Browse Prior Art Database

Notching Die and Compound Die

IP.com Disclosure Number: IPCOM000082931D
Original Publication Date: 1975-Mar-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Tognelli, C: AUTHOR

Abstract

Described is a compound die for removing the selvage, and forming an expansion loop in a multielement lead frame for semiconductor devices, in which the material from which the lead frame is formed is inserted in a handling solder fixture. This fixture is automatically removed from the die after fabrication of the lead frame.

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Notching Die and Compound Die

Described is a compound die for removing the selvage, and forming an expansion loop in a multielement lead frame for semiconductor devices, in which the material from which the lead frame is formed is inserted in a handling solder fixture. This fixture is automatically removed from the die after fabrication of the lead frame.

A shaped hollow lead frame holder 11 having a plurality of openings 12 in its upper surface 13, is positioned in a recess 14 in a rotating die 15. The rotating die 15 is provided with a number of pusher pins 18, each of which rest on a respective ramp or inclined plane 19 provided in the base 16 on which the rotating die 15 is mounted. When the rotating die 15 is turned, the pins 18 ride up planes 19 to cause the ring 11 to be forced out of the recess 14.

In use a foil, previously electrolytically etched in the form of a spoked rim, is placed over the holder 11, seated in the recess 14, in the rotating die 15, and a top punch 21 is placed over the die 15 and lead frame foil. The top punch 21 comprises an outer motion strip 22 for clamping the foil 20 in its fixed position and an inner core 23, which cuts off the inner selvage of the spoked rim. The inner core 23 clamps the free inner ends of the lead frame after the inner selvage is removed.

A forming die 25 having a series of teeth 26 which mate with and pass through the pluralities of openings 12 in the surface of the lead frame, is disposed between the outer...