Browse Prior Art Database

Multiple Chip Heat Sink Package

IP.com Disclosure Number: IPCOM000062382D
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Lumbra, DL: AUTHOR [+4]

Abstract

A multiple chip package is comprised of a conductive material, e.g., beryllium-copper preformed "muffin tin" to which the backs of semiconductor chips, already wire bonded to a lead frame assembly and burn-in tested, are thermally contacted via conductive grease. The lead frame assembly is bonded to chip edges and to flat portions of the "muffin tin" by double-sided tape. A layer of flex circuit is tape bonded and electrically connected to the lead frame wiring. The flex circuit is used to form the connections to the next level of packaging. A second "muffin tin", chip, lead frame, and flex circuit assembly may be tape bonded to a first such assembly, resulting in a completely enclosed, high volume density, multi-chip package with good heat dissipation characteristics.

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Multiple Chip Heat Sink Package

A multiple chip package is comprised of a conductive material, e.g., beryllium- copper preformed "muffin tin" to which the backs of semiconductor chips, already wire bonded to a lead frame assembly and burn-in tested, are thermally contacted via conductive grease. The lead frame assembly is bonded to chip edges and to flat portions of the "muffin tin" by double-sided tape. A layer of flex circuit is tape bonded and electrically connected to the lead frame wiring. The flex circuit is used to form the connections to the next level of packaging. A second "muffin tin", chip, lead frame, and flex circuit assembly may be tape bonded to a first such assembly, resulting in a completely enclosed, high volume density, multi-chip package with good heat dissipation characteristics. Since the chips make good thermal connection to the "muffin tin" via grease, there is no stress applied to chips or chip connections if there is relative motion between the heat sink "muffin tin" and the chip. Fig. 1 is a cross-section showing the assembly of a single chip, Fig. 2 is a top view and Fig.2A is an end view of a completed package containing eighteen chips. Referring to Fig. 1, the chips 2 are tape 4 bonded and electrically connected via wire bonds 12 to the lead frame assembly
6. Once all of the chips are thus attached to one lead frame assembly, the chips are burn-in tested. Any of the chips failing the burn-in test may be removed and replaced with oth...