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Browse Prior Art Database

Method of Molding for Molded Heat Spreader Plastic Flat Package

IP.com Disclosure Number: IPCOM000114709D
Original Publication Date: 1995-Jan-01
Included in the Prior Art Database: 2005-Mar-29
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Hayashida, S: AUTHOR

Abstract

This article describes a method of molding for thermally enhanced plastic package which has a heat slug inside the package.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Method of Molding for Molded Heat Spreader Plastic Flat Package

      This article describes a method of molding for thermally
enhanced plastic package which has a heat slug inside the package.

By devising a gate design of a mold, resin bleed on the surface of
the exposed heat slug can be eliminated.

      Fig. 1 shows the structure of Molded Heat Spreader Plastic Flat
Package.  The heat slug (1) touches a backside of a die paddle (2)
without any adhesive or glue.  The heat slug radiates a heat which is
generated in the semiconductor chip (3).  A mold resin (4)
encapsulates the whole structure, such as chip, lead frame (5) and
the heat slug in a same mold.

      Fig. 2 shows the gate design of the mold for the package.  The
gate (6) is designed at the opposite side of the die to which heat
slug is placed.  During resin transferring into a cavity on the mold,
the flow of mold resin (7) pushes the heat slug down by cause se of
downward stream of mold resin.  The pushing force prevents the mold
resin from coming into a interface between the heat slug and bottom
mold surface (8).

      This method of molding makes it possible to prevent the resin
from bleeding on the exposed heat slug surface, without any extra
process such as deflash process to remove the resin bleed.  This
leads to cost reduction of packaging process.