Patent Application
20240076504
This disclosure relates generally to coatings for electronic device structures and, more particularly, to visible-light-reflecting coatings for conductive electronic device structures.
Electronic devices such as cellular telephones, computers, watches, and other devices contain conductive structures such as conductive housing structures. The conductive structures are provided with a coating that reflects particular wavelengths of light so that the conductive components exhibit a desired visible color.
It can be challenging to provide coatings such as these with a desired color brightness. In addition, if care is not taken, the coatings may exhibit unsatisfactory optical performance across different operating environments and conductive structure geometries.
An electronic device may include conductive structures such as conductive housing structures. A visible-light-reflecting coating may be formed on the conductive structures. The coating may have adhesion and transition layers, an opaque coloring layer on the adhesion and transition layers, and a multi-layer thin-film interference filter on the opaque coloring layer. The multi-layer thin-film interference filter may be a three-layer thin-film interference filter. The three-layer thin-film interference filter may have an uppermost SiC layer, a lowermost SiCrCN layer, and a CrC layer interposed between the SiC layer and the SiCrCN layer. The opaque color layer may be a CrSiCN layer. The coating may exhibit a light violet color that has a relatively uniform visual response even when the underlying conductive structures have a three-dimensional shape.
An aspect of the disclosure provides an apparatus. The apparatus can include a conductive substrate. The apparatus can include a coating on the conductive substrate and having a color. The coating can include adhesion and transition layers. The coating can include a thin-film interference filter on the adhesion and transition layers, wherein the thin-film interference filter comprises a SiC layer that forms an uppermost layer of the thin-film interference filter, a SiCrCN layer that forms a lowermost layer of the thin-film interference filter, and a CrC layer interposed between the SiCrCN layer and the SiC layer.
Another aspect of the disclosure provides an apparatus. The apparatus can include a conductive substrate. The apparatus can include a coating on the conductive substrate and having a color. The coating can include adhesion and transition layers. The coating can include an opaque layer on the adhesion and transition layers. The coating can include a three-layer thin-film interference filter on the opaque layer, the three-layer thin-film interference filter having an uppermost layer comprising SiC.
Yet another aspect of the disclosure provides an electronic device. The electronic device can include a conductive structure. The electronic device can include a coating on the conductive structure and having a color. The coating can include adhesion and transition layers. The coating can include an opaque layer on the adhesion and transition layers. The coating can include a two-layer thin-film interference filter on the opaque layer.
Electronic devices and other items may be provided with conductive structures. Coatings may be formed on the conductive structures to reflect particular wavelengths of visible light so that the conductive structures exhibit a desired color. A visible-light-reflecting coating may be deposited on a conductive substrate. The coating may include adhesion and transition layers on the substrate, an opaque coloring layer on the adhesion and transition layers, and a three-layer thin-film interference filter on the opaque coloring layer. The thin-film interference filter may have an uppermost SiC layer. The thin-film interference filter may have a lowermost SiCrCN layer. The thin-film interference filter may have a middle CrC layer. The opaque coloring layer may be a CrSiCN layer. The coating may exhibit a robust light violet color that exhibits a relatively uniform visual response when the underlying conductive structures have a three-dimensional shape.
An illustrative electronic device of the type that may be provided with conductive structures and visible-light-reflecting coatings is shown in
In the example of
Display 14 may be formed at (e.g., mounted on) the front side (face) of device 10. Housing 12 may have a rear housing wall on the rear side (face) of device 10 that opposes the front face of device 10. Conductive housing sidewalls in housing 12 may surround the periphery of device 10. The rear housing wall of housing 12 may be formed from conductive materials and/or dielectric materials.
The rear housing wall of housing 12 and/or display 14 may extend across some or all of the length (e.g., parallel to the X-axis of
Display 14 may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures.
Display 14 may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light-emitting diode (OLED) display pixels, an array of electrowetting display pixels, or display pixels based on other display technologies.
Display 14 may be protected using a display cover layer. The display cover layer may be formed from a transparent material such as glass, plastic, sapphire or other crystalline dielectric materials, ceramic, or other clear materials. The display cover layer may extend across substantially all of the length and width of device 10, for example.
Device 10 may include one or more buttons. The buttons may be formed from a conductive button member that is located within (e.g., protruding through) openings in housing 12 or openings in display 14 (as examples). Buttons may be rotary buttons, sliding buttons, buttons that are actuated by pressing on a movable button member, etc.
A cross-sectional side view of device 10 in an illustrative configuration in which display 14 has a display cover layer is shown in
Display cover layer 16 may be formed from a transparent material such as glass, plastic, ceramic, or crystalline materials such as sapphire. Illustrative configurations in which a display cover layer and other transparent members in device 10 (e.g., windows for cameras and other light-based devices that are formed in openings in housing 12) are formed from a hard transparent crystalline material such as sapphire (sometimes referred to as corundum or crystalline aluminum oxide) may sometimes be described herein as an example. Sapphire makes a satisfactory material for display cover layers and windows due to its hardness (9 Mohs). In general, however, these transparent members may be formed from any suitable material.
Display cover layer 16 for display 14 may be planar or curved and may have a rectangular outline, a circular outline, or outlines of other shapes. If desired, openings may be formed in the display cover layer. For example, an opening may be formed in the display cover layer to accommodate a button, a speaker port, or other component. Openings may be formed in housing 12 to form communications or data ports (e.g., an audio jack port, a digital data port, a port for a subscriber identity module (SIM) card, etc.), to form openings for buttons, or to form audio ports (e.g., openings for speakers and/or microphones).
Device 10 may, if desired, be coupled to a strap such as strap 28 (e.g., in scenarios where device 10 is a wristwatch device). Strap 28 may be used to hold device 10 against a user's wrist (as an example). Strap 28 may sometimes be referred to herein as wrist strap 28. In the example of
If desired, light-based components such as light-based components 24 may be mounted in alignment with an opening 20 in housing 12. Opening 20 may be circular, may be rectangular, may have an oval shape, may have a triangular shape, may have other shapes with straight and/or curved edges, or may have other suitable shapes (outlines when viewed from above). Window member 26 may be mounted in window opening 20 of housing 12 so that window member 26 overlaps component 18. A gasket, bezel, adhesive, screws, or other fastening mechanisms may be used in attaching window member 26 to housing 12. Surface 22 of window member 26 may lie flush with exterior surface 23 of housing 12, may be recessed below exterior surface 23, or may, as shown in
Conductive structures in device 10 may be provided with a visible-light-reflecting coating that reflects certain wavelengths of light so that the conductive structures exhibit a desired aesthetic appearance (e.g., a desired color, reflectivity, etc.). The conductive structures in device 10 may include, for example, conductive portions of housing 12 (e.g., conductive sidewalls for device 10, a conductive rear wall for device 10, a protruding portion of housing 12 used to mount window member 26, etc.), attachment structures 30, conductive portions of wrist strap 28, a conductive mesh, conductive components 32, and/or any other desired conductive structures on device 10. Conductive components 32 may include internal components (e.g., internal housing members, a conductive frame, a conductive chassis, a conductive support plate, conductive brackets, conductive clips, conductive springs, input-output components or devices, etc.), components that lie both at the interior and exterior of device 10 (e.g., a conductive SIM card tray or SIM card port, a data port, a microphone port, a speaker port, a conductive button member for a ringer button, power button, volume button, or other buttons, etc.), components that are mounted at the exterior of device 10 (e.g., conductive portions of strap 28 such as a clasp for strap 28), and/or any other desired conductive structures on device 10.
Conductive sidewall 12W may include one or more ledges 34. Ledges 34 may be used to support a conductive and/or dielectric rear wall for device 10 (e.g., at the rear face of device 10) and/or to support display cover layer 16 of
In practice, the coating may have different thicknesses across its surface area due to changes in the underlying geometry of the conductive structure (e.g., because of coating deposition equipment limitations in depositing uniform coatings across the underlying geometry). For example, coating 36 of
Coating 36 may include adhesion and transition layers 40 on substrate 35. Coating 36 may include an opaque color layer such as opaque coloring layer 42 on adhesion and transition layers 40. Coating 36 may include a multi-layer thin-film interference filter such as thin-film interference filter (TFIF) 38 on opaque coloring layer 42. An optional oleophobic coating or other films, coatings, or layers (e.g., layers that do not substantially contribute to the color response of the coating) may be layered over thin-film interference filter 38 if desired. Opaque coloring layer 42 may, for example, have a first lateral surface that directly contacts adhesion and transition layers 40 and may have a second lateral surface opposite the first lateral surface. Thin-film interference filter 38 may, for example, have a third lateral surface that directly contacts the second lateral surface and may have a fourth lateral surface opposite the third lateral surface (e.g., the fourth lateral surface may form an uppermost or outermost layer of coating 36). Thin-film interference filter 38 may include multiple layers (films) stacked on opaque coloring layer 42. In some implementations, thin-film interference filter 38 may include three stacked layers (films). In other implementations, thin-film interference filter 38 may include two stacked layers (films). This is merely illustrative and, if desired, thin-film interference filter 38 may include other numbers of layers (e.g., four layers, five layers, more than five layers, etc.).
The layers of coating 36 may be deposited on substrate 35 using any suitable deposition techniques. Examples of techniques that may be used for depositing the layers in coating 36 include physical vapor deposition (e.g., evaporation and/or sputtering), cathodic arc deposition, chemical vapor deposition, ion plating, laser ablation, etc. For example, coating 36 may be deposited on substrate 35 in a deposition system having deposition equipment (e.g., a cathode). Substrate 35 may be moved (e.g., rotated) within the deposition system while the deposition equipment (e.g., the cathode) deposits the layers of coating 36. If desired, substrate 35 may be moved/rotated dynamically with respect to speed and/or orientation relative to the deposition equipment (e.g., the cathode) during deposition. This may help provide coating 36 with as uniform a thickness as possible across its area, even in scenarios where substrate 35 has a three-dimensional shape (e.g., minimizing the difference between thicknesses T1 and T2 of
Thin-film interference filter 38 may be formed from a stack of layers of material such as inorganic dielectric layers with different index of refraction values. The thin-film interference filter layers may have higher index of refraction values (sometimes referred to as “high” index values) and lower index of refraction values (sometimes referred to as “low” index values). The high index layers may be interleaved with the low index layers if desired. Incident light may be transmitted through each of the layers in thin-film interference filter 38 while also reflecting off the interfaces between each of the layers, as well as at the interface between the thin-film interference filter and opaque coloring layer 42 and at the interface between the thin-film interference filter and air. By controlling the thickness and index of refraction (e.g., composition) of each layer in thin-film interference filter 38, the light reflected at each interface may destructively and/or constructively interfere at a selected set of wavelengths such that reflected light that passes out of the thin-film interference filter 38 is perceived by an observer with a desired color and brightness across a corresponding range of viewing angles (angles of incidence, e.g., from 0 to 60 degrees relative to a normal axis of the conductive structure), while also exhibiting a response that is relatively invariant across the lateral area of the coating even when deposited onto an underlying substrate 35 having a three-dimensional (e.g., curved) shape.
Unlike the layers of thin-film interference filter 38, opaque color layer 42 is substantially opaque and does not transmit light incident upon coating 36. On the other hand, opaque color layer 42 may reflect incident light received through thin-film interference filter 38 back towards and through thin-film interference filter 38. The thickness and/or composition of opaque coloring layer 42 may contribute to the color response of the light upon exiting coating 36 as viewed by a user (e.g., in combination with the interference effects imparted to the transmitted and reflected light by thin-film interference filter 38). Opaque color layer 42 may sometimes also be referred to herein as a non-interference filter layer or an intrinsic color layer.
In the example of
Layer 44 may include silicon carbide (SiC) and may therefore sometimes be referred to herein as SiC layer 44. Layer 46 may include chromium carbide (CrC) and may therefore sometimes be referred to herein as CrC layer 46. Layer 48 may include silicon chromium carbo-nitride (SiCrCN) and may therefore sometimes be referred to herein as SiCrCN layer 48. Layer 76 may include SiH and may therefore sometimes be referred to herein as SiH layer 76. Put differently, thin-film interference filter 38 may include an uppermost SiC layer 44, a lowermost SiCrCN layer 48, and a middle CrC layer 46 interposed between layers 44 and 48. The example of
The composition and thicknesses of the layers of thin-film interference filter 38 may be selected so that coating 36 exhibits a violet color across a predetermined range of angles of incidence. The thickness 54 of SiCrCN layer 48 may, for example, be selected to be 50-100 nm, 40-120 nm, 80-100 nm, 75-95 nm, 30-150 nm, 80-90 nm, 70-95 nm, 60-70 nm, 50-80 nm, 45-85 nm, greater than 30 nm, greater than 50 nm, greater than 80 nm, greater than 60 nm, less than 70 nm, less than 100 nm, less than 150 nm, or other thicknesses. The thickness 52 of CrC layer 46 may be selected to be 20-30 nm, 15-25 nm, 15-30 nm, 10-30 nm, 10-40 nm, 20-24 nm, 18-26 nm, 5-35 nm, 8-28 nm, greater than 10 nm, greater than 15 nm, greater than 20 nm, less than 25 nm, less than 30 nm, less than 35 nm, less than 40 nm, or other thicknesses. The thickness 50 of SiC layer 44 may be selected to be 20-30 nm, 20-35 nm, 15-35 nm, 25-31 nm, 18-33 nm, 10-40 nm, 5-50 nm, greater than 10 nm, greater than 15 nm, greater than 20 nm, greater than 25 nm, less than 25 nm, less than 30 nm, less than 35 nm, less than 40 nm, or other thicknesses. The thickness of opaque coloring layer 42 may be greater than thickness 54 and/or greater than the thickness of the entire thin-film interference filter 38 (e.g., 400-600 nm, 500 nm, 300-700 nm, 200-800 nm, or other thicknesses).
In a first implementation that is described herein as an example, thickness 50 is greater than thickness 52 (e.g., 1-10 nm greater, 5-15 nm greater, more than 5 nm greater, less than 10 nm greater, less than 20 nm greater, etc.) and less than half of thickness 54. In a second implementation that is described herein as an example, thickness 52 is greater than thickness 50 (e.g., 1-10 nm greater, 2-6 nm greater, 5 nm greater, less than 10 nm greater, less than 15 nm greater, more than 1 nm greater, etc.) and thickness 52 is less than the thickness 54 in the first implementation (e.g., 20 nm less, 10-30 nm less, 30 nm less, etc.).
As shown in
As shown by curve 56, coating 36 exhibits a relatively high percentage (e.g., a peak) of Cr atoms within CrC layer 46 of
As shown by curve 58, coating 36 exhibits a relatively high percentage (e.g., a peak) of Si atoms within SiC layer 44 of
As shown by curve 60, coating 36 exhibits a relatively high percentage (e.g., a peak) of N atoms within SiCrCN layer 48 of
Coating 36 may exhibit different amounts of Cr, Si, N, and C atoms in each of the layers. For example, the composition of SiC layer 44 of
The composition of SiCrCN layer 48 may be selected such that the atomic percentage of Si atoms in SiCrCN layer 48 is 10-20%, 5-25%, 12-27%, 5-30%, greater than 5%, greater than 10%, greater than 15%, less than 20%, less than 25%, less than 30%, or other values. The composition of SiCrCN layer 48 may be selected such that the atomic percentage of C atoms in SiCrCN layer 48 is greater than the atomic percentage of Si atoms (e.g., 20-40%, 10-50%, greater than 10%, greater than 20%, greater than 30%, less than 40%, less than 50%, or other values). The composition of SiCrCN layer 48 may be selected such that the atomic percentage of N atoms in SiCrCN layer 48 is greater than the atomic percentages of C atoms, Si atoms, and Cr atoms in SiCrCN layer 48 (e.g., 40-50%, 30-60%, 35-65%, greater than 30%, greater than 40%, greater than 45%, less than 50%, less than 60%, or other values).
The composition of opaque coloring layer 42 may be selected such that the atomic percentage of Cr atoms in opaque coloring layer 42 is greater than the atomic percentages of Si, C, and N atoms in opaque coloring layer 42 (e.g., 50-60%, 40-70%, 35-65%, greater than 30%, greater than 40%, greater than 50%, less than 60%, less than 70%, or other values). The composition of opaque coloring layer 42 may be selected such that the atomic percentage of Si atoms in opaque coloring layer 42 is greater than the atomic percentages of C and N atoms in opaque coloring layer 42 (e.g., 10-20%, 5-25%, 12-27%, 5-30%, greater than 5%, greater than 10%, greater than 15%, less than 20%, less than 25%, less than 30%, or other values). The composition of opaque coloring layer 42 may be selected such that the atomic percentage of N atoms in opaque coloring layer 42 is greater than the atomic percentage of C atoms in opaque coloring layer 42. These examples are merely illustrative and, in general, the layers of coating 36 may have other compositions.
In practice, it can be difficult to provide coating 36 with a uniform thickness across its surface (lateral) area, particularly when depositing on substrates 35 having non-planar three-dimensional shapes. The three-layer thin-film interference filter with underlying opaque coloring layer of
As shown in
The layer thicknesses and compositions of the layers of coating 36 of
The example of
The examples of
As shown in
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As shown in
The examples of
The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.
This application claims the benefit of U.S. Provisional Patent Application No. 63/403,499, filed Sep. 2, 2022, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63403499 | Sep 2022 | US |
