Coatings for galvanic corrosion mitigation

Patent metadata

Field	Value
Publication number	US-2024276660-A1
Application number	US-202418423800-A
Country	US
Kind code	A1
Filing date	Jan 26, 2024
Priority date	Feb 15, 2023
Publication date	Aug 15, 2024
Grant date	—

Abstract

To eliminate galvanic corrosion, a housing includes a clad. The clad includes an interior metal disposed within an exterior metal and a clad interface. The exterior metal includes a lower electrical conductivity potential than the interior metal. An aperture can extend through the exterior metal and the clad interface and an actuator or a plug can be disposed within the aperture. The housing further includes a corrosion resistant coating disposed on a portion of the interior metal at the clad interface. The corrosion resistant coating can include a thickness between about 2 μm and about 10 μm.

First claim

What is claimed is:

1 . A housing for an electronic device, comprising:
a clad comprising an interior metal and an exterior metal, the exterior metal being different than the interior metal, and the interior metal and the exterior metal being joined at a clad interface, the exterior metal comprising a lower electrical conductivity than the interior metal; the housing defining an aperture extending through the exterior metal and the clad interface; an actuator or a plug disposed within the aperture; and a corrosion resistant coating disposed on a portion of the interior metal at the clad interface, the coating comprising a thickness between about 1 μm and about 10 μm.

2 . The housing of claim 1 , wherein the actuator comprises at least one of a button, a speaker, or a switch.

3 . The housing of claim 1 , wherein:
the exterior metal comprises stainless steel or titanium; and the interior metal comprises aluminum.

4 . The housing of claim 1 , wherein the exterior metal is substantially free of the corrosion resistant coating.

5 . The housing of claim 1 , wherein the corrosion resistant coating comprises an electrophoretic deposition.

6 . The housing of claim 1 , wherein the corrosion resistant coating comprises a vapor deposition.

7 . The housing of claim 1 , wherein the corrosion resistant coating comprises parylene.

8 . A method of forming a protective interface in a clad housing, the clad housing including an exterior metal defining an exterior surface and an interior metal defining an interior surface, the exterior metal and the interior metal joined at a clad interface, the method comprising:
masking a portion of the exterior metal; and applying a corrosion resistant coating to a portion of the interior metal and a portion of the clad interface.

9 . The method of claim 8 , wherein applying the corrosion resistant coating comprises a chemical vapor deposition process.

10 . The method of claim 8 , wherein applying a corrosion resistant coating comprises a physical vapor deposition process.

11 . The method of claim 8 , wherein applying a corrosion resistant coating comprises a vapor deposition polymerization process.

12 . The method of claim 8 , wherein:
the exterior metal comprises at least one of stainless steel or titanium; the interior metal comprises aluminum; and the corrosion resistant coating comprises at least one of parylene or a polyurethane.

13 . The method of claim 8 , wherein:
the corrosion resistant coating comprises a first coating; and the method further comprises applying a second coating to at least a portion of the interior metal.

14 . The method of claim 13 , wherein the first coating and the second coating comprise different compositions.

15 . The method of claim 8 , wherein masking a portion of the exterior metal comprises masking the exterior surface prior to the application of a corrosion resistant coating.

16 . The method of claim 15 , wherein masking the exterior metal comprises applying a removable coating to the exterior metal.

17 . A system configured to prevent galvanic corrosion of a housing for an electronic device, comprising:
a clad structure comprising an exterior metal and an interior metal joined at an interface, the exterior metal comprising a lower electrical conductivity than the interior metal, the housing defining an orifice extending through the exterior metal and the interface; and a corrosion resistant coating disposed on the interior metal; wherein the exterior metal is substantially free of the corrosion resistant coating.

18 . The system of claim 17 , wherein the corrosion resistant coating is temperature resistant up to about 120° C.

19 . The system of claim 17 , wherein:
the corrosion resistant coating comprises a thickness between about 1 μm and about 10 μm; and the interior metal defines at least one of a cut-out, an overhang, or an aperture.

20 . The system of claim 17 , wherein the coating comprises at least one of parylene or a polyurethane.

Assignees

• Apple Inc

Inventors

• Yang Isabel
• Mintz Todd S
• Curran James A
• Burks Timothy D
• Shinde Harshal U

Classifications

• C23C14/12

  Organic material · CPC title

• B05D1/60

  Deposition of organic layers from vapour phase (vapour phase deposition in general C23C14/00, C23C16/00) · CPC title

• H05K5/0217 Primary

  Mechanical details of casings (covers, lids, hoods or members for covering apertures H05K5/03) · CPC title

• C25D13/00

  Electrophoretic coating characterised by the process (C25D15/00 takes precedence; compositions for electrophoretic coating C09D5/44) · CPC title

• C23C16/44

  characterised by the method of coating (C23C16/04 takes precedence) · CPC title