Browse Prior Art Database

A LOW COST, ADHESIVE-LESS, HEATSPREADER EQUIPPED PLASTIC PACKAGE

IP.com Disclosure Number: IPCOM000007601D
Original Publication Date: 1996-May-01
Included in the Prior Art Database: 2002-Apr-09
Document File: 2 page(s) / 80K

Publishing Venue

Motorola

Related People

Frank Djennas: AUTHOR [+3]

Abstract

The plastic Quad Flat Package has evolved into a large, high pin count package, however higher costs and thermal dissipation requirements constitute the boundary conditions it must overcome to evolve as a viable high density package. The present mold com- pounds used as encapsulants have poor thermal con- ductivity and represent a large portion of the ther- mal resistance in the plastic package. Existing thermally enhanced plastic packages are prone to delamination, and command steep prices.

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Technical Developments

A LOW COST, ADHESIVE-LESS, HEATSPREADER EQUIPPED PLASTIC PACKAGE

by Frank Djennas, Bennett Joiner and Les Posthlewaith

  The plastic Quad Flat Package has evolved into a large, high pin count package, however higher costs and thermal dissipation requirements constitute the boundary conditions it must overcome to evolve as a viable high density package. The present mold com- pounds used as encapsulants have poor thermal con- ductivity and represent a large portion of the ther- mal resistance in the plastic package. Existing thermally enhanced plastic packages are prone to delamination, and command steep prices.

  A new heatspreader equipped plastic package is proposed herein that uses no die pad nor die or heatspreader attach and achieves a high level ofther- mal performance, at a cost comparable to the stand- ard plastic package. The elimination of die pad and

die and heatspreader attach adhesives and the juxta- position ofthe die (heat source) to the heat spreader significantly improves heat dissipation and keeps costs very low. Vacuum is utilized to perform the ftmc- tion of the die and heat spreader attach processes. Vacuum is used both at the wirebonding and mold- ing assembly processes, where it is used in a conju- gated way such that both die and heat spreader are held in place simultaneously during the encapsulation process. The resulting package has a thermal per- formance that is similar to and in cases better than existing...