Flexible circuit laminate for surface mount devices

• US 4,851,613 A
• Filed: 06/08/1988
• Issued: 07/25/1989
• Est. Priority Date: 06/08/1988
• Status: Expired due to Fees

• Current Assignee: Flex Technology Incorporated (Vulcan Electric Co.)
• Original Assignee: Flex Technology Incorporated (Vulcan Electric Co.)
• Inventors: Jacques, Roland
• Primary Examiner(s): NIMMO, MORRIS
• Application Number:
  US07/204,113
• Time in Patent Office: 412 Days
• Field of Search: 361/397, 361/398, 361/400, 174/685
• US Class Current: 174/254
• CPC Class Codes: H05K 1/028 Bending or folding regions of flexible printed circuits H05K1/0283 takes precedence
• CPC Class Codes: H05K 1/0366 reinforced, e.g. by fibres, fabrics H05K1/036 takes precedence
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 2201/0278 Polymeric fibers
• CPC Class Codes: H05K 2201/029 Woven fibrous reinforcement or textile
• CPC Class Codes: H05K 2201/09036 Recesses or grooves in insulating substrate
• CPC Class Codes: H05K 2201/0989 Coating free areas, e.g. areas other than pads or lands free of solder resist
• CPC Class Codes: H05K 3/281 by means of a preformed insulating foil H05K3/284 takes precedence

Abstract

The disclosed invention provides a flexible circuit board for use in surface mount technology. A polyaramid fiber reinforced resin provides a substrate for a copper cladding in which a circuit is formed. Overlaying the circuitry are a plurality of spaced insulating pads also reinforced with polyaramid fiber for dimensional stability. The spaces insulated pads define fold-lines along which the circuit may be folded, thereby providing a degree of flexibility required for flexible circuit applications.

Claims

1. A flexible circuit board for surface mount components comprising:

a dielectric substrate including a polyaramid layer;

a layer of conductive material adhered to at least a portion of said substrate;

an insulating layer adhered to said conductive layer, said insulating layer including;

a plurality of insulating panels adhered to said conductive layer and spaced along one dimension of said circuit board to provide for fold-lines therebetween, said insulating panels each comprising a woven fabric of polyaramid fiber.

2. A flexible circuit board in accordance with claim 1 wherein said conductive material defines an electrical circuit.

3. A flexible circuit in accordance with claim 2 wherein windows are cut out of at least one of said insulating panels to allow surface mount devices to be soldered to said circuit through said windows.

4. A flexible circuit in accordance with claim 2 wherein said conductive material is copper.

5. A flexible circuit in accordance with claim 1 wherein said polyaramid layer is woven fabric of polyaramid fiber.

6. A flexible circuit in accordance with claim 5 wherein said woven fabric of said substrate and said woven fabric of said insulating panels are impregnated with a resin.

7. A flexible circuit in accordance with claim 5 wherein said resin is an acrylic resin.

8. A flexible circuit in accordance with claim 1 wherein said panels are approximately coextensive with said circuit board in the direction transverse to said one dimension.