PATENT DOCUMENT

Publication Number: US-12050436-B2
Application Number: US-202117406826-A
Country: US
Kind Code: B2

Title: Bright color coatings for electronic devices

Abstract:
An electronic device may include conductive structures such as conductive housing structures. A high-brightness, visible-light-reflecting coating may be formed on the conductive structures. The coating may have adhesion and transition layers and an uppermost coloring layer on the adhesion and transition layers. At least the uppermost coloring layer may be deposited using a high impulse magnetron sputtering (HiPIMS) process. The uppermost coloring layer may include a TiCrN film, a TiCrCN film, a TiCN film, or a metal nitride film that contains Ti, Zr, Hf, or Cr. The coating may exhibit a high-brightness gold color.

Claims:
What is claimed is: 
     
       1. Apparatus comprising:
 a conductive substrate; and 
 a coating on the conductive substrate and having a color, the coating comprising:
 adhesion and transition layers, and 
 an uppermost layer on the adhesion and transition layers, the uppermost layer comprising a TiCrN film, wherein the coating has an L* value greater than 75 in a CIELAB color space, an a* value between 0 and 5 in the CIELAB color space, and a b* value between 10 and 15 in the CIELAB color space. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the TiCrN film is opaque. 
     
     
       3. The apparatus of  claim 1 , wherein the TiCrN film has a thickness between 0.1 and 1.0 microns. 
     
     
       4. The apparatus of  claim 1 , wherein an atomic percentage of Ti atoms in the TiCrN film is greater than 40% and less than 60%. 
     
     
       5. The apparatus of  claim 4 , wherein an atomic percentage of Cr atoms in the TiCrN film is greater than 5% and less than 20%. 
     
     
       6. The apparatus of  claim 4 , wherein an atomic percentage of N atoms in the TiCrN film is greater than 25% and less than 40%. 
     
     
       7. The apparatus of  claim 1 , wherein an atomic percentage of Cr atoms in the TiCrN film is greater than 5% and less than 20%. 
     
     
       8. The apparatus of  claim 7 , wherein an atomic percentage of N atoms in the TiCrN film is greater than 25% and less than 40%. 
     
     
       9. The apparatus of  claim 1 , wherein the adhesion and transition layers comprise a Cr seed layer on the conductive substrate and a CrN transition layer on the Cr seed layer, the TiCrN film being layered on the CrN transition layer. 
     
     
       10. The apparatus of  claim 1 , wherein the apparatus comprises a wristwatch and the conductive substrate comprises a conductive housing wall of the wristwatch. 
     
     
       11. The apparatus of  claim 1 , wherein the TiCrN film is deposited on the adhesion and transition layers using a high impulse magnetron sputtering (HiPIMS) process. 
     
     
       12. The apparatus of  claim 11 , wherein the adhesion and transition layers are deposited on the conductive substrate using a non-HiPIMS magnetron sputtering process. 
     
     
       13. An electronic device comprising:
 a conductive structure; and 
 a coating on the conductive structure and having a color, the coating comprising:
 adhesion and transition layers, wherein the adhesion and transition layers comprise a chromium (Cr) layer on the conductive structure and a chromium nitride (CrN) layer on the Cr layer, and 
 a titanium chromium nitride (TiCrN) layer on the adhesion and transition layers, wherein the TiCrN layer is an outermost layer of the coating. 
 
 
     
     
       14. The electronic device of  claim 13 , wherein the coating has an L* value greater than 75 in a CIELAB color space, an a* value between 0 and 5 in the CIELAB color space, and a b* value between 10 and 15 in the CIELAB color space. 
     
     
       15. The electronic device of  claim 13 , wherein the conductive structure comprises a conductive housing wall. 
     
     
       16. The electronic device of  claim 13 , wherein the conductive structure comprises a button. 
     
     
       17. A wearable electronic device comprising:
 a conductive housing wall; and 
 a coating on the conductive housing wall and having a color, the coating comprising:
 a chromium (Cr) layer on the conductive housing wall, 
 a chromium nitride (CrN) layer on the Cr layer, and 
 a titanium chromium nitride (TiCrN) layer on the CrN layer, wherein the TiCrN layer is an outermost layer of the coating. 
 
 
     
     
       18. The wearable electronic device of  claim 17 , wherein the wearable electronic device comprises a wristwatch.

Description:
This application claims the benefit of U.S. Provisional Patent Application No. 63/073,352, filed Sep. 1, 2020, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to coatings for electronic device structures and, more particularly, to visible-light-reflecting coatings for conductive electronic device structures. 
     BACKGROUND 
     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. 
     SUMMARY 
     An electronic device may include conductive structures such as conductive housing structures. A high-brightness, visible-light-reflecting coating may be formed on the conductive structures. The coating may have adhesion and transition layers and an uppermost coloring layer on the adhesion and transition layers. At least the uppermost coloring layer may be deposited using a high impulse magnetron sputtering (HiPIMS) process. The uppermost coloring layer may include a TiCrN film, a TiCrCN film, a TiCN film, or a metal nitride film that contains Ti, Zr, Hf, or Cr. The coating may exhibit a high-brightness gold color. 
     An aspect of the disclosure provides an apparatus. The apparatus can have a conductive substrate. The apparatus can have a coating on the substrate. The coating can have a color. The coating can have adhesion and transition layers. The coating can have an uppermost layer on the adhesion and transition layers. The uppermost layer can include a TiCrN film. 
     Another aspect of the disclosure provides an apparatus. The apparatus can have a conductive substrate. The apparatus can have a coating on the conductive substrate. The coating can have a color. The coating can have adhesion and transition layers. The coating can have an uppermost layer on the adhesion and transition layers. The uppermost layer can include a TiCrCN film. An atomic percentage of Cr atoms in the TiCrCN film may be greater than 12%. 
     Yet another aspect of the disclosure provides an apparatus. The apparatus can have a conductive substrate. The apparatus can have a coating on the conductive substrate. The coating can have a color. The coating can have adhesion and transition layers. The coating can have an uppermost layer on the adhesion and transition layers. The uppermost layer can include a TiN film, a TiNSiC film, a ZrN film, a ZrNC film, a ZrNSi film, a ZrNSiC film, a HfN film, a HfNC film, a HfNSi film, a HfNSiC film, a CrN film, or a CrNSi film. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an illustrative electronic device of the type that may be provided with conductive structures and high-brightness coatings in accordance with some embodiments. 
         FIG.  2    is cross-sectional side view of an illustrative electronic device having conductive structures that may be provided with high-brightness coatings in accordance with some embodiments. 
         FIG.  3    is a cross-sectional side view of an illustrative high-brightness coating in accordance with some embodiments. 
         FIG.  4    is a cross-sectional side view of an illustrative high-brightness coating having a TiCrN top coloring layer in accordance with some embodiments. 
         FIG.  5    is a plot of the atomic percentage of different elements in an illustrative TiCrN top coloring layer for a high-brightness coating of the type shown in  FIG.  4    in accordance with some embodiments. 
         FIG.  6    is a cross-sectional side view of an illustrative high-brightness coating having a TiCrCN top coloring layer in accordance with some embodiments. 
         FIG.  7    is a plot of the atomic percentage of different elements in an illustrative TiCrCN top coloring layer for a high-brightness coating of the type shown in  FIG.  6    in accordance with some embodiments. 
         FIG.  8    is a plot of a*b* color space for illustrative high-brightness coatings of the types shown in  FIGS.  4 - 7    in accordance with some embodiments. 
         FIG.  9    is a cross-sectional side view of an illustrative high-brightness coating having a TiCN top coloring layer in accordance with some embodiments. 
         FIG.  10    is a plot of the atomic percentage of different elements in an illustrative TiCN top coloring layer for a high-brightness coating of the type shown in  FIG.  9    in accordance with some embodiments. 
         FIG.  11    is a cross-sectional side view of an illustrative high-brightness coating having a metal nitride top coloring layer that contains Ti, Zr, Hf, or Cr in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     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 high-brightness, visible-light-reflecting coating may be deposited on a conductive substrate. The coating may include transition and adhesion layers on the substrate and an uppermost coloring layer on the transition and adhesion layers. The uppermost coloring layer may include a TiCrN film, a TiCrCN film, a TiCN film, or a metal nitride film that contains Ti, Zr, Hf, or Cr. The coating may be deposited using a high impulse magnetron sputtering (HiPIMS) process. The coating may exhibit a bright gold color without using real gold in the uppermost coloring layer. 
     An illustrative electronic device of the type that may be provided with conductive structures and high-brightness, visible-light-reflecting coatings is shown in  FIG.  1   . Electronic device  10  of  FIG.  1    may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch device (e.g., a watch with a wrist strap), a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user&#39;s head (e.g., a head mounted device), or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, a wireless base station, a home entertainment system, a wireless speaker device, a wireless access point, equipment that implements the functionality of two or more of these devices, or other electronic equipment. In the illustrative configuration of  FIG.  1   , device  10  is a portable device having a substantially rectangular lateral outline such as a cellular telephone or tablet computer. Other configurations may be used for device  10  if desired. The example of  FIG.  1    is merely illustrative. 
     In the example of  FIG.  1   , device  10  includes a display such as display  14 . Display  14  may be mounted in a housing such as housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). Housing  12  may have metal sidewalls or sidewalls formed from other materials. Examples of metal materials that may be used for forming housing  12  include stainless steel, aluminum, silver, gold, titanium, metal alloys, or any other desired conductive material. 
     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  FIG.  1   ) and width (e.g., parallel to the Y-axis) of device  10 . Conductive sidewalls of housing  12  may extend across some or all of the height of device  10  (e.g., parallel to Z-axis). 
     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  FIG.  2   . As shown in  FIG.  2   , display  14  may have one or more display layers that form pixel array  18 . During operation, pixel array  18  forms images for a user in an active area of display  14 . Display  14  may also have inactive areas (e.g., areas along the border of pixel array  18 ) that are free of pixels and that do not produce images. Display cover layer  16  of  FIG.  2    overlaps pixel array  18  in the active area and overlaps electrical components in device  10 . 
     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&#39;s wrist (as an example). Strap  28  may sometimes be referred to herein as wrist strap  28 . In the example of  FIG.  2   , wrist strap  28  is connected to attachment structures  30  in housing  12  at opposing sides of device  10 . Attachment structures  30  may include lugs, pins, springs, clips, brackets, and/or other attachment mechanisms that configure housing  12  to receive wrist strap  28 . Configurations that do not include straps may also be used for device  10 . 
     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  FIG.  3   , be proud of exterior surface  23  (e.g., surface  22  may lie in a plane that protrudes away from surface  23  in the −Z direction). In other words, window member  26  may be mounted to a protruding portion of housing  12 . Surface  23  may, for example, form the rear face of housing  12 . 
     Conductive structures in device  10  may be provided with a high-brightness, 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, etc.), or 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 . 
       FIG.  3    is a cross-sectional diagram of a high-brightness, visible-light-reflecting coating that may be provided on conductive structures in device  10  (e.g., portions of housing  12  of  FIGS.  1  and  2   , conductive components  32  of  FIG.  2   , etc.). As shown in  FIG.  3   , high-brightness, visible-light-reflecting coating  36  may be formed on substrate  34 . High-brightness, visible-light-reflecting coating  36  may sometimes be referred to herein as high-brightness coating  36  or simply as coating  36 . Substrate  34  may be a conductive structure in device  10  such as a conductive portion of housing  12  ( FIGS.  1  and  2   ) or a conductive component  32  ( FIG.  2   ). Substrate  34  may be thicker than coating  36 . The thickness of substrate  34  may be 0.1 mm to 5 mm, more than 0.3 mm, more than 0.5 mm, between 5 mm and 20 mm, less than 5 mm, less than 2 mm, less than 1.5 mm, or less than 1 mm (as examples). Substrate  34  may include stainless steel, aluminum, titanium, or other metals or alloys. In other suitable arrangements, substrate  34  may be an insulating substrate such as a ceramic substrate, a glass substrate, or substrates formed from other materials. 
     Coating  36  may include adhesion and transition layers  40  on substrate  34  and a top (uppermost) coloring layer (film)  38  on adhesion and transition layers  40 . Top coloring layer  38  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. Adhesion and transition layers  40  may have thickness  44  (e.g., between 0.1 and 3 microns). 
     Top coloring layer  38  may, for example, be an intrinsically-colored layer (e.g., a layer that is opaque to visible light) that preferentially absorbs incident light at particular wavelengths to reveal the color of the reflected wavelengths to an observer. The composition of top coloring layer  38  may provide coating  36  with an intrinsic color (e.g., top coloring layer  38  may configure coating  36  to absorb and reflect light at selected wavelengths to impart coating  36  and thus substrate  34  with a desired high-brightness color and reflectivity). In another suitable arrangement, top coloring layer  38  may be a thin film interference filter. 
     In one suitable arrangement that is sometimes described herein as an example, top coloring layer  38  and coating  36  may have a gold color (e.g., coating  36  may impart a golden color to substrate  34 ). In some arrangements, coating  36  is deposited on substrate  34  using a magnetron sputtering process. However, in practice, use of a magnetron sputtering process in depositing coating  36  may impose an upper limit on the brightness of the color of the coating (e.g., an L* value in a CIE L*a*b* (CIELAB or Lab) color space). This may cause the coating to have an undesirably dark color. 
     In some arrangements, the color may be brightened by including the element gold (Au) in the coating or by forming substrate  34  itself from gold metal. However, use of real gold may undesirably increase the cost and weight of device  10  and may cause the substrate to exhibit unreliable variations in structure and optical performance across devices. In order to provide coating  36  with a gold color having maximal brightness without using real gold, at least some of coating  68  may be deposited using a high impulse magnetron sputtering (HiPIMS) process. 
     The HiPIMS process involves the use of deposition equipment that applies high impulses of energy to sputter material onto substrate  34  (e.g., using a higher energy plasma than other magnetron sputtering processes). The other magnetron sputtering processes (sometimes referred to herein as non-HiPIMS magnetron sputtering processes) may, for example, involve using the deposition equipment to apply a regular series of pulses at a first power level. On the other hand, the HiPIMS process involves using the deposition equipment to apply a series of less-frequent pulses at a second power level that is greater than the first power level (e.g., greater by as much as three orders of magnitude). The HiPIMS process may produce higher ionization, denser microstructure, and finer material grains and thus a smoother surface on coating  36  than the non-HiPIMS magnetron sputtering processes (e.g., the non-HiPIMS magnetron sputtering processes may produce coarser material grains and thus a rougher surface on coating  36  than the HiPIMS process). At the same time, the HiPIMS process may allow coating  36  to exhibit a gold color with greater brightness (e.g., a greater L* value) than the non-HiPIMS magnetron sputtering processes. For example, the HiPIMS process may configure the coating to exhibit an L* value that is as much as 1.0-15.0 greater than the L* value that would be produced by the non-HiPIMS magnetron sputtering processes. 
     In one suitable arrangement that is described herein as an example, the entirety of coating  36  (e.g., adhesion and transition layers  40  and top coloring layer  38 ) may be deposited on substrate  34  using the HiPIMS process. In some cases, because the HiPIMS process involves very high power, using the HiPIMS process to deposit all of coating  36  may produce undesirable artifacts in the coating due to electric arcing during deposition. In another suitable arrangement, in order to mitigate the risks of arcing, the HiPIMS process may be used to deposit top coloring layer  38  onto adhesion and transition layers  40  after adhesion and transition layers  40  have already been deposited onto substrate  34  using a non-HiPIMS magnetron sputtering process. This may serve to minimize the production of visible artifacts produced by arcing during the deposition of coating  36  and may, for example, reduce cycle time for the deposition. This example is merely illustrative and, if desired, the layers of coating  36  may be deposited using any desired combination of deposition techniques (e.g., physical vapor deposition such as evaporation and/or sputtering, cathodic arc deposition, chemical vapor deposition, ion plating, laser ablation, etc.). 
       FIG.  4    is a cross-sectional side view showing one illustrative composition for coating  36  (e.g., to provide coating  36  with a gold color with sufficient brightness without using real gold). As shown in  FIG.  4   , coating  36  may be layered on substrate  34 . Adhesion and transition layers  40  may be deposited on substrate  34  using a non-HiPIMS magnetron sputtering process or, optionally, using the HiPIMS process. Top coloring layer (film)  38  may be deposited on adhesion and transition layers  40  using the HiPIMS process. 
     As shown in  FIG.  4   , adhesion and transition layers  40  may include a seed (adhesion) layer such as seed layer  46  on substrate  34  and one or more transition layers such as transition layer  48  on seed layer  46 . Seed layer  46  may couple substrate  34  to transition layer  48 . In the example of  FIG.  4   , seed layer  46  is formed from chromium (Cr) and transition layer  48  is formed from chromium nitride (CrN). This is merely illustrative. If desired, seed layer  46  may include chromium silicon (CrSi), titanium (Ti), other metals, metal alloys, and/or other materials. If desired, transition layer  48  may include CrN, chromium silicon nitride (CrSiN), chromium silicon carbonitride (CrSiCN), chromium silicon carbide (CrSiC), chromium carbonitride (CrCN), and/or other materials. Coating  36  may include multiple stacked transition layers  48  if desired. 
     Transition layer  48  may have thickness  50 . Thickness  50  may be, for example, 1.0 micron, 1.1 microns, 1.2 microns, 0.7 microns, 0.6 microns, between 0.7 and 1.1 microns, or any other desired thickness. Seed layer  46  may have thickness  52 . Thickness  52  may be, for example, 0.1 microns, 0.2 microns, 0.3 microns, between 0.1 and 0.3 microns, or any other desired thickness. 
     Coating  36  may include top coloring layer  38  layered on transition layer  48 . In the example of  FIG.  4   , top coloring layer  38  includes titanium chromium nitride (TiCrN) (e.g., top coloring layer  38  may be a TiCrN film on transition layer  48 ). Top coloring layer  38  may have thickness  42 . Thickness  42  may be 0.3 microns, 0.4 microns, 0.5 microns, 0.2 microns, between 0.3 and 0.5 microns, greater than 0.3 microns, less than 0.6 microns, between 0.1 and 1.0 microns, or any other desired thickness. 
     When configured in this way, top coloring layer  38  may configure coating  36  to exhibit an a* value between 0 and 1, between 0 and 3, between 0 and 5, between 0.5 and 1.5, between 0.5 and 1, or another a* value in the CIELAB color space. Top coloring layer  38  may also configure coating  36  to exhibit a b* value between 10 and 15, between 14 and 15, between 13 and 16, greater than 10, greater than 12, less than 16, between 13 and 15.5, between 14.5 and 15, or another b* value in the CIELAB color space. Top coloring layer  38  may configure coating  36  to exhibit an L* value that is greater than would be obtained by a non-HiPIMS process. For example, top coloring layer  38  may configure coating  36  to exhibit an L* value that is greater than 70, greater than 72, greater than 75, greater than 76, between 70 and 80, between 72 and 80, between 72 and 78, between 75 and 78, between 76 and 80, or another L* value in the CIELAB color space. In other words, top coloring layer  38  may configure coating  68  to exhibit a high-brightness gold color without the use of real gold. 
       FIG.  5    is a plot of illustrative atomic percentages for the different elements in top coloring layer  38  in examples where top coloring layer  38  is a TiCrN layer (e.g., in the configuration of coating  36  as shown in  FIG.  4   , such as a configuration in which coating  36  is configured to exhibit a high-brightness gold color). 
     As shown in  FIG.  5   , the composition of top coloring layer  38  may be selected such that the atomic percentage of titanium (Ti) atoms in top coloring layer  38  lies within region  54  (e.g., a region extending between upper limit A 1  and lower limit A 2 ). The atomic percentage of chromium (Cr) atoms in top coloring layer  38  lies within region  56  (e.g., a region extending between upper limit A 3  and lower limit A 4 ). The atomic percentage of nitrogen (N) atoms in top coloring layer  38  lies within region  58  (e.g., a region extending between upper limit A 5  and lower limit A 6 ). 
     In the example of  FIG.  5   , atomic percentage A 2  is greater than atomic percentage A 5  and atomic percentage A 6  is greater than atomic percentage A 3 . This is merely illustrative and, in general, these percentages may have other relative magnitudes. Regions  54 ,  56 , and  58  may have other relative positions along the vertical axis of  FIG.  5    and may have other relative sizes (e.g., where the size of each region is determined by the difference between its corresponding upper and lower limits). 
     In one suitable arrangement that is sometimes described herein as an example, the upper limit A 1  of region  54  (e.g., the upper limit on the atomic percentage of Ti atoms in top coloring layer  38 ) may be between 50% and 60%, between 54% and 56%, between 51% and 57%, between 45% and 51%, greater than 50%, greater than 55%, less than 60%, 60%, or other values. The lower limit A 2  of region  54  (e.g., the lower limit on the atomic percentage of Ti atoms in top coloring layer  48 ) may be between 50% and 55%, between 50% and 52%, between 48% and 52%, between 45% and 55%, less than 55%, less than 52%, greater than 45%, 45%, greater than 50%, or other values less than upper limit A 1 . 
     The upper limit A 3  of region  56  (e.g., the upper limit on the atomic percentage of Cr atoms in layer  38 ) may be between 10% and 20%, between 11% and 15%, between 13% and 15%, between 12% and 22%, greater than 13%, greater than 12%, greater than 10%, 20%, less than 20%, less than 15%, or other values that are less than lower limit A 2  of region  54 . The lower limit A 4  of region  56  (e.g., the lower limit on the atomic percentage of Cr atoms in layer  38 ) may be between 5% and 14%, between 8% and 12%, between 9% and 11%, between 5% and 11%, less than 15%, less than 12%, less than 11%, greater than 5%, greater than 8%, 12% (e.g., layer  38  may have an atomic percentage of Cr that is greater than or equal to 12%), or other values less than upper limit A 3 . 
     The limits of region  58  may be defined by the balance of atomic percentage remaining in layer  38 . For example, the upper limit A 5  of region  58  (e.g., the upper limit on the atomic percentage of N atoms in layer  38 ) may be between 30% and 40%, between 35% and 45%, between 36% and 41%, between 35% and 39%, greater than 30%, greater than 35%, less than 40%, less than 42%, less than 45%, or other values less than lower limit A 2  of region  54 . The lower limit A 6  of region  58  (e.g., the lower limit on the atomic percentage of N atoms in layer  38 ) may be between 30% and 40%, between 30% and 35%, between 25% and 34%, greater than 30%, greater than 25%, less than 35%, less than 33%, or other values less than upper limit A 5 . The atomic percentage of Cr atoms in transition layer  48  of  FIG.  4    may, for example, be between 90% and 95%, between 85% and 95%, less than 96%, greater than 90%, greater than 85%, or other values. The balance of the atomic percentage of transition layer  48  may be filled by the N atoms in transition layer  48 . These examples are merely illustrative and, in general, other atomic percentages of these elements may be used (e.g., regions  54 ,  56 , and  58  may have other heights, relative positions, and/or relative sizes). 
     The example of  FIGS.  4  and  5    in which top coloring layer  38  is a TiCrN layer is merely illustrative. In another suitable arrangement, top coloring layer  38  may be a titanium chromium carbonitride (TiCrCN) layer (e.g., a TiCrCN film deposited using the HiPIMS process), as shown in the cross-sectional side view of  FIG.  6   . The example of  FIG.  6    in which transition layer  48  is a CrN layer and seed layer  46  is a Cr layer is merely illustrative. If desired, seed layer  46  may include CrSi, Ti, other metals, metal alloys, and/or other materials. If desired, transition layer  48  may include CrSiN, CrSiCN, CrSiC, CrCN, and/or other materials. Coating  36  of  FIG.  6    may include multiple stacked transition layers  48  if desired. 
     When configured in this way, top coloring layer  38  may configure coating  36  to exhibit an a* value between 1 and 2, between 0 and 3, between 0 and 5, between 1.5 and 2, between 1 and 3, or another a* value in the CIELAB color space. Top coloring layer  38  may also configure coating  36  to exhibit a b* value between 11 and 16, between 14 and 17, between 13 and 18, greater than 15, between 10 and 20, greater than 14, less than 16, between 13 and 15.8, between 14.5 and 15.9, or another b* value in the CIELAB color space. Top coloring layer  38  may configure coating  36  to exhibit an L* value that is greater than would be obtained by a non-HiPIMS process. For example, top coloring layer  38  may configure coating  36  to exhibit an L* value that is greater than 70, greater than 72, greater than 75, between 70 and 80, between 72 and 80, between 72 and 76, between 74 and 77, between 73 and 80, or another L* value in the CIELAB color space. The L* value of coating  36  of  FIG.  6    may be less than the L* value of coating  36  of  FIG.  4   , the a* value of coating  36  of  FIG.  6    may be greater than the a* value of coating  36  of  FIG.  4   , and the b* value of coating  36  of  FIG.  6    may be greater than the b* value of coating  36  of  FIG.  4   , as an example. In other words, top coloring layer  38  may configure coating  68  to exhibit a high-brightness gold color (e.g., with a slightly different hue than is produced by coating  36  of  FIG.  4   ). 
       FIG.  7    is a plot of illustrative atomic percentages for the different elements in top coloring layer  38  in examples where top coloring layer  38  is a TiCrCN layer (e.g., in the configuration of coating  36  as shown in  FIG.  6   , such as a configuration in which coating  36  is configured to exhibit a high-brightness gold color). 
     As shown in  FIG.  7   , the composition of top coloring layer  38  may be selected such that the atomic percentage of Ti atoms in top coloring layer  38  lies within region  60  (e.g., a region extending between upper limit B 1  and lower limit B 2 ). The atomic percentage of Cr atoms in top coloring layer  38  lies within region  62  (e.g., a region extending between upper limit B 3  and lower limit B 4 ). The atomic percentage of carbon (C) atoms in top coloring layer  38  lies within region  64  (e.g., a region extending between upper limit B 5  and lower limit B 6 ). The atomic percentage of N atoms in top coloring layer  38  lies within region  66  (e.g., a region extending between upper limit B 7  and lower limit B 8 ). 
     In the example of  FIG.  7   , atomic percentage B 2  is greater than atomic percentage B 7 , atomic percentage B 8  is greater than atomic percentage B 3 , and atomic percentage B 4  is greater than atomic percentage B 5 . This is merely illustrative and, in general, these percentages may have other relative magnitudes. Regions  60 ,  62 ,  64 , and  66  may have other relative positions along the vertical axis of  FIG.  7    and may have other relative sizes (e.g., where the size of each region is determined by the difference between its corresponding upper and lower limits). 
     In one suitable arrangement that is sometimes described herein as an example, the upper limit B 1  of region  60  (e.g., the upper limit on the atomic percentage of Ti atoms in layer  38 ) may be between 50% and 60%, between 54% and 56%, between 51% and 57%, between 45% and 60%, greater than 50%, greater than 52%, less than 60%, or other values. The lower limit B 2  of region  60  (e.g., the lower limit on the atomic percentage of Ti atoms in layer  48 ) may be between 40% and 50%, between 44% and 46%, between 44% and 52%, between 41% and 49%, less than 50%, less than 48%, greater than 42%, greater than 40%, or other values less than upper limit B 1 . 
     The upper limit B 3  of region  62  (e.g., the upper limit on the atomic percentage of Cr atoms in layer  38 ) may be between 10% and 20%, between 12% and 19%, between 16% and 19%, between 12% and 22%, greater than 15%, greater than 16%, greater than 10%, less than 20%, less than 19%, or other values that are less than lower limit B 8  of region  66 . The lower limit B 4  of region  62  (e.g., the lower limit on the atomic percentage of Cr atoms in layer  38 ) may be between 10% and 15%, between 8% and 14%, between 12% and 14%, between 5% and 15%, less than 15%, less than 14%, greater than 10%, greater than 12%, or other values less than upper limit B 3 . 
     The upper limit B 7  of region  66  (e.g., the upper limit on the atomic percentage of N atoms in layer  38 ) may be between 30% and 40%, between 34% and 36%, between 31% and 41%, between 29% and 42%, greater than 30%, greater than 34%, less than 36%, less than 40%, or other values that are less than lower limit B 2  of region  60 . The lower limit B 8  of region  66  (e.g., the lower limit on the atomic percentage of N atoms in layer  38 ) may be between 28% and 32%, between 25% and 35%, between 29% and 31%, less than 35%, less than 32%, greater than 25%, greater than 28%, or other values less than upper limit B 7 . 
     The limits of region  64  may be defined by the balance of atomic percentage remaining in layer  38 . For example, the upper limit B 5  of region  64  (e.g., the upper limit on the atomic percentage of C atoms in layer  38 ) may be between 10% and 15%, between 11% and 13%, between 8% and 15%, greater than 5%, greater than 10%, less than 15%, less than 13%, less than 10%, or other values less than lower limit B 4  of region  62 . The lower limit B 6  of region  64  (e.g., the lower limit on the atomic percentage of C atoms in layer  38 ) may be greater than 1%, less than 10%, less than 5%, less than 12%, or other values less than upper limit B 5 . The atomic percentage of Cr atoms in transition layer  48  of  FIG.  6    may, for example, be between 75% and 95%, between 85% and 95%, less than 96%, greater than 80%, or other values. The balance of the atomic percentage of transition layer  48  may be filled by the N atoms in transition layer  48 . These examples are merely illustrative and, in general, other atomic percentages of these elements may be used (e.g., regions  60 ,  62 ,  64 , and  66  may have other heights, relative positions, and/or relative sizes). 
     The arrangement of  FIGS.  4  and  5    and the arrangement of  FIGS.  6  and  7    may respectively configure coating  36  to exhibit slightly different high-brightness gold colors.  FIG.  8    is an exemplary plot of CIE a*b* color space for the visible light that is reflected by coating  36  (e.g., where a* values are plotted on the horizontal axis and b* values are plotted on the vertical axis). As shown in  FIG.  8   , region  68  represents an exemplary color profile of coating  36  when provided with a TiCrN top coloring layer  38  ( FIGS.  4  and  5   ). Region  70  represents an exemplary color profile of coating  36  when provided with a TiCrCN top coloring layer  38  ( FIGS.  6  and  7   ). As shown by regions  68  and  70 , using TiCrCN to form top coloring layer  38  may provide coating  36  with a greater a* value and likely a greater b* value than using TiCrN to form top coloring layer  38 . The example of  FIG.  8    is merely illustrative. In general, regions  68  and  70  may have other shapes, sizes, or relative positions. While regions  68  and  70  are shown as non-overlapping in  FIG.  8    for the sake of clarity, in practice, regions  68  and  70  may be at least partially overlapping. 
     The examples of  FIGS.  4 - 8    in which top coloring layer  38  is a TiCrN layer or a TiCrCN layer is merely illustrative. In another suitable arrangement, top coloring layer  38  may be a titanium carbonitride (TiCN) layer (e.g., a TiCN film deposited using the HiPIMS process), as shown in the cross-sectional side view of  FIG.  9   . 
       FIG.  10    is a plot of illustrative atomic percentages for the different elements in top coloring layer  38  in examples where top coloring layer  38  is a TiCN layer (e.g., in the configuration of coating  36  as shown in  FIG.  9   , such as a configuration in which coating  36  is configured to exhibit a high-brightness gold color). 
     As shown in  FIG.  10   , the composition of top coloring layer  38  may be selected such that the atomic percentage of Ti atoms in top coloring layer  38  lies within region  72  (e.g., a region extending between upper limit C 1  and lower limit C 2 ). The atomic percentage of C atoms in top coloring layer  38  lies within region  74  (e.g., a region extending between upper limit C 3  and lower limit C 4 ). The atomic percentage of N atoms in top coloring layer  38  lies within region  76  (e.g., a region extending between upper limit C 5  and lower limit C 6 ). 
     In the example of  FIG.  7   , atomic percentage C 2  is greater than atomic percentage C 5  and atomic percentage C 6  is greater than atomic percentage C 3 . This is merely illustrative and, in general, these percentages may have other relative magnitudes. Regions  72 ,  74 , and  76  may have other relative positions along the vertical axis of  FIG.  10    and may have other relative sizes (e.g., where the size of each region is determined by the difference between its corresponding upper and lower limits). 
     In one suitable arrangement that is sometimes described herein as an example, the upper limit C 1  of region  72  (e.g., the upper limit on the atomic percentage of Ti atoms in layer  38 ) may be between 50% and 60%, between 50% and 55%, between 53% and 55%, between 45% and 60%, greater than 50%, greater than 53%, less than 55%, less than 60%, or other values. The lower limit C 2  of region  72  (e.g., the lower limit on the atomic percentage of Ti atoms in layer  48 ) may be between 40% and 55%, between 48% and 52%, between 50% and 52%, less than 55%, less than 52%, greater than 45%, greater than 50%, or other values less than upper limit C 1 . 
     The upper limit C 5  of region  76  (e.g., the upper limit on the atomic percentage of N atoms in layer  38 ) may be between 30% and 45%, between 40% and 45%, between 42% and 44%, between 35% and 50%, greater than 40%, greater than 42%, less than 45%, less than 50%, or other values that are less than lower limit C 2  of region  72 . The lower limit C 6  of region  76  (e.g., the lower limit on the atomic percentage of N atoms in layer  38 ) may be between 30% and 40%, between 35% and 45%, between 32% and 50%, less than 40%, less than 39%, greater than 35%, greater than 30%, or other values less than upper limit C 5 . 
     The limits of region  74  may be defined by the balance of atomic percentage remaining in layer  38 . For example, the upper limit C 3  of region  74  (e.g., the upper limit on the atomic percentage of C atoms in layer  38 ) may be between 10% and 15%, between 10% and 12%, between 8% and 15%, greater than 5%, greater than 10%, less than 15%, less than 13%, or other values less than lower limit C 6  of region  76 . The lower limit C 4  of region  74  (e.g., the lower limit on the atomic percentage of C atoms in layer  38 ) may be greater than 1%, greater than 2%, between 1% and 5%, less than 10%, less than 5%, or other values less than upper limit C 3 . These examples are merely illustrative and, in general, other atomic percentages of these elements may be used (e.g., regions  72 ,  74 , and  76  may have other heights, relative positions, and/or relative sizes). 
     The examples of  FIGS.  4 - 10    in which top coloring layer  38  is a TiCrN layer, a TiCrCN, or a TiCN layer is merely illustrative. In another suitable arrangement, top coloring layer  38  may be metal nitride layer that contains Ti, Zr, Hf, or Cr, as shown in the cross-sectional side view of  FIG.  11   . As shown in  FIG.  11   , top coloring layer  38  may, if desired, be a titanium nitride (TiN) layer, a titanium nitrogen silicon (TiNSi) layer, a titanium nitrogen silicon carbide (TiNSiC) layer, a zirconium nitride (ZrN) layer, a zirconium nitrogen carbide (ZrNC) layer, a zirconium nitrogen silicon (ZrNSi) layer, a zirconium nitrogen silicon carbide (ZrNSiC) layer, a hafnium nitride (HfN) layer, a hafnium nitrogen carbide (HfNC) layer, a hafnium nitrogen silicon (HfNSi) layer, a hafnium nitrogen silicon carbide (HfNSiC) layer, a chromium nitride layer (CrN), a chromium nitrogen carbide (CrNC) layer, a chromium nitrogen silicon (CrNSi) layer, or a chromium nitrogen silicon carbide (CrNSiC) layer, as examples. When provided with a top coloring layer  38  of the types shown in  FIGS.  4 - 11   , coating  36  may have a high brightness gold color that exhibits a desired color response over a variety of operating environments and underlying substrate geometries. 
     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.

Metadata:
Filing Date: 20210819
Publication Date: 20240730
Grant Date: 20240730
Priority Date: 20200901
Inventors: MATLAK, JOZEF M.
TRYON, BRIAN S.
BAO, LIJIE
SHARMA, MARUWADA SUKANYA
MANDEPUDI, SHIVA K.
POSTAK, Sonja R.
Assignee: APPLE INC
CPC Classifications: [{"code": "C23C14/0664", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/025", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/0015", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C28/34", "inventive": false, "first": false, "tree": "[]"}, {"code": "C23C14/35", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/0641", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01J37/3405", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01J37/3467", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/35", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/3485", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/0664", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/025", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/0641", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/0015", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C28/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C28/322", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C28/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0247", "inventive": true, "first": false, "tree": "[]"}, {"code": "G04G17/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "C23C28/30", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K5/0243", "inventive": true, "first": true, "tree": "[]"}, {"code": "C23C28/34", "inventive": false, "first": false, "tree": "[]"}, {"code": "C23C14/35", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/0664", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/0641", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/025", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/0015", "inventive": true, "first": false, "tree": "[]"}, {"code": "G04G17/08", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 80357326