbars at low sheet resistance electrodes, increasing the busbar length to the opposite electrode to increase uniformity. Thus, ideally, for large mirrors, the ratio of busbar lengths is greater than 5: 1, preferably greater than 9: 1, even more preferably greater than 13: 1, to achieve a timing factor of 3 or less. Most preferably, greater than 20: 1. Also, regardless of the length of the small busbars, uniformity is improved by increasing the length of the busbars to electrodes of high sheet resistance to obtain contact percentages that are preferably greater than approximately 58% and more preferably greater than approximately 85%. I also knew. Typical large EC mirrors have a contact percentage of less than 50%.

This is not only important for mirrors with opaque reflectors, but even more important for mirrors using transflective reflectors. In order to have a semipermeable coating, the metal must be thinned down to the semipermeable point. Therefore, the thinner the metal, the higher the sheet resistance value. In at least one embodiment of the present invention, the electro-optic element includes fast and uniform darkening by conventional busbar configurations having the optional point contact busbar configurations disclosed herein. A new transflective coating is described below, which is particularly suited to supplementing the above busbar configuration.

In addition, an opaque cover layer allows the electrochromic mirror to darken more evenly over its entire area or to first darken from its center (with most of the headlights) outward to the top and bottom of the field of view. Alternatively, the conductivity can be patterned under the opaque cover layer stack. In US Patent Application No. 20040032638A1 to Tonar et al., "Electrochromic devices with thin bezel-covered edge," which is incorporated herein by reference in its entirety, relates to the associated electrical contact. A low sheet resistance coating can be provided in the adjacent area or near the periphery area and the sheet resistance can increase as the distance from the electrical contact increases. ”This is especially true when point contact is used. It is possible. Typically, the electrochromic element is intended to provide contrast (in Ω) with no or very minimal visible contrast to the reflector when no voltage is applied to it.

In order to obtain sufficient contrast between the higher and less conductive areas of the electrochromic device to enable preferential darkening of certain areas, it is necessary to include a non-metallic material in the stack. The reason for doing this is that opaque layers or stacks of more reflective metals and alloys tend to be conductive enough to provide reasonable darkening properties to automotive electrochromic mirrors without compensating for more conductive patterns beneath them. . An example of such a material stack comprising a semimetal is US Patent 5,535,056 "method for making elemental semiconductor mirror for vehicles" (incorporated herein by reference in its entirety). It is constructed similarly to that described, wherein the opaque silicon layer is covered with approximately 1/4 wave optical thickness of indium tin oxide, which is covered with 20 to 25 nanometers of silicon, which is approximately Covered with 20 nm of indium tin oxide. This coating layer, which is opaque, is placed underneath in a pattern in which additional material has a minimal effect on its appearance from the front. This stack is also sufficiently conductive throughout so as not to lose the benefit of its patterning. In addition, if it is found to be still too conductive when deposited under conditions that typically show approximately 12 Ω / sq at about 1400 angstroms thick, ITO is made less conductive by adjusting process conditions or changing the ratio of indium to tin. Can be.

Elements constructed in accordance with the principles described in US20040032638A1 having the form of FIGS. 5F and 7 with conductive epoxy along the top, bottom and left edges and with point contacts approximately in the middle of the right edges may be used to form another third surface coating laminate and conductive material. Made in a pattern. Reference is made to the entire third surface, which refers to the surface before the laser process, in order to create the insulating areas required for the configuration according to commonly assigned US patent application 20040022638A1.

An element with a third surface reflector of 1/2 Ω / sq throughout the field of view has 1/2 Ω / sq in a stripe of 1/2 "or 1" or 2 "over the center of the element covered with the opaque layer 4Ω / sq conductivity in the rest of the field of view and the elements appear fairly uniform in the bright state.When darkening the element, the center of the element is darker when compared to the edge with the contrasting conductive area. There was a slight decrease in the propensity to delay.

To have a higher level of conductive contrast, the elements were manufactured in a configuration similar to that in the previous paragraph, with two elements placed across the center of the single on the third surface ITO, approximately 12 Ω / sq and 40 Ω / sq, respectively. "With a conductive stripe of silver, this single was covered with a flash layer of transparent conductive oxide (for processing durability). After making a complete electrochromic device, the elements were placed on silver plated glass. When evaluating the darkening properties, there is a reflector of similar intensity to the silver stripe behind the region with relatively transparent 12Ω / sq and 40Ω / sq ITO. It has been found that a device having an area has less iris effect when darkening than an element having an area in contrast to 12Ω / sq to 1 / 2Ω / sq when viewed under these conditions.

The element was manufactured according to the previous paragraph except that an additional coating was used on the third surface. These coatings contain an additional flash layer of conductive oxide (leave it there for adhesion as treatment-related vacuums intervene in the coating process), approximately 300 nm silicon, approximately 60 nm ITO, another 20 nm silicon, and then 10 nm ITO. Consists of The silicon layer may be prone to surface oxidation, which can form surface oxides on certain EC elements, which interfere with the uniformity and consistency of darkening. ITO or other TCO or other materials described herein as flash layers or overlays can be used to prevent the formation or negative effects of the oxides. The element starting with the initial layer of 40 Ω / sq (according to the previous example) was about 24 Ω / sq in the upper and lower regions (according to FIGS. 5F and 7) as measured by four point probes. It had a third surface conductivity of <1Ω / sq in the central region. Elements starting with an initial ITO layer of 12 Ω / sq had 10-12 Ω / sq in the upper and lower regions. According to the previous example, elements with high ohmic contrast tended to have the least iris effect or to darken from center to edge. These elements also had the following optical characteristics with the power off when using the D65 2 degree observer.

L * a * b * Y

High Ohmic Contrast (50 Ohm Base Layer) 76 -5 4 50

Low Ohmic Contrast (12 Ohm Base Layer) 75 -3 5 51

Preferred darkening of certain areas of the electrochromic device is the thickness of the coating, as described elsewhere herein, as well as by thin erase lines in the second surface transparent conductor (lamination) or the third surface reflection (lamination). It can be achieved by changing gradually. Using laser erasing as an example, it is generally possible to produce thinner laser lines as the operating wavelength of the laser is reduced. A 15 micron wide erase line was generated using a UV laser with a wavelength of 355 nm. These lines can still be distinguished, but much less distinct than those produced using longer wavelength lasers. As shorter wavelength lasers continue to become more available, it can be foreseen that erased lines that are decoratively non-reflective in the field of view may be possible under the normal conditions of automotive mirrors.

There is an erasure of the coating stack that becomes the third surface of the element in the lines or portions of the lines indicated throughout the center of FIGS. And when conductive epoxy is used on the remaining three sides of the element, the darkening properties are affected.

The pattern of erase was done by laser for both the lines shown inside the element as described in FIGS. 5F and 7 on the 1/2 ohm / sq reflector electrode.

1) The coating was completely erased in a thin line extending from the edge of the glass to 15 cm from the edge of the glass.

2) The coating was completely erased in thin lines with a repeat pattern of 8 mm erase and 2 mm micronear across the entire width of the portion.

3) The coating was completely removed in a thin line extending from the edge of the glass to 14 cm from the edge and then erased in a repeating pattern of 5 mm microgeometry and 5 mm erase over the rest of the portion.

4) The coating was completely removed from the line except for two microgauge segments of approximately 5 mm and 10 cm along a thin line extending from the edge of the glass to 15 cm from the edge.

Compared with similar parts without erase lines, these elements exhibited some "iris effect" to significantly less "iris effect" when darkening. Pattern 4 was best in overall decoration and even darkening among those with erase patterns. Nevertheless, all of these patterns required adjustment for proper darkening decoration, but showed a shift towards the desired darkening properties.

Referring to FIG. 8A, the first substrate 802a and the primary seal material 878a having at least one layer 808a of substantially transparent conductive material deposited on the second surface are spaced apart from each other with respect to each other. A profile view of a portion of a rearview mirror element is shown that includes a second substrate 812a having a stack of materials deposited on a third surface that is fixed in a spaced apart relationship defining a chamber therebetween. In at least one embodiment, an electro-optic medium 810a is located in the chamber. In at least one embodiment, the third surface material stack is a conductive tab portion 882a having a base layer 818a, a conductive electrode layer 820a, a metal layer 822a, and an overlapping portion 883a below the metal layer and the primary seal material. It includes. Note that conductive tab portion 882a may be deposited on top of metal coating 822a to create an overlapping portion as another alternative. In at least one embodiment, this substrate is titanium-dioxide. In at least one embodiment, this substrate is not used. In at least one embodiment, the conductive electrode layer is indium-tin-oxide. In at least one embodiment, the conductive electrode layer is omitted. In at least one embodiment, the conductive electrode layer is omitted and the base layer is a thick layer of any other substantially transparent material having a relatively high refractive index (ie, higher than ITO) such as titanium-dioxide or silicon carbide. In at least one embodiment, the conductive tab portion comprises chromium. It will be appreciated that the conductive tab portion may comprise any conductive material that adheres well to glass and / or other laminates or epoxies in the order of the layers and is resistant to corrosion under vehicle mirror test conditions. As can be appreciated, when the third surface material stack that can be corroded or at least the layers within the stack is within the area defined by the outer edge of the primary seal material, the element is subjected to problems associated with the third surface corrosion. Practically unaffected. It will be appreciated that as long as a protective overcoat or sealant, such as a conductive epoxy or overcoat layer, is included, the corroded layer or layers may extend beyond the primary seal material. It will be appreciated that any of the first, second, third and fourth surface material layers or stacks of materials may be as described in the cited documents cited herein or elsewhere herein. It will be appreciated that the conductive tab portion is optional as long as the conductive tab portion enhances conductivity to the conductive electrode and the conductive electrode layer has sufficient conductivity. In at least one embodiment, the conductive electrode layer provides the desired color related properties of the corresponding reflected beam in addition to providing the desired conductivity. Thus, when the conductive electrode is omitted, the color properties are controlled through the substrate material specification.

Referring to FIG. 8B, the first substrate 802b and the primary seal material 878b having at least one layer 808b of substantially transparent conductive material deposited on the second surface are spaced apart from each other. A profile view of a portion of a rearview mirror element including a second substrate 812b having a stack of materials deposited on a third surface that is fixed in a spaced apart relationship defining a chamber therebetween is shown. In at least one embodiment, an electro-optic medium 810b is located in the chamber. In at least one embodiment, the third surface material stack includes a base layer 818b, a conductive electrode layer 820b, a metal layer 822b and a conductive tab portion below the primary seal material. In at least one embodiment, void area 883c is defined between the metal layer and the conductive tab portion, and the conductive electrode provides electrical continuity therebetween. In at least one embodiment, the substrate is titanium-dioxide. In at least one embodiment, no substrate is used. In at least one embodiment, the conductive electrode layer is indium-tin-oxide. In at least one embodiment, the conductive tab portion comprises chromium. It will be appreciated that the conductive tab portion may comprise any conductive material that adheres well to glass and / or other laminates or epoxy in order of layers and is resistant to corrosion under vehicle mirror test conditions. As can be appreciated, when the third surface material stack that can be corroded or at least the layers in the stack is in an area defined by the outer edge of the primary seal material, the element is in a problem associated with the third surface corrosion. Practically unaffected. It will be appreciated that any of the first, second, third and fourth surface material layers or material stacks may be as disclosed herein or in cited documents cited elsewhere herein.

8C, at regular intervals relative to each other through a first substrate 802c and a primary seal material 878c having at least one layer 808c of substantially transparent conductive material deposited on a second surface. A profile view of a portion of a rearview mirror element is shown that includes a second substrate 812c having a stack of material deposited on a third surface that is fixed in a spaced relationship and defines a chamber therebetween. In at least one embodiment, an electro-optic medium 810c is located in the chamber. In at least one embodiment, the first metal layer 818c is deposited substantially over the third surface. In at least one embodiment, the second metal layer 820c is deposited over the first metal layer such that the outer edge of the second metal layer 820c is in an area defined by the outer edge of the primary seal material 878c. In at least one embodiment, the first metal layer comprises chromium. In at least one embodiment, the second metal layer comprises silver or silver alloy. It will be appreciated that any of the first, second, third and fourth surface material layers or stacks of materials may be as disclosed herein or in cited documents cited elsewhere herein.

Referring to FIG. 8D, a second substrate 812d is shown that includes a stack of materials substantially having an eyehole 822d1 in front of an optical sensor or information display. In at least one embodiment, the first metal layer 818d has a void area in the eye hole area. In at least one embodiment, the second metal layer 820d has a void area in the eye hole area. In at least one embodiment, a third metal layer 822d is provided. In at least one embodiment, only the third metal layer is deposited in the eye hole region. In at least one embodiment, the first metal layer comprises chromium. In at least one embodiment, the second metal layer comprises silver or silver alloy. In at least one embodiment, the third metal layer comprises thin silver, chromium or silver alloy. It will be appreciated that any of the first, second, third and fourth surface material layers or material stacks may be as described herein or in cited references cited elsewhere herein.

9A-9K, various options for selectively contacting certain portions of the second and third surface conductive electrode portions 922, 908 are shown. As will be appreciated, the result of the configuration of FIG. 7 results in the electrically conductive material being in contact with at least a portion of each of the second and third surface conductive electrode portions. It will be appreciated that the contact arrangement as shown may be rotated in any manner around the element.

The element configuration shown in FIG. 9A includes a first substrate 902a having a second surface material stack 908a and a second substrate 912a having a third surface material stack 922a. The third surface material stack is shown having a separation region 983a such that a portion of the third surface material stack in contact with the conductive epoxy 948a is separated from the rest of the third surface material stack. The first and second substrates are held in a spaced apart relationship from each other through the primary seal material 978a. It will be appreciated that other aspects of the element may have similar separation regions associated with the second surface material stack to provide contact with the third surface material stack in the field of view. It will be appreciated that the second or third surface material stack may be a single material layer as described elsewhere herein and also in the cited references cited herein.

The element configuration shown in FIG. 9B includes a first substrate 902b having a second surface material stack 908b and a second substrate 912b having a third surface material stack 922b. The first and second substrates are maintained in a spaced apart relationship with each other through the primary seal material 978b. Electrically conductive epoxy 948b is in contact with the third surface material stack and is electrically insulated from the second surface material stack via insulating material 983b. It will be appreciated that other aspects of the element may have similar separation regions associated with the second surface material stack to provide contact with the third surface material stack within the field of view. It will be appreciated that either the second or third surface material stack may be a single layer of material as described elsewhere herein and in the cited references cited herein.

The element of FIG. 9C includes a first substrate 902c having a second surface material stack 908c and a second substrate 912c having a third surface material stack 922c. The first and second substrates are held in a spaced apart relationship with each other through the primary seal material 978c. The second surface material stack extends beyond the primary seal material toward the edge of the first substrate to be in electrical contact with the first electrically conductive epoxy or first solder 948c1. The third surface material stack extends beyond the primary seal material toward the edge of the second substrate to be in electrical contact with the second electrically conductive epoxy or second solder 948c2. It will be appreciated that other aspects of the element may have similar separation regions associated with the second surface material stack to provide contact with the third surface material stack within the field of view. It will be appreciated that either the second or third surface material stack may be a single layer of material as described elsewhere herein and in the cited references cited herein.

9D shows that a second surface electrical contact 948d1 is made on both sides of the third surface electrical contact 948d2 of the element. 9E shows that a second surface electrical contact 948e1 is made on one side of the element and a third surface electrical contact is made at one end of the element. 9F shows that the second surface electrical contact 948f1 is on one side and continues to one end of the element, and the third surface electrical contact 948f2 is on the opposite side and continues to the opposite end of the element. will be. 9G shows that the second surface electrical contact 948g1 is on both sides of the element and the third surface electrical contact 948g2 is on one end of the element. 9H shows that a second surface electrical contact 948h1 is made on both sides of the element and a third surface electrical contact 948h2 is made at both ends of the element. 9I shows that the second surface electrical contact 948i1 is continued on both ends and one side of the element, and the third surface electrical contact 948i2 is on one side of the element. FIG. 9J shows that the second surface electrical contact 948j1 is continuously made at both ends and at least partially on one side as a whole on the other side, and the third surface electrical contact 948j2 is made on one side of the element. In at least one embodiment, it will be appreciated that long electrical contacts correspond to surfaces having the highest stack of material resistance. It will be appreciated that the electrical contact may be through an electrically conductive epoxy, solder or electrically conductive adhesive.

9K illustrates an element that includes a first substrate 902k having a second surface material stack 908k and a second substrate 912k having a third surface material stack 922k. The first and second substrates are held in a spaced apart relationship from each other via the peripheral first and second primary seals 948k1 and 948k2. The first primary seal serves to be in electrical contact with the second surface material stack and the second primary seal serves to be in electrical contact with the third surface material stack. The first and second primary seals keep the first and second substrates spaced apart relative to each other, preferably both primary seals are substantially outside the edge of each substrate.

Another way of establishing an electrical connection of an electro-optical element to an electrode or contact clip, such as a J clip or L clip, is through a solid phase welding process. Wire bonding is a welding process used in the electronics industry to establish reliable interconnects between electronic components (usually IC chips and chip carriers). The wire bonding process is described in Chapter A of Nordic Electronics Packaging Guidelines by Zonghe Lai and Johan Liu. Electrical interconnections made by wire bonding utilize metal wires or ribbons, and use a combination of heat, pressure, and / or ultrasonic energy to weld the wires or ribbons to associated metal surfaces. Typically, the wire or ribbon is welded using a special wedge or capillary bonding tool. Conventional bonding processes use heat and / or ultrasonic energy and generally fall into three main classes: thermocompression bonding, ultrasonic bonding and thermosonic bonding. The wire to be bonded can be terminated at the bond or multiple bonds can be made with continuous wires. Common forms of wire bonding include ball bonds, wedge bonds, and stitch bonds. Wires and ribbons made from many different metals and alloys, including aluminum, gold, silver, copper, and alloys thereof, can be wire bonded. These wires may be bonded to a number of metals or substrates coated with a metal layer, including but not limited to metal layers of gold, silver, nickel, aluminum and alloys made of these metals. In the case of bonding of the electro-optical element to the electrode, the preferred substrate is glass, and the preferred metal deposition process is by physical vapor deposition processes such as magnetron sputtering. An adhesive layer or adhesive layers of chromium, molybdenum, nichrome or nickel or the like may be applied between the wire bonded metal layer and the glass to achieve proper adhesion. The deposited metal layer thickness can be 5 angstroms to 1000 micrometers. More preferably, the metal layer thickness is between 100 angstroms and 1 micrometer, and most preferably the metal layer thickness is between 200 and 1000 angstroms. The wire diameter or ribbon thickness can be 10 to 250 micrometers, with a diameter or thickness of 25 to 100 micrometers preferred and a diameter or thickness of 50 to 75 micrometers most preferred. In at least one embodiment, the continuous wire may be wedge or stitch bonded to a chrome ring on the second surface of the electrochromic mirror along the perimeter edge of the substrate. The wire or ribbon busbar may be electrically connected to a clip such as a nickel J or L clip by welding the wire or ribbon to the clip and then looping the cup to the substrate and welding it to the associated electrode. The wire or ribbon may start along the metal clip and go along the EC electrode or start along the EC electrode and loop into the clip and back to the electrode. In at least one embodiment, it is preferred to have redundant welded connections to the associated electrode and / or from the EC electrode to the associated electrical contact clip for reliability and uniform coloring of the device. Multiple welded connections to the substrate may be made every 0.005 inches to 10 inches, with a spacing of 0.040 inches to 2 inches being preferred, with a spacing of 0.100 to 0.50 being most preferred. The welded wire or ribbon busbars can be protected from damage by encapsulating the wires and welds with sealant. The preferred method is to protect the bus bar by encapsulating the wire / ribbon and welded bond in the perimeter seal of the associated element. Preference is given to metal wires / foils which are chemically suitable for the EC medium which surrounds the busbar (inside the perimeter seal) in the device. Wire busbars can also be used to complement the conductivity of the associated electrode inside the element. Wires with diameters of 75 micrometers or less are not readily visible to the human eye. Welded wire bonding is attractive from a manufacturing standpoint, because the bonding is a room temperature or a low temperature process, no post-cure or post-treatment action is required, and the technique is well established with proven reliability and fast bonding (per bond) About 100 milliseconds).

Wire bonding can also be used to electrically connect the electronic component to the substrate surface of the element. For example, many metals are electrochemically stable when used as cathodes rather than as cathodes in elements. It is desirable to provide protection by diodes or the like to limit the operation of the EC device when the polarity is reversed. (This is described in detail below with reference to FIGS. 11A-11C.) An electrical component such as a surface mount diode can be attached to the substrate or busbar clip and electrically connected to the substrate and / or the clip by wire bonding. Can be. In another embodiment, a light emitting diode (LED) that is part of a signaling or alarm system can be attached to an associated substrate, for example in the form of a chip, and formed by patterning a metal coating by etching, masking or laser ablation. It may be electrically connected to a circuit on the substrate. These LEDs or other electrical components can be mounted on the substrate surface 1, 2, 3 or 4 in the element. It is sometimes desirable to increase the drive voltage applied to the solution phase electrochromic device as the temperature increases to compensate for the increase in diffusion rate of the electrochromic species and to maintain good device darkening properties over a wide temperature range. Thermistors and electronic components required for the temperature modulated variable voltage drive circuit can be mounted on the associated substrate surface and electrically connected to a metal coating on the substrate by wire bonding. Example: An aluminum wire is bonded to a metal coating on a glass substrate as follows:

First layer of chromium and second layer of nickel (CN), first layer of chromium and second layer of ruthenium (CR), first layer of chromium, second layer of ruthenium and third layer of nickel (CRN) A vacuum sputtered coated glass with a layer of approximately 400 Angstroms thick, comprising: 0.00125 "diameter aluminum alloy wire (1-4% elongation, 19-21 grams tensile strength) containing 1% silicon wire-bonded to metal-coated glass substrate using Westbond Model 454647E wirebonder with the following settings .

Setting First Bonding Second Bonding

"CN" power 175 150

30 milliseconds 30 milliseconds

Power 26g 26g

"CRN" power 175 150

30 milliseconds 30 milliseconds

Power 26g 26g

"CR" power 150 125

75 milliseconds 100 milliseconds

Power 26g 26g

The bonding strength of the wire was evaluated by pulling the wire and measuring the force after one hour exposure to 300 degrees Celsius after bonding.

Wire Bonding Average Tensile Strength:

After bonding 300C after baking

"CN" 14.51g 9.02g

"CRN" 19.13g 8.2g

"CR" 12.42g 8.7g

The main failure after bonding was wire cutting at the end of the first welded bond. After baking, the main failures were wire cutting in the middle range for the "CN" and "CRN" groups and wire cutting at the end of the first bonding for the "CR" group. This example shows that a number of reliable welded bonds can be made to a conventional sputtered metal layer on glass.

10 shows a variable transmittance window 1010 that can be used in a multi-passenger vehicle, with a window control system 1008 electrically connected to a variable transmittance window 1010 that controls the transmittance state of the variable transmittance window 1010. Is an overview. The window control system 1008 includes a window control unit 1009 connected to each of the variable transmittance windows 1010, which controls the transmittance of each of the variable transmittance windows 1010. Each window control unit 1009 includes a slave control circuit 1070 that controls the transmittance state of the associated variable transmittance window 1010. Each window control unit 1009 also provides a user input mechanism 1060 connected to the slave control circuit 1070 that provides user input to the slave control circuit 1070 to change the transmittance state of the associated variable transmittance window 1010. Is shown. Each window control unit 1009 is also shown connected to a power source and a ground line to provide power to the slave control circuit 1070, the user input mechanism 1060, and the variable transmittance window 1010. As shown, power is provided to the variable transmittance window 1010 from the power supply and ground line 1011 via the slave control circuit 1070.

Each window control unit 1009 is also shown to be connected to a window control system bus 1013. Other devices also connected to the window control system bus 1013 include a master control circuit 1090 and other electronic devices 1092. The master control circuit 1090 is configured to monitor the signals provided by the window control units 1009 onto the window control system bus 1013 and to provide control signals to each of the window control units 1009 via the bus. have. The master control circuit 1090 includes processing circuitry including logic, memory, and bus interface circuitry that enables the master control circuit 1090 to generate, transmit, receive, and decode signals on the window control system bus 1013. The slave control circuit 1070 included in each of the window control units 1009 receives the desired window transmittance state from the user input mechanism 1060 and transmits the transmittance state of the variable transmittance window 1010 via the user input mechanism 1060. And provide electrical signals to the variable transmittance window 1010 to change to a state requested by the user. The slave control circuit 1070 is also configured to monitor various characteristics of the variable transmittance window 1010, including the power consumed by the variable transmittance window 1010 and the transmittance state of the variable transmittance window 1010. The slave control circuit 1070 also includes circuitry for receiving signals from and transmitting signals to the window control system bus 1013.

Certain metal films may be less stable when configured as anodes compared to transparent conductive oxides such as indium tin oxide films. This is seen in cycles in electrochromic devices by metal deplating from the anode, or by chemical changes in the metal surface such as oxidation, or by blurring the surface due to the rearrangement of moving metal atoms to a rougher surface. Can be. Certain metal and metal thin film stacks and thin film stacks including metal layers are more resistant to these effects than others. Nevertheless, it may be desirable to take measures to make the third surface reflector electrode cathode.

In certain embodiments, it may be desirable to include a material that is sensitive for use as the anode in the second surface transparent electrode. In this case, it may be desirable to drive the third surface electrode as an anode and drive the second surface electrode as a cathode to protect the second surface electrode.

In the case of an electrochromic mirror outside of the vehicle, there may be a power source that is not directly connected to the associated drive circuitry located in the associated internal mirror where the third surface reflector electrode can minimize the risk of being anode on that mirror (ie A given external mirror may comprise an independent drive circuit). However, it is common for the power of the outer mirror (or mirrors) to be supplied through the inner mirror. Often there are several connections between the inner mirror and the corresponding outer mirror (s). If the associated reflector / electrode is not durable enough to function as an anode, the polarity of the power supply from the inner mirror to the outer mirror may be reversed, thereby not tolerating the risk of the device's third surface reflector electrode becoming an anode.

Referring to FIG. 11A, a circuit 1101a having diodes in series with the outer mirror element 1102a not only prevents current flow with inverted polarity but also electrochromic function. The device degrades when operated with the correct polarity in that the mirror is darkened upon application of a normal voltage, but the external mirror cannot be discharged through its path in the event of a short circuit in the internal mirror circuit for clearing. Performance can be achieved. Thus, the outer mirror element is primarily discharged when the positive and negative charged species neutralize each other in solution, but not when discharged to the conductive surface of the device. As a result, the clearing speed of the device can be significantly slowed.

The circuit 1100b shown in FIG. 11B includes a diode 1101b in parallel across the leads near the outer mirror element 1102b. A short circuit is caused when the polarity of the current provided to that portion of the circuit is reversed. The current then flows through the diode, not the electrochromic element. This short circuit is detected by the internal mirror circuit 1103b, and the voltage is automatically disconnected. This allows for proper operation of the mirror when the polarity is correct, but this circuit completely disables the electrochromic function of the mirror if the polarity is reversed.

However, when the diode 1110c and the circuit 1100c which do not first stop the application of the voltage when excessive current (short) reverses the voltage are connected, the mirror element 1102c remains in operation and the reflector electrode is automatically In this way, a suitable polarity is transferred to the element to reconnect as a cathode. In this circuit 1100c, when excessive current is detected, two solid state switches 1104c1 and 1104c2 are automatically reconfigured to change the current through element 1102c in the opposite direction. If excessive current is detected in this configuration, the solid state switch resets and stops driving the element, because some other failure may be causing excessive current draw.

Figure 11d shows an alternative configuration for an electro-optical drive circuit that provides automatic compensation for inverted polarity. Diodes 1101d1, 1101d2, 1101d3, 1101d4 define a rectifier bridge that provides a dual current path. The actual path current flow will always have the desired direction of the anode and cathode of the electro-optical element 1102d.

Circuits 1100a, 1100b, 1100c, and 1100d of FIGS. 11A-11D are shown for a single outer mirror. If it is desired to protect two or more external mirrors, the desired circuit can be adapted accordingly.

In an electro-optical element similar to that shown in FIG. 7 with a fourth surface reflector (not shown), when there is no potential difference between the transparent conductors 708, 718, the electrochromic medium in the chamber 710 is basically colorless or Nearly colorless, incident light I _O enters through the front element 702 and passes through the transparent coating 708, the electrochromic medium in the chamber 710, the transparent coating 718, the rear element 712. Reflected off the layer, it passes back through the device and exits to the front element 702. It will be appreciated that aspects of the present invention regarding variable transmittance windows as described above may not include a reflective layer. In other embodiments, a third surface reflector / electrode can be used. Typically, the size of the reflected image I _R in the absence of a potential difference is from about 45 percent to about 85 percent of the incident light intensity I _O. The exact value is determined by many of the variables described below, for example the frontal element 702 and the front transparent electrode 708, the front transparent electrode as well as the residual reflection I ′ _R from the front surface of the front element. 708 and the electrochromic medium, the electrochromic medium and the second transparent electrode 718, and the secondary reflections from the interface between the second transparent electrode 718 and the rear element 712. These reflections are known and are due to the difference in refractive index of these materials as light passes through the interface between one material and the other. If the front and back elements are not parallel, the residual reflection I ' _R or other secondary reflections do not overlap with the reflected image I _R from the mirror surface and a double image appears (observer If appears to be double or triple, then that number of objects are actually present in the reflected image).

The minimum requirement for the magnitude of the intensity of the reflected light depends on whether the electrochromic mirror is inside or outside the vehicle. For example, according to current requirements from most car manufacturers, the interior mirror preferably has a minimum high end reflectivity of at least 40 percent, and the exterior mirror must have a minimum top reflectance of at least 35 percent. Should be.

Electrode layers 708 and 718 are connected to an electronic circuit (eg, FIGS. 10-11D) effective to electrically energize the electrochromic medium, thereby applying a potential across conductors 708 and 718. When the electrochromic medium in chamber 710 is darkened, incident light I ₀ is attenuated as light passes through the reflector and then reflects back. By adjusting the potential difference between the transparent electrodes, the preferred device functions as a "gray-scale" device, and the transmittance varies continuously over a wide range. In the case of a solution phase electrochromic system, when the potential between the electrodes is removed or returned to zero, the device spontaneously returns to the same zero-potential equilibrium color and transmission that the device had before the potential was applied. It will be appreciated that other materials for making electrochromic devices are available, and that aspects of the invention are applicable regardless of which electro-optic technology is used. For example, the electro-optic medium may include solid metal oxides, redox active polymers, and materials that are hybrid combinations of solution and solid metal oxides or redox active polymers. However, the solution-phase design described above is representative of most of the electrochromic devices currently in use.

Various attempts have been made to provide an electro-optic element with a second surface transparent conductive oxide having a relatively low sheet resistance while maintaining low absorption. In conventional electrochromic windows or electro-optical devices, as well as the electrochromic mirrors described above, the transparent conductive layers 708, 718 are often made of indium tin oxide. Other attempts have focused on reducing the intrinsic stress of the ITO layer applied to the associated glass substrate to minimize bending or warping of the substrate. Further attempts have been made to optimize optical properties such as reflectance by adjusting 1/4 and / or 1/2 wave thickness of the ITO layer (s) or to minimize the weight of the associated assembly as a whole. However, due to the aforementioned physical limitations, efforts to simultaneously optimize both the optical and physical properties described above have been rarely successful.

One such previous method of optimizing the optical characteristics of a given electrochromic assembly was to manipulate the composition of the electrode therein. Specifically, some optical properties can be obtained by adjusting the reflectance of the reflective electrodes of the assembly. More specifically, by manipulating the material composition of the laminated layers comprising the reflective electrode, its reflectivity can be increased, thus negating the relative absorption of the associated transparent electrode. However, increasing the reflectance of the reflective electrode typically requires the additional use of metals used to construct reflective electrodes such as rhodium, ruthenium, chromium, silver and the like. Since many of these metals are relatively expensive, adding more metal to the electrochromic element raises the cost of the element unacceptably. In addition, many of the more inexpensive metals that provide good reflective properties are unsuitable for the manufacturing process and / or harsh environmental conditions experienced by the entire assembly, such as the outer mirror assembly and outer window assembly.

Other methods of using ITO electrodes required the balance of several non-complementary optical and physical parameters with each other. For example, increasing the thickness of a transparent ITO conductive layer to achieve a low sheet resistance can result in the absorption, location of quarter and / or half wave points associated with the layer, and as described in detail below, and It may adversely affect the bending of the substrate to which the ITO layer is applied.

As is known in the art, reducing the sheet resistance of an ITO layer can be achieved by increasing the thickness of that layer. However, increased thickness of the ITO layer is achieved with an undesirable increase in light absorption of the layer. In addition, the increase in the thickness of the ITO layer is typically limited to a certain amount of 1/2 wave in a given wavelength range (typically centered at approximately 550 nm) to minimize the relative reflectance from the outer surface of the ITO layer. In addition, increasing the thickness of the ITO layer can increase the bending of the substrate to which the ITO layer is attached. As is known, the ITO layer includes an internal stress applied to the substrate, and if this internal stress is applied to any thin substrate, bending of the substrate can occur as a result. In many applications, the substrate comprises relatively thin glass to reduce the absorption of the glass and the weight associated therewith, resulting in unacceptable bending as the thickness of the ITO layer increases. This is particularly common in large applications such as large windows such as those used inside aircraft or in buildings. The bending of the associated substrate can affect the distance between two electrodes within the assembly, thereby affecting the clearing speed, color, relative uniformity of the assembly dark or light at various points across the surface of the assembly and even a single This may cause optical distortions on the points of multiple reflected images generated rather than on the image of. Previous methods of reducing the internal stress of the ITO layer concentrate on the method used to produce the electrochromic elements. One prior art method of attaching an ITO layer to an associated substrate includes magnetic sputtering. To date, these attempts have only been adequately successful due to several disadvantages, one of which is the physical limitations inherent in the method, and one example of these physical limitations is the collapse of the laydown of the ITO layer at increased pressure. As a result, clustering of ITO occurs. This clustered ITO layer exhibits an increase in sheet resistance, haze and absorption.

In at least one embodiment, an ITO layer having uniform darkness or lightness throughout the assembly, reducing the weight of the assembly as a whole, using reduced sheet resistance, reduced absorption, and low stress, and any of these, An electro-optical element having a subcombination or combination is provided.

In at least one embodiment, an electro-optical element is provided having a relatively reduced sheet resistance while simultaneously providing a relatively reduced absorption, a relatively reduced bending of the associated substrate to which the associated ITO layer is attached, the optical element having its total weight. It provides relatively uniform darkness or lightness over the entire assembly while reducing

Although a general mirror assembly is used to describe many of the details of the invention herein, it should be noted that embodiments of the invention apply equally to the construction of an electro-optical window, as described elsewhere herein. It is possible. The inner mirror assembly of FIGS. 6A-6D and the outer rearview mirror assembly of FIGS. 5A-5F include Canadian Patent 1,300,945, US Patent 5,204,778, or US Patent 5,451,822, which are incorporated herein by reference in their entirety. Photosensitive electronic circuits of the type illustrated and described herein, and other circuitry capable of sensing light and ambient light and supplying a drive voltage to the electrochromic element.

As noted above, in high performance electro-optical elements (mirrors or windows), the electrodes and / or reflectors and transparent conductive electrodes 708 on the third surface may be moderated to provide uniform overall coloring, increased coloring and clearing speed, and the like. To provide high conductivity. While improvement of the mirror element is achieved by using a third surface reflector / electrode, improvements to the transparent electrodes 708, 718 are desired. As also mentioned above, merely increasing the overall thickness of the ITO transparent electrodes 708 and 718 while improving conductivity by reducing sheet resistance adversely affects other optical and physical properties of the electrochromic element. Table 4 shows the drop in reflectance of the EC elements with varying ITO thickness for three ITO coatings with different optical constraints. Different ITO coatings in this example have different imaginary refractive indices. Exemplary element configurations consist of 1.7 mm glass, 50 nm Cr, 20 nm Ru, 140 micrometers EC fluid, various ITOs and 1.7 mm glass. The thicknesses of the different ITO layers are shown in Table 4. In many side mirror applications, customer specifications require reflectance to exceed 55%. The thickness is limited according to the properties of the ITO, and thus practical sheet resistance is also limited. In a typical manufacturing process, it is not always possible to operate the process at the lowest absorption level. Therefore, the upper limit of the actual thickness and the lower limit of the sheet resistance are constrained by the variation in the manufacturing process. In addition, ITO with low absorption often undesirably corresponds to high sheet resistance. Thick, low absorption ITO may also correspond to having high sheet resistance, thereby limiting the benefits of thick coatings.

[Table 4]

Another design attribute desirable for EC elements is to have low reflectance in the dark. This results in a high contrast ratio for the mirror element. Table 5 shows the reflectance values in the dark state for the EC mirror as a function of the ITO thickness. In this example, the EC fluid is set to be substantially opaque. If the EC fluid is not completely opaque, the light reflected from the mirror coating increases the reflectivity in Table 5. As shown, the reflectance in the dark state reaches a minimum in a half wave coating having a design wavelength of about 140-150 nm or 550 nm. As the thickness deviates from this half wave thickness, the reflectance in the dark state rises and the contrast ratio deteriorates. Thus, the ITO thickness should not be set to any thickness to achieve a given sheet resistance value. ITO thickness is constrained by both the absorption of the coating and the reflectance requirements of the dark state.

[Table 5]

In at least one embodiment, the electro-optic element comprises at least one ITO transparent electrode 128 having a reduced bulk resistance and thus improved conductivity without sacrificing other related optical and physical properties. Specifically, the electro-optical element is constructed through a sputtering process at relatively high pressures and relatively high oxygen flow rates. Up to now, the conventional sputtering process used to apply the ITO layer to the substrate has been limited to some maximum pressure. Exceeding these pressures previously resulted in poor quality ITO layers, specifically clustered heterogeneous depositions that exhibited poor electrical and optical properties.

In at least one embodiment, the ITO coating was made on a vertical inline sputtering coater. The cathode was approximately 72 "in length and two or four cathodes were used to create the coating. The cathodes had ceramic ITO tiles commonly used in the industry. The conveyor speed was increased to produce a coating of the desired thickness. The power applied to the cathode was 5 kilowatts, unless otherwise noted, each process section has two pairs of cathodes in opposing and aligned configuration. Unless mentioned, the process section consists of four cathodes: When two process sections are operated, an equal amount of oxygen is fed into both chambers, and the total amount of oxygen is used for four cathodes in one process chamber. The glass substrate is preheated to approximately 300 degrees Celsius. The turing gas was regulated and oxygen was introduced at a given flow rate or as a percentage of the total gas fed to the system, however, those skilled in the art would appreciate that different chambers have different pumping configurations, gas inlets and manifolds, cathodes and power. It will be appreciated that the present invention is not limited to the exact flow rates and percentages described herein, since it is understood that its pressure is measured at different points in the process. It will be appreciated that the resulting properties of the coating, including bulk resistance, stress and form, are novel and that the disclosure herein can be readily extended or applied to other sputtering systems without cancellation of the experiment. Has been conducted at a glass substrate temperature of 300C, but the trends and results It can be applied to high temperature and lower temperature, even if the absolute values described herein may not be achieved at different temperatures results in an improved condition of the standard.

In at least one embodiment of the invention, the increase in process pressure is offset by an increase in oxygen flow. As noted above, the specific relationship of pressure to oxygen flow rate depends on several factors, including the specific inert gas used during the sputtering process. Although two inert gases, Krypton and Argon, are described in detail herein, other gases can be used by extrapolating details from other data to other gases.

For krypton, pressures greater than or equal to 1 mT (millitorr) are good at 5% oxygen, pressures greater than or equal to 2mT at 4% oxygen, and greater than 3mT at 3% oxygen Pressures greater than or equal to 4.5 mT at 2% oxygen flow rate are best.

For argon, a pressure greater than or equal to 2 mT at 4% oxygen is better, a pressure greater than or equal to 3mT at 3% oxygen is better, and greater than or equal to 4.5mT at 2% oxygen The pressure is much better and the pressure greater than or equal to 6 mT at 1% oxygen percent is best.

As mentioned above, other gases may also be used. For example, at the expected high pressure, neon may be used at pressures that are preferably greater than or equal to 3 mT, more preferably greater than or equal to 7 or 8 mT. In addition, xenon allows the use of relatively low pressures compared to krypton. In addition, those skilled in the art will appreciate that a good percentage of oxygen may vary depending on the details of the sputtering apparatus. The above percentages are exemplary and non-limiting. The total flow of oxygen needed to achieve the optimal combination of material properties generally increases with increasing pressure. The amount of oxygen required does not increase at the same rate as the sputtering gas, so the percentage of oxygen decreases with increasing pressure.

Typically, ITO is operated at low pressure, ie 2 mT or less. However, low pressures tend to produce ITO coatings with compressive stress. In particular, because the thickness of the glass is reduced, the stress in the ITO can be high enough to bend the glass. As the thickness of the glass decreases to make the EC element lighter, the deflection of the glass due to ITO stress increases. If the mirror element or window size is large, the deflection of the glass can be several millimeters. In conventional mass production processing, as the thickness of the ITO is increased, the deflection of the substrate generally increases.

The deflection of the glass can be expressed in several ways. One way is to think of glass deflection as a lens. Magnification values are directly related to the deflection of the glass and are independent of the size of the glass. The magnification value is related to the radius of curvature using the following formula and the radius of curvature = (3124 mm) / (1-1 / magnification). Perfectly flat glass has a magnification of 1.0. When the coated glass is viewed from the coated side when the coating is at compressive stress, it becomes convex on the coated side. If the coating is at tensile stress, the glass becomes concave at the coated side. As a result of the compression coating, the warp or magnification value is less than one, and conversely, when the coating is tensile, the magnification or warp value is greater than one. Warp values on the order of 0.85 distort much from flat glass. This amount of warp creates an EC mirror or window that can have a double image, since reflections from the first and third surfaces cannot overlap. In addition, it is difficult to produce a practical seal with glass having an invalid warp. Glass having a warp value as high as 0.97 can cause problems in manufacturing or problems with double image.

Referring to FIG. 12, labeled “Argon Pressure Test,” warp values were measured for an ITO coating on 1.6 mm glass. When ITO or other stressed coatings are applied, glass thickness plays an important role in deflection and warping. The amount of deflection generally varies inversely to the cube of the thickness of the glass (assuming that the internal stress of the coating is constant with the thickness of the coating). Thus, thin glass warps in a non-linear manner against thick glass. Thin glass is generally warped with a thin ITO coating as compared to thick glass. The amount of warping is scaled linearly with the thickness of the coating. In Figure 12, the coatings were all approximately 50 nm thick. To calculate warps at different thickness values, the following formula, new warp = [1- (1-warp value) * new thickness / old thickness] can be used. Applying this formula to the value of 0.98 in FIG. 12 yields a warp of 0.94 for a 150 nm thick ITO coating and a warp of 0.74 for a 650 nm thick coating. If the glass is thinner, these values deviate much more from the flat.

12 shows some important findings. First, the warp value or stress (y-axis) at ITO produced at 2.1 mT does not change much over the oxygen flow rate range (x-axis) in this experiment. Over this range, ITO passes the minimum sheet resistance and bulk resistance values. One may incorrectly conclude that it is not possible to optimize both electrical and stress properties simultaneously, not to mention other necessary optical properties. At very high oxygen flow rates, the warp values begin to deflect much more from the flatness.

At high pressures (4.0 mT), a trend appears. At low oxygen flow rates, the stress of the ITO coating is reduced. At high pressures, however, this translates to a lower percentage of oxygen in the overall sputtering environment. In sputtering techniques it is common to control the pressure while keeping the oxygen percentage constant. These trends and findings that result in one embodiment of the present invention are therefore not revealed when conventional experiments are used. At the higher argon pressure of 4 mT, represented by line 1202, a strong tendency appears, whereby the stress in the ITO is minimized at low oxygen flow compared to line 1201. The low stress is due to the inherent microstructure or shape in the ITO coating described in detail below. At high oxygen flow rates, the warp value deviates from flatness, but at any particular oxygen flow rate, the warp value remains higher than that achieved at low pressures. This trend continues for even higher pressures than shown in FIG. 12. These advantages continue at pressures above 7 mT. Further improvements can also be achieved at much higher pressures, but limitations in certain sputtering chambers can limit experimentation at pressures above this value.

The graph of FIG. 13 shows the effect on the bulk resistance of the relative increase in argon pressure and oxygen flow. This particular test was performed using argon as the sputtering gas. For 400 sccm argon (line 1301) produces a pressure of 3.7 mT, 550 sccm (line 1302) produces a pressure of 5 mT, 700 sccm (line 1303) produces a pressure of 6.2 mT, and 850 sccm (line) 1304 produces a pressure of 7.4 mT. The rate of oxygen flow on the x-axis is in units of sccm. Note that significant improvements in terms of bulk resistance are achieved with increasing argon pressure and oxygen flow. In addition, low argon pressure tends to have a minimum at high bulk resistance values as compared to high pressure. For reference, a coating made at a pressure of 2 mT includes a bulk resistance value of about 180 to 200 μΩcm. In a recently published patent application, another manufacturer of electrochromic devices announced that the current technology of ITO coatings in EC applications corresponds to a bulk resistance of 200 μΩcm. This indicates that the benefits and properties of ITO practical for EC applications do not anticipate improved ITO coatings of the present invention. The high pressures described herein do not achieve their minimum in the range of oxygen tested.

The graph of FIG. 14 shows that a relatively thin ITO coating is obtained on the substrate as a result of the high pressure. This fact also contributes to why this embodiment of the present invention has not been achieved previously. As shown, when the oxygen flow and argon pressure are increased, the thickness of the ITO coating is reduced. Bulk resistance, an essential measure of the quality of the ITO's electrical properties, is the sheet resistance multiplied by the thickness. It is common to measure only sheet resistance, but much information is lost if the coating is not characterized in detail. Since the coating is becoming thinner with changes to the process gas, the sheet resistance does not follow the same tendency as the bulk resistance. A continuing analysis of the bulk resistance achieved with high argon pressure (which indicates that line 1404 is the highest for lines 1401, 1402, 1403) and oxygen flow is shown in a similar analysis of sheet resistance. If only sheet resistance is examined, it can be concluded that the 3.7 mT case is best and good properties are achieved at relatively low oxygen flow rates. Another benefit of low bulk resistance is that the real part of the refractive index is reduced. Half wave coatings with low refractive index are physically thicker than those with high refractive index, resulting in much lower sheet resistance.

The graph of FIG. 15 shows the effect of using argon gas in connection with increased argon pressure and increased oxygen flow, while the graph of FIG. 16 shows the achieved ITO half-wave bulk resistance. In order to achieve a half wave coating, two process chambers were used. The 200 sccm case represents the standard of conventional ITO coatings in EC technology. Prior art half-wave coatings have sheet resistances in excess of 12.5 Ω / sq, whereas for high pressures in accordance with at least one embodiment of the present invention a value lower than 12 Ω / sq and much lower than 11 Ω / sq. Was achieved. A significant improvement in bulk resistance achieved at high pressures is illustrated in FIG. 16. In this case, it can be seen that oxygen is not optimized at high pressures and the bulk resistance remains relatively constant in the argon flow of 400-800 SCCM.

Although bulk resistance of ITO is important, as mentioned elsewhere herein, sheet resistance is the primary factor affecting the darkening speed in the EC element. Bulk resistance of 200 μΩcm is equivalent to sheet resistance of 13.7 Ω / sq for half-wave coating, bulk resistance of 180 is equivalent to sheet resistance of 12.4 Ω / sq, and bulk resistance of 140 is equivalent to sheet resistance of 9.6 Ω / sq . The 9.6 Ω / sq is a 30% reduction compared to 13.7 Ω / sq, resulting in a new bus configuration which results in a significant improvement in darkening time and also improves element darkening uniformity as described elsewhere in the present invention. Make it possible.

In the following example, the coating was produced in another coater. This coater has a cathode approximately 27 inches long. The experiment was performed with both argon and krypton at a pressure of 2.73 mT. The coating was made next to the cathode in two passes. Oxygen was varied as shown in the relevant figures and tables. The resulting ITO coating is approximately 600 nm thick. In FIG. 17 the absorption in the coating (y-axis) is shown as a function of oxygen flow rate (x-axis). As can be seen, samples made with krypton (line 1701) have higher absorption at a given oxygen flow rate compared to samples produced using argon (line 1702) as the sputtering gas.

In FIG. 18, the warp in the glass (y-axis) is shown as a function of oxygen flow rate (x-axis). It can be seen that the sample produced with krypton (line 1801) has a warp value closer to 1, indicating that the krypton produced ITO coated glass is flatter than the argon (line 1802) produced glass. FIG. 18 shows previously provided data showing that in this case the warp increases with increasing oxygen flow rate.

In FIG. 19, warps of glass (y-axis) are shown for absorption (x-axis). The krypton generated sample (line 1901) has more absorption when shown for oxygen flow rate, but when the warp is compared with the absorption, the krypton generated sample is flatter than the argon generated sample (line 1902).

FIG. 20 shows the warp (y-axis) versus transmittance (x-axis) for krypton (line 2001) and argon (line 2002). Flat glass is obtained for a given increased transmittance value. Further improvement is possible by using krypton or xenon or even argon at high pressures. High pressures enable the simultaneous achievement of low stress, high transparency and low sheet resistance.

The form or surface characteristics of the ITO coating also vary with pressure and oxygen flow rate. There is an interaction effect between these values, where different forms are achieved at different oxygen flow rates when the pressure changes. The ITO coated samples shown in FIGS. 21-23 were produced in a coater having a 72 "cathode. All samples were prepared at 2.1 mT, 5 kw per target, 1 process chamber (2 targets / side) and linear speed of 32 ipm. Oxygen flow rates were 2, 8 and 17 for the samples of Figures 21, 22 and 23, respectively, and the samples of Figures 21 and 23 show the extremes of form, the so-called node 2101 form. 23 has the form of platelets 2302. Examination of the sample of Fig. 21 shows the structure of the background platelets 2102. The sample of Fig. 21 is thought to have some mixed form. The sample of has, in medium oxygen flow, very few nodes 2202 and overall predominant platelet 2202. Platelet morphology correlates with high stress in the coating, while nodal forms occur in coatings with small stresses. Given fair value Depending on the pressure, the transition between these two different forms is abrupt or gradual The low oxygen node shape is characterized by a large peak-valley roughness (described in detail with reference to Figures 33A and 33B). Occurs significantly above the surface of, thus creating a large peak-valley roughness When the node transitions to the platelet microstructure, the surface roughness is reduced This roughness is minimal when the node has just disappeared from the surface. At this point, they have a shallow “cliff” 2103, 2203, 2303 or platelet microstructures with regions between platelets, as the oxygen flow is further increased, the height of the cliff between platelets increases, so that the surface roughness is desirable. Increase it not to.

The samples of FIGS. 24 to 26 are also made with both 2 sccm oxygen at power and linear velocities similar to those of FIGS. 21 to 23. Process gas pressures were 3.7, 2.1 and 1.6 mT, respectively. As the pressure increases, the shape becomes increasingly dependent on the node shape. The transition between node forms 2401, 2501, 2601 and platelet forms is more gradual at high pressures, thus allowing for fine tuning between the desired optical and mechanical properties in the coating. While much less prevalent, platelet 2402 form is still present in the background of the 3.7 mT sample. As the pressure is further reduced, the node components ultimately disappear, leaving only platelet form.

The use of krypton or other heavier sputtering process gas is similar in some respects to operating at high pressures. As shown in Figs. 27 to 29, three SEM images of 1/2 wave ITO samples generated with varying oxygen flow rates with krypton as the process gas are compared. These samples are described in more detail with reference to Table 6. These samples were made at 40 imp linear speed and 6.2 kw using two process chambers (four cathodes / sides). The glass thickness was 1.1 mm. In FIGS. 27, 28 and 29 the oxygen flow rates are 8, 12 and 16 sccm, respectively. Oxygen flow rates are process chamber specific. The surface of the sample shown in FIG. 27 produced at 8 sccm oxygen has almost no platelet components and is extremely stress free, with the surface of the sample prevailing at node 2701. The sample shown in FIG. 27 and the other half-wave samples from Table 6 have warp values of 1 by default. The surface structure of the sample shown in FIG. 28 generally consists of node 2801 and has the shape of a very small amount of platelets 2802 with some cliff 2803. The sample of FIG. 29 is basically a platelet 2902 surface structure with well defined cliffs 2903. These samples have very low bulk resistance values of approximately 150 μΩcm. The absorption of these coatings is quite low in the 12 sccm case with the best combination of flatness, resistance and absorption. Low stress values for these coatings indicate that even when using high pressures or created with heavier sputtering gases, even certain platelet forms can be used successfully.

Samples D, E, and F shown in FIGS. 30-32 are for the two-wave ITO case shown in Table 7, respectively, and correspond to 8, 12, and 16 sccm flow rates, respectively. The linear velocity in this case was 7 ipm, otherwise the process conditions were equivalent to those in Table 6. These coatings are approximately five times thicker than their half-wave counterparts. The shape of the coating is somewhat different in these samples with the form of nodes 3001, 3101, 3201 of thinner samples, resulting in a more granular structure (sample D in FIG. 30). There is a void between the particles shown in FIG. 30, which results in undesirable high blurring and degraded conductivity, which is illustrated with a relatively high bulk resistance value of 200 μΩcm for this sample. Sample E, made of 12 sccm of oxygen, has a very low bulk resistance (131 μΩcm) and a fine grain microstructure. The 16 sccm case also has a similar microstructure, but in this case, no platelet morphology exists because of the thinner coating. The stress levels of these krypton-generated coatings are relatively low. Warp values basically range from 1 for the low oxygen case to 0.956 for the highest oxygen case. These samples were made of 1.1 mm glass, which is more susceptible to warpage compared to the thick 1.6 mm glass described above. Still, the warp value is very close to one. This is in a coating that is at least ten times thicker than the 50 nm coating first mentioned for 1.6 mm glass. This coating not only has extremely low stress, but also has better bulk resistance and reasonable absorption values.

Peak-valley surface roughness (defined in the description below with reference to FIGS. 33A and 33B) for these coatings is preferably less than or equal to 200 microns, more preferably less than 150 microseconds, and more preferably greater than 100 microseconds. Less than or equal, even more preferably less than or equal to about 50 Hz, and most preferably less than or equal to about 25 Hz.

To illustrate additional features and advantages of electrochromic mirrors constructed in accordance with at least one embodiment of the present invention, a summary of the experimental results is provided in Tables 6 and 7 below. In these summaries, reference is made to the spectral characteristics of the elements of the electrochromic mirror constructed according to the parameters specified in each example. When discussing color, it is useful to refer to the Commission Internationale de I'Eclairage's (CIE) 1976 CIELAB Chromaticity Diagram (commonly referred to as the L ^* a ^* b ^* chart). While color technology is relatively complex, a fairly comprehensive description is available from Principles of Color Technology, 2nd Edition, J. Wiley and Sons Inc. by FW Billmeyer and M. Saltzman. (1981), the present invention generally follows its description when it comes to color techniques and terminology. In the L ^* a ^* b ^* chart, L ^* defines brightness, a ^* represents red / green values, and b ^* represents yellow / blue values. Each electrochromic medium has an absorption spectrum at each particular voltage that can be converted into three numerical representations, ie its L ^* a ^* b ^* values. To calculate a series of color coordinates, such as L ^* a ^* b ^* values, from the spectral transmittance or reflectance, two more items are needed. One is the spectral power distribution of the source, ie the light source. The invention simulates light from an automobile headlamp using CIE standard light source A and simulates sunlight using CIE standard light source D65. The second item required is the spectral response of the observer. The present invention uses a 2 degree CIE standard observer. The light source / observer combination commonly used for mirrors is expressed in A / 2 degrees, and the combination commonly used for windows is expressed in D _65/2 degrees. Many of the examples below refer to the value Y from the 1931 CIE standard because the value corresponds more closely to the spectral reflectance than L ^* . The value C ^* , also described below, is equal to the square root of (a ^* ) ² + (b ^* ) ² , thus providing a measure of quantifying color neutrality.

Tables 6 and 7 summarize the experimental results for the elements constructed in accordance with the present invention. Specifically, experiments were performed within the range of 8 sccm to 16 sccm oxygen flow for both half-wave and two-wave thickness with krypton as the sputtering gas and at a pressure of 3 mTorr. Table 6 summarizes the results for ITO thickness slightly smaller than half wave, Table 7 summarizes the results for ITO thickness slightly larger than half wave, and half wave thickness is applicable to mirror application, for example, Two wave thicknesses are applicable, for example, to window applications. In addition, it is noted that these tables contain the results for both monolayer and bilayer elements.

TABLE 6

[Table 7]

Table 8 shows the inter-dependencies between bulk resistance, electron mobility and electron carrier concentration. Note that there is a continuous carrier concentration and mobility combination that produces a given bulk resistance.

[Table 8]

The electron carrier concentration is preferably greater than or equal to 40e ²⁰ electrons / cc and the mobility is greater than or equal to 25 cm ² / Vs. Carrier concentration and electron mobility, thickness and surface roughness provided herein are derived from ellipsometric analysis of the coating. The electron concentration and mobility may differ from those determined using the hole characterization method, and those skilled in the art will appreciate that there may be an offset between the measurement methods. As noted above, there is a continuous carrier concentration and mobility value that can achieve a given bulk resistance. In embodiments where low refractive index is preferred, it is preferred to adjust the deposition process to obtain high carrier concentration. In another embodiment where low absorption is preferred, it is preferred to adjust the deposition process to achieve high electron mobility. In other embodiments, intermediate levels of carrier concentration and mobility may be desired.

In at least one embodiment, the electro-optical element simultaneously exhibits reduced bulk resistance, reduced absorption, thereby reducing the bending or warping of the associated substrate to which the ITO is applied, while maintaining uniform darkness and lightness of the overall assembly and reducing its weight. An improved ITO layer that reduces.

Surface topologies, shapes or roughness are typically not critical in non-microscale electrical applications dealing with metal coatings. Surface topologies are of particular interest when metals are used in optical applications. When the surface roughness becomes too large, the coating has significant non-specular reflectivity, ie blur. This roughness, in most applications, will often have to be addressed first, because it can have a negative impact on visual appearance but not necessarily on functionality. In the case of optical applications, such as many of the applications described herein, the presence of unpleasant blurring is considered the worst case scenario. Surface roughness can have other negative consequences at much smaller roughness levels than those that result in unpleasant blurring. The surface roughness level defines a reasonable form for the metal film in order to allow it to function properly in other optical applications. The disadvantage associated with not properly controlling the surface morphology is often an increase in cost, because expensive metals with high reflectivity are often needed in order to overcome the problems associated with inadequate surface morphology. Thin-film modeling techniques are used to analyze the effects of different levels of shape or surface roughness. These techniques have been adopted in the field of thin film technology and have been found to accurately describe the actual thin film or coating system and thus can be used to predict the effects of different changes on the coating. This is beneficial because it can be costly or time consuming to manufacture or fabricate the large number of samples required to achieve the effect. In this case, a commercial thin film program called TFCalc, supplied by Software Spectra, Inc., was used to perform the calculations.

Roughness, as used herein, is defined as the average peak-valley distance. 33A and 33B illustrate two different roughness scenarios. In FIG. 33A, large crystallites 3302a are shown. In FIG. 33B, small particles 3302b are shown. In both of these cases, the peak-valley distances 3301a and 3301b are shown to be the same. In addition, both examples have the same void to bulk ratio. It will be appreciated that the valleys and peaks may not be at the same height. Thus, average peak-valley measurements provide more representative quantification values.

If the layer is thin, the layer can be approximated to a single homogeneous layer with a uniform refractive index. There are several ways to approximate the refractive index of the mixed layer. This is called effective medium approximation (EMA). Each different EMA has its advantages and weaknesses. In these examples, the Bruggeman EMA method was used. When the thickness of the layer becomes large, the roughness does not approximate well when a single fixed refractive index is used. In these cases, the roughness can be approximated as several slices of different ratios of voids and bulk materials to form an inclined refractive index approximation.

Several metals are modeled herein to provide representative examples of optical effects on the reflection of surface roughness. Tables 9, 10 and 11 show the effect of roughness thickness on the reflectance of the surface for Ag, Cr and Rh, respectively. The thickness of the layer is in nanometers and the Cap Y value represents the reflectance from the coated surface. For each of these metals the reflectance drops as the thickness of the roughness increases. Depending on the application, the amount of reasonable roughness is different. The roughness should be an average peak-valley less than 20 nm, preferably less than 15 nm, more preferably less than 10 nm, even more preferably less than 5 nm, and most preferably less than 2.5 nm. These preferred ranges depend on application as mentioned above. For example, in one embodiment, the thickness of the flash layer, cover layer, barrier layer or adhesive layer (ie, functional layer) may need to be scaled according to the degree of thickness of the lower surface. Due to the thickness of the functional layer required by the roughness of the lower surface, undesirable effects such as changes in the optical properties of the resulting laminate, high cost or other negative effects may occur. Means for planarizing the surface prior to deposition of the functional layer are described below. It should be noted that there may be certain embodiments where increased surface roughness may be beneficial, such as creating a substantially larger surface area for good adhesion to the seal material.

Tables 9, 10 and 11 also contain values labeled "% of theoretical maximum". This measure defines how closely the reflectance of the coating with the rough surface matches the reflectance of the ideal perfectly flat surface. Coatings whose percent theoretical maximum is 100% have a maximum reflectance theoretically achievable for the material. If the percent of theoretical maximum is 85%, the reflectance achieved is only 85% of the value of the ideal flat coating or 0.85 times the reflectance of the coating with zero roughness.

The reflectance of a metal or alloy coating depends on many properties of the coating, even the relatively flat coating. The density of the coating, the presence of internal voids, the stress level all play a role in how the reflectivity reaches some ideal maximum. The theoretical maximum reflectivity defined herein is not related to this ideal reflectance of the ideal coating but rather to the reflectance value of a flat real world coating. In practice, the theoretical maximum is obtained through a combination of optical analysis and thin film modeling. Refractive index versus wavelength and surface roughness can be obtained by analyzing real world coatings having surface roughness using optical techniques such as Variable Angle Spectroscopic Ellipsometry (VASE). Refractive index versus wavelength can be entered into a thin film modeling program such as TFCalc or Essential Macleod and the reflectance can be calculated. The reflectance thus calculated using the measured refractive index data is the theoretical maximum reflectance value from that particular film or coating.

Preferably, the reflectance of the coating is greater than 85% of the theoretical maximum, more preferably greater than 90% of the theoretical maximum, and most preferably greater than 95% of the theoretical maximum.

TABLE 9

[Table 10]

TABLE 11

In certain applications, it is desirable to have a high second surface reflectivity, in which case the reflectance is for the metal layer when viewed through glass. In this case, embedded voids in addition to surface roughness are important. The amount of voids (% to bulk) may vary, and the thickness of the void layer may also vary. The general rules described above for surface roughness also apply here.

When the metal layer often includes low sheet resistance, surface roughness is particularly important. Metals or other electrically conductive materials have intrinsic properties called bulk resistance. The sheet resistance of the coating is obtained by dividing the bulk resistance number by the thickness of the coating. In principle, as long as the coating is thick enough, any sheet resistance value can be obtained from any conductive material. Difficulties or limitations in achieving low sheet resistance arise when other properties are needed in addition to sheet resistance or conductivity.

As the thickness of the coating increases, the surface roughness typically increases, which leads to a decrease in specular reflectivity as described above. Very thick coatings often have reflectance levels significantly lower than those of perfectly smooth surfaces. The degree of roughness the coating exhibits is a function of a number of factors. The nature of the material itself is the main driving force, but within limits the deposition process parameters (along with the deposition process used) can modify the surface properties of the coating.

Due to other considerations, the material with the best surface roughness may not always be selected for a given application. Other factors also play a role. For example, adhesion and cost are important issues that affect the choice of materials for coating lamination. Often, it is not possible to select a single material that meets all requirements, so multilayer coatings are used. Some platinum group metals, such as rhodium, ruthenium and iridium, have high reflectivity but are very expensive. Thus, the entire coating with low sheet resistance made from these materials is ridiculously expensive. When extreme adhesion may be required for glass or other materials, these materials may be found to have weaker bonding strengths than other materials. Silver based coatings may have insufficient stability as anodes and, depending on the coating lamination, may also be problematic in terms of adhesion. Metals such as chromium are relatively inexpensive compared to other metals and are known to have very good adhesion. Thus, chromium can function as an adhesive layer and can be fabricated to a sufficient thickness to achieve the desired electrical properties.

Unfortunately, chromium is very reactive and has an inherent tendency to result in relatively large surface roughness values. High reactivity is important in that when a coating is deposited using, for example, a Magnettron Sputter Vacuum Deposition (MSVD), the chromium atoms tend to attach to the first landing. The rate of junction formation is very fast, which limits the ability of atoms to diffuse along the surface to find low energy positions. Typically, a low energy stable position in the coating is a position suitable for low surface roughness. This tendency not to go to a low energy state also causes degradation of the bulk resistance of the coating. Therefore, thicker layers are required to achieve the target sheet resistance, and surface roughness tends to be worse. These competing effects make it difficult to simultaneously achieve the purpose of low sheet resistance and high reflectance.

It is known that the reflectivity of low reflectivity metals can be increased by placing a thin layer of high reflectance metals on the metal. For example, the above metals such as rhodium or ruthenium may be used. The thickness of these metals needed to achieve a given level of reflectivity is a direct result of the surface roughness of the underlying chromium layer. Other metals that can be used as conductive layers include aluminum, cadmium, chromium, cobalt, copper, gold, iridium, iron, magnesium, molybdenum, nickel, osmium, palladium, platinum, rhodium, ruthenium, silver, tin, tungsten and zinc. This is not restrictive. Alloys of these metals with each other or with other metals or metals may be possible. The suitability of these materials for a given application depends on the full list of requirements. For example, ruthenium may be an expensive metal in one application, but in other applications it may be less expensive than other metals such as rhodium and thus fall within the spirit of the present invention. In other non-limiting embodiments, a given metal or alloy may not be suitable for all other components in the application. In such cases, sensitive metals may be separated in different ways from embedded or restricted components. Layers deposited on top of chromium usually pattern the roughness of the underlying layer. Thus, a thin layer of high reflectivity metal also does not have its ideal reflectance due to the layer or layers below it. In most cases, the preferred embodiment is that a high reflectance metal is oriented towards the viewer. Many of the high conductivity metals listed above have high reflectivity. These metals may need to be alloyed with other metals to have appropriate chemical, environmental or physical properties. The metal or alloy may have an inappropriate color or tint. The overall reflectance intensity may be appropriate for the desired application, but if the reflected color does not meet the requirements, the metal or alloy is unsuitable. In this case, similar to the above description, a metal or alloy can be buried under a layer having a low intrinsic reflectance but having a better reflected color.

Reference samples were prepared to evaluate the tradeoff between reflectance and sheet resistance for chromium-ruthenium bilayer coating laminations. In these samples, chromium was applied to obtain the target sheet resistance. The samples were then overcoated with ruthenium of different thickness. The following process conditions were used.

All coatings were processed at 3.0 mTorr.

Cr @ 4.0Kw @ 130 = approximately 1000 angstroms

Cr @ 4.0Kw @ 130 X 9 = .7 ohms squ.

Cr @ 4.0Kw @ 130 X 3 = 1.5 ohms squ.

Cr @ 4.0Kw @ (87) X 1 = 3 ohms squ.

Cr @ 4.0Kw @ 170 X 1 = 6 ohms squ.

Ru @ 1.7Kw @ 130 = 400 Angstroms

Ru @ .85Kw @ (130) = 200 Angstroms

Ru @ .43Kw @ (130) = 100 Angstroms

Ru @ .43Kw @ 260 = 50 Angstroms

Ru @ .43Kw @ (520) = 25 Angstroms

All chromium samples were deposited at 4 kw. The linear velocity (in parentheses—in arbitrary units) and the number of passes (eg, X 9) were varied to control the thickness of the coating to achieve the sheet resistance goal. A ruthenium layer was created with varying linear velocity and power to achieve the target thickness level. The results of this matrix are shown in Table 12. Reflectivity generally drops as thickness increases and sheet resistance decreases. Some samples prepared for 3 Ω / sq do not fit this trend. This is because they were manufactured at a different linear velocity than the rest of the chromium coating. As the linear velocity decreases, the substrate moves at a slower rate. In a linear process, this means that the initial nucleation layer is formed primarily of sputtered high angle deposition material. As described below, high angle deposition results in inferior material properties. Shielding is often used to eliminate this high angle deposition. The 3 Ω / sq chrome case in this study is an excellent example of how high angles can degrade the optical properties of the coating.

[Table 12]

As can be seen from Table 12, even in the case of 6 Ω / sq, only the chromium coating has a relatively low reflectance value. For this sample, the reflectance was only about 61%. Chromium produced by other means or process conditions must be able to achieve values in excess of 65%. Therefore, even at such an appropriate sheet resistance value, the chromium reflectance fell.

When a 3 Ω / sq coating is desired, ruthenium of 100 and 200 angstroms is required on top of chromium to obtain an appropriate reflectance value. Ideally, ruthenium coatings should be able to achieve reflectance in excess of 72%. Even 400 angstroms on top of 6 Ω / sq chromium is 2% below the theoretical optimum. Low ohmic samples are unlikely to reach theoretically achievable reflectance values. Thus, where both low sheet resistance and high reflectivity are required, standard chromium-ruthenium bilayers do not meet the requirements. Other means must be used to solve this problem.

Deposition process parameters can be adjusted to minimize surface roughness during formation of the coating. In the case of metals, the surface roughness can be reduced and the reflectance can be increased by performing the process at low pressure and preferably using a neon or argon-neon mixture as sputtering gas, which is described in detail below. These parameters contribute to proper momentum and energy transfer in the deposition process, resulting in less rough surfaces and low bulk resistance.

Table 13 shows how surface roughness, reflectance and electrical properties change as process parameters are adjusted. The 3mT case is provided for reference. The thickness of the coating is about 600 angstroms. This thickness is important because the coating is nearly opaque at this level and the sheet resistance is relatively low. As can be seen, lowering the pressure reduces roughness by about 17% and achieves an increase in reflectance of almost 2%. Further improvement is obtained by lowering the pressure and sputtering with a 50:50 mixture of argon and neon. Roughness is about 20% lower than the reference case and reflectance is about 2.7% higher. The last case is a much higher amount of neon, ie approximately 70% of the sputtering gas is neon. The reflectance is about 3.5% higher than the reference case and the roughness is reduced by about 24%. Thickness and roughness values are obtained using variable angle spectroscopic ellipsometry (VASE).

[Table 13]

The result can be further improved by lowering the pressure and increasing the neon content in the sputtering gas. In addition, increasing the substrate temperature also contributes to a flatter coating. Higher substrate temperatures result in higher surface mobility of the deposited atoms, resulting in a flatter surface.

Table 13 also includes bulk resistance values for chromium coatings. The theoretical minimum bulk resistance for chromium is about 13 μΩcm. A reference case made at a typical pressure of 3 mT in argon has a bulk resistance value of at least six times the theoretical bulk resistance. By improving the deposition properties, a bulk resistance value of up to five times the theoretical minimum value can be achieved. Preferably, the bulk resistance is no more than five times the theoretical minimum value, more preferably no more than four times the theoretical minimum value, more preferably no more than three times the theoretical minimum value, and most preferably the theoretical minimum value. 2 times or less.

The presence of oxygen (or water) in the system can be particularly harmful in terms of surface roughness. Chromium is very reactive with oxygen and tends to react immediately. This makes the coating rougher. Therefore, a coating with less oxygen is recommended. Table 14 shows the effect of oxygen on the roughness. Oxygen levels in Table 14 refer to the percentages in the sputtering gas. The unit of pressure is mT and the unit of thickness is Angstroms. A reasonable amount of oxygen in the coating is 5 atomic percent or less, preferably 2 atomic percent or less, ideally 1 atomic percent or less.

[Table 14]

The amount of reasonable roughness depends on the application. If high reflectance values are desired, lower roughness is also desirable. If the reflectance requirements are not so stringent, the roughness may be higher. In general, the roughness should be less than about 200 angstroms, preferably less than 100 angstroms, more preferably less than 50 angstroms, much better than less than 25 angstroms, and most preferably less than 15 angstroms. do. The term roughness, as used herein, refers to the average peak-valley distance obtained using ellipsometry or atomic force microscopy.

Other means may be used alone or in conjunction with each other or with the methods described above to minimize surface roughness. For example, the cathode can be shielded to minimize grazing (high) angle deposition. Other methods for obtaining flat surfaces include the use of ion assisted sputtering or ion assisted deposition, plasma assisted sputtering, and other means of increasing the surface mobility of atoms. The cathode type may be chosen to facilitate a flatter coating, such as the use of "twin mag", unbalance magnetron, rf superimposed dc power, microwave assisted sputtering, high power pulse deposition, AC sputtering or other such means. Can be.

Although chromium was used as the conductive layer in the above examples, other metals, alloys or multilayer coating materials described herein and in the references cited herein may be used within the spirit of the present invention. Different materials may require different process conditions to achieve a flat surface. For example, ITO does not necessarily need to have a flat surface under the desired conditions for the metal. In the case of ITO, the surface morphology is modified by a number of process variables. Controlling the surface properties of ITO is much more difficult than in the case of metals. ITO is not always conductive like metal, and in some process settings where a flat coating can be obtained in the case of metal, a highly conductive coating may not be obtained in ITO. Therefore, it is quite difficult to control the form taking into account the different properties of the material. In general, for high temperature coatings on glass or other glassy substrates, relatively flat coatings can be achieved at the high pressures and relatively high oxygen settings described herein. To vary the process parameters in order to flatten the coating may be applied to other materials of the multi-layer TiO ₂ or the like, such as TiO _2, and ITO described in transflective coating applications.

As noted above, the roughness generally increases with the thickness of the coating. Often, the above process settings are insufficient to obtain a coating with a reasonable roughness level. This is the case when extremely low sheet resistance is required. In this scenario, there is a need for alternative means to achieve coatings having relatively low surface roughness and at the same time having low sheet resistance values.

In commonly assigned US Patent Application Publication No. 2006/0056003, which is incorporated herein by reference in its entirety, an ion beam is introduced as a means for thinning the coating in localized areas on the coated substrate. As described in detail herein, ion beams can also be used to planarize (shown in FIGS. 33A and 33B) a rough coating (shown in FIG. 37). The ion beam may be used alone or in combination with other methods described herein to reduce the roughness of the coating and thus increase the reflectance. Ion beam sources differ in design and function. For this description, any design that is capable of delivering ion flux in the energy ranges described herein is suitable.

Ion beams are a group of positive or negative ions with relatively high collimated energy. The energy of the ions is a function of the operating potential of the ion beam. The current, ie the flux of ions, is a function of the operating potential and the amount of gas injected through the beam and the background pressure in the chamber. Sufficient ion energy is desirable to etch, mill and / or planarize the coating material. An example of a related phenomenon is billiards. Think of the incoming ions as cue balls and the coating as rack balls at the start of the game. If the cue ball is shot into the rack with very low energy, the rack does not shatter. Conversely, if the cue ball is shot with high energy, the rack can shatter very violently.

FIG. 34 shows the sputtering yield as a function of argon ion energy for various materials. There is a threshold energy at which no sputtering occurs or at least occurs. As the energy increases, the sputtering yield increases. Ionized atoms can also affect the sputtering rate. The good mass of sputtering ions with the maximum sputtering yield varies with the energy of the sputtering ions and the mass of the atoms to be sputtered. 35 shows sputtering yield as a function of sputtered ions and sputtered atomic mass at 500 eV ion energy. The data shown in FIG. 35 was generated using a computer simulation program called "SRI M (Stopping and Range of Ions in Matter)". As shown, there is a range of optimal sputtering gas ion masses that yield reasonable sputtering yield for a given target atomic mass. In general, as the beam energy increases, the optimal ion mass increases to maximize sputter yield. Preferred ions depend in part on the mass of the sputtering atom. For optimal energy and momentum, the transport of atoms must have a relatively similar mass. 34 shows that the threshold energy depends on the sputtered material. Some materials take more energy to release than others. The graph of FIG. 34 also shows that the sputtering yield does not tend to increase at relatively high ion energies. At these relatively high energies, the process begins to enter the area of ion implantation rather than ion sputtering. For efficient sputtering or etching, the ion energy should be at least 100 eV, preferably at least 500 eV, and most preferably at least 1000 eV.

The planarization effect will be described with reference to FIGS. 36 and 37. In FIG. 36, ions collide with a flat surface. When ions strike the surface, energy is transferred either in the direction parallel to the surface or in the direction perpendicular to the surface. Some of the energy transferred in a direction parallel to the surface becomes a component perpendicular to the surface, resulting in the emission of atoms. In Fig. 37, the same ions collide with the rough surface. As can be seen, ions are much more likely to be released from the coating. Most of the energy directed perpendicular to the surface can result in the release of atoms, with more surface area and more directions capable of releasing atoms. As the ion milling process continues, the coating becomes even more flat. In these and other examples, the ion beam consists of one atom. Indeed, clusters of ions / atoms may be used instead of one ion. Known methods of creating clusters can also be used in this situation.

In a similar manner, an ion beam impinging on a surface at an angle can have a substantially higher sputtering efficiency and planarization effect. In this case, the angled ion beam has a high probability of releasing the material laterally relative to the coating surface.

As will be seen below, the reflectance, transmission, absorption and sheet resistance properties of certain semipermeable coatings were limited by the roughness in the layers. One related coating is glass / ITO / Si / Ru, referred to herein as "Option 4". ITO is best suited for 3/4 or 5/4 wave coatings, 2100 or 3600 Angstroms respectively. The Si layer is about 220 angstroms and the ruthenium layer is about 70 angstroms. In addition, as described below, other variations of this lamination are possible. The reflectance and transmittance of this stack are highly dependent on surface and interface roughness. When considering multilayer stacking, such as option 4 consisting of a dielectric, a semiconductor layer, a transparent conductive oxide and a metal, the surface roughness as well as the interface roughness must be considered.

Table 15 shows the effect of ion milling the surface of ITO, one of the underlayers used in Option 4 lamination. This data was obtained using ellipsometry to characterize the coating. Table 15 also shows the initial properties of the ITO coating. Initial roughnesses for the 3/4 and 5/4 wave coatings are 7.4 and 11.5 nm, respectively. These values are relatively high. The samples were ion milled with one beam (38 cm long beam) operating at 270 mA current and 3000 volts with argon implanted at 200 sccm and the operating pressure in the chamber was 2.5 mT. Ion beam is a closed drift hole-effect anode layer type design. The linear velocity for 2B (2 beam equivalent at 30 ipm) was 15 ipm and the linear velocity for 4B (4 beam equivalent at 30 ipm) was 7.5 ipm. The beam was in a direction perpendicular to the surface of the coated glass. The ion beam removed about 17 nm / beam equivalent at 30 ipm for 3/4 wave ITO and about 11.1 nm / beam equivalent at 30 ipm. In both cases the surface roughness drops dramatically and the 3/4 wave ITO is almost perfectly flat. However, the 5/4 wave ITO did not become that flat, since it started in a much coarser initial state, it may require a slower linear velocity or additional beam to achieve the minimum roughness value.

[Table 15]

The main explanation is that the ion milling process significantly increases the reflectance. In Table 16a, the ITO coatings described in Table 15 were overcoated with approximately 22 nm of Si and 7 nm of Ru. Transmittance is generally reduced by ion milling due to the high reflectivity of these coatings. More importantly, the absorption of ion milled ITO samples is considerably low. This results in a high light output of the associated light source through the coating at the same reflectance level. The difference is even more significant when all of these coatings are normalized to the same reflectance level. In order to achieve the same reflectance level for the non-ion milled portion, the thickness of the ruthenium layer is significantly increased. This, in turn, further reduces transmittance and increases absorption, which is undesirable in some applications.

These coated lites (shown in Table 16a) were included in the electro-optic mirror elements (shown in Table 16b) to evaluate the optics in the actual EC elements. Multiple 2 "x5" cells were prepared and the transmittance and reflectance (mirror reflection and non-mirror reflection) were measured. The increase in reflectance of the assembled elements is correlated with the results observed in the single data. The transmitted color is much amber biased, although the reflected color is quite neutral. This suggests that this design, due to its inherent constituent material, transmits more red light than blue light. This may be particularly beneficial when, for example, a red display is disposed behind the mirror element.

Table 16b also shows specularly excluded reflectance (mirror reflective exclusion) data for the sample elements. Ion milling flattens the surface, which substantially reduces scattered light. The resulting image is much clearer and more vivid due to the small amount of scattered light.

Many automotive companies have specifications that force reflectivity to exceed 55% for exterior mirror applications. Samples that were not ion milled did not meet this specification and had initial roughness on ITO. Ion milled samples, even the 5/4 wave ITO portion, meet the specification. The switching speed of the mirror element, in particular the darkening speed, depends on the sheet resistance of the coating. By allowing the use of more than 5/4 waves of ITO, ion beam milling allows for faster switching times while also meeting reflectance requirements. In addition, some of the 3/4 wave elements have reflectance values that significantly exceed the minimum requirements. If the overall design requirements benefit from this change, these coatings can be adjusted to have high transmittance values by reducing the thickness of the ruthenium or other high reflectivity metal used as the top layer. In the absence of ion beam planarization methods, the range of useful reflectance and transmittance options is limited.

[Table 16a]

Table 16b

In other applications, the use of ion milling has been performed to planarize ITO for non-permeable applications. In this case, the coating is glass / ITO / Cr / Ru. Chromium and ruthenium are masked inside the epoxy seal and ITO is used to carry current from the electrode into the EC element. ITO has some roughness that is reduced by treatment with ion beams. 38 shows the reduced roughness with the inverse of the linear velocity at a fixed beam current. In another example, the linear velocity of the glass through the coater was 30 inches per minute (ipm). A single ion beam was used and the current adjusted to change the ion milling speed. 39 shows the increase in reflectance versus the beam current. A 0.5% increase in reflectance is achieved even with these suitable ion milling conditions. In these examples, the ITO coating maintained its initial roughness to facilitate, if possible, improved adhesion of ITO to the epoxy in the region of the seal while milling the ITO in the field of view to achieve improved optical properties.

In other applications using ion milling, the color and reflectance of the so-called chrome ring type coatings were investigated. In this application, a multilayer metal coating is applied over the ITO coating on the glass. ITO coated glass is ion-etched in the form of a ring around the element to thin the ITO coating at this location, improving the color and reflectivity of the chrome ring stack while allowing for low sheet resistance of thick ITO at the center of the portion. 40 shows reflectance under different conditions when viewed through glass. Reflectance without ion milling is shown by the thick line. Reflectances at several different linear velocities are also shown. As the speed decreases, the residence time under the beam increases and the roughness decreases. As a result, the reflectance is increased. Although the reflectance seems to have stopped increasing, there was an arc of some beam that could affect the results during this test. The main result is that by ion milling, the reflectance is increased even when an arc is present. 38 shows the linear velocity versus the change in ITO roughness in these tests in the absence of arcs.

A series of other tests on the same coater examined the color of the chrome ring if there was ion milling. The linear velocity was adjusted to change the amount of ITO removed. ITO started with a half wave, and the goal was to reduce the thickness to approximately 80% of the half wave, in other words from about 145 nm to about 115 nm. Fig. 41 shows the reflected b ^* of the chrome ring according to the linear velocity adjustment. The reflected b ^* correlates directly with the thickness of the ITO as described in the priority document cited herein. B ^* for half-wave ITO is about 16. As the linear velocity decreases, the amount of etched material decreases. In at least one embodiment, a b ^* of about 2.5 is desired as an ideal match for the central field of view. Therefore, the linear velocity should be about 12.5 ipm. If faster linear velocity is required, more ion beams may be used.

In another example where a reduction in sheet resistance is desired, the effect of ion milling on reflectivity and material use has been investigated. As mentioned above, the roughness of the coating increases with thickness and the reflectance decreases with roughness. In this example, a coating of 1.5 Ω / sq with a layer structure of glass / chromium / ruthenium was desired. Chromium thickness was set at approximately 2500 angstroms to provide most of the contribution to sheet resistance. Ruthenium was initially set at 400 angstroms. In situations where the surface is perfectly flat, maximum reflectance is achieved with ruthenium as low as 180 to 200 angstroms. A level of 400 angstroms was used to make ruthenium thick enough to compensate for the rough surface of chromium to some extent. Additional ruthenium increases the reflectance but also increases the cost.

42 shows the reflectance versus linear velocity inverse for ion beam treatment of the chromium layer prior to the application of the ruthenium layer. The beam current was set to about 250 mA. At a linear velocity of about 4 "/ min, the coating achieves a maximum reflectance of nearly 70.5%. There was no additional reflectance increase due to further reduction in linear velocity. If a faster linear velocity is desired, additional beams are used. Can be.

Figure 43 shows how reducing the amount of ruthenium can be used in coatings due to the planarization effect of the ion beam. The linear velocity was about 2.1 ipm and the beam current was similar to the result in FIG. Ruthenium as low as 160 angstroms can be used to obtain maximum reflectance. As a result, there is a significant cost savings compared to the basic case where additional ruthenium was used to compensate for the roughness of the initial layers. In addition, a 1.5 Ω / sq coating of chromium and ruthenium with relatively high reflectance may not be practical without ion beam planarization.

Typically, the roughness of the resulting coating will vary between approximately 10-20% of the total thickness of the coating without special effort to make a flat coating. Table 17 shows the thickness of the chromium / ruthenium stack required to obtain various sheet resistance values. As the bulk resistance changes, the bulk resistance of the chromium layer changes to show how the thickness of the chromium layer changes to obtain different sheet resistance values. This can be used as an example of variation in chromium bulk resistance properties, or can be thought of as a means of explaining what happens when a material with a different or varying bulk resistance value replaces chromium.

The range of roughness is calculated in Table 17 as 10 and 20% of the bulk thickness. Ruthenium is set to 200 angstroms slightly above the thickness needed to achieve maximum reflectance for the material in ideal applications. If the chromium layer is flat or planarized by ion beam, this thickness represents the optimal reflectance case. Table 17 shows the results of the calculation, and the thickness of the transmittance is compared with the total thickness. The contribution of roughness is considered to be the average in the 10 and 20% cases. The percentage of lamination that is ruthenium varies depending on the target sheet resistance of the lamination and the bulk resistance of the chromium or base layer. If the sheet resistance is greater than or equal to 6 Ω / sq, it is desirable for ruthenium or other high reflectivity metal to be less than 50% of the total thickness. If the sheet resistance of the stack is approximately 2 Ω / sq, the ruthenium thickness should be less than about 25% of the total thickness. The thickness percentage of the high reflectance layer also varies with the bulk reflectance and reflectance targets of this metal. The appropriate high reflectance percentage of the total thickness is a function of the desired reflectivity of the stack, the desired sheet resistance of the stack, and the bulk resistance of the other materials used to construct the stack. The percentage of high reflectance material should be less than 50 of the total thickness, preferably less than 25%, more preferably less than 15%, even more preferably less than 10%, most preferably the total thickness Should be less than 7.5% of In this example, chromium and ruthenium are used to illustrate the advantages of one embodiment of the present invention. Other metals may replace the chromium layer as a means of providing most of the sheet resistance. So-called high reflectivity metals are defined as metals having a high reflectance compared to the layers that contribute most of the sheet resistance. In this example, the role of the top layer is described as having a high reflectance with respect to the electrically conductive layer. In other embodiments, the electrically conductive layer or electrically conductive layers may have an inappropriate color or hue. Although the reflectance intensity may be reasonable, the reflected color may be considered unpleasant. In this embodiment, the top high reflectance layer can function to provide reasonable color without actually increasing the reflectance. In one example, the electrically conductive layer may be colored a lot, with neutral reflected color being preferred. In this case, the so-called high reflectance layer serves to make the color more neutral.

In other embodiments, the electrically conductive layer may have a neutral reflected color, with much colored reflections preferred. Here, the high reflectance metal of the top can be selected to provide a non-neutral appearance. In another embodiment, a multilayer stack may be applied over the electrically conductive layer, such that the stack has the flexibility to adjust color through adjustments to the multilayer stack disposed over the electrically conductive layer while achieving low sheet resistance. have. In this example, the multilayer stack may consist of a metal, a dielectric layer, and / or a semiconductor layer. The choice of materials that make up the stack, its thickness, orientation to the electrically conductive layer, and neighboring media is determined by the design criteria of the given application.

TABLE 17

As the sheet resistance in various applications decreases, the thickness must be increased, thus increasing the surface roughness and decreasing the reflectance. The reflectance of the coating drops to a value lower than the theoretical maximum. The lower the target sheet resistance value, the lower the percentage of theoretical maximum reflectance value achieved. For coatings having a sheet resistance of about 6 Ω / sq or less, the techniques described herein can achieve reflectivity greater than 90% of the theoretical maximum, preferably greater than about 95% of the theoretical maximum. have. For coatings having a sheet resistance of about 3 Ω / sq or less, the techniques described herein are greater than 80% of the theoretical maximum, preferably greater than about 85% of the theoretical maximum, and more preferably Reflectances greater than about 90% of the theoretical maximum, and preferably greater than about 95% of the theoretical maximum, can be achieved. For coatings having a sheet resistance of about 1.5 Ω / sq or less, the techniques described herein are greater than 75% of the theoretical maximum, preferably greater than about 85% of the theoretical maximum, and more preferably Reflectances greater than about 90% of the theoretical maximum, and preferably greater than about 95% of the theoretical maximum, can be achieved. For coatings having a sheet resistance of about 0.5 Ω / sq or less, the techniques described herein are greater than 70% of the theoretical maximum, preferably greater than about 80% of the theoretical maximum, and more preferably Reflectances greater than about 90% of the theoretical maximum, and preferably greater than about 95% of the theoretical maximum, can be achieved.

In commonly assigned US Patent Application Publication No. 2006/0056003, which is incorporated herein by reference in its entirety, various metal stacks for “chrome ring” mirror elements are described. A thin chromium adhesive layer is deposited on the ITO, and a layer of metal with high intrinsic reflectance is deposited on the chromium layer. Various high reflectance metals have been described. A second chromium layer is described that does not contribute to appearance when viewing the coating on the glass side but is applied to minimize the transmission of visible and UV light. The reduction in visible light is to conceal the seal material while reducing the UV light to protect the seal material during exposure to sunlight. In this example, chromium was considered to be a low cost means for reducing the transmittance of light, whether UV light or visible light. Other low cost metals can provide the same function as long as they have good adhesion to the seal and high reflectivity metal.

The thickness of the high reflectivity metals can also be simply increased to reduce the light transmittance, but the high reflectance metals are often relatively expensive and the use of these metals increases the cost of the coating.

The ITO layer can be any transparent conductive oxide or other transparent electrode. The transparent conductive oxide or transparent electrode may consist of a single layer or multiple layers. The layers in the multilayer can be selected to modify the reflected color or appearance so that the "ring" has the appropriate optical properties. One such multilayer may include the use of a color suppression layer disposed between the glass substrate and the transparent conductive oxide. The use of this layer allows for more choice of color for the ring when the ITO layer thickness is adjusted.

The adhesive layer may be chromium, Ni, NiCr, Ti, Si or silicon alloys of various compositions, or other suitable adhesion enhancing layer. "High reflectance metal" is selected from metals and alloys with bulk reflectance values higher than chromium. Exemplary metals include aluminum, ruthenium, rhodium, iridium, palladium, platinum, cadmium, copper, cobalt, silver, gold and alloys of these materials. In addition to the alloy, a mixture of these metals with each other or with another metal may be used. Multiple layers may also be used instead of the single layer shown in the schematic for high reflectivity metals. Similarly, the UV blocking layer can be made of a single material, alloy, multilayer or other combination that results in a suitable transmittance reduction.

The adhesion of materials, layers or coatings may also be improved by the use of ion beam treatments described herein. For example, ion beam treatment of the ITO surface was performed using argon followed by a mixture of argon and oxygen. These tests were compared with the surfaces that were not ion milled. This sample was attached to the test glass by epoxy material to form a sealed cavity. A hole is drilled in the upper light of the glass and pressure is applied to the cavity to determine the pressure required for the cavity to fail. Failure aspects can include adhesion failure in the epoxy, adhesion of the epoxy to the coating, cracking of the glass or the coating falling off the substrate, or failure in adhesion in the coating.

The ITO surface was ion beam treated with argon, argon / oxygen mixtures or no treatment. This surface was then coated with a thin layer of chromium about 50 angstroms thick, followed by a layer of ruthenium about 500 angstroms thick (called a beta ring). The coated glass was bonded to the other glass with epoxy commonly used in EC elements, followed by curing of the epoxy. Table 18 shows the pressure values at failure and the amount of metal lift from the ITO coating. The control portion has a small amount of metal bumps. The argon beamed part had significant metal bumps, but the pressure at failure was basically the same. The use of oxygen again had a similar pressure value on failure, but the elevation of the metal from the ITO was removed. Oxygen improves the adhesion of chromium to ITO. The ion beam preferentially sputters oxygen, a component that aids in the adhesion of chromium. In the case of argon alone, minimization of critical oxygen and weaker junctions are obtained. Adding oxygen to the beam is considered to "heale" the surface of the ITO, thus strengthening the bond and minimizing metal bumps. The pressure values at failure do not correlate because the glass cracks during the test. These cracks determine the pressure value at the time of failure and thus dominate the test. In this example, there may be situations where oxygen is required, but other gases may be good or only argon may be a better choice.

In another example, when ruthenium was deposited directly on ITO, a dramatic change in pressure value and failure pattern was observed upon failure. If ion beam treatment is not used, the pressure value at failure is very low, approximately 6-7 psi, the coating bumps are failure patterns, and the glass does not crack. If the ITO surface is treated with an oxygen containing beam and then ruthenium is deposited on the surface, the pressure value at failure increases by more than two times, and glass cracking is the main failure pattern. The coating is still raised from ITO, but the adhesive strength is dramatically increased.

[Table 18]

The top layer that may be used in certain applications may be an electrically conductive stabilizing material. Its role is to provide good electrical conductivity between the ring metal and the bus bar or silver paste. This material may be selected from platinum group metals such as iridium, osmium, palladium, rhodium and ruthenium. Mixtures or alloys of these metals with each other or other suitable metals may be used.

The thickness and selection of the material in the layers is preferably chosen to provide the appropriate color and reflectance intensities as disclosed in the cited patent application. The thickness of the layer should also be chosen to achieve the required transmittance characteristics. The visible transmittance should be set so that the epoxy seal is not visible when viewed. The visible transmittance should be less than 5%, preferably less than 2.5%, more preferably less than 1%, and most preferably less than about 0.5%. The UV transmittance may or may not be correlated exactly with the visible transmittance. In the case of UV transmission, the appearance of the ring is not a problem, but the protection of the seal is a major concern. This, of course, assumes that the selected seal is sensitive to UV light. The amount of acceptable UV light depends on how the seal is affected by the UV light. Ideally, the coating should be designed so that the ring coating is opaque to UV light, but unfortunately this level of UV transmission can be enormously expensive. In addition, the adhesion of the layers may drop if the total thickness becomes too large. The stress that may be present in the layers results in a deformation large enough to cause the layers to peel off from the glass or other layers of the coating. For this reason, it is necessary to consider finite UV transmittance. UV transmittance should be less than about 1%, preferably less than 0.5%, more preferably less than 0.1%, and most preferably less than 0.05%.

One feature / area that is gaining popularity is the use of exterior mirrors to display features such as turn signals, heater on / off indicators, door open warnings or warnings that doors may be opened for oncoming vehicles. Mirrors or mirror housings are also used to house poodles or entry lamps.

This requirement is unique to the interior mirrors when compared to mirrors for the exterior of the vehicle. In at least one embodiment, the mirror reflection of the inner mirror is preferably at least 60% and preferably has sufficient transmittance in front of the display to pass the appropriate amount of light through the associated mirror element. In addition, the inner mirror does not have to withstand the harsh chemical and environmental challenges encountered in outer mirror applications. One problem is balancing the need to meet automotive specifications for rearview mirrors and the desire to include an aesthetically pleasing information center. Providing high mirror element light transmittance is one means of compensating display technology for limited light output. Occasionally high transmissions make the circuit and other hardware behind the mirror element visible. To deal with this problem, an opaque layer is applied on the fourth surface of the mirror element.

The auxiliary turn signal shown in FIG. 5A is an example of the desired display feature in the outer mirror assembly. One way to include signal features behind the electrochromic mirror element is to laser strip a portion of the reflective material from the element so that light can pass through it. The desire to provide alternative styles and designs is the motivation for using transflective mirror element technology. The transflective method of certain embodiments of the present invention enables features in mirrors that have a much more "hidden" (hidden) appearance. By concealing, the light can pass through the transflective element while not seeing the light source. By concealing, in addition or as another alternative, it may mean that there is minimal contrast between the display area and the main reflective area. In some cases, there is a desire to clearly display a display or feature with color contrast or reflectance contrast to provide a framing effect so that the viewer has a clear indication of where to find the desired information. Conventional materials used in exterior mirror applications typically have a low reflectance and / or high sheet resistance associated with achieving significant levels of transmission.

Ruthenium, for example, is often used for external EC applications because of its relatively high reflectance and environmental durability. The 23 nm Ru coating, reflector in the EC element, has a reflectance of approximately 57.5%, a level that meets most commercial mirror reflectance specifications. This coating has a sheet resistance of approximately 20 Ω / sq and the EC element has a transmission of approximately 2.5%. Neither transmittance nor sheet resistance are available for practical applications. Other environmentally durable metals may have slightly different reflectivity, transmittance and sheet resistance values, but none have the properties to meet the requirements in EC applications.

The low reflectivity requirements for OEC elements allow silver, silver alloys, chromium, rhodium, ruthenium to be deposited for associated reflective and / or translucent layer (s) with less difficulty in meeting preferred reflectance, durability and electrochromic performance characteristics. It allows the use of other configurations of materials including rhenium, palladium, platinum, indium, silicon, semiconductors, molybdenum, nickel, nickel-chromium, gold and alloy combinations. Some of these materials have an advantage over silver or silver alloys in that silver and silver alloys are susceptible to damage in an external mirror environment. The use of harder metals is beneficial for the durability of the mirror elements in terms of manufacturing options and more robust end products. Reflective and / or semi-permeable laminates can also be produced with dielectric materials that exhibit reflectance levels high enough for use in OEC elements.

Ag based materials generally achieve approximately 1% transmission per reflectance reduction percentage in the mid-visible region. An advantage associated with increased transmission is the availability of inexpensive, low power light sources such as displays or LEDs. External mirrors have generally been used in display type displays using customizable LEDs with very high light output. A new design is disclosed herein that enables the use of Ag-based semipermeable coatings in interior and exterior mirror applications. These new designs address the limitations of using Ag-based materials in external applications while maintaining the inherent optical properties and benefits derived from the Ag layer. Other coating options may be considered when low transmission is part of a design criterion using / without an Ag based layer. One great advantage for low transmittance is that the need for an opaque layer is reduced or no opaque layer is needed.

In many markets, the size of mirrors is increasing to allow more visibility. Darking time for large mirrors is a challenge and an important consideration in design options. In general, large mirrors associated with external mirrors require increased or improved conductivity to maintain reasonable darkening and clearing speeds. The previous limitation of the single thin metal coating described above is solved by innovatively using transparent conductive oxide (TCO) for lamination. TCO provides a means of achieving good conductivity while maintaining high levels of transmission. Some of the examples below can be achieved with relatively thick indium tin oxide (ITO. ITO is one particular example of a broadly TCO-based material) with a satisfactory level of transmission to the outer mirror. Other TCO materials include F: SnO ₂ , Sb: SnO ₂ , doped ZnO, IZO, and the like. The TCO layer is overcoated with a metal coating which may consist of a single metal or alloy or a multilayer metal coating. For example, the use of multiple metal layers may be necessary to facilitate adhesion between different materials. In other embodiments, a semiconductor layer may be added in addition to or instead of the metal layer. The semiconductor layer provides some inherent properties described below. When the thickness of the ITO / TCO layer (s) is increased to improve conductivity, the effect of coating roughness needs to be considered. The increase in roughness may cause the reflectance to be lowered, which in turn requires an increase in metal thickness which may lower the transmittance. Increasing the roughness can cause inconvenient haze as described elsewhere. Roughness problems may be solved by modifying the deposition process for ITO and / or implementing ion beam planarization after deposition of the ITO layer after ITO deposition. Both methods have been described in detail above. In addition, the improved ITO materials described above can be used in this embodiment to lower the sheet resistance of the transflective coating as a whole.

The semiconductor layer may comprise silicon or doped silicon. Small amounts of additional elements or elements may be added to alter the physical or optical properties of the silicon to facilitate its use in other embodiments. The advantage of the semiconductor layer is that it has less absorption compared to metal and improves the reflectance. Another advantage of many semiconductor materials is that they have a relatively low band gap. This is equivalent to a significant amount of absorption in the blue to green wavelengths of the visible spectrum. Selective absorption of one or more light bands allows the coating to have a relatively pure transmission color. High transmission color purity is equivalent to having any part of the visible or near infrared spectrum with a transmission value greater than 1.5 times the transmission of the low transmission region. More preferably, the transmission in the high transmission region is greater than twice the transmission in the low transmission region and most preferably more than four times the transmission in the low transmission region. As another alternative, the transmissive color of the transflective stack should have a C * value [sqrt (a ^{* 2} + b ^{* 2} )] greater than about 8, preferably greater than about 12, most preferably greater than about 16. . Other semiconductor materials from which semipermeable coatings with relatively high purity transmission colors are obtained include SiGe, InSb, InP, InGa, InAlAs, InAl, InGaAs, HgTe, Ge, GaSb, AlSb, GaAs and AlGaAs. Other practical semiconductor materials are those with a bandgap energy of about 3.5 eV or less. In applications where secret properties are desired and red signals are used, materials such as Ge or SiGe mixtures may be preferred. Ge has a smaller bandgap than Si, resulting in a larger wavelength range with relatively low transmittance levels. This may be desirable because low transmission at wavelengths other than the display is more effective at hiding certain features behind the mirror. If uniform transmission is required, it is advantageous to select a semiconductor material having a relatively high bandgap.

The display area may be secret in nature so that the viewer cannot recognize that the mirror has a display until the display is activated or backlighted. Covert is achieved when the reflectance of the display area is relatively similar to the rest of the field of view and the color or hue contrast is minimal. This feature is very beneficial because, as described above, the display area does not reduce the field of view of the mirror.

A small amount of transmitted light can reveal features behind the mirror, such as circuit boards, LED arrays, shrouds, and heater terminals. The use of light blocking layers (opaque layers) can be used to avoid this problem. Opaque layers are often applied on the fourth surface of the mirror using various materials such as paints, inks, plastics, foams, metals or metal foils. The difficulty of applying this layer is complicated at the outer mirror. Most outer mirrors have a convex or aspherical shape which makes the application of the film or coating more difficult.

An opaque layer can be included in the third surface stack of the elements. A semi-transmissive area may be masked, and a suitable stack, such as ruthenium, rhodium or other single or multilayer stacks (metal, metal / dielectric and / or dielectric) that provides adequate reflectivity and color (opaque), may be applied on the remaining surfaces. Can be applied. Covert appearance is achieved when the desired color and reflectance match or discrepancy is maintained. In one preferred embodiment, the display area of the mirror element and the main field of view are hardly distinguishable. In other embodiments, it may be desirable for the transflective area to have a different color with contrasting aesthetic pleasure.

Another option is to maintain a high transmittance level in a portion of the visible spectrum that has a low overall transmittance to achieve a secret appearance. The use of narrow spectral bandpass filters can also be used to achieve the secret effect.

A relatively opaque layer (either the same material as the material of the adjoining layer or a Material, or otherwise), may be included in the third surface coating stack that is otherwise translucent. The addition of this layer can affect the reflectivity of the area where this layer is inserted. The reflectance in this area can then be adjusted through the selection of the material and its thickness, thus maintaining the uniformity of the appearance of the device by hardly distinguishing the difference between the display area of the mirror element and the relatively opaque area.

It also intentionally offsets the reflectance and / or hue of the display area to provide a visual clue as to where it is when the display is active and to provide some indication that the display function is included in the mirror even when the display is off. It can be beneficial. When a conductive material is used to add opacity, the conductivity of the relatively opaque portion of the display is now greater and the corresponding voltage drop across the majority of the field of view is correspondingly higher, providing a faster coloring speed. do. The additional opaque layer (s) may be such that the reflectance from the back of the area is substantially smaller than in the absence of the opaque layer (s), otherwise it may occur due to stray light. The effect of multiple reflections can be reduced. One such device that illustrates the above principles is approximately 400 Angstroms of TiO ₂ over approximately the entirety of the third surface, followed by 200 Angstroms of ITO and approximately 90 Angstroms of chromium and a third except about the area on the display. And a third surface coating laminate of an alloy of approximately 320 Angstroms of 7% gold 93% silver over nearly the entire surface.

The opening to the display on the interior car mirror of this particular model is too small to measure the reflectance with any spherical-based spectrophotometer, so the element can be used to facilitate the measurement of the reflectance of different parts of the stack. Different parts were made to span the entirety of their viewing surface. Transmittance and reflectance measurements were made from both the front and back of the element.

Tables 19 and 20 show the resulting measurements along with the graphs of FIGS. 44 and 45, respectively.

TABLE 19

TABLE 20

In this particular example, it can be seen that adding chromium to the stack increases opacity and reduces reflectance from the back of the element. If the thickness of the silver alloy is increased in the non-display area to achieve opacity, it does not lead to a decrease in reflectance from the rear of the element as can be seen in this example, but from the rear of the element if chromium is omitted The view further increases the already relatively high reflectance. Furthermore, although transmission is sufficient for the display area to serve as a translucent, it can be seen that the display area of this design has a relatively small difference in hue, such as a difference in brightness, when compared to the area containing the chrome area. .

Also note that in the previous example, by increasing or decreasing the thickness of the silver alloy layer in the transflective region, a larger or smaller "blue bias" in the transmission properties of this display region is achieved respectively. Using an RGB video display behind this area can benefit from adjusting the relative intensities of the red, green, and blue emitters to maintain better color rendering. For example, if the transmission is larger in the blue region of the spectrum and smaller in the red region, it may be desirable to reduce the intensity of the blue emitter and increase the intensity of the red emitter. This type of adjustment is appropriate in this transflective design and other transflective designs, whether the spectral bias of the transmission is a gentle slope or has more different transmission bands.

If the display is for use when the mirror element is brightness controlled, intensity adjustments can be made to compensate for any spectral bias from the coated and / or activated electrochromic medium. The intensity adjustment may be a function of the operating voltage of the device and / or other feedback mechanism to properly match the relative RGB intensity for a given point in the color excursion of the electrochromic element. When dyes such as those that can be used to create "blue mirrors" are used even when the electrochromic species are not active, the intensity of the emitter can be adjusted to have improved color rendering. As the mirror element is reduced in reflectance, any spectral bias of the first and / or second surface coating is rather a factor, and the degree of compensation of the intensity of the different colors of the display can be adjusted accordingly. UV additives and other additives to the EC medium may also affect the visible absorption of the element, and intensity adjustments may be included to improve the color rendering of the associated display.

It may be beneficial to design transflective coatings for both display and signal or other indicator applications. If high power is needed for a signal or indicator, the transmittance spectrum of the transflector can be biased to increase the transmittance in this region. RGB displays with the same intensity in the red, green and blue portions of the spectrum have different intensities after passing through the transflective layer (and other components of the mirror element). This intensity offset can then be compensated accordingly by adjusting the output of the individual RGB colors to obtain proper color rendering.

There may be situations where the reflectance match between the opaque area and the display area is more desired than the examples of Tables 19 and 20. In addition, there may be advantages to having a reflectance match in a range of different reflectance values. As such, the transmittance of the display area can be adjusted without degrading the reflectance match between the opaque field of view and the display area. Another design goal is to match the colors in the field of view and the display, or in different ways in aesthetically pleasing way. Color matching can be beneficial if it is desired that the perceived difference between the two regions be minimal. In other situations, it may be beneficial to have reflectance match and color mismatch to help guide the viewer where the display is.

Other means may be used to further reduce the reflectance in the opaque region when viewed from the opposite direction regardless of the first surface reflectance. Another aspect of the invention relates to the recognition of a display area relative to an opaque area or a field of view. The viewer in the field of view sees only the reflected light, while the viewer in the display area sees the combination of reflected and transmitted light. The addition of transmitted light in this area can make the display area more visible, even if the reflectance in both areas is the same. Thus, the reflectance in the display area can be reduced to compensate for the added transmitted light.

Note that in the previous example, the reflectance match between the opaque area and the display area is a function of the thickness of the layers. The thicknesses of chromium and AgAu7x have been optimized to have relatively low transmittances while the reflectance matches are relatively close. The change in reflectance and transmittance as a function of chromium and AgAu7x thickness is shown in Table 21. The data in Table 21 is modeled data for electrochromic elements consisting of the identified stack, an EC fluid of 0.14 micrometers, and a top plate with a half wave ITO coating on the second surface. The reflectance difference between the opaque area and the display area is lower when the chromium layer is relatively thin and / or when the AgAu7x layer is relatively thick. This method provides a means of manufacturing a mirror having an opaque area and a display with a very good match in certain transmittance and reflectance ranges.

TABLE 21

Means are preferred for achieving reflectance matching over a wide range of desired reflectance values while maintaining opacity in the field of view and maintaining high transmittance in the display area. This is accomplished by adding additional layers to the stacking described in the example of Table 21 in at least one embodiment. This preferred third surface stack is TiO ₂ / ITO / AgAu7x / Cr / AgAu7x. By dividing AgAu7x, it is possible to achieve reflectance matching over a wide intensity range and to simultaneously control the transmittance of the stack in the opaque region. Transmittance in the display area is limited to the values described above for the AgAu7x stack.

While the chromium layer is masked in the display area, other layers may be present in the display area on almost the entire surface or at a minimum. This example uses a TiO ₂ / ITO net quarter wave bilayer (so-called GTR3 base layer) to neutralize the color of the transflective silver or silver alloy layer in the display area. Other transflective color neutralizing layers may be substituted for the display and are within the scope of this embodiment. The chromium layer dividing the AgAu7x layer provides a novel feature of optically separating the lower layers from the upper AgAu7x layer as well as providing opaque properties to the stack in this application. 46 shows how the reflectance changes with the thickness of the chromium layer. As can be seen, at a thickness slightly larger than 5 nm, the thin chromium layer substantially separates the underlying silver gold alloy layer from contributing to reflection. This separation results in a thin layer of chromium that allows the chromium thickness to be adjusted to achieve a range of transmittance values without significantly affecting the overall reflectance of the stack.

One advantage of this method extends to the display area. Since only a thin chromium layer is needed to separate the lower AgAu7x layer from contributing to the reflectance, the thickness of the lower AgAu7x layer can be varied to achieve other design goals. For example, it may be achieved to match the reflectance in the opaque area and the display area as described above. In the example where the transflective mirror element has regions of relatively high transmittance and low transmittance, the term "opaque" is used to conceal the presence of the part behind the fourth surface without adding an opaque material on the fourth surface. To indicate that it is low enough. In certain embodiments, the transmittance should be less than 5%, preferably less than 2.5%, even more preferably less than 1%, and most preferably less than 0.5%. Since AgAu7x is separated in the opaque region, the thickness can be adjusted as needed to achieve the desired reflectivity in the display region. The AgAu7x top layer will have higher reflectivity when deposited on Cr vs. TiO ₂ / ITO (present in the display area). The lower AgAu7x thickness can be set such that the display area matches the reflectivity of the opaque area. The reflectance value for the mirror element can be as low as the reflectance value of the chromium layer alone to the reflectance of the thick AgAu7x layer. The reflectance can be adjusted to any desired value over this range, and the transmittance can also be adjusted. Desirable reflectance matching between the display area and the field of view is also achievable.

The silver containing layer may be another alloy or combination of alloys in addition to 7% Au93% Ag. For example, it may be advantageous to have more gold in the alloy above the layer (s) than under the opaque layer (s). This may be due to obtaining a more durable interface between the opaque layer and the upper silver containing layer, the desired color, or the reason associated with the durability of the upper silver containing layer during treatment or when in contact with the electrochromic medium. If the two silver containing layers contain different levels of material that readily diffuse through silver, such as gold, platinum, palladium, copper, indium, etc., the semi-transmissive region where the silver layer no longer has one or more intermediate opaque layers After or after this treatment, there is a possibility that the alloy is a weighted average of the upper alloy and the lower alloy. For example, when the silver-platinum alloy is used as the upper silver containing layer and the silver-gold alloy is used in the lower layer, there is a possibility that the semi-transmissive region becomes the silver-gold-palladium tertiary alloy layer. Similarly, if two silver containing layers of the same thickness of 7% gold containing silver and 13% gold containing silver were used, the resulting layer in the semi-transmissive region would basically be a layer with a uniform distribution of 10% gold in silver. There is a possibility.

The opaque layer may be a separate layer bonded to the transflective region, where one, two or all of the layers may not contain silver. For example, among many possible combinations, a silver alloy on top of silicon or ruthenium on top of silicon can be used in the transflective region.

Among other materials, US Pat. No. 6,700,692 useful in flash layers, including indium tin oxide, other conductive oxides, platinum group metals and alloys thereof, nickel, molybdenum and alloys thereof, the entire contents of which are incorporated herein by reference. Flash overcoat layers of materials referred to may also be included in the design described above. Depending on the thickness and optical properties of the materials selected for the flash layer (s), adjustments to the underlying stack may be necessary to maintain a similar degree of agreement or mismatch between the relatively opaque and semi-transmissive region (s).

As noted above, the achievable transmittance in the "opaque" region depends on both the silver base layer and the chromium or "opaque" layer. The thicker the chromium layer, the lower the transmission at a given reflectance level. The chromium layer can be thinned to a desired level in order to reach the transmittance of the display area. It is sometimes difficult to control the thickness of very thin layers when a high level of transmission is required. Thick layers can be used when the metal opaque layer is partially oxidized. Thick layers may be needed to achieve higher transmissions compared to thin pure metal layers. Fig. 47 shows the relationship between the transmittance and the reflectance for the case where the CrOx layer is used as the lamination and opaque layers from Table 21 above. 47 shows the transmittance versus reflectivity for different opaque layers and thicknesses. The symbols in the diagram represent AgAu7x layers of different thicknesses. The thick layer is on the right and the thin layer is on the left.

As can be appreciated, as the AgAu7x layer thickness becomes thinner, the reflectivity approaches the value of the chromium or opaque layer. The thickness of the opaque layer affects the low end reflectance of the mirror element. For example, when the Cr layer is 10 nm thick, the bottom reflectance is 41.7%, 20 nm is 50.5%, and 30 nm is 52.7%. As the opaque layer increases in thickness, the bottom reflectance approaches a constant value, but for thin layers, the reflectivity drops when the layer becomes too thin. This can be an advantage or disadvantage depending on the design criteria of a given application. Limitations between reflectance and transmittance for the chromium layer can be overcome by replacing the chromium layer entirely with another material or adding additional layers.

Referring to US Pat. No. 6,700,692, other metals, semiconductors, nitrides or oxides are disclosed above or below the Ag containing layer. These layers and materials are chosen to provide an improvement in lamination. A base layer underneath a reflector, which can be a conductive metal, metal oxide, metal nitride or alloy, is disclosed. They may also be intermediate layers or intermediate layers between the base layer and the reflective material. These metals and materials may be selected to be free of galvanic reactions between the layers and / or to enhance adhesion to the substrate and reflector or other layer (s). These layers may be deposited on the substrate or there may be additional layers beneath the base layer described above that provide additional desirable properties. For example, there may be a dielectric pair comprising TiO ₂ and ITO with an optically effective thickness of odd quarter waves. The thicknesses of the TiO ₂ and ITO layers can be adjusted as needed to meet specific conductivity and optical requirements.

If the metal layer is deposited under a silver containing layer, the metal layer is an alloy of chromium, stainless steel, silicon, titanium, nickel, molybdenum, and chromium / molybdenum / nickel, nickel / chromium, molybdenum, and a nickel-based alloy, inconel, indium , Palladium, osmium, tungsten, rhenium, iridium, molybdenum, rhodium, ruthenium, stainless steel, silicon, tantalum, titanium, copper, nickel, gold, platinum, and alloys containing principally the above materials, any other platinum group Metal, and mixtures thereof. In addition, the layer below the reflector layer may be an oxide or metal oxide layer, such as chromium oxide and zinc oxide.

The optional metal layer on top of the silver containing layer may be selected from the group consisting of rhodium, ruthenium, palladium, platinum, nickel, tungsten, tantalum, stainless steel, gold, molybdenum, or alloys thereof.

The present invention contemplates an opaque layer with a transflective portion of the mirror or optical element. This provides a new or additional design criterion that affects the choice of metal that acts to reduce the transmission in certain areas of the element or mirror. Table 22 below shows the reflectance and color of various suitable base or opaque layer metals on TiO ₂ / ITO dielectric layer stacks in EC cells. All metal layers are 30 nm thick. Color and reflectance change with the thickness of the metal layer. Table 22 shows the relative differences in color and reflectance of the various suitable metal opaque layers relative to the bottom reflectivity when the opaque metal is relatively thick and without AgAu7x or other Ag containing top layer. As is known, alloys of these metals with each other or with other metals have different optical properties. In some cases, these alloys behave like mixtures of individual metals, but in other cases, these alloys do not have reflective properties that are merely interpolation of the individual metals. The metal or alloy can be selected for its galvanic properties, reflectance, color or other properties as needed.

In silver containing reflective layer stacks, the reflectance and color change when deposited on these other metals or alloys. Table 23 shows the metal containing laminates with AgAu7x of 20 nm on top. The color and reflectance of the 20 nm Ag containing layer stack is altered by the properties of the metal used as in the opaque layer. The transmittances of the other laminates are also shown. As indicated above for chromium, the transmittance, reflectance and color can be changed by changing the thickness of the opaque metal. It is clear from these examples that the desired color, transmittance and reflectance can be obtained by changing the properties of the opaque metal layer or the opaque metal layers.

Table 22

TABLE 23

In the field of view, color and reflectivity adjustment can be further reinforced or enhanced by combining the metal opaque layer with a dielectric layer additionally described in US Pat. No. 6,700,692. This dielectric layer can often modify both color and reflectance without significantly affecting absorption in the stack.

In order to match color and reflectance in the display area, the above-described bilayer base layer can be used below the silver containing reflective layer. Table 24 shows how the reflectance and color change with changes in ITO and TiO ₂ thickness for fixed AgAu7x. As can be seen, the thickness of the bilayer not only affects the reflectance but also the color can be adjusted. These layers can then be adjusted as needed to achieve both the desired reflectance and color. The tunability of color and reflectance can be further extended by adjusting the thickness of the AgAu7x or silver containing reflective layer. Additional color and reflectance variations can be obtained by adding additional dielectric or metal layers as part of the display stack above or below the silver containing layer or by changing the refractive index of the dielectric layer.

TABLE 24

For example, if the color in the field of view is biased yellow, blue, green or red by the selection of the metal under the silver reflective layer or by the silver reflective layer itself or by a combination of these layers, the color and / or reflectance match is This can be accomplished by adjusting the layers in the display area. One advantage of this method is that although the layers can be applied almost entirely on the surface, due to the inherent optical shielding properties of the opaque layer or opaque layers, these underlying layers do not contribute to reflectance and color in the field of view or opaque region and are opaque. Layers or opaque layers are fully functional in the masked display area. The present invention is not limited to layers that function in the display area covering the entire portion. This is particularly applicable to the layers below the opaque layer. If the manufacturing process warrants this method, these layers can be deposited only over the entire area of the display as needed.

In some situations, it may be advantageous that the reflecting hue of the reflector and / or transflective is bluish. It may also be advantageous to combine the bluish opaque reflector region and the bluish translucent region in the same element for a secret appearance.

It is known to produce blue electrochromic elements with a blue tint even when no potential is applied through the use of a dye, as in US Pat. No. 5,278,693, which is incorporated herein by reference in its entirety. There is also a practical method of using a third surface coating laminate to produce a device that meets the typical requirements of an external automotive electrochromic device. These techniques can also be used in combination if possible. Such devices should now have reflectance values in excess of 35% in the United States and over 40% in Europe. Preferably, in at least one embodiment, reflectance values greater than 50% or 55% are preferred. Whatever third surface stack is used in the electrochromic device, it needs to be durable, chemically, physically and electrically.

A bluish electrochromic device can be achieved by depositing a basically opaque chromium layer on glass followed by approximately 900 A of ITO on top of it and then completing the fabrication of the electrochromic device. The coating laminates produced and used in this manner had the color values shown in Table 25 and the reflection spectra shown in FIG. 53. Table 25 and Figure 53 show the values after inclusion in the EC element when the coating is on a single glass light.

When the coating on glass is measured in air there is a significant reflectance drop compared to the reflectance of the finished device. To compensate, it is conceivable that an opaque layer of silver or silver alloy may be used instead of or in addition to a chromium layer having similar top layers or top layers. However, silver optics have become more difficult to obtain high reflectivity bluish coatings on top of silver based materials. This is partly due to the slight yellow spectral bias of silver and also because the reflectance is already too close to 100% over the visible spectrum, coherently increasing the reflectivity of silver in any part of the spectrum to provide a significant color. It is also due to the fact that there is very little that can be done.

However, placing a translucent layer of silver or silver alloy between chromium and ITO in the stack can still significantly increase the reflectance, maintain bluish color and improve the conductivity of the third surface reflector electrode.

If a translucent layer of silver is present, according to the disclosure included in this document, it is possible to create translucent regions by adding color neutralizing layer (s) and "split" the silver to mask the openings in chrome. have.

For example, a reflective stack of approximately 40 nm TiO ₂ , 20 nm ITO, 14 nm silver, 50 nm chromium, 10 nm silver, and 90 nm ITO is modeled as similar to the same stack without a chromium layer in hue and brightness. In the absence of a chromium layer, the transmittance of the stack is calculated to be suitable for use as the display or light sensor area. Thus, it is possible to produce chromium masking during the deposition of the layer and to produce (ie, covert) electrochromic elements with similar bluish hue and brightness in both the opaque and transflective portions of the device.

By inserting a low refractive index layer between chromium and ITO, or by alternating low and high refractive index layers, the reflectivity of the chromium / ITO stack can also be increased. However, most low index oxide and fluoride materials that are of sufficient layer thickness to have adequate optical effects become electrical insulators. However, silver itself is a low refractive index material and this partly explains its advantages when placed between chromium and ITO.

TABLE 25

Another feature that is beneficial in the area of display windows and transflective coatings is the antireflective feature from the opposite direction. Often, the display reflects or scatters around the rear of the mirror element and eventually emits a significant amount of leaked light that exits the display area. By having the element have a relatively low reflectance from the opposite direction, this leakage light can be reduced. Achieving low reflectance without additional layers on the fourth surface has the added benefit of cost savings.

Cr / TiO ₂ / ITO / AgAu7x / Cr / AgAu7x is provided in the opaque region, that is, the clock region, while the display region has TiO ₂ / ITO / AgAu7x / AgAu7x. The first chromium layer is thin, about 2-15 nm thick, preferably about 5-10 nm thick, and masked in the display area. The second chrome is also masked in the display area and its thickness is adjusted to obtain the desired transmittance in the field of view. The TiO ₂ / ITO bilayer covers the entire surface and is adjusted to provide a suitable color to the display area from the front of the portion while obtaining an antireflective effect from the opposite direction in the field of view.

Table 26 shows the reflectance from the opposite direction or from the fourth surface. The first case is the reference case. This is the stacking described above for the opaque region of the mirror element, ie the field of view. As can be seen, the reflectance from the rear is quite high, about 61%. In the second case, a thin chromium layer (˜5 nm) is added below the dielectric layer. Adding this thin layer to the field of view reduces the reflectance to approximately 6%, reducing the intensity by 10 times. In this way, scattering of leakage light is reduced. This reflectance value and its color can be adjusted by the thickness of the chromium layer and the dielectric layer. Approximately 4% of the 6.2% reflectance is due to the fourth uncoated surface of the glass. If further reduction in reflectance is desired, additional conventional antireflective layers may be added. The reflectance value of 6.2% can be reduced to a value of 2.5% or less.

TABLE 26

The amount of reflectance reduction and its absolute value depend on the properties of the first silver containing layer and the subsequent chromium layer. As mentioned above, these layers are adjusted to adjust the transmittance as well as the reflectance towards the viewer. Since these layers are adjusted to meet various design goals or goals, the dielectric layer and / or base chromium layer can be adjusted to achieve the optimal antireflection effect.

Other metals or absorbent layers other than chromium may be used as the antireflective layer. Materials such as tungsten, chromium, tantalum, zirconium, vanadium and other similar metals also provide a wide range of antireflective properties. High reflectance for more colors can be obtained with other metals. In addition, chromium or other metal layers may be doped with a small amount of oxygen or nitrogen to alter the optical properties of the metal to adjust the antireflective properties.

The utility of alternating sets of high or low refractive index layers or sets of many such layers to modify the optical properties of a surface or thin film stack is mentioned elsewhere in this document. Materials such as metal oxides, nitrides, nitrates, fluorides, which are generally considered to be low refractive indices, tend to be poor conductors. Typically, the greater the difference in refractive index between adjacent materials, the greater the optical effect. This is because materials with refractive indices of about 1.6 or less are usually used as low refractive index materials. However, if the material to be combined with the TCO has a sufficiently high refractive index and as a result a high refractive index-low refractive index pair is obtained, a beneficial effect is obtained with a high refractive index material such as a transparent conductive oxide. Specifically, when titanium dioxide is used as a relatively high refractive index material combined with a relatively low refractive index material, indium tin oxide, an optically and electrically advantage is obtained. In particular, titanium dioxide is a relatively high index of refraction material that is not good enough to insulate an optical film, such as ITO, other TCO, or more conductive thin films disposed thereon or below, such as metal or semimetal layer (s). to be. When TiO ₂ is applied as an optical thin film between even more conductive layers such as indium tin oxide, TiO ₂ does not insulate the ITO layers from each other in the electrochromic element, and the desired optical effect of high-low-high lamination is achieved. In other words, most of the cumulative conductivity benefits of the total thickness of ITO in the thin film are maintained, along with obtaining the optical advantages of the high and low refractive index layers. The following examples generally illustrate the advantages of this principle and detail the advantages of these materials. All base layers were deposited and measured on soda lime glass (where n is approximately 1.5 in the visible spectrum).

Base layer A = 1/2 wave optical thickness ITO of approximately 145 nm physical thickness and 23 Ω / sq sheet resistance (created under conditions less than ideal). Base layer B = approximately 40 nm titanium dioxide below approximately 20 nm ITO, having a sheet resistance of approximately 110 to 150 Ω / sq. Base layer A with base sheet C = approximately 16 Ω / sq + base layer B (lower-than-expected sheet resistance capping A's ITO layer before vacuum cutting and cooling improves conductivity compared to layer A alone) May be due to the fact that Base layer D = approximately 42.5 nm titanium dioxide, 42.5 nm ITO, 42.5 nm titanium dioxide, 42.5 nm ITO with a sheet resistance of about 40 Ω / sq. 54A shows the reflection spectra in air of these base layers on glass (without additional coating and before assembly to the electrochromic element).

Samples from the same coating operation (notice that there are variations within the operation) as the samples of FIG. 54A are approximately 25 nm 6% Au 94% Ag (called 6x) according to the principles described elsewhere in this document. Additional coatings of alloys were provided and assembled into electrochromic elements. A half wave optical thickness with approximately 12 Ω / sq on glass was used as the second surface coating for these elements. Subsequently, spectrophotometric measurements were performed as shown in FIGS. 54B and 54C. The results are shown in Table 27.

TABLE 27

As mentioned above, in most cases it is often useful to mask the silver alloy so that it is not deposited below the seal area. As a result, when the option is selected, electrical contact of the element to the substrate (s) on the third surface is made. In this case, the low sheet resistance of the substrate becomes more important than it is entirely silver or silver alloy to the point of electrical contact through the bus bar or conductive epoxy or other means.

Resistance measurements for the described substrates were made using a four point probe, which can give false results regarding surface conductivity when the probe penetrates the insulating layer. Thus, elements having only the base layer (s) as the third surface coating were prepared and compared to determine the coloring and clearing properties. The performance of the elements was consistent in sheet resistance measurements made through a four point probe.

In one embodiment of the invention, color and reflectance matching between the field of view and the display area may be desired. In some examples described above, there may be two different metal stacks in two regions, and if the same metal is the top layer, the layers may have different thicknesses or different metals may or may not be below the top metal layer. By itself, before being placed in the EC element, the reflectivity of the two regions can be adjusted to be substantially the same. After placement, if the medium in contact with the metal changes from air to EC fluid, the reflectances in the two regions may be different. This is because each stack interacts with the new incidence medium in a different way.

For example, ruthenium as the top layer in one design (glass / TiO ₂ 45nm / ITO 18nm / Ru 14nm) and the other design (glass / TiO ₂ Both AgAu7x at 45nm / ITO 18nm / AgAu7x 19nm) alone are adjusted to have a 70.3% reflectivity, and when assembled into the element, the Ru side drops to 56.6% reflectivity while the AgAu7x side drops to 58.3%.

Another example TiO ₂ 40nm / ITO 18nm / Cr 25nm / AgAu7x 9nm alone has a reflectance of 77.5% and 65.5% when assembled into the element, whereas TiO ₂ 40nm / ITO 18nm / AgAu7x 23.4nm alone has a 77.5% It has a reflectance and 66% when assembled to the element. The difference in this case is not as dramatic as the previous example, but shows that even buried layers can affect the reflectance degradation when going from single to element. This is to illustrate that reflectance mismatch may be necessary for the coating alone when reflectance match is desired in the element.

The above method for achieving good reflectance and color matching in two areas of the mirror assumes that the appearance in the two areas is almost entirely due to the reflectance. However, the viewer perceives not only the reflectance but also the transmitted light in the display area. In the field of view, ie the opaque region, the viewer perceives only the reflectance because of its relatively low transmission. The amount of transmitted light is a function of the transmittance in the display area and the reflectance of the component behind or in contact with the fourth surface of the mirror. The amount of light perceived by the viewer increases as the transmittance of the coating in the display area increases. Likewise, as the reflectance of the components behind the mirror increases, so does the light perceived by the viewer. This can add a significant amount of light, and the viewer perceives this as the display area is brighter than the field of view. As a result, even if the two areas have the same reflectance, the display area may appear brighter. This effect can be mitigated by creating elements with components with low reflectance and / or by setting the transmission in the field of view to a relatively low level. If the output brightness of the display is relatively limited or low, reducing the transmittance can significantly dim the display.

In another example, the EC element consisting of 40nm TiO ₂ / 18nm ITO / EC fluid / 140nm ITO / Glass having a reflectance of 8.1%, deposited on a 5nm ruthenium layer onto the fourth surface to simulate a display in the mirror rear If (i.e., 5nm Ru / glass _{/ 40nm TiO 2 / 18nm ITO /} EC fluid / ITO / glass) the reflectance rises to 22.4%. Glass _{/ 40nm TiO 2 / 18nm ITO /} 22nm AgAu7x / EC fluid / ITO / EC element consisting of Glass has a reflectance of 61.7%. The laminate with 5 nm ruthenium has a reflectance of 63.5%, which is an increase in reflectance of approximately 2%. This degree of reflectance can be well recognized by the viewer. As mentioned above, the actual increase in reflectance depends on the reflectance of the components behind the mirror and the transmittance of the EC elements.

In order to reduce the perceived difference in brightness in the two areas, the relative reflectance in the two areas can be adjusted to compensate for the transmitted light component. Thus, to achieve a net 2% brighter area in the display section of the mirror, selectively increase the reflectance in the field of view or reduce the reflectance in the display area. The amount of adjustment depends on the specific situation of the system.

Example 1a

In this example, the third surface of the 2.2 mm glass substrate is coated with approximately 400 ns of TiO ₂ , then approximately 180 ns of ITO, and finally approximately 195 ns of silver-gold alloy (93% silver / 7% gold by weight). . Titanium dioxide and ITO are preferably applied substantially to the edge of the glass and the silver alloy is preferably masked inside at least the outer side of the associated seal. In at least one embodiment, the second surface comprises a half wave (HW) ITO layer. Associated element reflectance and transmittance models are shown by lines 4801a and 4801b in FIGS. 48A and 48B, respectively. This model reflectance is approximately 57% at approximately 550 nm and transmittance is approximately 36.7%.

Example 1b

This example is configured similarly to Example 1a except that the chrome / metal tab extends under the seal along at least a portion of the peripheral region of the third surface to improve conductivity between the associated clip contact region and the silver alloy. have. The appearance remains the same, but the darkening speed is improved. This feature can be applied to many of the following examples to improve the electrical conductivity from the third surface to the associated electrical contact. As can be seen from FIGS. 48A and 48B, the reflectances and respective transmissions associated with the elements of Example 1A are dramatically different, which represents one of the advantages of the present invention.

Example 1c

Example 1c is constructed similarly to Example 1a, but after the display area is first masked and the mask is removed (ie, only Cr / Ru is on the glass in the display area), the stack of Cr / Ru is substantially full surface. Is deposited on. Cr / Ru opaque lamination can be replaced by a number of combinations. Reflectance and transmittance results are shown as lines 4802a and 4802b in FIGS. 48A and 48B, respectively. Opaque stacking preferably has a low contrast of both reflectance and color with respect to the display area. Another advantage in this example is that the metal commonly used in the opaque layer can extend to the edge of the glass to connect the associated electrical connection clip and the third surface silver-gold alloy. The model reflectance is approximately 56.9% at approximately 550 nm, transmittance is <10% in the field of view, preferably <5%, more preferably <1%, and the best design goal is <0.1% (this is all Applied to similar designs) The transmittance in the display area is approximately 36.7%. It will be appreciated that the optical sensor may be located behind the "display area" in addition to or instead of a display or other light source.

Example 2a

In this example, the third surface of the mirror element is coated with about 2000 kW of ITO, then about 50% transmittance chromium, and finally about 170 kW of silver-gold alloy. Preferably, ITO and chromium are coated substantially to the edge of the glass and the silver alloy is masked inside at least the outer side of the seal. The Cr thickness is preferably adjusted such that the ITO and Cr layers have 50% transmission through only the back plate. In at least one embodiment, the second surface preferably comprises an HWITO layer. Reflectance and transmittance of the elements are shown by lines 4901a and 4901b, respectively, in FIGS. 49A-49D. The Cr layer can be adjusted (thicker or thinner) to control the final transmission of the transflective element. As the Cr layer becomes thicker, the transmittance drops, and when the Cr layer becomes thin, the transmittance increases. A further advantage of the Cr layer is that the lamination is relatively color stable to the typical vacuum sputter deposition process variations in the base ITO layer. The physical thickness of the chromium layer is preferably approximately 5 kPa to 150 kPa, more preferably 20 to 70 kPa, most preferably 30 to 60 kPa. Model reflectance is approximately 57% at approximately 550 nm and transmittance is approximately 21.4%.

Example 2b

Example 2b is similar to Example 2a except that the chromium / ruthenium bond stack is coated to achieve 50% transmission when measuring only the back plate (ie, before being included in the mirror element). The addition of the Ru layer provides improved stability during curing of the epoxy seals. The thickness ratio of Ru and chrome can be adjusted and there are certain design limits. Chromium is mainly included to improve Ru adhesion to ITO. Ru has good bonding to Ag or Ag alloy. Other metals or metals may be disposed between the Cr and Ru layers as long as appropriate materials and physical properties are maintained. Reflectance and transmittance characteristics are shown by lines 4901c and 4902c, respectively, in FIG. 49C.

Example 2c

Example 2c is similar to Examples 2a and 2b, except that a Cr / Ru layer (or other opaque layer) is deposited almost entirely on the third surface after the display area is first masked and the mask is removed. Transmittance and reflectance results are shown by lines 4902a and 4902b in FIGS. 49A and 49B, respectively. Associated advantages are similar to those of Example 1c.

Example 3a

In this example, the third surface of the EC element is coated with about 400 mmW TiO ₂ , then with about 180 mmW ITO, then with about 195 mmW silver, and finally with about 125 mmW Izo-Tco.

This example is similar to Example 1a, wherein TiO ₂ and ITO are coated substantially to the edge of the glass, silver is masked inside at least the outer side of the seal, and indium zinc oxide or other TCO is then It is applied on top as a protective barrier against EC fluids. As another alternative, the IZO / TCO layer may extend substantially to the edge of the glass. In at least one embodiment, the second surface preferably comprises an HWITO layer. Element reflectance and transmittance are represented by lines 5001a and 5001b in FIGS. 50A and 50B, respectively. Model reflectance is approximately 57% at approximately 550 nm and transmittance is 36%.

Example 3b

Example 3b is configured similarly to Example 3a except that the display area is masked and a stack of Cr / Ru is deposited on almost all of the unmasked area of the third surface. Cr / Ru opaque lamination can be replaced with multiple material combinations. Reflectance and transmittance results are shown as lines 5002a and 5002b in FIGS. 50A and 50B, respectively. The advantage in this example is that the metal commonly used in the opaque layer can extend substantially to the edge of the glass and provide a connection between the associated electrical contact clip and the silver alloy. Relevant reflectance and transmittance measurement data are shown by lines 5001c and 5002c in FIG. 50C, respectively.

Example 4a

In this example, the third surface of the EC element is coated with approximately 2100 ns of ITO, then approximately 225 ns of silicon, and finally approximately 70 ns of Ru or Rh.

All layers can be coated to substantially the edge of the glass. As another alternative, the glass can be processed onto a sheet and then cut into singles for inclusion in the mirror element. The Ru or Rh layer can be replaced with one of several high reflectivity metals or alloys. In at least one embodiment, the second surface is preferably coated with HWITO. This example shows the advantage of an increase in transmittance at different wavelengths. The base ITO layer can be replaced with layers having different thicknesses. In certain embodiments, it is desirable for the ITO to be an odd multiple of 1/4 wave. In these cases, the reflectance is slightly improved by ITO. This effect is slightly reduced as ITO thickens. The advantage of thick ITO is generally lower sheet resistance, which results in faster element darkening times. Model reflectance is approximately 57% at approximately 550 nm and transmittance is approximately 11.4%. Modeled reflectance and transmittance are shown in FIGS. 51A and 51B, respectively. The measured reflectance and transmittance are shown by lines 5101c and 5102c, respectively, in FIG. 51C.

Example 5

In this example, the third surface of the EC element is coated with about 2100 mm 3 of ITO, then about 50 mm 3 of chromium, then about 75 mm 3 Ru, and finally optionally about 77 mm Rh.

All layers can be coated substantially up to the edge of the glass, or the glass can be processed onto a sheet and then cut into singles for insertion into the mirror element. The Ru layer may be replaced with one of several high reflectivity metals or alloys, or additional layer (s) such as rhodium may be added. The metal layer can be adjusted to achieve higher or lower reflectance / transmittance balance. In at least one embodiment, the second surface is preferably coated with an HWITO layer. One advantage of thick ITO is lower sheet resistance, which results in faster element darkening times. Thicker ITO can increase the third surface lamination roughness, which can result in lower reflectance. This effect is observed when comparing the model transmittance and reflectance of FIGS. 52A and 52B with the transmittance and reflectance obtained from the experiment, respectively (lines 5201c1 and 5202c2, respectively, in FIG. 52C). The model reflectance is approximately 57% at approximately 550 nm and the transmittance is approximately 7.4%.

Example 6a third Surface Opaque layer

In this example, an opaque layer is included in the third surface coating laminate. A base layer stack of about 600 microns of chromium followed by about 600 microns of ITO is deposited on the glass substrate, and the display area is masked during the deposition process of the base layer stack or the base layer stack is then laser removed from the display area. Thereafter, approximately 700 kPa of ITO layers (approximately 180 kPa of silver-alloy Ag-X (where X represents an option for the alloy of Ag)) are applied. This way the field of view is substantially opaque and the display area is translucent.

This alloy can be masked relatively far from the seal to improve the life of the element in harsh environments. The model reflectance is approximately 52% at approximately 550 nm and the transmittance is approximately 41%.

Example 6b

Example 6b is similar to Example 6a. In this example, the third surface is first coated with a base layer stack of approximately 600 microns of chromium except for the display area, followed by approximately 100 microns of ITO, then approximately 500 microns of TiO ₂ , and finally approximately 50 microns of chromium. Thereafter, the entire third surface is coated with approximately 150 ns of TiO ₂ , then approximately 500 ns of ITO, and finally approximately 180 ns of silver-gold alloy. Model reflectance is approximately 54% at approximately 550 nm and transmittance is approximately 41%.

The electrochromic mirror may have a limited reflectance (R) if a high transmittance (T) level is desired, or alternatively, may have a limited transmittance if a high reflectance is required. This can be explained by the relation R + T + A = 1 assuming that absorption A is constant. In some displays or light sensor mirror applications, it may be desirable to have a high level of transmitted light (luminance) to properly view the associated display through the mirror element or to transmit appropriate light. Often, the resulting mirror has a lower reflectance than desirable.

A solution to addressing the above limitations is described in other examples herein, where the thickness of the metal layer or metal layers is appropriate for reflectance in the field of view and is thinner only in the display area. Other examples use different metal layers or coating stacks in the display area to match the color and reflectance of the different areas. Often sudden changes in reflectance or color are offensive to the observer. For example, referring to FIGS. 55 and 56A, the boundary C between the two regions is sharp. Region A has a higher transmittance than region B. The area C distinguishes two areas. In FIG. 63, the boundary at the beginning of the transition between the high and low reflectance regions is also sharp. The slope of the change in reflectivity per unit distance approaches infinity as it transitions between regions.

In at least one embodiment, the transition of the metal layer thickness is gradual. Gradual changes in reflectance and / or transmittance in the transition region are more difficult for the human eye to detect. The two regions still have different reflectance and transmittance values, but the boundary between these two regions is inclined. This slope eliminates abrupt discontinuities and converts discontinuities into gradual transitions. The human eye is not drawn that much when the interface is tilted. As shown in FIGS. 56B-56D, the slope may be linear, curved, or some other form of transition. The sloped distance can vary. In at least one embodiment, this distance is a function of the reflectance difference between the two regions. If the reflectance difference between the two regions is relatively small, the distance of the inclination may be relatively short. If the reflectance difference is large, longer slopes may be desired to minimize the visibility of the transition. In at least one embodiment, the length of the slope is a function of the application and intended use, observer, lighting, and the like.

In at least one embodiment shown in FIG. 56E, the transmission may be reduced to near zero in one or more portions. In other cases described herein, the reflectances may be the same or different. The "secret" embodiment described elsewhere herein can be used to allow the transmittance to be adjusted as desired in various parts of the mirror element while keeping the reflectance relatively constant.

The present invention is not limited to having two or more regions of constant transmittance or reflectance. One embodiment is shown in FIG. 56F. Region B has a relatively low transmission, which can be zero. This may be desirable if one of the design goals is to allow area B to block incoming light from an object disposed behind the transflective coated substrate. The coating stack may have a gradual transition from the area B through the slope C. Region A may have another slope in itself. Possible advantages for this are described below.

In certain applications, enough length may not be available to achieve a dual plateau situation. In these cases, as shown in Fig. 57A, it is advantageous to use a continuous slope over the region where the transflective characteristic is desired. The change in reflectance is gradual, the advantage of high transmittance is obtained, and there is no sharp interface between the regions.

The slope between the two regions can take many forms. In the broadest sense, the element may comprise regions of different and uniform transmittance and reflectance. In the examples shown in FIGS. 57A-57C, there is no area of constant reflectance and transmittance. These cases have a gradual and continuous change in optical properties. The advantage of this method is shown in FIG.

When the viewer is looking at the display through a mirror element or a coated glass substrate, there is a continuous path length and angle relative to the closer portion of the display relative to the farther portion of the display. The relative effective angle of incidence changes depending on the orientation of the mirror element display, the size of the element, the distance from the viewer, and the like. This results in different amounts of transmission through the glass in various parts of the display area. Different amounts of transmittance in turn cause a change in the brightness of the display. If constant light output from all areas of the display is desired, the transflective coating can be varied to account for the loss of transmittance resulting from the viewing angle and path difference through the glass. If the effective viewing angle varies from about 45 degrees to 60 degrees, the transmission through the glass changes by about 6%. Thus, having an inclined translucent coating in the area of the display can compensate for this effect to some extent, so that the perceived light across the display is more equal.

The inclined transition zone can be used for displays such as rear cameras or conventional compass temperature displays. In some of the "secret" examples described elsewhere herein, a so-called "split Ag" stack in which an opaque layer is disposed between two Ag layers to help match the appearance between transflective and opaque properties. This is provided. In another embodiment of the covert display, an Ag layer is disposed over the opaque layer. Both of these embodiments can benefit from inclined transitions between regions. The opaque layer or Ag layer or all layers can be inclined. In at least one embodiment, the opaque layer can be inclined to minimize the sharpness of the transition between the regions.

To change the material thickness in a layer or layers to create a transition region, such as masking, movement or speed variation on a substrate or coating source, magnetic field variation in a magnetron, or ion beam etching or other suitable means described herein. Many methods can be used, including but not limited to layer reduction techniques.

59 shows a back plate 5914 of glass, a layer 5722 comprising a sub-layer of approximately 440 microns of titanium dioxide and a sub-layer of about 200 microns of ITO, one region having a thickness of about 140 microns and the other region of about 235 microns. A layer 5978 of 6Au94Ag having a thickness, and a third region between the first two regions (the thickness gradually transitions between the two regions), an electrochromic fluid / gel 5925 having a thickness of approximately 140 micrometers, An example of an electrochromic mirror configuration having an ITO layer 5928 of approximately 1400 kPa and a glass plate 5912 of 2.1 mm is shown. The resulting reflectivity of the element ranges from about 63% in most of the mirrors to about 44% in the area in front of the display.

An electrochromic device similar to that described above was fabricated, wherein the thickness of layer 5978 was varied in a manner similar to that described and illustrated in FIG. 57C using a combination of masking techniques and magnetic manipulation of the deposition source. The best method depends on the exact features required of the finished element and what processing methods are available. 60 and 61 show corresponding reflectance data as a function of position on the mirror. The display is in this case arranged behind the region of low reflectance, high transmittance.

Another application of the inclined transition is in electrochromic elements with a second surface reflector that hides the epoxy seal, and reflectance and color matching between the "ring" and the reflector disposed on the third or fourth surface can be achieved. The best match is when the reflectivity of the ring matches the reflector reflectance. In at least one embodiment, the reflectivity of the reflector is further increased without changing the ring. This can happen due to durability, manufacturing or other considerations. Means for maintaining the match between the reflector and the ring can be obtained when the reflectivity of the reflector is inclined as described above. When a gradual change in reflectance occurs, the reflectance of the reflector can be adjusted to match the reflectivity of the ring in the vicinity of the ring, and then gradually increases as it moves away from the ring. As can be seen from FIG. 62, the reflectance at the center of the field of view is relatively high.

In a similar manner, the ITO can be gradually changed from the ring area to the center of view in order to maintain a thickness range required for proper color while allowing a relatively high reflectance at the center of the element. As such, the mirror darkens relatively quickly compared to when the ITO coating is relatively thin across the element.

The same concept can be extended to metal reflector electrodes. In this case, the slope can be used so that the sheet resistance of the coating changes gradually with position. This method complements various busbar structures, resulting in faster and more uniform darkening. Figure 63 shows an embodiment of a mirror element according to the prior art for the present invention.

It will be appreciated that the description provided herein is to enable one skilled in the art to make and use the best of the various embodiments of the invention. These descriptions should never be interpreted as limiting the scope of the appended claims. The claims, as well as each individual claim restriction, should be construed as encompassing all equivalents.

Claims (46)

A vehicular rearview mirror assembly comprising a mirror element having a transflective region and an opaque region, the vehicular rearview mirror assembly comprising:
The mirror element,
An optically transparent first substrate;
A lower reflective layer disposed on the optically transparent first substrate;
An opaque layer disposed on a portion of the lower reflective layer, wherein a boundary of the opaque layer defines a boundary of at least a portion of the transflective area and the opaque layer is located outside of the transflective area; And
An upper reflecting layer disposed over a portion of the lower reflecting layer located within the transflective region and over the opaque layer,
The upper reflective layer and the lower reflective layer have a common surface over at least a portion of the transflective region,
The opaque layer separates the upper reflective layer and the lower reflective layer,
Automotive rearview mirror assembly. The method of claim 1,
At least one of the lower reflective layer, the opaque layer, and the upper reflective layer has a non-uniform thickness over at least one of the transflective region and the opaque region. The method of claim 1,
And the difference between the reflectance value of the opaque region and the reflectance value of the transflective region does not exceed 5%. The method of claim 1,
And a color difference between ambient light reflected by the opaque region and light reflected by the transflective region is less than 10 C ^* units. The method of claim 1,
And a color difference between ambient light reflected by the opaque region and light reflected by the transflective region is less than 5 C ^* units. The method of claim 1,
The opaque layer is a group consisting of chromium, stainless steel, silicon, titanium, nickel, molybdenum, inconel, indium, palladium, osmium, tungsten, rhenium, iridium, rhodium, ruthenium, tantalum, copper, gold, platinum, and alloys thereof A rearview mirror assembly for a vehicle comprising a material selected from. The method of claim 1,
And a base layer deposited on the optically transparent first substrate below the lower reflective layer. The method of claim 7, wherein
And the base layer has a quarter-wave optical thickness. 9. The method of claim 8,
And said base layer comprises a coating containing a non-metallic bilayer. 9. The method of claim 8,
And the base layer comprises a coating containing a TiO ₂ / ITO bilayer. The method of claim 1,
And the opaque layer optically isolates a portion of the lower reflective layer from a portion of the upper reflective layer. The method of claim 1,
And said transmittance of said opaque region does not exceed 5%. The method of claim 1,
And said transmittance of said opaque region does not exceed 2.5%. The method of claim 1,
The transmittance of the opaque region does not exceed 0.5%, and the transmittance of the transflective region exceeds 0.5% and does not exceed 25%. The method of claim 1,
And the lower reflecting layer and the upper reflecting layer comprise silver or a silver alloy. 16. The method of claim 15,
A rearview mirror assembly for a vehicle further comprising a flash layer of metal disposed below the silver containing layer. 16. The method of claim 15,
And a flash layer of metal disposed over the silver containing layer. 18. The method according to claim 16 or 17,
And the flash layer comprises at least one of a conductive oxide, a platinum group metal or an alloy thereof, nickel or an alloy thereof, and molybdenum or an alloy thereof. The method according to any one of claims 1 to 6 and 15,
Internal lighting assembly, global positioning system (GPS), external lighting controller, information display, light sensor, blind spot indicator, turn signal, operator interface, compass, temperature display, microphone and at least one of a microphone, a dimming circuitry, and a warning system. The method of claim 1,
And the mirror element has a uniform reflectivity of at least 50% relative to the reflector. The method of claim 1,
And the lower reflecting layer and the upper reflecting layer comprise ruthenium. The method of claim 1,
The mirror element further includes a second substrate including an electrochromic element, the second substrate being disposed in parallel relation spaced at regular intervals with respect to the first substrate, and the second substrate adjacent to the upper reflective layer. The surface of the vehicle having a reflector ring circumferentially disposed about a periphery of the surface of the second substrate. The method of claim 22,
And at least one of a reflectance and a color of light reflected by a region corresponding to the reflector ring on the second substrate corresponds to at least one of a reflectance and a color of light reflected by a thin film stack of the first substrate. The method of claim 1,
And the mirror element comprises a prismatic element. A rearview mirror assembly for a vehicle comprising a transmissive region and an opaque region and a mirror element having a transition region therebetween,
The mirror element,
An optically transparent first substrate;
An opaque layer disposed on the optically transparent first substrate, a boundary of the opaque layer defining a boundary of at least a portion of the translucent region and the opaque layer is disposed outside the translucent region of the mirror element; And
An upper reflective layer disposed on the opaque layer and extending within the boundary of the opaque layer beyond the opaque layer to the transflective region of the mirror element,
At least one of the opaque layer and the upper reflective layer is configured such that the thickness is gradually changed between a first thickness value corresponding to the opaque region and a second thickness value corresponding to the transflective region within the transition region. And at least one of reflectance and transmittance of ambient light by the element varies gradually between the opaque region and the transflective region. 26. The method of claim 25,
And the mirror element comprises a prismatic element. 26. The method of claim 25,
And a transmittance in said opaque region of said mirror element does not exceed 5%. 26. The method of claim 25,
And said transmittance in said opaque region of said mirror element does not exceed 2.5%. 26. The method of claim 25,
The transmittance in the opaque region of the mirror element does not exceed 0.5%, and the transmittance in the translucent region of the mirror element exceeds 0.5% and does not exceed 25%. 26. The method of claim 25,
A lower reflecting layer covering said transflective region and disposed adjacent said optically transparent first substrate below said opaque layer, said lower reflecting layer having a common surface over said upper reflecting layer and at least a portion of said translucent region and being opaque And the layer separates the upper reflecting layer and the lower reflecting layer. 31. The method of claim 30,
And the upper reflective layer has a thickness that gradually varies between a thickness value corresponding to the opaque region and a thickness value corresponding to the transflective region within the transition region. 31. The method of claim 30,
And at least one of the lower reflecting layer and the upper reflecting layer comprises silver. 26. The method of claim 25,
And the upper reflective layer comprises silver or silver alloy. The method according to any one of claims 25, 26 or 30,
And a color difference between ambient light reflected by the opaque region and light reflected by the transflective region is less than 5 C ^* units. 35. The method of claim 34,
The opaque layer is a group consisting of chromium, stainless steel, silicon, titanium, nickel, molybdenum, inconel, indium, palladium, osmium, tungsten, rhenium, iridium, rhodium, ruthenium, tantalum, copper, gold, platinum, and alloys thereof A rearview mirror assembly for a vehicle comprising a material selected from. 35. The method of claim 34,
Further comprising a flash layer of material interposed between the top reflective layer and the opaque layer in the opaque region, essentially covering the opaque layer, wherein the flash layer comprises a conductive oxide, a platinum group metal or an alloy thereof, A rearview mirror assembly for a vehicle comprising nickel or an alloy thereof, and molybdenum or an alloy thereof. 37. The method of claim 36,
The flash layer comprises a ruthenium vehicle rearview mirror assembly. 35. The method of claim 34,
And the lower reflecting layer and the upper reflecting layer comprise silver. The method according to any one of claims 25, 26 or 30,
Internal lighting assembly, global positioning system (GPS), external lighting controller, information display, light sensor, blind spot indicator, turn signal, operator interface, compass, temperature display, microphone and at least one of a microphone, a dimming circuitry, and a warning system. 26. The method of claim 25,
The transmittance value of the transition region varies between the opaque region and the transflective region, and the reflectance value of the transition region remains the same between the opaque region and the transflective region. 26. The method of claim 25,
And a base layer deposited on the optically transparent first substrate below the upper reflective layer. 42. The method of claim 41,
And the base layer has a quarter-wave optical thickness. 43. The method of claim 42,
And the base layer comprises a coating containing a TiO ₂ / ITO bilayer. 43. The method of claim 42,
And said base layer comprises a coating containing a non-metallic bilayer. 26. The method of claim 25,
The mirror element further comprises a second substrate including an EC element and disposed in a parallel relationship spaced at regular intervals with respect to the optically transparent first substrate, the second substrate being adjacent to the upper reflective layer. And a surface having a reflector ring circumferentially disposed about a periphery of the surface of the second substrate. The method of claim 45,
And at least one of a reflectance and a color of light reflected by a region corresponding to the reflector ring on the second substrate corresponds to at least one of a reflectance and a color of light reflected by a thin film stack of the first substrate.

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