Browse Prior Art Database

IC Direct Bonding by Laser

IP.com Disclosure Number: IPCOM000100134D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Ishida, K: AUTHOR [+2]

Abstract

A laser bonding technique for TAB (Tape Automated Bond- ing) packages is disclosed in which a laser beam is focused on the welding spot of a lead through a lead pressing member acting as a condenser lens.

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IC Direct Bonding by Laser

       A laser bonding technique for TAB (Tape Automated Bond-
ing) packages is disclosed in which a laser beam is focused on the
welding spot of a lead through a lead pressing member acting as a
condenser lens.

      The figure shows the present bonding technique.  In the bonding
process, TAB leads 3 are properly positioned on corresponding IC
metal pads 2 of an IC chip 1.  Only one lead 3 and only one
pad 2 are shown in the figure.  The leads 3 are preferably
gold-plated copper.  The leads 3 are pressed against the pads 2 by a
lead pressing member 4 to bring the leads 3 into close contact with
the pads 2 and apply pressure required for bonding.  The pressing
member 4 is made of a transparent material such as crystal glass and
shaped to act as a condenser lens.  The laser beam is focused on the
bonding site through the pressing member 4 to melt the lead 3,
resulting in bonding between the lead 3 and the pad 2.  The bonding
is preferably performed in an inert gas atmosphere.

      An opaque pressing member such as a metal plate which has a
small hole equal in diameter to the desired beam spot may be used in
place of the transparent pressing member 4 to provide a narrow
welding laser beam, if desired.