White appearing anodized films

Patent metadata

Field	Value
Publication number	US-10941503-B2
Application number	US-201816215417-A
Country	US
Kind code	B2
Filing date	Dec 10, 2018
Priority date	Jun 22, 2012
Publication date	Mar 9, 2021
Grant date	Mar 9, 2021

Abstract

The embodiments described herein relate to forming anodized films that have a white appearance. In some embodiments, an anodized film having pores with light diffusing pore walls created by varying the current density during an anodizing process is described. In some embodiments, an anodized film having light diffusing micro-cracks created by a laser cracking procedure is described. In some embodiments, a sputtered layer of light diffusing aluminum is provided below an anodized film. In some embodiments, light diffusing particles are infused within openings of an anodized layer.

First claim

What is claimed is:

1. An enclosure for a portable electronic device having a white appearance, comprising:
a metal substrate;
an anodized layer that overlays the metal substrate, wherein the anodized layer includes (i) pores, and (ii) spot areas having micro-cracks; and
light reflective particles that are infused within the micro-cracks, wherein the light reflective particles include light reflective surfaces such that when visible light is incident upon an external surface of the anodized layer, the light reflective surfaces diffusely reflect the visible light in multiple different directions.

2. The enclosure of claim 1 , wherein the spot areas are comprised of crystallized metal oxide.

3. The enclosure of claim 1 , wherein the light reflective particles include titania or alumina.

4. The enclosure of claim 1 , wherein a width of the micro-cracks is greater than an average diameter of the pores.

5. The enclosure of claim 1 , wherein the anodized layer further includes light translucent areas having the pores, and the light translucent areas are separated by the spot areas.

6. The enclosure of claim 5 , wherein the spot areas include irregularly shaped pores.

7. The enclosure of claim 1 , wherein the micro-cracks have an average width between about 100 nm to about 600 nm.

8. The enclosure of claim 1 , wherein the spot areas are substantially uniformly spaced apart from each other.

9. The enclosure of claim 1 , wherein an average distance between the spot areas is equal to an average diameter of the spot areas or less.

10. A part for a portable electronic device, comprising:
a metal substrate;
an anodized layer includes (i) light translucent portions, and (ii) light diffusing portions separated by the light translucent portions, wherein the light diffusing portions include micro-cracks; and
light reflective particles that are infused within the micro-cracks, wherein the light reflective particles include a textured surface such that when visible light is incident upon an external surface of the anodized layer, the textured surface diffusely reflects the visible light in multiple different directions.

11. The part of claim 10 , wherein the light diffusing portions include crystallized metal oxide material.

12. The part of claim 10 , wherein the micro-cracks have an average width between about 100 nm to about 600 nm.

13. The part of claim 10 , wherein the light translucent portions are without the micro-cracks.

14. The part of claim 10 , wherein the light reflective particles include alumina or titania.

15. The part of claim 10 , wherein the light diffusing portions are uniformly separated from each other.

16. A method for forming an enclosure, the method comprising:
forming an anodized layer over a metal substrate;
forming spot areas within the anodized layer by (i) heating metal oxide material of the anodized layer, and (ii) cooling the metal oxide material that was heated to form micro-cracks; and
infusing light reflective particles within the micro-cracks, wherein the light reflective particles include multiple light reflective surfaces.

17. The method of claim 16 , wherein the light reflective particles include alumina or titania.

18. The method of claim 16 , wherein the anodized layer further includes light translucent areas having pores, and the light translucent areas are separated by the spot areas.

19. The method of claim 16 , wherein the micro-cracks have an average width between about 100 nm to about 600 nm.

20. The method of claim 16 , wherein the spot areas are substantially uniformly spaced apart from each other.

Assignees

• Apple Inc

Inventors

• Browning Lucy E
• Lynch Stephen B
• Prest Christopher D
• Russell-Clarke Peter N
• Tatebe Masashige
• Nashner Michael S
• Mcdonald Daniel T
• Tryon Brian S
• Akana Jody R

Classifications

• C25D11/024 Primary

  Anodisation under pulsed or modulated current or potential · CPC title

• Y10T428/13

  Hollow or container type article [e.g., tube, vase, etc.] · CPC title

• C25D11/18 Primary

  After-treatment, e.g. pore-sealing · CPC title

• Y10T428/24471

  Crackled, crazed or slit · CPC title

• C25D11/12 Primary

  Anodising more than once, e.g. in different baths · CPC title