Browse Prior Art Database

Low-Cost Multilayer Flex Board and Ribbon Cable

IP.com Disclosure Number: IPCOM000039763D
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Ledermann, PG: AUTHOR

Abstract

A method of producing a multilayer flex board or ribbon cable is provided and comprises: producing substrate layers comprising silicone adhesive on a polyimide film, punching holes in each substrate layer for vias, using the polyimide film to lift patterned copper lines from a plate; connecting the copper lines of the different layers by providing finished vias in the holes either by spot welding or by a solder paste and reflow technique, and providing a final cover layer which masks exposed lines while providing appropriate holes for components. The holes in the final cover layer typically expose or contain adhesive which permits surface mount components to be mounted without the need of additional adhesive.

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Low-Cost Multilayer Flex Board and Ribbon Cable

A method of producing a multilayer flex board or ribbon cable is provided and comprises: producing substrate layers comprising silicone adhesive on a polyimide film, punching holes in each substrate layer for vias, using the polyimide film to lift patterned copper lines from a plate; connecting the copper lines of the different layers by providing finished vias in the holes either by spot welding or by a solder paste and reflow technique, and providing a final cover layer which masks exposed lines while providing appropriate holes for components. The holes in the final cover layer typically expose or contain adhesive which permits surface mount components to be mounted without the need of additional adhesive. The provided method is in contrast to the conventional methods which use copper plating baths and multiple process steps to produce the flex board, and which require positive hold down methods for surface mounting parts. In order to produce this multilayer flex board or ribbon cable, substrate layers having a silicone adhesive on a polyimide film are used. As will be indicated hereinafter, the silicone adhesive is used both for lifting fine copper lines and for bonding the layers of the multilayer flex board together. In order to provide electrical connections between the layers of the flex board, holes for copper vias are punched in each substrate layer. The silicone adhesive of the punched layer is then used to lift patterned copper lines from a plate which was especially arranged to permit such lifting. The resulting structure is a layer having patterned copper held to a polyimide film by an adhesive. In order to provide electrical connection between...