Visible-light-reflecting coatings for electronic devices

Patent metadata

Field	Value
Publication number	US-11719865-B2
Application number	US-202117176992-A
Country	US
Kind code	B2
Filing date	Feb 16, 2021
Priority date	Mar 11, 2020
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

An electronic device may include conductive structures having a visible-light-reflecting coating. The coating may include a seed layer, transition layers, a neutral-color base layer, and an uppermost layer that forms a single-layer interference film. The neutral-color base layer may be opaque to visible light. The interference film may include silicon and may have an absorption coefficient between 0 and 1. The interference film may include, for example, CrSiCN or CrSiC. The composition of the interference film, the thickness of the interference film, and/or the composition of the base layer may be selected to provide the coating with a desired color in the visible spectrum (e.g., at blue or purple wavelengths). The color may be relatively stable even if the thickness of the coating varies across its area.

First claim

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,
a CrSiN layer on the adhesion and transition layers, the CrSiN layer being opaque to light of the color, and
an uppermost layer on the CrSiN layer, the uppermost layer comprising a CrSiC film.

2. The apparatus of claim 1 , wherein the CrSiC film forms a single-layer interference filter.

3. The apparatus of claim 1 , wherein the CrSiC film has a thickness between 0.01 and 0.1 microns.

4. The apparatus of claim 3 , wherein an atomic percentage of Cr atoms in the CrSiC film is greater than 25% and less than 35% and wherein an atomic percentage of Si atoms in the CrSiC film is greater than 50% and less than 60%.

5. The apparatus of claim 4 , wherein an atomic percentage of Cr atoms in the CrSiN layer is greater than 55% and less than 65% and wherein an atomic percentage of Si atoms in the CrSiN layer is greater than 20% and less than 30%.

6. The apparatus of claim 5 , wherein the CrSiC film has a thickness between 0.04 and 0.06 microns.

7. The apparatus of claim 6 , wherein the coating has an L* value between 45 and 55 in a CIELAB color space, an a* value between −5 and 0 in the CIELAB color space, and a b* value between −14 and −10 in the CIELAB color space.

8. The apparatus of claim 3 , wherein an atomic percentage of Cr atoms in the CrSiC film is greater than 50% and less than 60% and wherein an atomic percentage of Si atoms in the CrSiC film is greater than 30% and less than 40%.

9. The apparatus of claim 8 , wherein an atomic percentage of Cr atoms in the CrSiN layer is greater than 60% and less than 70% and wherein an atomic percentage of Si atoms in the CrSiN layer is greater than 10% and less than 25%.

10. The apparatus of claim 9 , wherein the CrSiC film has a thickness between 0.01 and 0.04 microns.

11. The apparatus of claim 10 , wherein the coating has an L* value between 35 and 40 in a CIELAB color space, an a* value between 0 and 5 in the CIELAB color space, and a b* value between −10 and −5 in the CIELAB color space.

12. The apparatus defined in claim 1 ,
wherein the adhesion and transition layers comprise a seed layer on the conductive substrate and a transition layer on the seed layer, wherein the seed layer comprises a material selected from the group consisting of: Cr, CrSi, and Ti, and wherein the transition layer comprises a material selected from the group consisting of: CrSiN, CrSiCN, CrN, and CrCN.

13. The apparatus defined in claim 1 , wherein the conductive substrate comprises a conductive substrate selected from the group consisting of: a conductive electronic device housing wall and a three-dimensional conductive structure for an electronic device.

14. Apparatus comprising:
a conductive substrate; and
a coating on the conductive substrate and having a color, the coating comprising:
adhesion and transition layers,
a CrSiN layer on the adhesion and transition layers, the CrSiN layer being opaque to light of the color, and
an uppermost layer on the CrSiN layer, the uppermost layer comprising a CrSiCN film, wherein the CrSiCN film has a thickness between 0.01 and 0.1 microns.

15. The apparatus of claim 14 , wherein the CrSiCN film forms a single-layer interference filter.

16. The apparatus of claim 15 , wherein an atomic percentage of Cr atoms in the CrSiCN film is greater than 30%, wherein an atomic percentage of Si atoms in the CrSiCN film is greater than 20%, and wherein an atomic percentage of C atoms in the CrSiCN film is greater than 30%.

17. The apparatus of claim 16 , wherein the atomic percentage of Cr atoms in the CrSiCN film is less than 36% and wherein the atomic percentage of Si atoms in the CrSiCN film is less than 30%.

18. The apparatus of claim 17 , wherein an atomic percentage of Cr atoms in the CrSiN layer is greater than 30% and less than 40% and wherein an atomic percentage of Si atoms in the CrSiN layer is greater than 10% and less than 20%.

19. The apparatus of claim 18 , wherein the thickness is between 0.05 and 0.07 microns.

20. The apparatus of claim 19 , wherein the coating has an L* value between 45 and 50 in a CIELAB color space, an a* value between −5 and −2 in the CIELAB color space, and a b* value between −12 and −8 in the CIELAB color space.

21. Apparatus comprising:
a conductive substrate; and
a coating on the conductive substrate and having a color, the coating comprising:
a Cr seed layer,
a CrN transition layer on the Cr seed layer, and
an uppermost layer on the CrN transition layer, wherein the uppermost layer comprises TiSiN.

22. The apparatus of claim 21 , wherein the uppermost layer has a thickness between 0.3 and 0.5 microns and wherein an atomic percentage of Ti atoms in the uppermost layer is greater than 50% and less than 60%.

23. The apparatus of claim 22 , wherein the coating has an L* value between 70 and 80 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.

24. Apparatus comprising:
a conductive substrate; and
a coating on the conductive substrate and having a color, the coating comprising:
adhesion and transition layers,
a CrSiCN layer on the adhesion and transition layers, the CrSiCN layer being opaque to light of the color, and
an uppermost layer on the CrSiCN layer, the uppermost layer comprising a CrSiCN film.

Assignees

• Apple Inc

Inventors

• Tryon Brian S
• Bao Lijie
• Melcher Martin
• Postak Sonja R

Classifications

• G02B5/0833 Primary

  comprising inorganic materials only · CPC title

• G02B5/286 Primary

  having four or fewer layers, e.g. for achieving a colour effect · CPC title

• G02B5/0808 Primary

  having a single reflecting layer (G02B5/0883, G02B5/0891 take precedence) · CPC title

• G02B5/28

  Interference filters · CPC title

• C23C14/0015

  characterized by the colour of the layer · CPC title