Method of forming a conformal electromagnetic interference shield

Patent metadata

Field	Value
Publication number	US-9282630-B2
Application number	US-201213460400-A
Country	US
Kind code	B2
Filing date	Apr 30, 2012
Priority date	Apr 30, 2012
Publication date	Mar 8, 2016
Grant date	Mar 8, 2016

Abstract

Systems and methods for shielding circuitry from interference with conformal coating are disclosed. Systems having conformal EMI shields according to embodiments are provided by applying insulating and conductive layers to areas of a printed circuit board (PCB). This produces systems that may be thinner and also smaller in surface area, and that may be suitable as part of electronic devices.

First claim

What is claimed is:

1. A method of forming a conformal electromagnetic interference (EMI) shield, the method comprising:
applying a mask to cover a portion of a printed circuit board (PCB), the PCB having one or more circuit components, wherein the portion of the PCB comprises a plurality of grounding contacts, wherein the portion surrounds one or more of the circuit components, and wherein the portion is spaced a minimum predefined distance from an outer surface of any circuit component immediately adjacent to the portion;
applying an insulating layer to the entire PCB;
removing the mask, wherein removing the mask further comprises removing portions of the insulating layer applied on the mask;
treating at least one of the applied insulating layer and the portion for conductive layer adhesion; and
disposing a conductive layer onto the treated at least one of the applied insulating layer and the portion.

2. The method of claim 1 , wherein the plurality of grounding contacts comprises at least one of pads and vias.

3. The method of claim 1 , wherein the treating comprises forming a conductive layer adhesive on the at least one of the applied insulating layer and the portion.

4. The method of claim 1 , wherein:
the disposing comprises physical vapor deposition (PVD); and
the treating comprises treating the at least one of the applied insulating layer and the portion with plasma.

5. The method of claim 1 , wherein:
the conductive layer comprises a foil; and
the treating comprises treating the at least one of the applied insulating layer and the portion with solder.

6. The method of claim 1 , wherein:
the treating comprises treating only the portion; and
the disposing comprises coupling the conductive layer to the treated portion.

7. The method of claim 1 , wherein:
the treating comprises treating each of the applied insulating layer and the portion; and
the disposing comprises disposing the conductive layer onto both of the treated insulating layer and the treated portion.

8. The method of claim 1 , wherein:
the treating comprises treating each of the applied insulating layer and the portion; and
the disposing comprises disposing the conductive layer only onto the treated insulating layer and the treated portion.

9. The method of claim 1 , wherein:
the insulating layer comprises CVD Parylene; and
the conductive layer comprises inkjet printing.

10. The method of claim 1 , wherein:
the insulating layer comprises CVD Parylene; and
the conductive layer comprises PVD.

11. The method of claim 1 , wherein:
the insulating layer comprises CVD Parylene; and
the conductive layer comprises dispensed ink.

12. A method of forming a conformal electromagnetic interference (EMI) shield, the method comprising:
processing portions of a printed circuit board (PCB) for insulating layer adhesion, the PCB having one or more circuit components and a perimeter of grounding contacts;
applying an insulating layer to the processed portions;
treating at least one of the applied insulating layer and the perimeter for conductive layer adhesion; and
disposing a conductive layer onto the treated at least one of the applied insulating layer and the perimeter, wherein:
the insulating layer comprises at least one of potting material and coating material; and
the processing comprises treating areas of the PCB other than the perimeter with plasma.

13. A method of forming a conformal electromagnetic interference (EMI) shield, the method comprising:
processing portions of a printed circuit board (PCB) for insulating layer adhesion, the PCB having one or more circuit components and a perimeter of grounding contacts;
applying an insulating layer to the processed portions;
treating at least one of the applied insulating layer and the perimeter for conductive layer adhesion; and
disposing a conductive layer onto the treated at least one of the applied insulating layer and the perimeter, wherein:
the insulating layer comprises chemical vapor deposition (CVD) Parylene; and
the processing comprises applying silicon to areas of the PCB other than the perimeter.

14. A method of forming a conformal electromagnetic interference (EMI) shield, the method comprising:
processing portions of a printed circuit board (PCB) for insulating layer adhesion, the PCB having one or more circuit components and a perimeter of grounding contacts;
applying an insulating layer to the processed portions;
treating at least one of the applied insulating layer and the perimeter for conductive layer adhesion; and
disposing a conductive layer onto the treated at least one of the applied insulating layer and the perimeter, wherein:
the conductive layer comprises inkjet printing deposits; and
the treating comprises treating the at least one of the applied insulating layer and the perimeter with UV ozone material.

15. A method of forming a conformal electromagnetic interference (EMI) shield, the method comprising:
applying adhesive to portions of a printed circuit board, the printed circuit board having one or more circuit components and a perimeter portion that contains a plurality of grounding contacts, wherein the perimeter portion surrounds the one or more circuit components, wherein applying adhesive to portions of the printed circuit board comprises only applying adhesive to portions of the printed circuit board that are interposed between the one or more circuit components and the perimeter portion;
applying adhesive over the one or more circuit components;
applying an insulating layer to the printed circuit board such that the insulating layer is adhered to both the printed circuit board and the one or more circuit components, wherein the perimeter is uncovered by the insulating layer;
treating only the perimeter portion for conductive layer adhesion; and
disposing a conductive layer onto the insulating layer and the perimeter portion.

Assignees

• Merz Nicholas
• Apple Inc

Inventors

• Merz Nicholas

Classifications

• H05K3/284

  for encapsulating mounted components (H05K1/185 takes precedence) · CPC title

• H05K1/0216 Primary

  Reduction of cross-talk, noise or electromagnetic interference (grounding H05K1/0215) · CPC title

• C23C14/086

  of zinc, germanium, cadmium, indium, tin, thallium or bismuth · CPC title

• C23C14/185

  by cathodic sputtering · CPC title

• H05K2201/09872

  Insulating conformal coating · CPC title