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Joining Integrated Circuit Chips to Substrates

IP.com Disclosure Number: IPCOM000074752D
Original Publication Date: 1971-Jun-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Schmeckenbecher, AF: AUTHOR

Abstract

Conductive leads from integrated circuit chips to the substrate are angled twice to provide high flexibility for the relief of stresses; to give easy access for a cooling fluid, and to facilitate the replacement of defective chips. The joining method is simple and easily adapted to automated production.

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Joining Integrated Circuit Chips to Substrates

Conductive leads from integrated circuit chips to the substrate are angled twice to provide high flexibility for the relief of stresses; to give easy access for a cooling fluid, and to facilitate the replacement of defective chips. The joining method is simple and easily adapted to automated production.

An insulating rigid or flexible substrate 10 with suitable electrical and thermal properties and with any thermal coefficient, such as fiber glass-epoxy-composites or polyamide-imide sheets of KAPTON* is provided with holes by mechanical or laser punching or other means. The holes are preferably rectangular with dimensions slightly smaller than those of the width and length of the integrated circuit chips.

A conducting metal layer 12, such as copper foil, is applied to one side of the substrate, e.g. by laminating with an adhesive at elevated temperature and pressure. The desired conductor pattern, such as a fan-out pattern with leads 14 extending into the hole areas is photo-etched nto the metal foil by the usual techniques. The free standing leads may be covered with a nontinnable coat, e.g. a temperature resistant lacquer. A plunger 16 with a cross section slightly smaller than the holes 11 is pushed from the metal side into the holes, while a flat support piece 18 with an abrasive surface is held against the other side of the substrate.

The leads 14 are somewhat longer than the thickness of the substrate, so that the leads are bent tw...