Browse Prior Art Database

REPLACEABLE COVER PLATE TO REDUCE MOLDED PACKAGE RESIN BLEED

IP.com Disclosure Number: IPCOM000007203D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2002-Mar-05
Document File: 4 page(s) / 261K

Publishing Venue

Motorola

Related People

Cliff J. Scribner: AUTHOR [+2]

Abstract

Transfer molding technology, especially in the semiconductor field, has advanced dramatically in the last decade. Despite the steady advancements, one of the great challenges continues to be accom- modating traditional manufacturing techniques with packages having more complex configurations, larger physical dimensions and asymmetrical internal pack- age geometry's, Several mold related projects facing this chal- lenge are currently in the development stage at the Motorola Semiconductor Products Sector Chandler facility. One particular project is the Pilot Line pro- duction of the AC Ring Quad Flat Pack (40x40 mm) plastic Micro-Cool package, including the family of package variations. The package is molded with thermoset epoxy either in a 232 or 304 lead contig- uration. Both configurations include a molded car- rier ring that is formed outside the molded package body, Some versions include a heat sink that pro- vides enhanced thermal performance while others are ofthe Multi-Chip-Module (MCM) configuration.

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0 M MO-LA

Technical Developments Volume 22 June 1994

REPLACEABLECOVERPLATETOREDUCE

MOLDED PACKAGE RESIN BLEED

by Cliff J. Scribner and James H. Knapp

INTRODUCTION

  Transfer molding technology, especially in the semiconductor field, has advanced dramatically in the last decade. Despite the steady advancements, one of the great challenges continues to be accom- modating traditional manufacturing techniques with packages having more complex configurations, larger physical dimensions and asymmetrical internal pack- age geometry's,

  Several mold related projects facing this chal- lenge are currently in the development stage at the Motorola Semiconductor Products Sector Chandler facility. One particular project is the Pilot Line pro- duction of the AC Ring Quad Flat Pack (40x40 mm) plastic Micro-Cool package, including the family of package variations. The package is molded with thermoset epoxy either in a 232 or 304 lead contig-

uration. Both configurations include a molded car- rier ring that is formed outside the molded package

body, Some versions include a heat sink that pro- vides enhanced thermal performance while others are ofthe Multi-Chip-Module (MCM) configuration.

  An Aperture Plate Mold die and mold base assembly, manufactured by the DUSAN Corpora- tion (Aperture Plate Mold U.S. Patents, 4,332,537 & 4,368,168 & 4,442,056) in Gilroy, California, is mounted inside the press platens. The plate mold concept incorporates the use of a 3 plate molding system that includes the runner plate which pro- vides the travel path for the mold compound and includes the plastic cull, a top aperture plate as well as a bottom aperture plate that fit together. A picto- rial representation of the Aperture Plate Mold assem- bly, including a portion of the mold press, is shown in Figure 1.

TRANSFER CYLINDER yh ~ MOLD PLUNGER

FIXED PLATEN 7

OLD BASE (TOP)

HEATER RODS

RUNNER PLATE (CORE PINS)

APERTURE PLA (rw

APERTURE PLATE (SOTTOM)

COVER PLATE

MOVING PLATEN 1 i i%URE2 \

FIGURE l-APERTURE PLATE MOLD ASSEMBLY

The press, in addition to other mentioned fea- the ability to control mold pressure on the plunger tures, has a process controller that specifically has side, plunger velocity, plunger position, as well as

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Technical Developments Volume 22 June 1994

many other useful process parameters that are recorded during mold transfer.

die has specific areas of registration (6 packages and 1 cull) that concentrate the clamp pressure from the bottom side of the mold die to reduce package parting line resin bleed.

  Drawing CHD-93-056-00, "REPLACEABLE COVER PLATE BOTTOM:' is the prototype of the invention.

PURPOSE OF INVENTION

The Replaceable Cover Plate is composed of a
10.25" x 10.25" x 3/32" thick piece oflow carbon flat ground steel that fits on top of the cover plate assem- bly shown in Figure 1. The opposing assembly has protruding core pins that slide th...