Protecting anodized surfaces during manufacturing processes

• US 10,443,145 B2
• Filed: 08/24/2017
• Issued: 10/15/2019
• Est. Priority Date: 08/24/2017
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Curran, James A., Paterson, Aaron D., Burke, William D.
• Primary Examiner(s): Mulvaney, Elizabeth E
• Application Number:
  US15/686,026
• Publication Number:
  US 20190062939A1
• Time in Patent Office: 782 Days
• CPC Class Codes: B44C 1/228 by laser radiation
• CPC Class Codes: C23C 22/58 Treatment of other metallic material
• CPC Class Codes: C25D 11/18 After-treatment, e.g. pore-sealing
• CPC Class Codes: C25D 11/22 for colouring layers
• CPC Class Codes: C25D 11/243 using organic dyestuffs
• CPC Class Codes: C25D 11/246 for sealing layers
• CPC Class Codes: G06F 1/16 Constructional details or arrangements
• CPC Class Codes: G06F 1/1613 for portable computers cooling arrangements therefor G06F1/203; constructional details or arrangements for pocket calculators, electronic agendas or books G06F15/0216; constructional details of portable telephone sets: with several bodies H04M1/0202
• CPC Class Codes: G06F 1/1656 Details related to functional adaptations of the enclosure, e.g. to provide protection against EMI, shock, water, or to host detachable peripherals like a mouse or removable expansions units like PCMCIA cards, or to provide access to internal components for maintenance or to removable storage supports like CDs or DVDs, or to mechanically mount accessories mounting of accessories to a computer display G06F1/1607; display hoods G06F1/1603; cooling arrangements for portable computers G06F1/203
• CPC Class Codes: H05K 5/0086 portable, e.g. battery operated apparatus casings for switching devices H01H9/02
• CPC Class Codes: H05K 5/04 Metal casings

Abstract

Treatments for anodic coatings that provide improved resistance to staining and cracking during various manufacturing processes are described. According to some embodiments, the methods include placing the anodic coatings in partially sealed states by sealing only the outermost portions of the anodic coatings, which protect the outer surfaces of the anodic coatings from contamination and staining. Inner portions of the anodic coatings are left unsealed, thereby making the anodic coatings more compliant and resistant to cracking when exposed to manufacturing processes, even those that involve exposure to high temperatures or high mechanical stress. Subsequent to the processing, another sealing process can be implemented to fully seal the anodic coatings so that they provide good corrosion and wear resistance.

Claims

1. A part, comprising:

an anodic film overlaying a metal substrate, the anodic film having a first section and a second section,

wherein the first section is characterized as having a substantially fully sealed pore such that the first section has an electrical impedance measurement of about 30 μ

S or less, and the second section is characterized as having a partially sealed pore.

2. The part of claim 1, wherein a polymer is adhered to a surface of the second section.

3. The part of claim 1, wherein the first section is laterally adjacent to the second section.

4. The part of claim 1, wherein the second section is characterized as having an electrical impedance measurement that is at least ten times that of the first section.

5. The part of claim 1, wherein the substantially fully sealed pore has a colorant infused therein.

6. The part of claim 1, wherein the partially sealed and the substantially fully sealed pores are characterized as having diameters ranging between about 10 nanometers to about 30 nanometers.

7. The part of claim 1, wherein the substantially fully sealed and the partially sealed pores include a sealant material.

8. The part of claim 1, wherein an outer section of the partially sealed pore includes a metal oxide hydroxide plug, and an interior section of the partially sealed pore includes a non-continuous metal oxide hydroxide structure.

9. The part of claim 7, wherein the sealant material includes nickel.

10. A method of treating a part having an anodic layer that overlays a metal substrate, the method comprising:

partially sealing pores of the anodic layer;

exposing the anodic layer to thermal energy by performing one or more manufacturing operations on the part; and

subsequent to exposing the anodic layer to the thermal energy, fully sealing at least some of the pores of the anodic layer.

11. The method of claim 10, wherein the pores define an interior volume, and the pores are partially sealed with a sealant material.

12. The method of claim 11, wherein the pores are partially sealed when a minority of the interior volume includes the sealant material.

13. The method of claim 10, wherein the one or more manufacturing operations include a laser marking process, a thermal cure cycle, or an artificial aging process.

14. The method of claim 13, wherein partially sealing the pores of the anodic layer prevents cracks from forming within the anodic layer when the anodic layer is exposed to the thermal energy.

15. The method of claim 14, wherein the cracks form within the anodic layer due to a difference in coefficients of thermal expansion between the anodic layer and the metal substrate.

16. The method of claim 10, wherein partially sealing the pores of the anodic layer includes applying a silicate layer on an exterior surface of the anodic layer, wherein fully sealing the pores of the anodic layer includes using a hydrothermal sealing process.

17. A part, comprising:

an anodic layer formed from a metal substrate and having pores that (i) extend towards the metal substrate, and (ii) include a sealant material, wherein an outer region of the anodic layer is characterized as having a concentration of the sealant material that is at least 20 weight % or greater, and an interior region of the anodic layer is characterized as having a concentration of the sealant material that is no more than about 1 weight %.

18. The part of claim 17, wherein the anodized part includes a first section and a second section, wherein the first section is characterized as having a substantially fully sealed pore, and the second section is characterized as having a partially sealed pore.

19. The part of claim 18, wherein the second section is characterized as having an electrical impedance that is at least ten times that of the first section.

20. The part of claim 17, wherein the sealant material includes nickel.