CN117735848A

CN117735848A - Coating for curved surfaces

Info

Publication number: CN117735848A
Application number: CN202311210386.4A
Authority: CN
Inventors: V·S·韦拉撒米
Original assignee: Apple Inc
Current assignee: Apple Inc
Priority date: 2022-09-20
Filing date: 2023-09-19
Publication date: 2024-03-22

Abstract

The present disclosure relates to "coatings for curved surfaces". The transparent structure may have multiple layers, such as an inner layer and an outer layer, which may be formed of glass. The transparent structure may include a larger curved surface with compound curvature and high geometric strain, and may include one or more layers. In order to apply a physical vapor deposition coating having a uniform thickness on a curved surface, the cathode power may be modulated during deposition, a mask having openings curved to match the curved surface may be used, the shape of the cathodes may be changed, the cathodes may sputter the coating outward toward the curved surface, the magnetic field may modulate the flux generated by the cathodes, and/or the pressure and/or flow of the gas may be adjusted. By modifying the physical vapor deposition coater in one or more of these ways, the coating can have a uniform thickness across the curved surface and thus a uniform color.

Description

Coating for curved surfaces

The present application claims priority from U.S. patent application Ser. No. 18/447,918, filed 8/10, 2023, and U.S. provisional patent application Ser. No. 63/408,404, filed 9/20, 2022, which are incorporated herein by reference in their entirety.

Technical Field

This document relates generally to structures that pass light, and more particularly to windows.

Background

The window typically includes a transparent layer, such as a glass layer. The coating may be applied to the transparent layer.

Disclosure of Invention

A system such as a vehicle, building, or electronic device may have a window. The window may separate an interior region from an exterior region, such as an interior region and an exterior region of a vehicle. The window may have structural window layers, such as an inner layer and an outer layer. The inner layer and the outer layer may be separated by an air gap.

The window may be a larger curved window with compound curvature and high geometric strain. One or more physical vapor deposition coatings may be applied to the inner and/or outer layers. In order to apply the physical vapor deposition coating with a uniform thickness on the window layer, the cathode power may be modulated during the deposition, a mask with curved openings based on the curvature of the window may be used, the shape of the cathodes may be changed, the cathodes may sputter the coating outward toward the window, the magnetic field may modulate the flux generated by the cathodes, and/or the gas pressure and/or gas flow may be adjusted.

By modifying the physical vapor deposition coater in one or more of these ways, the coating can have a uniform thickness, and thus a uniform color, across the surface of the window layer.

Drawings

Fig. 1 is a schematic diagram of an exemplary apparatus according to some embodiments.

Fig. 2 is a cross-sectional side view of an exemplary window with a coating according to some embodiments.

Fig. 3 is a cross-sectional side view of an exemplary coating on a window layer according to some embodiments.

Fig. 4 is a perspective view of an exemplary curved window layer according to some embodiments.

Fig. 5 and 6 are cross-sectional side views of the exemplary curved window layer of fig. 4, according to some embodiments.

Fig. 7 is a top view of an exemplary physical vapor deposition coater according to some embodiments.

Fig. 8 is a graph of an exemplary power modulation of a cathode in a physical vapor deposition coater according to some embodiments.

Fig. 9 is a side view of an exemplary mask through which a coating may be applied to a substrate, according to some embodiments.

Fig. 10 is a side view of an exemplary cylindrical cathode according to some embodiments.

Fig. 11 is a side view of an exemplary frame-shaped cathode for sputtering a coating onto a substrate according to some embodiments.

Fig. 12 is a top view of an exemplary physical vapor deposition coater with internal cathodes coating a substrate by sputtering outward, according to some embodiments.

FIG. 13 is a top view of an exemplary PVD coater having electromagnets for varying the thickness of the PVD coating applied in accordance with some embodiments.

Figure 14 is a side view of an exemplary hollow tile magnetron according to some embodiments.

Fig. 15 is a graph of exemplary uniformity of a physical vapor deposition coating across a substrate, according to some embodiments.

Detailed Description

The present invention provides a system that may have a window. The window may include an optical coating, such as a coating for blocking infrared light. Optionally, additional coatings (such as anti-reflective layers) or photo-electrically adjustable components may also be incorporated into the window. The system may be an electronic device, a building, a vehicle, or other suitable system. An exemplary configuration in which the system with the window is a vehicle may sometimes be described herein as an example. This is merely illustrative. The window structure may be formed in any suitable system.

An electrically adjustable component in the window can be used to adjust the optical properties of the window. For example, the electrically adjustable window may be adjusted to change the absorption of light and thus the light transmission of the window. The adjustable light modulator layer may be used, for example, as an electrically adjustable awning for a roof window, or may be used to implement an electrically adjustable window shade for a side window, front window, or rear window. In an exemplary configuration, a liquid crystal light modulator (such as a guest-host liquid crystal light modulator) may be used to modulate the transparency of the window. The adjustable optical component layer may also be used to display images, provide illumination, and/or otherwise adjust the appearance and behavior of the window.

The window for the system may include multiple glass layers. For example, the window may include an inner transparent structural layer (sometimes referred to as an inner glass layer) and an outer transparent structural layer (sometimes referred to as an outer glass layer). The inner and outer layers of the window may be separated by a gap. The gap may be filled with air or may be filled with a polymer, liquid or other functional dielectric. Exemplary configurations in which the inner and outer glass layers are separated by air are sometimes described herein as examples.

The glass layer of the window may be a single glass layer (e.g., a single layer of heat strengthened or tempered glass), or in some configurations, may be a multi-layer structure formed, for example, from a first glass layer and a second glass layer laminated together. The laminated glass layers can have a polymer, such as polyvinyl butyral (PVB), that bonds the first and second glass layers to form a laminated glass sheet. The multiple layer glass structure (laminated glass layer formed from two or more laminated glass layers with interposed PVB) and the single layer glass layer can include optional tints (e.g., dyes, pigments, etc.). The polymer layer (e.g., PVB layer) in the laminated glass layer can also optionally be passively colored.

As an alternative to glass, a polymer layer may be used to form the window. For example, the window may include one or more polymer layers, such as polycarbonate or acrylic layers. The laminated window structure may be formed from multiple polymer layers having interlayers, such as Thermoplastic Polyurethane (TPU) interlayers. Generally, any desired interlayer may be used.

The structure may be curved, regardless of the material used to form the window structure. For example, the window layer may have a compound bend and a geometric strain of at least 0.1%, at least 0.5%, at least 0.8%, at least 5%, or other desired value. It may be desirable to apply one or more coatings to the window layer. In some embodiments, a physical vapor deposition coating may be applied to the layer. A physical vapor deposition coater with one or more cathodes may be used to sputter a physical vapor deposition coating onto the layer.

To ensure uniformity of the physical vapor deposition coating on the window layer, the power supplied to the one or more cathodes may be varied as the curvature of the window layer varies; a mask having a curved-based opening may be used between the cathode and the window layer; a cathode having a cylindrical shape or a cathode having a frame shape including a torsion magnet may be used; the physical vapor deposition coater may have an inner cathode sputtered outwardly toward the window layer; electromagnets may be used to vary the flux emitted by the coater and thus vary the thickness of the coating; the coater may include a magnetron matching the curvature of the window layer; and/or the gas pressure and/or gas flow rate (of the gas used for physical vapor deposition, for example) may be adjusted.

FIG. 1 shows an exemplary system of the type that may include a window having one or more physical vapor deposition coatings. The system 10 may be an electronic device, a vehicle, a building, or any other desired system. For example, the system 10 may be an electronic device such as a cellular telephone, a laptop computer, a desktop computer, a tablet computer, a television, or any other desired electronic device. The electronic device may include a device housing, a display located on a front face of the device housing, and electronic components within the device housing. In other examples, the system 10 is a vehicle having a body with wheels, propulsion and steering systems, and chassis to which other vehicle systems are mounted. The vehicle body may include doors, trunk structures, hoods, side body panels, roofs, and/or other body structures. The interior of the vehicle body may form a seat. However, these examples are merely illustrative. In general, the system 10 may be any desired system.

Regardless of the particular system, system 10 may include one or more windows, such as window 16. Window 16 may separate the interior of system 10 from the external environment surrounding system 10. For example, window 16 may include windows located at the following positions: on the front and/or rear of the electronic device; on the front, rear, top and/or side of the vehicle; or for example on the side of a building.

The input-output device 21 may include sensors, audio components, displays, and other components. For example, the input-output device 21 may provide an output to an occupant of the vehicle, may measure an environment surrounding the vehicle, and may collect an input from the occupant of the vehicle. Some input-output devices may operate through window 16 if desired. In some examples, input-output device 21 may include a communication device, such as a radio, that receives and/or transmits radio waves through window 16.

The control circuit 23 may include storage and processing circuits such as volatile and non-volatile memory, microprocessors, application specific integrated circuits, digital signal processors, microcontrollers, and other circuits for controlling the operation of a system such as a vehicle. During operation, the control circuit 23 may control components of the vehicle based on input from the input-output device 21.

An exemplary configuration of a window, such as one of the windows 16 of FIG. 1, is shown in FIG. 2. As shown in fig. 2, window 16 may separate an interior region 14 (e.g., a region inside system 10, such as a region inside a vehicle) from an exterior region 18 (e.g., a region outside system 10, such as a region outside a vehicle). Window 16 may include an inner layer 20 and an outer layer 22. Layers 20 and 22 may be glass layers, ceramic layers, sapphire layers, polymer layers (such as polycarbonate or acrylic layers), or any other desired layers, and may be transparent or partially transparent (e.g., may be colored to reduce the transmission of some visible light). Layers 20 and 22 may also be referred to herein as substrates (e.g., when a coating is applied to the layers).

Layers 20 and 22 may be formed from a single layer glass structure and/or a multiple layer glass structure. These single layer glass structures may be strengthened (e.g., by annealing, heat strengthening, tempering, and/or chemical strengthening). In general, the inner layer 20 may be a single layer glass structure (e.g., a single layer of tempered glass) or a laminated glass layer, and the outer layer 22 may be a single layer glass structure (e.g., a single layer of tempered glass) or a laminated glass layer. In embodiments where layer 20 and/or layer 22 are laminated glass layers, they may include multiple glass layers laminated together using one or more polymer layers. In embodiments in which layer 20 and/or layer 22 are laminated polymer layers, they may include multiple polymer layers laminated together using one or more additional polymer layers. The polymer layer may be a polyvinyl butyral layer, a thermoplastic polyurethane layer, or other suitable polymer layer for attaching a glass layer.

Layers 20 and 22 may be separated by a gap 25. The gap 25 may be an air gap, a vacuum, or the gap 25 may be filled with any desired substance. For example, the gap 25 may be filled with a polymer, gas, liquid, or other dielectric. In some cases, the gap 25 may be omitted, if desired.

Light may be incident on window 16. For example, light may be incident on window 16 from outer region 18 and/or light may be incident on window 16 from inner region 14. Light may include visible, infrared, ultraviolet, and other wavelengths. To reduce transmission of undesired wavelengths of light (such as infrared wavelengths) through window 16, inner layer 20 may be coated with a physical vapor deposition coating 24. For example, physical vapor deposition coating 24 may be an infrared reflective coating that includes a plurality of thin film layers (such as at least one silver layer) that prevent infrared light from reaching interior region 14 (e.g., reduce transmission of infrared light through a window by at least 70%, at least 50%, at least 40%, or other values). However, in general, the physical vapor deposition coating 24 may be any desired physical vapor deposition coating, such as a coating that blocks one or more desired wavelengths of light (e.g., ultraviolet light), an anti-reflective coating formed from a stacked thin film interference filter comprising dielectric layers having alternating refractive indices, and/or any other desired physical vapor deposition coating.

Although the physical vapor deposition coating 24 is shown on the outer surface of the inner layer 20 in fig. 2, this is merely illustrative. As shown in fig. 2, the physical vapor deposition coating 24 may be located at a location 24' on the inner surface of the outer layer 22 instead of or in addition to being located on the inner layer 20. Alternatively or additionally, the physical vapor deposition coating 24 may be formed on the outside of the window 16 (e.g., on the outer surface of the outer layer 22 or on the inner surface of the inner layer 20), or may be formed on an additional layer formed between the inner layer 20 and the outer layer 22. Generally, the physical vapor deposition coating 24 may be formed anywhere within the window 16.

Regardless of where one or more physical vapor deposition coatings, such as physical vapor deposition coating 24, are formed, the physical vapor deposition coating may include multiple layers. For example, the physical vapor deposition coating may include multiple layers for forming an infrared reflective coating, a thin film interference filter, or other desired coating. Fig. 3 shows an exemplary stack of physical vapor deposition coatings.

As shown in fig. 3, the physical vapor deposition coating 24 may be applied to a substrate 30. The substrate 30 may be, for example, a window layer, such as window layer 20 or 22 of fig. 2. The physical vapor deposition coating 24 may include one or more physical vapor deposition coatings 34. Each of the layers 34 may comprise a different material, or the layers 34 may comprise alternating materials. In some embodiments, physical vapor deposition coating 24 may include a plurality of thin film layers having alternating refractive indices to form a thin film interference filter.

Although the physical vapor deposition coating 24 is shown as being directly on the substrate 30, this is merely illustrative. One or more layers may be bonded between the physical vapor deposition coating 24 and the substrate 30, if desired. In some embodiments, a buffer layer, such as a polymer layer, may be incorporated between the substrate 30 and the physical vapor deposition coating 24 to reduce stress applied to the substrate 30 during the physical vapor deposition process.

The windows in system 10 (e.g., window 16) may be entirely planar (e.g., the inner and outer surfaces of the windows may be flat) and/or some or all of the windows in system 10 may have surface curvatures. The inner and outer surfaces of each window may, for example, have compound curvature (e.g., a non-deployable surface characterized by a curved cross-sectional profile taken along the X and Y directions) and/or may have a deployable surface (a surface with zero gaussian curvature that may be flattened without deformation). The curved window shape may be formed by heating the glass until the glass is soft enough to be shaped (e.g., using a mold, using gravity, using glass slumping techniques, and/or using other glass shaping methods).

Fig. 4 is a perspective view of an exemplary curved window layer. In the example of fig. 4, the surface of the window layer (formed from a transparent layer, such as layer 30 of fig. 4) has a compound curvature. In particular, layer 30 has a non-developable surface characterized by a curved cross-sectional profile taken along the X and Y directions of fig. 3. Fig. 5 is a cross-sectional side view of layer 30 of fig. 4 taken along line 48 and viewed in the +x direction. As shown in fig. 5, the cross-sectional profile of layer 30, as seen in the +x direction, is curved. Fig. 6 is a cross-sectional side view of layer 30 of fig. 4 taken along line 50 of fig. 4 and viewed in the +y direction. As shown in fig. 5, the cross-sectional profile of layer 30, as seen in the +y direction, is curved. The layer 30 with compound curvature may also have one or more planar (non-curved) regions and/or one or more regions with a deployable surface (curved surface area without compound curvature), if desired. In some configurations, a curved layer such as layer 30 may have only a deployable surface and no compound curvature (and optionally a planar portion). Arrangements in which the flex layer for window 14, such as layer 30, has only compound curves or a combination of one or more compound curve regions and one or more flat regions may also be used. The process of forming layer 30 into a shape having a curved cross-sectional profile may sometimes be referred to as bending or shaping. One or more layers 30 may be used to form the window 16, and each layer 30 (and window 16) may have any suitable shape (rectangular, triangular, circular, shape with curved edges and/or straight edges, etc.).

Windows in system 10, such as window 16, may be curved by an amount such that window 16 exhibits at least 0.1%, at least 0.8%, at least 1%, at least 3%, at least 3.5%, at least 4%, at least 5%, between 3% and 7.5%, between 3.5% and 7%A geometric strain value between 4% and 6.5%, between 4.5 and 6%, less than 7%, less than 6.5%, or other suitable geometric strain amount. Alternatively or additionally, the window 16 may be larger (e.g., may have a larger surface area in the X and Y directions of fig. 4). For example, window 16 may be at least 1m ² At least 1.5m ² At least 0.75m ² Or have another desired surface area.

Due to the geometric strain and size of the window 16, it may be difficult to apply a coating to the surface of the window 16. In particular, conventional processes may not be suitable for handling such large windows (e.g., these processes may crack or overstress the window) or may not uniformly coat windows having complex bends. Fig. 7 shows an exemplary physical vapor deposition coater that may be used to deposit a physical vapor deposition coating on window 16.

As shown in fig. 7, the physical vapor deposition coater 31 may include cathodes 32A, 32B, 32C, and 32D. The cathode 32 may, for example, release a plasma toward the target materials (e.g., may bombard the target materials), and some of the target materials may be sputtered as vapors that may be deposited onto the substrate 34. In this way, a physical vapor deposition coating may be sputtered onto the substrate 30 using the cathode 32. However, the physical vapor deposition process is merely illustrative. In general, cathode 32 may be used in any desired physical vapor deposition process for depositing a physical vapor deposition coating onto substrate 30.

A mask 34 may be interposed between the cathode 32 (and the target material) and the substrate 30. For example, mask 34 may be a finger mask having one or more openings that are patterned to match the curvature of substrate 30. Sputtered (or otherwise emitted) material may pass through mask 34 and then be deposited on substrate 30. Since the mask 34 has openings based on the curvature of the substrate, sputtered material can be deposited across the surface of the substrate 30 in a uniform manner. For example, a physical vapor deposition coating may have a uniform thickness across a surface even though the curvature of the surface is non-uniform. However, depending on the curvature of the substrate 30, the mask 34 may be omitted if desired.

When a physical vapor deposition coating is applied to the substrate 30 using the cathode 32, the substrate 30 may be rotated relative to the cathode 32 (e.g., rotated about the midpoint of the physical vapor deposition coater such that the substrate is exposed to deposition from all cathodes), if desired. Alternatively or additionally, the cathode 32 may be rotated relative to the substrate 30 during the deposition process. By rotating the substrate 30 and/or the cathode 32, the physical vapor deposition coating formed on the substrate 30 may be more uniform than if the substrate 30 and the cathode 32 were stationary. The rotational speed of the substrate 30 relative to the cathode 32 (and mask 34) may be adjusted if desired. A more uniform coating may be achieved based on the rate of bending adjustment of the substrate 30.

Other conditions may also be changed to account for bending of the substrate 30. For example, the pressure of the system may be increased or decreased as needed to account for different bending regions of the substrate. Alternatively or additionally, the pressure of the gas used for physical vapor deposition may be increased or decreased based on the bending of the substrate. In one illustrative example, the operating pressure of the system and/or the pressure of the gas may be about 1 millitorr. However, the pressure may be increased, such as to about 4 millitorr or 5 millitorr, to increase uniformity. These examples merely illustrate the pressures that may be used and are not limiting. Any suitable pressure may be used.

Generally, adjusting the gas pressure can increase the uniformity of the coating. However, in embodiments in which a silver layer is deposited (e.g., as part of an infrared reflective coating), higher pressures may reduce silver quality. Thus, the gas pressure may be selected to be a compromise based on the bending of the substrate (e.g., a higher gas pressure may be used for a substrate having a higher bending) and the desired silver quality (e.g., a lower gas pressure may be used if a higher silver quality is desired for a given infrared reflective coating).

In addition to or instead of varying the gas pressure, the gas flow may be varied. In particular, the gas flow rate may be modified to change the stoichiometry of the deposited layer, particularly when a dielectric layer (such as a thin film interference layer) is being deposited. As an illustrative example, the flow of oxygen may be adjusted based on the shape of the substrate and the desired coating material to form a given layer with the correct stoichiometry (e.g., if Deposition of oxygen-containing materials such as TiO ₂ Dielectric layer of TiZnO or other dielectric layer). In some embodiments, the flow of oxygen or other gas may be varied across the substrate to modify the deposited coating on the surface of the substrate. In this way, a desired coating can be deposited on the curved substrate.

Since the substrate 30 may have a curved surface (such as a surface with a compound curvature, having a geometric strain (or other desired strain) of at least 0.1%, at least 0.8%, at least 1%, at least 5%), the cathode 32 may be modulated during the deposition process to provide a coating having a uniform thickness on the substrate 30. Fig. 8 shows an illustrative example of modulating the power of the cathode in the physical vapor deposition coater 31.

As shown in fig. 8, the power required by a cathode, such as cathode 32 of fig. 7, to apply a uniform coating may vary over time as the substrate is moved relative to the cathode. In particular, curves 36 and 38 may be determined based on differences in substrate bending across different portions of the substrate. For example, curve 36 may reflect the amount of power required to uniformly coat a first portion of a substrate, while curve 38 may reflect the amount of power required to uniformly coat a second portion of the substrate. The local maxima of curves 36 and 38 may occur at times when the substrate is farther away from the cathode and target (e.g., more power is required to apply a uniform thickness of coating as the substrate is farther away), while the local minima of curves 36 and 38 may occur at times when the substrate is closer to the cathode and target (e.g., less power is required to apply a uniform thickness of coating as the substrate is closer). In other words, the dynamic deposition rate may be used by varying the power (e.g., voltage) of the sputtering. A high voltage will produce a high flux with high energy and can be used when the substrate is further away from the cathode and target, while a low voltage will produce a low flux with low energy and can be used when the substrate is closer to the cathode and target.

Curve 40 may be a regression curve of curves 36 and 38. By modulating the power applied to a cathode, such as cathode 32, according to curve 40, the physical vapor deposition coating may be applied more uniformly than if the power was constant during the deposition process. In other words, modulating the power applied to the cathode during the deposition process may produce a more uniform coating across the surface of the curved substrate.

Curves 36, 38 and 40 are merely illustrative examples of power modulation curves. In general, any desired number of individual power modulation curves may be determined for any desired number of substrate portions, and a regression power modulation curve may be determined from the individual power modulation curves. The regression power modulation profile may then be used during deposition to modulate the power applied to the cathode, resulting in a more uniform coating across the substrate.

In addition to or instead of modulating the power of the cathode during the deposition process, a mask may be used between the cathode/target and the substrate. As discussed in connection with fig. 7, mask 34 may have openings based on/corresponding to the curvature of the substrate. Fig. 9 shows an exemplary mask having such openings.

As shown in fig. 9, a mask, such as mask 34, may include portions 42 and openings 44 between portions 42. Portion 42 may be formed of any desired material, such as metal, polymer, or other desired material. The opening 44 may have a curvature 46 that corresponds to or is based on the curvature of a substrate (such as the substrate 30 of fig. 7) on which the physical vapor deposition coating is applied. Since the substrate may be rotated during the deposition process (as discussed with respect to substrate 30 of fig. 7), openings 44 may ensure that a uniform coating is applied to the substrate regardless of the curvature of the substrate at a given point.

To determine the shape of the mask 34 (e.g., the opening 44), the power modulation of fig. 8, and/or other conditions of the deposition process (such as movement of the substrate), an iterative process may be used. For example, known properties of a coater (e.g., coater 31) may be used in conjunction with plasma and transport simulation to determine a desired coating deposition on a substrate having a given curvature. Different properties such as shape of mask 34, power modulation, rotational speed, pressure, etc. may be modified in an iterative manner to determine the optimal combination of conditions in which the coating will be uniform over the curved substrate. This process can be accomplished for each substrate (e.g., each bend) to be coated, if desired. However, this iterative process is merely illustrative. Generally, the coating parameters may be selected and/or calculated in any desired manner.

The opening 44 is merely illustrative. In general, the openings 44 may have any desired shape that corresponds to the curvature of the substrate (e.g., openings having a shape that facilitates uniform deposition across the curved substrate as the substrate rotates relative to the cathode during the deposition process).

As an alternative or in addition to using the mask 34, the cathode in the physical vapor deposition coater may be designed to provide a uniform coating across the curved substrate. For example, the cathode may be associated with a torsion magnet that achieves a continuous directional change in the flux (and thus the deposition direction) produced by the cathode, and/or may be a frame-shaped cathode. Fig. 10 shows an illustrative example of a cathode that achieves continuous directional change.

As shown in fig. 10, a cathode, such as cathode 32, may include a cylindrical body 52 having an axis of symmetry 54. As indicated by arrow 56, the direction of the flux generated by cathode 32 may be continuously changed in any desired direction about axis 54. For example, the flux generated by cathode 32 may be varied during the physical vapor deposition process based on the curvature of the substrate on which the physical vapor deposition coating is applied. As the substrate rotates relative to the cathode 32, the bending relative to the cathode 32 will change and thus the direction of the flux and thus the direction of sputtering may change.

To provide for the change in flux direction 56, a torsion magnet associated with cathode 32 may be used. In particular, the magnets may be wrapped around the cathode 32 in a spiral arrangement, or the magnets may partially surround the cathode 32. Regardless of the location of the magnet, the magnetic field generated by the magnet (e.g., the voltage applied to the electromagnet may be varied) may be varied to change the direction of the flux generated by the cathode 32. In this way, the direction of sputtering can be changed during the deposition process based on the bending of the substrate, thereby achieving a more uniform physical vapor deposition coating.

Fig. 11 shows an illustrative example of a frame-shaped cathode that may be used to sputter a physical vapor deposition coating onto a curved substrate. As shown in fig. 11, a cathode, such as cathode 32, may have a frame-shaped body 57. Frame body 57 may surround a central portion through which ions may be emitted toward substrate 30 along a normal axis (intermediate targets not shown in fig. 11). The use of a frame-shaped cathode may improve the uniformity of the coating sputtered onto the substrate 30 and may provide more space outside of a physical vapor deposition coater such as the physical vapor deposition coater 31 of fig. 7. In this way, the size requirements for a physical vapor deposition coater can be reduced while improving the coater's ability to sputter a uniform physical vapor deposition coating.

Although fig. 11 shows the cathode 32 as a square frame-shaped cathode, this is merely illustrative. In general, cathode 32 can have any desired shape, such as an annular cathode.

Instead of or in addition to modifying the cathode, the physical vapor deposition coater itself may be modified to achieve uniform deposition on the curved substrate. In particular, while FIG. 7 shows a cathode that sputters the coating inwardly onto the substrate, the physical vapor deposition coater may be modified to have a cathode that sputters the coating outwardly onto the substrate. Fig. 12 shows an exemplary physical vapor deposition coater for outward sputter coating.

As shown in fig. 12, the cathode 32 may be disposed about the central structure 58 and may sputter a physical vapor deposition coating outward toward the substrate 30. During deposition, the substrate 30 may rotate about the cathode 32 and the central structure 58. The use of out-sputtering may improve the uniformity of the coating on the substrate 30 by at least 3%, at least 5%, at least 10%, about 20%, at least 15%, or other values. For example, a coating deposited on the substrate 30 using an outward sputter may have a uniformity of at least ±3%, at least ±2%, at least ±1.5% or other suitable uniformity across the surface of the substrate. Furthermore, if desired, the out-sputtering of fig. 12 may be used in conjunction with the power modulation of fig. 8, the mask design of fig. 9, and/or the cathodes of fig. 10 and 11 to provide a more uniform coating on the curved substrate.

Although fig. 12 shows four cathodes coating four substrates in bulk, this is merely illustrative. Generally, for example, a physical vapor deposition coater may include any desired number of cathodes, such as five cathodes, six cathodes, fewer than five cathodes, or three cathodes. A corresponding number of substrates may be batch coated based on the number of cathodes. However, if desired, a different number of substrates (e.g., more or less than the number of cathodes) may be batch coated.

It may also be desirable to use a magnet near the target to change the direction of sputtering based on the curvature of the substrate on which the physical vapor deposition coating is applied. Fig. 13 shows an illustrative example of using magnets in this manner.

As shown in fig. 13, cathode 32 may generate fluxes 64 and 66 by emitting ions toward target 62. To account for differences in bending of the substrate 30, electromagnets 60 may be positioned on both sides of the target 62. As shown, electromagnet 60 associated with cathode 32 may have a magnetic field that affects the direction of flux. If one side of the substrate 30 is closer to the target 62 than the other side, it may be desirable to have an unbalanced flux such that the flux is greater toward the more distant portions of the substrate 30. For example, if substrate 30 is farther from cathode 32 and target 62 on the left in fig. 13, left electromagnet 60 may be adjusted (e.g., the voltage applied to left electromagnet 60 may be increased) to have a larger magnetic field than right electromagnet 60. In this way, the flux 64 toward the left portion of the substrate 30 may be greater than the flux 66 toward the right portion of the substrate 30, thereby uniformly coating the substrate 30.

The example of fig. 13 in which two cathodes 32 and two sets of electromagnets 60 are used to coat a single substrate is merely illustrative. Generally, any desired number of cathodes and any desired number of electromagnets may be used in a physical vapor deposition coater to form a desired number of fluxes and to regulate these fluxes, respectively. In one illustrative example, each of the cathodes 32 can include a plurality of electromagnets 60 extending from an end closest to the magnetron 33 to an end closest to the substrate 30. For example, each cathode 32 may include at least three, at least five, or any other desired number of electromagnets. By varying which of these multiple magnets is activated (e.g., turned on) in a single cathode, the length of the magnetic field, and thus the associated flux, can be increased.

In addition to or instead of having one or more fluxes that vary based on the substrate bending, the one or more fluxes may vary over time. In particular, the magnetic field may increase at a first time when a portion of the substrate is farther from the cathode, and the magnetic field may decrease at a second time when a different portion of the substrate is closer to the cathode. By modifying the magnetic field and thus the flux over time, the coating can be applied more uniformly (e.g., the coating can match the curvature of the substrate). Additionally or alternatively, the magnets 60 may be directed to adjust the angle of the flux and evenly distribute the coating across the substrate 30.

The magnetron 33 may also be included in a physical vapor deposition coater. The magnetron 33 may generate a magnetic field that matches the shape of the substrate 30 and directs flux (e.g., fluxes 64 and 66) toward the substrate 30. In some implementations, the magnetron 33 can have a shape that matches the shape of the substrate 30. Fig. 14 shows an illustrative example of a magnetron.

As shown in fig. 14, a magnetron such as magnetron 33 may have an outer body portion 67 and a hollow inner portion 69. The hollow inner portion 69 may be tiled with tiles 65 if desired. The outer body portion 67 and the inner portion 69 may have a shape that matches the curvature of the substrate 30. In this way, the magnetic field generated by the magnetron 33 (e.g., the magnetic field generated in response to the voltage applied to the magnetron 33) may also have a shape that matches the curvature of the substrate 30. Since the generated magnetic field moves the ion flux toward the substrate 30, the resulting coating can be applied to the substrate 30 in a uniform manner.

Various ways of improving uniformity over curved substrates, such as substrates with compound curvature and larger geometric strains, have been described. In particular, the power modulation of FIG. 8, the mask design of FIG. 9, the cathode designs of FIGS. 10 and 11, the out-sputtering of FIG. 12, the unbalanced magnetic field of FIG. 13, and the magnetron design of FIG. 14 all improve coating uniformity. Fig. 15 shows an illustrative graph showing the uniformity improvement obtained using one or more of these methods.

As shown in fig. 15, curve 68 may correspond to the uniformity of the coating on the substrate when applied using one or more of the methods of fig. 7-14, while curve 70 may correspond to the uniformity of the coating on the substrate when applied without using any of the methods. Curve 70 shows that such a coating is non-uniform, particularly at the edges of the substrate. In contrast, a coating formed using one or more of the uniformity enhancements of fig. 7-14 can have a thickness that varies by less than 5%, less than 4%, less than 2%, less than 3%, about 2.5%, 2.5% or less, less than 1.5%, less than 0.5%, or other desired amount across the substrate (e.g., the entire surface of the substrate).

The coating may also have a uniform color across the surface of the substrate due to the uniformity of the coating thickness. In particular, the coating can have a color difference ΔE (such as ΔE) in the LAB color space of less than 1.4, less than 1.0, or other desired value across the entire surface (as compared to the uncoated window) ₉₄ Or delta E ₂₀₀₀ ). ΔE refers to the total color difference in the LAB color space. An exemplary ΔE equation is given by equation 1:

wherein L (also referred to as L ^* ) Is the brightness of the light passing through the window, a (also called a ^* ) And b (also called b ^* ) Is the color coordinates of the light passing through the window. The a and b color coordinates refer to the red/gray and blue/yellow differences, respectively. L, a and b difference values compare L, a and b values for light passing through a window with a physical vapor deposition coating with L, a and b values for light passing through an uncoated window. For example, the physical vapor deposition coating may thus change the color (Δe) of light passing through the window by only 1.0 or 1.4. In this way, the physical vapor deposition layer can impart low color change to the window.

Furthermore, if desired, a thicker coating may be applied toward the edge of the substrate than in the middle of the substrate (e.g., by adjusting the rotational speed of the substrate relative to the cathode and mask and/or by adjusting the pressure of the system). For example, an optical filter coating applied over a convex lens may be applied at a greater thickness at the edges of the lens than at the center of the lens. In particular, the optical filter may have a filtering property that varies based on an incident angle of light passing through the filter. It may be desirable to prevent the spectral profile of the coating from shifting at these high angles. By making the coating thicker at the edges of the lens, the spectral curves may not shift (or may shift less), and the spectral shift may be mitigated at high angles. Although thicker deposition at the edge of the substrate is described with respect to convex lenses, this is merely illustrative. Generally, the coating can be applied at an increased thickness at the edge on any desired substrate.

By using one or more of the methods of fig. 7-14, a coating having a uniform thickness and thus less color variation can be formed on a larger substrate having a compound bend (and a larger geometric strain).

According to one embodiment, there is provided a window comprising: a window layer comprising a surface, the window layer having a geometric strain of at least 0.8%; and a physical vapor deposition coating on the surface of the window layer, the physical vapor deposition coating being an infrared reflective coating, and the physical vapor deposition coating having a thickness that varies less than 3% across the surface.

According to another embodiment, the window layer has a thickness of at least 1m ² The thickness of the physical vapor deposition coating varies by 2.5% or less across the surface of the window layer, and the physical vapor deposition coating has a delta E across the surface of the window layer of less than 1.

According to another embodiment, the thickness of the physical vapor deposition coating varies by less than 1.5% across the surface of the window layer.

According to another embodiment, the physical vapor deposition coating has a Δe of less than 1.4 across the surface of the window layer.

According to another embodiment, the Δe of the physical vapor deposition coating is less than 1 across the surface of the window layer.

According to another embodiment, the window layer includes a portion having a compound curvature, and the physical vapor deposition coating is applied to the portion of the window layer.

According to another embodiment, the window layer has a thickness of at least 1m ² Is a part of the area of the substrate.

According to another embodiment, the physical vapor deposition coating has a Δe of less than 1 in LAB color space across the entire surface of the window layer.

According to another embodiment, the thickness of the physical vapor deposition coating varies by 2.5% or less across the surface of the window layer.

According to another embodiment, the physical vapor deposition coating comprises a plurality of thin film coatings forming the infrared reflective coating, and the plurality of thin film coatings comprises at least one silver layer.

According to one embodiment, there is provided a method of applying a physical vapor deposition coating to a curved window layer, the method comprising: sputtering a physical vapor deposition coating onto the curved window layer using a cathode through a mask having an opening matching the curvature of the curved window; and modulating power applied to the cathode based on the curvature of the curved window layer while sputtering the physical vapor deposition coating.

According to another embodiment, the method comprises: the window layer is rotated while sputtering the physical vapor deposition coating.

According to another embodiment, sputtering the physical vapor deposition coating onto the curved window layer comprises: the physical vapor deposition coating is sputtered outward from the inner cathode toward the curved window layer.

According to another embodiment, the method comprises: the electromagnet is adjusted to change the magnetic field between the cathode and the curved window while sputtering the physical vapor deposition coating.

According to another embodiment, sputtering the physical vapor deposition coating comprises: the physical vapor deposition coating is deposited on the curved window layer with a thickness that varies by 2.5% or less across the curved surface of the curved window layer.

According to another embodiment, sputtering the physical vapor deposition coating comprises: the physical vapor deposition coating is sputtered onto the curved window layer in a normal direction using a frame cathode.

According to another embodiment, the method comprises: in sputtering the physical vapor deposition coating, the direction of the sputtering is continuously changed by adjusting a magnet associated with the cathode.

According to another embodiment, the method comprises: in sputtering the physical vapor deposition coating, the pressure of the gas used to sputter the physical vapor deposition coating is adjusted.

According to another embodiment, the method comprises: the flow of the gas used to sputter the physical vapor deposition coating is adjusted while sputtering the physical vapor deposition coating.

According to another embodiment, adjusting the pressure and flow of the gas includes adjusting the pressure and flow of oxygen.

According to one embodiment, there is provided a window comprising: a glass layer having a compound bend; and a physical vapor deposition coating on the compound bend of the glass layer, the physical vapor deposition coating being an infrared reflective coating, and the physical vapor deposition coating having a thickness that varies by 2.5% or less across the glass layer.

According to another embodiment, the glass layer has a geometric strain of at least 0.8%.

According to another embodiment, the physical vapor deposition coating has a ΔE of less than 1.4 in LAB color space across the entire glass layer.

The foregoing is merely exemplary and various modifications may be made to the embodiments described. The foregoing embodiments may be implemented independently or may be implemented in any combination.

Claims

1. A window, comprising:

a window layer comprising a surface, wherein the window layer has a geometric strain of at least 0.8%; and

A physical vapor deposition coating on the surface of the window layer, wherein the physical vapor deposition coating is an infrared reflective coating, and wherein the physical vapor deposition coating has a thickness that varies less than 3% across the surface.

2. The window of claim 1, wherein the window layer has at least 1m ² Area of (2)Wherein the thickness of the physical vapor deposition coating varies by 2.5% or less across the surface of the window layer, and wherein the physical vapor deposition coating has a Δe of less than 1 across the surface of the window layer.

3. The window of claim 1, wherein a thickness of the physical vapor deposition coating varies less than 1.5% across the surface of the window layer.

4. The window of claim 1, wherein the physical vapor deposition coating has a Δe of less than 1 across the surface of the window layer.

5. The window of claim 1, wherein the window layer comprises a portion having a compound curvature and the physical vapor deposition coating is applied to the portion of the window layer.

6. The window of claim 1, wherein the window layer has at least 1m ² And wherein the physical vapor deposition coating has a Δe of less than 1 in LAB color space across the entire surface of the window layer.

7. The window of claim 6, wherein a thickness of the physical vapor deposition coating varies by 2.5% or less across the surface of the window layer.

8. The window of claim 1, wherein the physical vapor deposition coating comprises a plurality of thin film coatings forming the infrared reflective coating, and wherein the plurality of thin film coatings comprises at least one silver layer.

9. A method of applying a physical vapor deposition coating to a curved window layer, comprising:

sputtering a physical vapor deposition coating onto the curved window layer using a cathode through a mask having an opening matching the curvature of the curved window; and

the power applied to the cathode is modulated based on the curvature of the curved window layer while sputtering the physical vapor deposition coating.

10. The method of claim 9, further comprising:

the window layer is rotated while sputtering the physical vapor deposition coating.

11. The method of claim 9, wherein sputtering the physical vapor deposition coating onto the curved window layer comprises: the physical vapor deposition coating is sputtered outward from the inner cathode toward the curved window layer.

12. The method of claim 9, further comprising:

when sputtering the physical vapor deposition coating, an electromagnet is adjusted to change a magnetic field between the cathode and the curved window.

13. The method of claim 9, wherein sputtering the physical vapor deposition coating comprises: depositing the physical vapor deposition coating on the curved window layer with a thickness that varies by 2.5% or less across a curved surface of the curved window layer.

14. The method of claim 9, wherein sputtering the physical vapor deposition coating comprises: the physical vapor deposition coating is sputtered onto the curved window layer in a normal direction using a frame cathode.

15. The method of claim 9, further comprising:

the direction of the sputtering is continuously changed by adjusting a magnet associated with the cathode while sputtering the physical vapor deposition coating.

16. The method of claim 9, further comprising:

and adjusting the pressure of the gas used for sputtering the physical vapor deposition coating when sputtering the physical vapor deposition coating.

17. The method of claim 16, further comprising:

and adjusting the flow rate of the gas used for sputtering the physical vapor deposition coating when sputtering the physical vapor deposition coating, wherein adjusting the pressure of the gas and the flow rate of the gas comprises adjusting the pressure and the flow rate of oxygen.

18. A window, comprising:

a glass layer having a compound curvature; and

a physical vapor deposition coating on the compound bend of the glass layer, wherein the physical vapor deposition coating is an infrared reflective coating, and wherein the physical vapor deposition coating has a thickness that varies by 2.5% or less across the glass layer.

19. The window of claim 18, wherein the glass layer has a geometric strain of at least 0.8%.

20. The window of claim 19, wherein the physical vapor deposition coating has a Δe of less than 1.4 in LAB color space across the entire glass layer.