Browse Prior Art Database

TAB Inner Lead Punch And Reform Tool

IP.com Disclosure Number: IPCOM000120420D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Kelleher, RJ: AUTHOR [+3]

Abstract

Disclosed are Tape Automated Bond (TAB) technology chip carriers employing cantilever beams as inner leads to connect to chip pads. When an inner lead guard is used to protect the leads it is usually removed just prior to chip attach. It may also be desirable to bend the leads prior to chip attach to increase the clearance from the leads to the chip face and to provide stress relief to the lead.

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TAB Inner Lead Punch And Reform Tool

      Disclosed are Tape Automated Bond (TAB) technology chip
carriers employing cantilever beams as inner leads to connect to chip
pads.  When an inner lead guard is used to protect the leads it is
usually removed just prior to chip attach.  It may also be desirable
to bend the leads prior to chip attach to increase the clearance from
the leads to the chip face and to provide stress relief to the lead.

      Fig. 1A shows a die 1 which supports the TAB 2 during the
operation.  The stripper plate 3 holds the TAB 2 in place after the
location on pin 5.  Punch 6 comes down to TAB 2 as in Fig. 1B.
The cutting edge 7 of the punch is built with zero clearance to die 1
in order to cut copper inner lead 8 with minimum smear and to remove
inner lead guard 9.  Punch 6 and die 1 are designed to form the inner
lead with bends 10.

      For typical inner lead widths of 0.002" to 0.0025" the punch,
die and stripper plate are wire burned with a 0.002" diameter wire.
This allows inner leads to be cut to individual lengths, or to be
formed to or from different planes.