Flexible cable and method of manufacturing thereof

• US 4,748,293 A
• Filed: 02/25/1986
• Issued: 05/31/1988
• Est. Priority Date: 02/25/1985
• Status: Expired due to Term

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Kikuchi, Hiroshi, Akutsu, Naoji, Tanuma, Jiro
• Primary Examiner(s): NIMMO, MORRIS
• Application Number:
  US06/832,753
• Time in Patent Office: 826 Days
• Field of Search: 174/117 PC, 174/117 R, 174/117 F, 174/117 FF, 174/32, 174/34, 174/115, 333/238, 361/398, 361/212, 361/220, 339/17 F, 439/492
• US Class Current: 174/268
• CPC Class Codes: H01B 7/0838 Parallel wires, sandwiched between two insulating layers
• CPC Class Codes: H05K 1/0215 Grounding of printed circuits by connection to external grounding means
• CPC Class Codes: H05K 1/0259 Electrostatic discharge [ESD] protection
• CPC Class Codes: H05K 1/117 Pads along the edge of rigid circuit boards, e.g. for pluggable connectors
• CPC Class Codes: H05K 1/118 specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 2201/09354 Ground conductor along edge of main surface
• CPC Class Codes: H05K 3/28 Applying non-metallic protective coatings H05K3/0091 takes precedence; methods for intermediate insulating layers for build-up multilayer circuits H05K3/4673

Abstract

A flexible cable has a grounding pattern or patterns provided therein. Thereby, when an object having static electricity of high voltage is caused to approach the flexible cable, dielectric breakdown of a base and cover of a high polymer material of the cable, to a conducting portion of the cable which is not exposed at the interior of the flexible cable is prevented, and damage to an electronic circuit connected with the not exposed portion, due to electric discharge, can be prevented by causing the static electricity to be discharged to the exposed grounding pattern.

Claims

1. A longitudinally extending flexible cable having opposite lateral edges, said flexible cable comprising:

a longitudinally extending base of insulating material;

a plurality of longitudinally extending conductors spaced laterally from each other in the width direction of said base;

a longitudinally extending cover layer of insulating material covering said conductors;

said base and said cover layer forming insulation enclosing said conductors and insulating said conductors from each other;

means for protecting said insulation from dielectric breakdown resulting from subjecting said cable to an exterior source of high voltage static electricity, said protecting means comprising at least one additional conductor extending longitudinally at a position spaced laterally from said conductors, said insulation insulating said conductors from said additional conductor, and said additional conductor being exposed over the entire length thereof to the exterior of said cable.

2. A flexible cable as claimed in claim 1, wherein said at least one additional conductor is located at one of said lateral edges of said cable and is exposed only at said one lateral edge.

3. A flexible cable as claimed in claim 1, comprising two said additional conductors, one each said additional conductor being located and exposed only at a respective said lateral edge of said cable.

4. A flexible cable as claimed in claim 1, wherein said at least one additional conductor is positioned between said base and said cover layer and is exposed only at one of said lateral edges of said cable.

5. A flexible cable as claimed in claim 1, wherein said cover layer is bonded over said conductors and said base and over said additional conductor other than the exposed portion thereof.

6. A flexible cable as claimed in claim 1, wherein said at least one additional conductor is located laterally between two said conductors.