KR102462030B1 - Multi-colored dielectric coating and uv inkjet printing - Google Patents

Abstract

Multi-colored insulating coatings are formed using interleaved layers of insulating material with alternating refractive indices, causing reflections at selected wavelengths to appear, causing different colors to appear. Etching the preferred layers at selected locations changes the color appearance of the etched locations, forming a coating having multiple colors. The thickness of the layers is chosen such that the path-length difference for reflection from the different high-index layers is an integer multiple of the wavelength for which the coating is designed. An inkjet printer is used to print a design, which is cured using UV radiation.

Description

MULTI-COLORED DIELECTRIC COATING AND UV INKJET PRINTING

This application is incorporated herein by reference in its entirety in U.S. Provisional Application Serial No. 62/685,215, filed on June 14, 2018, U.S. Provisional Application Serial No. 62/791,568, filed January 11, 2019, and U.S. Patent Application No. 16/281,013, filed on February 20, 2019, claims priority.

The present disclosure relates generally to the field of optical and decorative coatings, such as multi-colored insulating coatings for covers or housings of electronic devices, and the manufacture of such optical coatings.

Mirrors are generally manufactured by applying a metallic coating to one side of a transparent substrate such as glass. A common function of the coating is to reflect light in the entire visible spectrum (eg, white light). For some applications, it is desirable to reflect light, but it is desirable to maintain the transparency of the glass. Since the metallic coating is opaque, an insulating coating called an insulating mirror or Bragg mirror is used in this case. The coating is formed by applying multiple interleaved layers of high refractive index and low refractive index insulating material. The reflection from the low-index layer has exactly half the wavelength in the path length difference, but goes from low-index to high-index when compared to the high-to-low index boundary. At the low-to-high index boundary, there is a 180 degree phase difference, which means that these reflections are also in phase. For a mirror at normal incidence, each layer has a thickness of one quarter wavelength.

In general, insulating mirrors have been applied to panel glass to replace standard mirrors and to enable the application of more complex mirrors. See, eg, US Publication No. 2015/0287957. Insulated mirrors provide privacy when viewed from one direction, but enable see-through when viewed from the other direction to enable transmission of a TV-like image placed behind the mirror. See, eg, US Pat. No. 9,977,157. The use of insulating mirrors as thermal barriers has also been proposed, as appropriate selection of material and thickness of the layer can be tailored to reflect different wavelengths of radiation. See, eg, US Publication No. 2014/0083115. Finally, insulating mirrors have also been proposed to be used to conceal elements from the user's point of view. See, eg, US Pat. No. 9,727,178.

The trend of mobile devices, such as cell phones and tablets, is to provide monolithic cases while reducing thickness. It has been found to be problematic at times, as cases made of milled metal can interfere with radio transmission and reception. Also, the metal case prevents wireless charging of the device. Accordingly, a trend has been developed to make the case from glass transparent to electromagnetic radiation. However, while glass can exhibit a monolithic appearance, it is necessary to provide an opaque glass appearance to conceal the interior of the device.

In order to provide a basic understanding of some aspects and features of the present invention, the following summary of the present disclosure is included. This summary is not an extensive overview of the invention, and is not specifically intended to delineate key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description presented below.

The disclosed embodiments enable a multi-colored insulating coating of glass, thereby providing a different color to the operator and concealing the interior of the device. Disclosed aspects provide a method and system that is transparent to electromagnetic radiation while imparting an attractive appearance to a mobile device by imparting a multi-colored insulating coating on glass.

In addition, the disclosed embodiments may incorporate printed matter into the insulating coating, providing the combined effect of the printed matter and color coating. In the disclosed embodiments, an inkjet printer is used for printing. The print can be used to control design effects, protection enhancement effects, or light reflection from color coatings. When using a clear or semi-transparent coating, the coating can be applied over the printed design, but when the substrate is transparent (glass), the color coating can be applied on the surface opposite to the surface of the print.

In disclosed embodiments, a multi-colored insulating coating is formed using interleaved layers of insulating material with alternating refractive indices, causing reflections at selected wavelengths to result in different colors appearing. Etching selected layers at selected locations changes the color appearance of the etched locations, forming a coating having multiple colors. The thickness of the layers is chosen such that the path-length difference for reflection from the different high-index layers is an integer multiple of the wavelength for which the coating is designed.

One aspect includes a method for forming a multi-colored insulating coating on a mobile device casing, the method comprising the steps of alternately depositing high-index and low-index transparent insulating coating layers - thickness and number of insulating coating layers at a selected wavelength selected to reflect light from , so that a first color appears; and etching the designed shape in at least one of the insulating coating layers so that the insulating coating layer reflects light of different wavelengths within the designed shape, resulting in different colors. The etching may be performed between the deposition of the insulating coating layer, or after the insulating coating layers are all deposited. The etching may be performed to create a stripe designed shape by securing the casing to the front side of the mask and continuously transporting the casing to the front of the mask, or to form a repeating design shape by stepping the casing forward to the mask. have. The etching may be performed by placing a mask on one side of the extraction grid and a casing on the opposite side of the extraction grid, such that the mask is between the plasma and the extraction grid.

According to one aspect, each layer is deposited to a thickness of one quarter the wavelength of the first color. The deposited layer is then etched to form the desired design having a thickness of one quarter the wavelength of the second color. Thus, all layers are first deposited to have a first thickness corresponding to one quarter of the wavelength of the first color, but each layer is partially etched to reduce its thickness to a second thickness at the location of the design or pattern. and the second thickness corresponds to a quarter of the wavelength of the second color.

In a general aspect, a processing system for forming multi-colors on a substrate is provided, the system comprising: a first chamber configured to deposit a first index of refraction insulating coating and a second index of refraction having a lower index of refraction than the first index of refraction insulating material a deposition processing section having a paired vapor transport deposition chamber including a second chamber configured to deposit an insulating coating; an etching section configured to perform etching on at least one of the layers formed by the deposition processing section; and a buffer section configured to enable different transport rates between the deposition processing section and the etching section. The system may further include a parking station configured to enable parking of the substrate carrier in a vacuum environment.

Disclosed embodiments include a method for forming a multi-colored coating, comprising: providing a transparent substrate; forming a plurality of transparent layers on a substrate a plurality of times by alternately forming a first refractive index layer having a first refractive index and a second refractive index layer having a second refractive index - the thickness and number of the layers are represented by a first color configured to produce a reflection of light; transferring the substrate to an etch chamber and etching at least one of the transparent layers through a mask, the depth of the etching being configured to create a reflection of light appearing as a second color different from the first color. A thickness of each of the first refractive index layer and the second refractive index layer may be set to 1/4 of the wavelength of the first or second color. Alternatively, the first and second refractive index layers are formed to have a thickness corresponding to 1/4 of the wavelength of the first color, and the first and second refractive index layers are formed to have a thickness corresponding to 1/4 of the wavelength of the second color. It is etched to have a corresponding thickness.

In another aspect, a combination of UV-curable inkjet printers is integrated with a sputtering system that enables multiple methods of making coatings. In one aspect, a substrate having a hybrid coating is prepared. Details such as letters, logos or other graphics are inkjet printed onto a substrate and then introduced into a vacuum coating system to apply blanket sputtered films. The PDV film may be for a blanket color behind the graphic on a transparent substrate, or if the graphic is on the exposed side of an opaque or transparent substrate, the PDV coating may be a protective encapsulation to improve the durability of inkjet printing. have.

According to another embodiment, the stress relief coating is inkjet printed onto the substrate surface prior to being introduced into the vacuum surface such that a PVD coating is applied over the stress relief coating.

According to another aspect, the removable mask is inkjet printed onto the substrate prior to entering the PVD system. After sputtering coating, the mask is removed along with the coating in the masked areas creating areas with no coating.

In another embodiment, the coating is first formed using PVD. An oleophobic inkjet coating is then applied to the exposed coated surface.

According to another aspect, transparent, low refractive index micron (5-25 um) size dots are inkjet printed on a substrate. The substrate is then introduced into a vacuum system and coated with a high refractive index sputtering coating. The resulting coating scatters light to produce a matt finish with 1-20% haze scattering. Similarly, other shapes, such as pyramids, can be printed to create light diffraction, changing the appearance of the sputtered coating.

In accordance with a disclosed aspect, a mobile device encasing is provided, comprising: a back panel made of an insulating material that is transparent to electromagnetic radiation; a plurality of insulating layers provided across the back panel, wherein the plurality of insulating layers consist of an interlaced series of an insulating layer having a first refractive index and an insulating layer having a second refractive index higher than the first refractive index; ; and an imprinted design of UV curable ink, wherein each of the plurality of insulating layers is individually transparent over the entire optical range of wavelengths.

A method for manufacturing a back panel for a mobile device is disclosed, comprising the steps of obtaining a plate made of an insulating material transparent to electromagnetic radiation, the printer for positioning the plate in a printer and printing an imprinted design on the plate. operating the; placing the plate in a vacuum system having at least two sputtering systems and at least one etching system and operating the system to deposit an n plurality of insulating layers across the plate, the plurality of insulating layers comprising a first consisting of an interlaced series of an insulating layer having a refractive index of 1 and an insulating layer having a second refractive index higher than the first refractive index; and etching the section of the plate to thin a plurality of insulating layers within the section.

An embodiment of the system includes a flatbed inkjet printer integrated into a sputtering system for printing onto a substrate after being loaded onto a system carrier. Printing takes place in the atmosphere before entering the PDV system. The PDV system has at least two magnetrons to create blanket multilayer dielectric coatings to cover the substrate and printed graphics. The system can integrate inkjet printing, reactive sputtering, and ion etching in one platform.

Other aspects and features of the invention will become apparent from the following detailed description made with reference to the drawings. It is to be understood that the detailed description and drawings provide various non-limiting illustrations of various embodiments of the invention as defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain and illustrate the principles of the invention. The drawings are for the purpose of schematically illustrating the main features of the exemplary embodiments. The drawings are not intended to represent all features of actual embodiments or the relative dimensions of depicted elements, which are not drawn to scale.
1 shows a dielectric coating stack configured to reflect light at a selected wavelength and appearing as one selected color, while FIG. 1A shows a portion of the coating being etched to produce reflection at a second wavelength. An embodiment that provides a multi-colored appearance is shown. 1b shows a cross-section of an insulating coating according to another embodiment in which the individual sections have the same layer, but different thicknesses.
Figure 2 shows a mobile device casing having an insulating coating of an etched design and thus appearing as a two-color coating. Figure 2a shows the coating as in Figure 2, except that during etching the casing is positioned at a distance from the etch mask, creating a fading or transition boundary between the background and the etched design.
3 shows a cross-section of an etch chamber according to one embodiment, with a mask positioned on one side of the extraction grid and a substrate positioned on the opposite side of the extraction grid, with the mask positioned between the plasma and the extraction grid.
3A and 3B show the mobile device casing coated with an insulating coating and then etched to create the designed shape, while FIG. 3A shows the stripe shape created by continuously moving the casing in front of the mask; 3B shows the repeated shape created when stepping the casing in front of the mask during etching.
4 depicts one embodiment of a system for producing a multi-colored insulating coating on a substrate. 4A shows one embodiment of a system for creating an insulating coating on a substrate and incorporating an inkjet printer. 4B shows an example of a cover with a multi-color coating and inkjet printed logo. 4C shows an example of a cover with multi-color coating and inkjet printed microdots.
5 shows another embodiment of a system for forming an optical coating. 5A shows one embodiment of a system for creating an insulating coating on a substrate and incorporating an inkjet printer.
6 shows an embodiment using an oblong carousel. 6A shows an embodiment of a system for creating an insulating coating on a substrate and incorporating an inkjet printer.

Embodiments of the inventive multi-color insulating coating and its treatment will be described with reference to the drawings. Different embodiments or combinations thereof may be used for different applications or to achieve different results or advantages. Depending on the result to be achieved, the different features disclosed herein may be used in part or in whole, alone or in combination with other features, balancing requirements and constraints. Accordingly, certain advantages will be emphasized with reference to other embodiments, but not limited to the disclosed embodiments. That is, the features disclosed herein are not limited to the embodiment in which they are described, but may be “mixed and matched” with other features and included in other embodiments.

The disclosed embodiments include a system and method for forming a multi-color coating using an insulating transparent layer in combination with a printed material, generally in the form of inkjet printing. In the following, a description is first given of the multi-color coating, and then the integration of the printed matter is described. Also, various effects produced by the printed matter will be described.

In the context of this disclosure, an insulating coating includes an arrangement of interleaved dielectric layers of different refractive indices configured to reflect light of a selected wavelength. By appropriately choosing the refractive index and thickness and number of layers, the insulating coating is tuned to reflect only white light or a selected wavelength, resulting in an article appearing colored. For example, although each layer is individually transparent, if the layers are selected to structurally reflect at a wavelength of 600 nm, the article appears yellow, and if the layers are configured to structurally reflect at a wavelength of 700 nm, the article appears red . In a first example, each of the layers may have a thickness of, for example, 150 nm (a quarter of 600 nm), and in a second example, each of the layers may have a thickness of 175 nm. Thus, in one example, each of the layers is first deposited to a thickness of 175 nm, and to create a design in a different color, each layer may be etched to a thickness of 150 nm in the design area, thus over a red background. Yellow design can be provided.

The high refractive index layer comprises (stoichiometric and non-stoichiometric) optical films of the following NbOx, ZrO, Y-ZrO, AlN, SiN, ZrN, TiO, CrO, CrN, CrTiO, and CrTiN The low refractive index layer may consist of one or a combination of SiOx, AlO, SiON, SiAlO.In this context, the terms low refractive index and high refractive index are not used as quantitative measurements. Rather, it is understood to be used as a relative descriptor that enables the distinction between alternating layers, etc. In the context of insulating coatings, it is not the specific value of the refractive index that is important, but the low refractive index layer to bring about the desired optical effect. The point is that it has a refractive index that is sufficiently lower than the refractive index value of the high refractive index.

In accordance with disclosed embodiments, multi-color coatings can be formed on various crystalline or non-crystalline substrates such as glass (including treated glass such as Gorilla Glass®), sapphire, and plastic. have. Such coatings are particularly useful for mobile device enclosures or casings. They do not create electrical/magnetic field (EMF) interference and provide an attractive colored film to the casing, which can degrade the radio transmit/receive and wireless charging capabilities required for today's mobile devices.

The disclosed embodiments may also be used to form non-conductive vacuum metallization (NCVM) coatings, which look metallic but do not conduct electricity. The NCVM coating does not block radiation, allowing good signal reception and/or wireless charging of the phone. In certain embodiments, the NCVM layer may be used in the high refractive index layer. In one example, silicon is sputtered to form an NCVM film with low stress and high refractive index.

As can be appreciated, the thickness and uniformity of all layers forming the insulating coating is important to achieve the desired color. Accordingly, in the disclosed embodiments, the layers are formed in a vapor transport system that deposits alternating layers of a high index material and a low index material with a high degree of accuracy sufficient to produce the desired optical appearance. To create a multi-color appearance, the coated substrate is transferred to an etch chamber and the coating is partially etched to create a design of two or more colors.

Etching can be performed through the mask to create the desired design. The mask may be placed in contact with the substrate or proximal to the substrate to create a defined boundary between the two collars. Conversely, the mask may be placed at a distance from the substrate configured to create a gradient or gradual boundary between the two colors. Also, the substrate can be stationary or moved relative to the mask to create different design effects. The etching species may be argon, fluorine or a mixture of argon and fluorine, having an energy of 200 to 2000 eV. In one embodiment, only the final layer of the stack is etched to produce a change in color.

1 shows a cross-section of an insulating coating 100 according to an embodiment. An insulating coating 150 is deposited over the glass substrate 1 and includes interleaving layers of a high index material and a low index material. In Figure 1, layers 2, 4 and 6 are made of a high refractive index material such as niobium oxide, and layers 3 and 5 are all made of low refractive index silicon oxide, all of which are individually It is a transparent layer. Whereas in the prior art the number and thickness of these layers are configured to reflect white light - thus forming an insulating mirror, in this embodiment the number and thickness of the layers are configured to structurally reflect light only at a specific wavelength λ ₁ . and thus appear as a color coating.

1A shows a cross-section of an insulating coating 100 according to another embodiment. In this embodiment, the insulating coating 150 is first formed according to the embodiment of FIG. 1 , thus reflecting light at the selected wavelength λ ₁ , and appears as a colored coating. In addition, a portion of the insulating coating 100 is etched to a specified depth to create a cross-section of the coating that reflects light at a different wavelength λ ₂ and appears as a different color coating than areas that reflect light at wavelength λ ₁ . As a result, a multi-colored insulating coating is produced. The etching process can be repeated multiple times at different depths over different areas, so that more colors are created.

1B shows a cross-section of an insulating coating 100 according to another embodiment in which the individual sections have the same layers but different thicknesses. In this embodiment, an insulating coating 150 is formed, each layer having the same thickness as according to the embodiment of FIG. 1 , thus reflecting light of the selected wavelength λ ₁ and appearing as a colored coating. However, after each layer is formed, it is necessary to change the color of the layer so that the portion of the coating belonging to region 152 reflects light at a different wavelength λ ₂ and appears as a different color coating than the region that reflects light at wavelength λ ₁ . It is etched to reduce the thickness.

2 shows an example of a pattern design on the back of a mobile phone. In this example, the rear surface of the mobile phone is made of glass 200 to enable transmission and reception of the antenna inside the mobile phone and to enable wireless charging. An insulating coating is formed over the entire surface of the glass to create a background color 205 , then a portion of the coating is etched using a mask to create a pattern color 210 . In the embodiment of FIG. 2 , the transition between the background color 205 and the pattern color 210 is sharp. This is done by bringing the patterned etch mask into proximity or physical contact with the glass 200 . In this regard, the term “close proximity” means that the distance between the mask and the substrate is insufficient to allow sufficient diffusion of the etchant species to obscure the boundaries of the etch design. On the other hand, in Fig. 2a, the mask is placed at a certain distance from the glass 200, so that the etching species has a sufficient travel distance to naturally spread, thus blurring the boundary between the background color 205 and the pattern color 210, so that the transition Create boundary 215 .

Accordingly, in one aspect, a mobile device casing is provided, comprising: a back panel made of an insulating material that is transparent to electromagnetic radiation; and a plurality of insulating layers provided across the back panel, wherein the plurality of insulating layers consist of an interlaced series of an insulating layer having a first refractive index and an insulating layer having a second refractive index higher than the first refractive index. wherein the first part of the rear panel has n plurality of insulating layers designed to reflect light of a first wavelength, and the second part of the rear panel has m pieces of insulation designed to reflect light of a second wavelength. It has a plurality of insulating layers.

In another aspect, a mobile device casing comprises: a back panel made of an insulating material that is transparent to electromagnetic radiation; a plurality of insulating layers provided across the back panel, the plurality of insulating layers comprising an interlaced series of an insulating layer having a first refractive index and an insulating layer having a second refractive index greater than the first refractive index; The first part of the panel has each of a plurality of insulating layers having a thickness of 1/4 the wavelength of the first color, and the second part of the back panel has a plurality of insulating layers each having a thickness of 1/4 the wavelength of the second color. each of the insulating layers.

Various methods and systems for achieving multi-colored insulating coatings will be described as follows.

3 is a cross-sectional view illustrating an etching chamber 335 according to an embodiment. An etch chamber 335 is attached to a sidewall of the transfer chamber 330 and provides an etchant species through a window 328 between the etch chamber 335 and the transfer chamber 330 . The substrate 300 is transferred to a transfer chamber 330 (the transfer direction is in/out of the page) mounted on the substrate carrier 315 and maintained in a vacuum state. The substrate 300 is exposed to the etchant when facing the window 328 . The etch chamber 335 is evacuated by a vacuum pump 340 , and plasma is maintained therein by, for example, an RF antenna 345 . Etchant species are extracted from the plasma by an extraction grid 350 and directed to the substrate 300 . As the etchant species emerge from the grid 350, they are naturally dispersed at a slight angle, for example 3%, as shown by the dashed arrows.

To create a pattern on the substrate, the mask needs to block some of the etchant species from reaching the substrate in areas where etching is not required. In general, when using masks in the prior art, often referred to as shadow masks, the masks are placed on the substrate to be etched. However, this arrangement allows the mask itself to also be etched continuously. This is particularly undesirable because particles etched from the mask may fall on the substrate and be easily and visually detected by an operator. Thus, in the embodiment of FIG. 3 , the mask 355 is inserted inside the etch chamber between the plasma and extraction grid 350 . In this way, the mask 355 limits the area from which the extraction grid can extract the etchant species, creating a pattern. In other words, while in the prior art the mask limits the etchants impinging on the substrate, in the embodiment of Figure 3, the mask limits spatial extraction of the etch species from the plasma.

In the embodiment of FIG. 3 , different patterns may be created by controlling the transport of the substrate carrier 315 . For example, to create a pattern corresponding to the pattern shown in FIG. 2A , the carrier is transported to a position in front of window 328 (eg, by wheel 320 ), and the pattern is etched into the insulating coating. As a result, it remains stationary. Conversely, to create the stripes shown in FIG. 3A , the carrier is continuously moved forward of the window 328 while the etching process is being performed. The pattern shown in Figure 3b is a stepping method of the carrier, i.e., after stepping the carrier, keeping the carrier in place while etching is performed, then moving the carrier to another step and stopping it for the etching process, etc. method, it is created by repeating as many times as necessary to obtain the desired pattern.

In the embodiment of FIG. 3 , a potential from a power source v is applied to the extraction grid 350 . Thus, to stop the etching process rather than extinguish the plasma, the potential to the extraction grid is stopped, but the plasma is maintained in a plasma compartment 337 . Thus, the potential to the grid is also stopped as the carrier moves between the steps.

As shown in FIG. 1 , the insulating coating includes a plurality of high refractive index layers and low refractive index layers. However, deposition sources for high and low index materials are rather expensive. Thus, although it appears that the coating must be formed by moving the substrate in front of as many sources as necessary, such an arrangement is not economical. Moreover, this arrangement is inflexible in that it does not adapt well to changes in patterns that may be required. Accordingly, the following examples show a flexible structure capable of forming a coating using a paired light source, a single high index source and a single low index source. This structure is also very flexible and the operator can change the pattern design and color of the coating without changing the hardware.

Accordingly, in one aspect, a method for manufacturing a back panel for a mobile device is provided, comprising: obtaining a plate made of an insulating material that is transparent to electromagnetic radiation; Positioning the plate within a deposition system and depositing over the plate a plurality of n insulating layers consisting of an interlaced series of an insulating layer having a first index of refraction and an insulating layer having a second index of refraction greater than the first index of refraction. operating the deposition system to cause the n plurality of insulating layers to be designed to reflect light at a first wavelength; and transferring the plate into an etching chamber and etching the section of the plate such that only the m plurality of insulating layers remain in the section, wherein the m plurality of insulating layers are designed to reflect light at a second wavelength. .

Also provided is a method for manufacturing a back panel for a mobile device, comprising: obtaining a plate made of an insulating material transparent to electromagnetic radiation; positioning the plate within a deposition system and depositing a plurality of insulating layers comprising an interlaced series of an insulating layer having a first refractive index and an insulating layer having a second refractive index greater than the first refractive index over the plate; operating the deposition system, each of the plurality of insulating layers having a thickness designed to reflect light at a first wavelength; and transferring the plate into an etch chamber and etching the section of the plate such that the plurality of insulating layers in the section have a thickness designed to reflect light at a second wavelength.

For either method, the etching step may be performed by extracting the etching species from the plasma and applying a potential source to the extraction grid to accelerate the etchant species towards the plate. A mask may be inserted between the plasma and the extraction grid.

4 shows an embodiment of a system architecture capable of depositing an insulating coating with etching to create a multi-colored appearance. For illustrative purposes, system 400 is shown with eight carriers being processed. Carriers are listed 1 to 8 in the order they enter the system, and each carrier can support a plurality of substrates. The carriers move on the track 402 and can each be transported individually at a designated speed. The speed at which each carrier is transported depends on its position in the process, as described below.

System 400 includes a transport chamber 430 divided into two parts 430a, 430b by a partition. The carrier moves in one direction in one part and in the opposite direction in the second part, as indicated by the dashed arrows. The turntable 406 transfers the carrier between the two parts of the transfer chamber 430 . At the instant shown in FIG. 4 , carriers 1 , 2 , 3 and 4 have completed processing in part 430a and are being processed in part 430b , while carriers 5 , 6 , 7 and 8 are Part 430b is being processed. Upon completion of this process, carriers 1, 2, 3, 4 are removed from the system and carriers 5, 6, 7, 8 are moved to part 430b. Conversely, carriers 1 , 2 , 3 and 4 may migrate back to part 430a to form an additional high refractive index layer, while carriers 5 , 6 , 7 , 8 may migrate to part 430b A low refractive index layer can be formed. This exchange may be performed using an exchanger chamber 442 .

Paired deposition chambers 420 , 422 are attached to transfer chamber 430 , where chamber 420 contains a target of a high index material and chamber 422 has a target of a low index material. In addition, at least one etching chamber is attached to the transfer chamber 430 , and FIG. 4 shows two etching chambers. In the embodiment of FIG. 4 , the illustrated carrier movement sequence moves to high n deposition chamber 420 , then etch 435 , then low n deposition chamber 422 , then etch 436 , except that chamber 422 , 436 can be reversed, such as higher n deposition 420 , followed by etch 435 , then second etch 436 , then lower n 422 . This switched arrangement is particularly advantageous when the etching process takes more time than the deposition process. In this arrangement, a portion of the etch may be performed in chamber 435 and the remainder may be performed in chamber 436 , or one carrier may be etch-processed in chamber 435 while the other carrier is etched in chamber 435 . It may be etched at 436 .

In the structure of the system 400 of FIG. 4 , the deposition process is performed in a pass-by mode, ie, the carrier moves continuously in front of the deposition chambers 420 and 422 . However, depending on the design to be etched on the substrate, the etching process can be performed in static mode (carrier fixed during etching), pass by mode, or step mode. An operator may select a mode using controller 450 . However, since the carrier cannot be stopped when the deposition process is performed, buffer regions 446 and 448 (see dashed rectangle) are provided between the deposition and etching chambers. Each carrier in buffer areas 446 and 448 can be individually accelerated, decelerated, or stopped in idle until the next chamber is ready to receive a carrier.

For example, when carriers 1, 2, 3, 4 are loaded into the system, they first traverse the high n deposition chamber 420 to deposit the first layer in pass-by mode. As soon as the carrier 1 completes the deposition of the first layer, it is accelerated in the buffer region 446 and enters the etching chamber 435 to start the etching process. When the carrier 2 completes the deposition of the first layer, if the carrier 1 is still in the etch process, the carrier 2 moves into the buffer region until the carrier 1 finishes the etch process in the chamber 435 . At 446 it is brought to rest, at which point the carrier 2 can be accelerated and positioned for an etch process. In this way, the transport rate of each carrier is independently controlled, allowing static, pass-by, and step-by-step processing of substrates as selected by the operator in controller 450 .

Also, once carrier 1, 2, 3, 4 has finished processing the high n layer and low n layer, if the operator chooses to deposit another high n layer, the carrier 1, 2, 3, 4 may be transferred to the exchange chamber 442 . The carriers 5, 6, 7, 8 are then moved onto the part 430b by the turntable 406, and the carriers 1, 2, 3, 4 can be returned back to the part 430a. . This exchange process can be performed multiple times to form multiple high n-layers and low n-layers as needed. Also, the exchange may be performed several times, skipping the etching process until a plurality of layers are formed, and only then can the carrier enter the etching process. Thus, as shown, system 400 provides the flexibility to provide for the number of layers formed, ie, the background color, and the type of etch that can be performed, ie, different design shapes and colors. All of this flexibility can be controlled by the controller 450 without changing any hardware or using just a pair of deposition chambers and at least one etcher.

Another embodiment is shown in FIG. 5 , which is a hybrid structure using a combination of rotary and linear conveying sections. One advantageous feature of this embodiment is that it allows the operator to decide how many passes through the deposition and/or etch station, allowing different designs at the operator level. In this embodiment, the longer the substrate is in the rotating transfer section, the greater the number of layers formed on the substrate, thus changing the color appearance of the substrate.

The hybrid structure of Figure 5 enables the programmable deposition and etch process required to achieve different colors and different designs. 5 , the rotary transfer deposition section 501 is connected to the linear transfer of the etch chamber 503 via a buffer section 502 . The deposition section 501 has a carousel 507 mounted with a carrier as shown by the arrow, which rotates. Two deposition sources 520 and 522 are attached to deposition section 501 in opposite directions. Thus, when one carrier faces the deposition chamber 520 , the other carrier faces the other deposition chamber 522 . As the carousel rotates, the substrate is continuously exposed to the deposition chamber and deposited with alternating insulating layers of different refractive indices. As long as the substrate remains in chamber 501, the number of deposited layers increases.

When the substrate on the carrier needs to be etched, the carrier is moved to a buffer chamber 502 and then to an etch chamber 503 having etch sources 535 and 536 . Etch chamber 503 is a linear processing chamber, meaning that the carrier is transported on a linear track as opposed to a deposition chamber in which the carrier is rotated on a rotating carousel. Thus, in the system of Figure 5, the carrier is subjected to both rotary and linear transport. Rotational transport is advantageous for deposition as the substrate must move continuously in front of the deposition source to ensure uniform deposition across the substrate. Conversely, linear aqueous is advantageous to allow flexibility to etch in static mode, pass-by mode, or step-by-step mode. Thus, the mixed transport mode of FIG. 5 is superior to the prior art system using only one transport mode.

Optionally, a turntable 506 is provided at the end of the linear transfer chamber 503 to allow substrate exchange between etch sources 535 and 536 . Optionally, or additionally, an exchange chamber similar to chamber 442 of FIG. 4 may be added to perform the same function as in the embodiment of FIG. 4 . Using the controller 550, the operator can program how many rotations the substrate undergoes on the carousel before being transferred to the linear chamber 503 for etching.

Accordingly, in one aspect, a system for manufacturing a multi-colored back panel for a mobile device is provided, comprising: a vacuum sealable transfer enclosure having a transfer mechanism configured to transfer a glass plate; a first sputtering chamber mounted on a sealable transfer enclosure and having a sputtering target made of a first insulating material having a first refractive index; a second sputtering chamber mounted on a sealable transfer enclosure and having a sputtering target made of a second insulating material having a second refractive index; and an extraction grid assembly mounted on a sealable transfer enclosure and configured to extract an etch specimen from the plasma compartment and plasma and accelerate the etch specimen through a window formed in the sealable transfer enclosure. includes a chamber.

In addition, carousel 507 has a generally circular shape and is shown rotating in a generally circular motion. However, carousel and rotation can be elliptical, elongated oval, rectangular, etc., so the terminology carousel and rotation is intended to cover such structures. An example of this is provided in FIG. 6 .

6 shows an embodiment using a rectangular carousel, also called a racetrack. The embodiment of Figure 6 is particularly useful when each deposition step is followed by an etching step. The number of deposition and etch chambers may vary depending on the process flow. In this particular example, two high refractive index sputtering chambers 620a and 620b are positioned in series, one positioned immediately after the other. Similarly, two low index sputtering chambers 622a, 622b are positioned in series, one immediately following the other. The two etch chambers 635a and 635b immediately follow the high refractive index sputtering chamber 620b. Similarly, two etch chambers 636a and 636b immediately follow the low index sputtering chamber 622b. This embodiment can also be used as a buffer chamber to synchronize processes in all chambers, or as an empty slot to add deposition and/or etch chambers if the process is changed, e.g. to create different or more colors. and three blank chambers 650a, 650b, 650c. Also provided is a pre-clean chamber 655 for cleaning the substrate prior to initiating the deposition of the high refractive index material. All chambers described are arranged around a carousel 607 that transports substrates or substrate carriers between chambers in a racetrack fashion.

In the example of FIG. 6 , the substrate enters and exits the system from the same side, which is simpler for factory automation. The substrate enters the vacuum environment of the system through a loadlock 660a and from there proceeds to a high vacuum lock 662a. A substrate or substrate carrier from the high vacuum lock is loaded onto the carousel 607 . Conversely, to remove the substrate from the vacuum environment of the system, the substrate or substrate carrier is offloaded from carousel 607 into high vacuum lock 662b. From there, the substrate moves to the load lock 660b and then exits the system. The load lock and lock chamber are isolated by a gate valve.

Optionally, to further modularize the system, a turntable 506 is added and the substrate carrier is transferred to an optional alternate etch chamber 637a and/or 637b, and/or an optional cluster chamber 638a and/or or 638b). Cluster chamber 638a and/or 638b may be, for example, a metrology tool for measuring the thickness of a deposited layer.

In the disclosed embodiment, the insulating layer is made of metal oxides, nitrides, or oxynitrides. Some examples include YsZ, AlxOy, AlN, SixNy, AlSiO, and SiON. In some embodiments, the various layers are formed using ion beam assisted deposition (IBAD) such that the target material consists of the metal to be deposited and oxygen or nitrogen is ion implanted during deposition. Therefore, the sputtering process is performed in a metal mode (also called metamode), the target is sputtered with (non-oxidized) metal, typically by argon ions, and a very thin film (generally up to 1 nm) is converted to an oxide or nitride by striking the deposited metal with an O2 or N2 ion beam. For example, a target for sputtering may be made of pure silicon or aluminum, and the ion beam may include O2 or N2 with or without argon to form a layer of SiO, SiN, AlO, etc. Also, in a preferred embodiment, the ratio of ion current to atomic arrival rate is less than 0.5, and the ion has a potential energy not exceeding 600 eV.

In some embodiments, the refractive index of any layer can be altered by alloying the material. For example, MgO may be used to alloy a high index material such as ZrOx or a low index material such as AlOx. Alloying can be achieved by adding 8-10% MgO, which lowers the crystallization temperature of the layer. In another example, about 10-12% chromium may be alloyed with titanium to improve toughness. One of the three mineral forms of titanium dioxide, anatase, has a high refractive index of 2.4, but its low hardness makes it suitable for alloying. Titanium itself can be used as an alloying agent to change the refractive index. Tantalum may be an alloying additive that changes the properties of a high refractive index material, while boron may be an alloying additive that changes the properties of a low refractive index material.

4A shows an embodiment having a combination of a UV-curable inkjet printer integrated into a sputtering system, thereby enabling multiple methods of making coatings. An example of a suitable inkjet printer is the model IEHK A3 UV printer available from IEHK Enterprises LLC of Wayne, PA. This system is particularly effective when the cover design requires delicate and/or complex tinting or when relatively small birches such as custom orders need to be executed. For example, a company may order a batch of phones for its employees, with each phone having the company's logo imprinted on the back, as shown in the example with logo 211 in FIG. 4B .

The system of FIG. 4A can be used to make a back cover with a hybrid coating, ie, an insulative color coating and an integrated print. In this implementation, details such as text, logos or other graphics are inkjet printed on a substrate and then introduced into a vacuum coating system to apply blanket sputtered films. The PVD film can use a blanket color over the graphic, such that the logo is visible on the colored background on the other side of the transparent substrate. That is, inkjet and sputtering form the back side of the glass, the facing surface inside the phone when it is assembled. In this way, both the imprinted and sputtered designs are protected as only the unprinted/colored glass surface is exposed. The unprinted/colored surface may be coated with protective and/or anti-finger printing clear coats.

According to another embodiment, the imprint design is done on the front side of the glass cover, ie the surface facing the outside when the phone is assembled. This can be done if the cover is opaque or if the background color has already been applied. In these applications, the PVD coating is a protective encapsulation and improves the durability of inkjet printing. For example, the front side of the substrate may be first sputtered with a background color, and then an inkjet printer is used which is used to exit the vacuum and apply the graphic design across the background color. The substrate can then be returned to vacuum and a transparent color is sputtered over the graphic and background color. Optionally, a transparent protective coating, such as a transparent diamond-like carbon (DLC) coating, may be sputtered over the substrate.

The system of Fig. 4a includes elements already shown in Fig. 4, which will not be repeated here. The main difference between the systems is that the exchanger chamber 442 of FIG. 4 has been replaced by the loadlock 471 and the inkjet printer 472 in the system of FIG. 4A. One load lock chamber 471 isolates the transfer chamber 430 from the load lock chamber 471, and an isolation valve for isolating the environment of the inkjet printer 472 from the load lock 471 is provided at each end on the opposite side. do. Also shown in FIG. 4A is UV light 473 that cures the printed graphic prior to introducing the substrate having the printed graphic into the vacuum environment of the transfer chamber 430 .

FIG. 5A shows an example of integrating an inkjet printer into a hybrid system like FIG. 5 . In this example, the chamber housing the turntable 506 also functions as a load lock separation between the vacuum environment and the inkjet printer atmospheric environment of the linear etch chamber 503 via an isolation valve.

Fig. 6a shows a variant of the system of Fig. 6 in which two inkjet printers are added. The alternate etch chambers 637a and/or 637b of FIG. 6 have been replaced by an inkjet printer 672 operating in an atmospheric pressure environment. Here, a separation valve is provided that isolates the atmospheric pressure part from the vacuum section 607 . The vacuum section is used to form the insulating color coating, and the atmospheric section is used to form the graphic.

Accordingly, a system for manufacturing a multi-colored back panel for a mobile device is provided, comprising: a vacuum sealable transport enclosure having a transport mechanism configured to transport a glass plate; a first sputtering chamber mounted on a sealable transfer enclosure and having a sputtering target made of a first insulating material having a first refractive index; a second sputtering chamber mounted on a sealable transfer enclosure and having a sputtering target made of a second insulating material having a second refractive index; and an etch chamber mounted on the sealable transfer enclosure and having an extraction grid assembly configured to extract the etch specimen from the plasma compartment and the plasma and accelerate the etch specimen through a window formed in the sealable transfer enclosure; an atmospheric pressure chamber housing the ink printer; and an isolation chamber interposed between the vacuum sealable transfer enclosure and the atmospheric pressure chamber. The atmospheric pressure chamber may include an ultraviolet source configured to cure the UV ink. The isolation chamber may include a loadlock and/or a turntable.

In the above-described embodiments, the processing may proceed in any order. First vacuum coating, then inkjet printing, first inkjet printing, then vacuum sputtering, or alternating between the two environments. In one example, an inkjet printing process may be used to first apply a stress-relieving coating prior to introducing the substrate to a vacuum environment for sputtering coating. In another embodiment, an inkjet printer is used to first apply a removable mask across the substrate. The substrate is then sputter coated to create a color coating. The mask is then removed and the previously applied glass or coating is exposed. This method can be used to obviate the need for a hard mask.

According to the described aspects, there is provided a back cover for a mobile device, comprising: a cover plate made of a material transparent to radio radiation and wireless charging; a cover plate having a front and a rear surface, the rear surface facing the inside of the mobile device when assembled; an imprinted design formed in direct contact with the rear surface; a sputtered coating formed across the back surface, wherein the sputtered coatings are each transparent to visible light and form an interlaced stack of an insulating layer having a first index of refraction and an insulating layer having a second index of refraction different from the first index of refraction It includes a plurality of insulating layers. The advantage of this aspect is that when the cover is scratched, the scratch does not change the color of the coating because the coating is on the back side and protected from the environment. So the scratches are not very visible. Similarly, the imprinted design is protected.

According to another embodiment, an inkjet printer is used to alter the appearance of a sputtered coating. For example, as shown in FIG. 4C , an inkjet printer can be used to print micron-sized dots (eg, 5-25 microns in diameter) on the surface of a substrate. The dots are made of a transparent material with a low refractive index. The refractive index of the dots may be different from the first refractive index or the second refractive index, and may be different from any one of the first refractive index or the second refractive index. The substrate is introduced into a vacuum system and forms a sputtered coating. Because micron-sized dots scatter light, the resulting color coating will appear as if it had a matte finish. Depending on the number, size, and distribution of printed dots, a 1 to 20% haze dispersion can be produced. For example, other shapes, such as pyramids, can be printed to create light scattering and change the appearance of the sputtered coating.

According to the described aspects, there is provided a back cover for a mobile device, comprising: a cover plate made of a material transparent to radio wave radiation and wireless charging; a plurality of dots formed on the surface of the cover plate and made of an insulating material having a first refractive index; and a sputtered coating formed across the surface, wherein the sputtered coating is each transparent to visible light and consists of an insulating layer having a second refractive index and an insulating layer having a third refractive index different from the second refractive index. and a plurality of insulating layers forming an interlaced stack. Each dot may have a diameter of 5 to 25 microns. The first index of refraction may be the same as or different from the second or third index of refraction.

It should be understood that the processes and techniques described herein are not inherently related to any particular apparatus, and may be implemented by any suitable combination of components. Also, various types of general purpose devices may be used in accordance with the teachings disclosed herein. The invention has been described in all respects with respect to specific examples, which are intended to be illustrative rather than restrictive. Those skilled in the art will appreciate that many different combinations are suitable for practicing the present invention.

Further, other implementations of the invention will become apparent to those skilled in the art from consideration of the specification and application disclosed herein. Various aspects and/or components of the described embodiments may be used alone or in any combination. The specification and examples are to be regarded as illustrative only, the true scope and spirit of the invention being indicated by the following claims.

Claims (21)

A mobile device encasing comprising:
a back panel made of an insulating material transparent to electromagnetic radiation; and
a plurality of insulating layers provided on a rear panel forming an opaque panel for covering the inside of the mobile device, the plurality of insulating layers comprising: a plurality of first insulating layers having a first refractive index n1 and a second refractive index higher than the first refractive index consisting of a plurality of second insulating layers having n2;
the plurality of first insulating layers are interlaced with the plurality of second insulating layers;
The first part of the rear panel has n plurality of insulating layers designed to reflect light of a first wavelength, and the second part of the rear panel has m plurality of insulating layers designed to reflect light of a second wavelength. With- n and m not equal-, mobile device encasing.
According to claim 1,
wherein each of said plurality of insulating layers is individually transparent over the entire optical range.
According to claim 1,
The thickness of the plurality of insulating layers is selected such that a resulting path-length difference for reflection from a different second refractive index layer is an integer multiple of the first or second wavelength.
According to claim 1,
The boundary between the first and second parts is formed steeply such that only the first and second wavelengths are reflected at the boundary.
According to claim 1,
a boundary between the first and second part transitions such that wavelengths in addition to the first and second wavelengths are reflected at the boundary.
According to claim 1,
wherein each of the plurality of insulating layers has a thickness of one quarter of the first wavelength.
According to claim 1,
wherein each of the plurality of insulating layers has a partial area having a thickness of one quarter of the first wavelength and a thickness of one quarter of the second wavelength.
According to claim 1,
wherein each of the plurality of first insulating layers comprises one or a combination of materials of NbOx, ZrO, Y-ZrO, AlN, SiN, ZrN, TiO, CrO, CrN, CrTiO, and CrTiN. Yixing.
9. The method of claim 8,
wherein each of the plurality of second insulating layers comprises one or a combination of materials of SiOx, AlO, SiON, SiAlO.
According to claim 1,
each of the plurality of first insulating layers comprises one or a combination of materials of AlN and SiN;
wherein each of the plurality of second insulating layers comprises one or a combination of materials of SiOx, AlO, SiON, SiAlO.
According to claim 1,
wherein the back panel is made of treated glass.
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