Browse Prior Art Database

Surface-Mounted Array-Type Plastic Chip Carrier

IP.com Disclosure Number: IPCOM000044291D
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Overfield, RB: AUTHOR [+2]

Abstract

Commonly available array-type chip packages typically provide peripheral accessibility and thus have somewhat limited input/output density. This article presents a novel design for high density, low cost array chip packaging for surface-mounted devices. Typically, I/O accessibility in semiconductor devices has been provided on the periphery of the package containing the given device. Because of this peripheral design, the I/O density of such devices -- i.e., the number of signals handled in and out -- has been limited to relatively low levels. The present package design (Figs. 1, 2, 3) provides a solution to this density limitation through the incorporation of an array format technique.

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Surface-Mounted Array-Type Plastic Chip Carrier

Commonly available array-type chip packages typically provide peripheral accessibility and thus have somewhat limited input/output density. This article presents a novel design for high density, low cost array chip packaging for surface-mounted devices. Typically, I/O accessibility in semiconductor devices has been provided on the periphery of the package containing the given device. Because of this peripheral design, the I/O density of such devices -- i.e., the number of signals handled in and out -- has been limited to relatively low levels. The present package design (Figs. 1, 2, 3) provides a solution to this density limitation through the incorporation of an array format technique. The product includes a low cost, plastic leadless area array chip carrier that can accommodate semiconductor products of a wide range of types. The new carrier is an injection-molded unit containing encapsulated pins arranged in array format, in which pins are formed to provided a head for interconnection to a pad on a printed circuit board. The interconnections to the circuits are made at the top surface by means of an etched opening in the film on the fan-out pattern pad, as shown in Fig. 1. The use of chips with tabs and wirebonds is illustrated in Figs. 2 and 3. Fabrication of the plastic carrier (essentially a square piece of plastic containing pins arranged in a grid) occurs in the following steps: - An injection mold is set up in which pins are automatically fed into a single fixed matrix. - Plastic mold injection and pin encapsulation take place. - The carrier is unloaded. - The bottoms of the pins are formed. - The top surface of the pins is prepared for bonding. The film printed circuit is the specially formed piece of film which actually carries th...