Plessey Incorporated

John M Frusco

Herbert Bothner

Dieter Spieth

Tools for stamping very delicate lead frames for semiconductor packages, including scored and bent-up tabs that retain groups of inner lead tips in position through subsequent operations, after which they are broken off. Sequential punch and die sets are used to (1) define the tabs, (2) bend down the leads, (3) score the tabs and coin the lead tips, and (4) bend the tabs up. At stations (3) and (4) means are provided to lift scored tabs out of the die and to allow the frame strip to move over the tab-bending die without interference.

Stamping tools

A stamped, 40-lead ceramic dual-in-line package (Cer-Dip) frame is disclosed. Increased usage and lowered costs of large scale, integrated circuits (LSI) for microprocessor and similar applications has created a demand for precision ceramic packaging of the forty-lead dual-in-line type that is adapted for automated chip insertion in high-volume and at a low cost. The present invention meets this need with a stamped lead frame wherein the longest and most fragile leads are held in precise spatial relation by means of break-off tabs. After embedment of the leads on the ceramic substrate with a glass composition, the tabs are broken and removed. Forming, scoring and bending of the tabs are carried out as an integral part of the progressive stamping operation. Lead frames according to the invention replace much more expensive etched parts. The invention may be applied in a variety of packages.

Growing community of inventors

Scotch Plains, NJ, United States of America

John M Frusco