Browse Prior Art Database

Removal of Heat From Direct Chip Attach Circuitry

IP.com Disclosure Number: IPCOM000036203D
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 3 page(s) / 94K

Publishing Venue

IBM

Related People

Schrottke, G: AUTHOR [+2]

Abstract

Packaging for high density memory and logic curcuitry is satisfied by packages such as single in-line packages, smart cards, functional islands, daughter cards, etc., typical packages for electronic circuits which are then connected with various means to the system. Direct Chip Attachment (DCA) onto a flexible carrier can be effectively used to accomplish all of these configurations of electronic packaging. (Image Omitted)

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Removal of Heat From Direct Chip Attach Circuitry

Packaging for high density memory and logic curcuitry is satisfied by packages such as single in-line packages, smart cards, functional islands, daughter cards, etc., typical packages for electronic circuits which are then connected with various means to the system. Direct Chip Attachment (DCA) onto a flexible carrier can be effectively used to accomplish all of these configurations of electronic packaging.

(Image Omitted)

For many applications, significant power is dissipated, resulting in a requirement for thermal management. To dissipate the heat generated, a means for first spreading the heat to a heat sink which can then be transferred to air must be provided. The means must be able to withstand thermal cycling without degradation of the heat-dissipative capability.

To describe the invention, a system of DCA-mounted chips, C4 mounted to a flexible carrier will be described. The flexible carrier is used to interconnect the chips. In one practical application of the invention, the flexible carrier is folded around a stiffener. The stiffener supplies thermal expansion matching for the silicon, a ground plane, and means for conducting heat away from the chips (through the C4 joints and the flexible carrier).

The chips are bonded to a flexible carrier, as described in Figs. 1-4. However, instead of folding the flexible carrier over the spreader with the chips on the outside (Fig. 4), the chips in this embodiment (...