System and method of preventing damage to metal traces of flexible printed circuits

• US 7,643,305 B2
• Filed: 03/07/2008
• Issued: 01/05/2010
• Est. Priority Date: 03/07/2008
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Lin, Peng Cheng
• Primary Examiner(s): LEA EDMONDS, LISA S
• Application Number:
  US12/044,841
• Publication Number:
  US 20090231816A1
• Time in Patent Office: 669 Days
• Field of Search: 361/681, 361/679, 361/683, 361749-751
• US Class Current: 361/749
• CPC Class Codes: H05K 1/0281 Reinforcement details thereof
• CPC Class Codes: H05K 2201/09145 Edge details
• CPC Class Codes: H05K 2201/09354 Ground conductor along edge of main surface edge contacts H05K3/403
• CPC Class Codes: H05K 2201/09781 Dummy conductors, i.e. not used for normal transport of current; Dummy electrodes of components
• CPC Class Codes: H05K 2201/1028 Thin metal strips as connectors or conductors
• CPC Class Codes: H05K 2201/2009 Reinforced areas, e.g. for a specific part of a flexible printed circuit
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.

Abstract

Stiffeners in are provided in a flexible printed circuit to prevent damages to leads and traces of the flexible circuit caused by bending, folding and other stresses.

Claims

1. An electronic system comprising:

at least one panel;

at least one flexible circuit connected to the panel;

the flexible circuit comprising at least one stiffener, wherein the stiffener is co-planar with traces of the flexible circuit, wherein the stiffener is positioned along a central portion of the flexible circuit and parallel to an edge of the flexible circuit, and wherein the at least one stiffener resides in either one or both of;

a region where the flexible circuit crosses an edge of the panel such that the stiffener extends across the edge; and

a region where the flexible circuit bends such that the stiffener extends around the bend.

2. The electronic system of claim 1 wherein the stiffener is positioned along an edge of the flexible circuit.

3. The electronic system of claim 1 wherein the panel comprises a display array.

4. The electronic system of claim 1 wherein the flexible circuit comprises notches in the region where the stiffener is present.

5. The electronic system of claim 1 wherein the stiffener comprises metal.

6. The electronic system of claim 5 wherein the stiffener comprises copper.

7. The electronic system of claim 5 wherein the stiffener is grounded.

8. The electronic system of claim 5 wherein the stiffener is connected to a signal source.

9. The electronic system of claim 5 wherein the stiffener is connected to a power source.

10. The electronic system of claim 5, wherein the stiffener is connected to a test trace.

11. The electronic system of claim 1, wherein the stiffener is rectangular in shape.

12. The electronic system of claim 1, wherein the stiffener is not rectangular in shape.

13. The electronic system of claim 1, wherein a neck connects two sections of the stiffener to form a region where the flexible circuit is bent.

14. The electronic system of claim 5 wherein the stiffener is one millimeter to two millimeters in width.

15. A electronic system comprising:

at least one panel;

at least one flexible circuit; and

means for stiffening a portion of the flexible circuit wherein the means for stiffening is co-planar with traces of the at least one flexible circuit and wherein the means for stiffening is positioned along a central portion of the flexible circuit and parallel to an edge of the flexible circuit.

16. The electronic system of claim 15 wherein the panel comprises a display array.

17. The electronic system of claim 15 wherein the flexible circuit comprises notches in the region where the stiffening means is present.

18. The electronic system of claim 15 wherein the stiffening means comprises a metal strip.

19. The electronic system of claim 15 wherein the stiffening means comprises copper.

20. A method for preventing damage to metal conductors on or in a flexible circuit, the method compromising providing at least one stiffener at either one or both of a region where the flexible circuit overlaps a panel edge, and a region where the flexible circuit is bent wherein the at least one stiffener is co-planar with traces of the flexible circuit and wherein the at least one stiffener is positioned along a central portion of the flexible circuit and parallel to an edge of the flexible circuit.

21. The method of claim 20 comprising forming the stiffener by retaining metallic strips during an etching processing during fabrication of the flexible circuit.

22. The method of claim 20 comprising placing notches on the flexible circuit in a region where the flexible circuit is bent.

23. An electronic system comprising:

at least one panel;

at least one flexible circuit connected to the panel;

the flexible circuit comprising at least one stiffener, wherein the stiffener is co-planar with traces of the flexible circuit, wherein the at least one stiffener is connected to at least one of a power source, a signal source, and a test trace, and wherein the at least one stiffener resides in either one or both of;

a region where the flexible circuit crosses an edge of the panel such that the stiffener extends across the edge; and

a region where the flexible circuit bends such that the stiffener extends around the bend.

24. A electronic system comprising:

at least one panel;

at least one flexible circuit; and

means for stiffening a portion of the flexible circuit wherein the means for stiffening is co-planar with traces of the at least one flexible circuit and wherein the means for stiffening is connected to at least one of a power source, a signal source, and a test trace.

25. A method for preventing damage to metal conductors on or in a flexible circuit, the method compromising providing at least one stiffener at either one or both of a region where the flexible circuit overlaps a panel edge, and a region where the flexible circuit is bent wherein the at least one stiffener is co-planar with traces of the flexible circuit and wherein the at least one stiffener is connected to at least one of a power source, a signal source, and a test trace.