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APPARATUS/METHOD TO CONTROL FILL RATE OF MOLDED PACKAGE WITH CARRIER RING

IP.com Disclosure Number: IPCOM000007069D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2002-Feb-22
Document File: 4 page(s) / 256K

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 advancements, one of the great challenges continues to be accommodat- ing traditional manufacturing techniques with more complex package configurations.

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This is the abbreviated version, containing approximately 29% of the total text.

Page 1 of 4

MOTOROLA Technical Developments Volume 21 February 1994

APPARATUS/METHOD TO CONTROL FILL RATE OF MOLDED PACKAGE WITH CARRIER RING

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 advancements, one of the great challenges continues to be accommodat- ing traditional manufacturing techniques with more complex package configurations.

  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 ofthe AC Ring Quad,Flat Pack (40x40 mm) plastic micro-cool package. The package is molded with thermoset epoxy either in a 232 or 304 lead configuration. Both configurations include a molded carrier ring that is formed outside the molded pack- age body as well as a heat sink located on one side of the package that provides enhanced thermal performance.

  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 ofthe Aperture Plate Mold assem- bly, including a portion of the mold press, is shown in Figure 1.

  The press, in addition to other mentioned fea- tures, has a process controller that specifically has the ability to control mold pressure on the plunger side, plunger velocity, plunger position, as well as many other useful process parameters that are recorded during mold transfer.

TRANSFER CYLINDER \r

FIXED I'MTEN -.,

I+ ,,/ - MoLD PLUNGER

1

: i MOLD BASE (TOP)

HEATER RODS

APERTURE PLATE

MOVING PLATEN / FIGURE2 '

Figure 1. APERTURE PLATE MOLD ASSEMBLY

0 Motorola. 1°C. 1994

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Page 2 of 4

MOTOROLA Technical Developments Volume 21 February 1994

PURPOSE OF INVENTION

  Drawing CHD-93-028-00, "AC Mold PKG. Fill Control Gate (Bottom):' is the prototype used to implement the inventionon the AC Ring plate mold die. The gate insert is placed into the 6 cavities on the bottom aperture plate of the assembled mold die. Each cavity in the bottom plate is machined to fit the gate for each package.

  The bottom gate of an AC Ring (40 x 40 mm QFP PKG.) Plate Mold die is redesigned to provide a reliable means to control the fill rate ofmold com- pound simultaneously flowing into the package and carrier ring during mold transfer. A raised protru- sion is added to the bottom gate, thus insuring the package is filled last during the critical compaction phase of the fill sequence. Parting...