Grounded flexible circuits

• US 7,672,142 B2
• Filed: 01/05/2007
• Issued: 03/02/2010
• Est. Priority Date: 01/05/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Schlub, Robert W., Wang, Erik L., Jenks, Kenneth A., Hill, Robert J., Hobson, Philip Michael
• Primary Examiner(s): Lee; Jinhee J
• Assistant Examiner(s): Chen; Xiaoliang
• Application Number:
  US11/650,116
• Publication Number:
  US 20080164055A1
• Time in Patent Office: 1,152 Days
• Field of Search: 361/789, 361/683, 361/685, 361/719, 361/760, 361/792, 361/828, 174/251, 174/262, 174/268, 298/46, 298/84, 324/754
• US Class Current: 361/789
• CPC Class Codes: G06F 1/189 Power distribution
• CPC Class Codes: H05K 1/0215 Grounding of printed circuits by connection to external grounding means
• CPC Class Codes: H05K 1/118 specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 9/0039 Galvanic coupling of ground layer on printed circuit board [PCB] to conductive casing printed shielding conductors, ground planes or power planes for reduction of cross-talk or noise in printed circuits H05K1/0218

Abstract

Electronic devices may be provided with one or more electrical components that may be coupled to one or more circuit boards by flexible circuits that can have reduced ground lengths. Each flexible circuit can include at least one ground conductor that may run along its length and that may have at least one portion exposed for coupling to a grounding element that may also be coupled to a ground plane.

Claims

1. An electronic device, comprising:

an electrical component;

a circuit board;

a flexible printed circuit coupled between the electrical component and the circuit board, wherein the flexible printed circuit has a first end coupled to the electrical component and a second end coupled to the circuit board;

wherein the flexible printed circuit is formed from flexible polymer films, wherein the flexible printed circuit includes a ground conductor trace that has a length and includes a signal conductor trace, and wherein the ground conductor trace and the signal conductor trace are formed from metal traces surrounded by the flexible polymer films of the flexible printed circuit;

a conductive housing that encloses the electronic device and that forms a ground plane; and

at least one grounding element electrically coupled between the ground conductor trace and the conductive housing, wherein the grounding element is electrically coupled to the ground conductor trace at least one point along the length of the ground conductor trace between the first and second ends of the flexible printed circuit and wherein the flexible polymer films have at least one hole through which the grounding element passes to electrically couple the ground conductor trace that is surrounded by the flexible polymer films to the conductive housing.

2. The electronic device of claim 1, wherein the grounding element is a conductive adhesive.

3. The electronic device of claim 1, wherein the grounding element is a solder.

4. The electronic device of claim 1, wherein the grounding element is a clip.

5. The electronic device of claim 1, wherein the grounding element is a weld.

6. The electronic device of claim 1, wherein the electrical component is an antenna.

7. The electronic device of claim 1, wherein the electronic device is a mobile telephone.

8. The electronic device of claim 1, wherein the electronic device is a remote control.

9. The electronic device defined in claim 1 wherein the at least one grounding element is electrically coupled to the ground conductor trace substantially along the entire length of the flexible printed circuit between the electrical component and the circuit board.

10. The electronic device defined in claim 1 further comprising a conductive metal layer between the conductive housing and the flexible printed circuit, wherein the grounding element is electrically coupled between the ground conductor trace and the conductive metal layer and wherein the conductive metal layer is electrically coupled to the conductive housing.

11. The electronic device defined in claim 1 further comprising a conductive metal layer of copper between the conductive housing and the flexible printed circuit, wherein the grounding element is electrically coupled between the ground conductor trace and the conductive metal layer of copper and wherein the conductive metal layer of copper is electrically coupled to the conductive housing.

12. The electronic device defined in claim 1 wherein the at least one grounding element is electrically coupled to the ground conductor trace along the entire length of the flexible printed circuit between the electrical component and the circuit board.

13. A flexible printed circuit in an electronic device having a conductive housing that encloses the electronic device, comprising:

a first end for coupling to an electrical component;

a second end for coupling to a circuit board;

at least one grounding element;

flexible polymer films extending between the first end and the second end;

a flexible circuit ground trace extending between the first end and the second end; and

a flexible circuit signal trace extending between the first end and the second end, wherein the flexible circuit ground trace and the flexible circuit signal trace are formed from metal traces surrounded by the flexible polymer films, wherein the flexible circuit ground trace is electrically coupled to the conductive housing through the grounding element at least one point along the flexible polymer films between the first end and the second end, and wherein the flexible polymer films have at least one hole through which the grounding element passes to electrically couple the flexible circuit ground trace that is surrounded by the flexible polymer films to the conductive housing.

14. The flexible circuit of claim 13, wherein the grounding element is a conductive adhesive.

15. The flexible circuit of claim 13, wherein the grounding element is a solder.