Browse Prior Art Database

COMMON STRIP LEADFRAME WITH BREAK-OFF FEATURE

IP.com Disclosure Number: IPCOM000006320D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-24
Document File: 3 page(s) / 117K

Publishing Venue

Motorola

Related People

James J. Casto: AUTHOR

Abstract

There are several leadframe designs currently in use which are called "common strip:' These designs allow front end assembly equipment such as die bonders and wire bonders to handle leadframes for several very different package types (e.g. SOJ, PLCC, DII: PQFP) with only minor changeovers. See Figure 1. Backend tooling such as molds and trim and form die sets are nec- essarily dedicated to only one package type, and are purchased to be compatible with this "common strip" leadframe design.

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MOTOROLA INC. Technical Developments Volume 14 December 1991

COMMON STRIP LEADFRAME WITH BREAK-OFF FEATURE

by James J. Casto

   There are several leadframe designs currently in use which are called "common strip:' These designs allow front end assembly equipment such as die bonders and wire bonders to handle leadframes for several very different package types (e.g. SOJ, PLCC, DII: PQFP) with only minor changeovers. See Figure 1. Backend tooling such as molds and trim and form die sets are nec- essarily dedicated to only one package type, and are purchased to be compatible with this "common strip" leadframe design.

  A new die bonder is being purchased, which is very inflexible as regards leadframe strip width and pitch. It requires major changeovers when converting from one package type to another. This bonder will be needed for assembly of two package types, 32 lead SOJ and 36 lead SOJ. These two packages are designed on two dif-

ferent leadframe strip widths (the pitch and length are the same.) Production-scale backend tooling has already been purchased for the 32 lead SOJ, at a significant cost, which cannot conveniently be modified to run a dier- ent strip width. In addition, the 36 lead SOJ will not fit on the strip width of the 32 lead SOJ.

  A novel leadframe design is disclosed that will allow the new die bonder to run,both the 32 lead SOJ and the 36 lead SOJ, as well as allowing the continued use of the existing 32 lead SOJ backend tooling. Principal fea- t...