Browse Prior Art Database

Multi-Directional Vacuum Chuck for Holding Very Small Objects

IP.com Disclosure Number: IPCOM000118414D
Original Publication Date: 1997-Feb-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 72K

Publishing Venue

IBM

Related People

Chalco, PA: AUTHOR

Abstract

Disclosed is a multi-directional vacuum chuck where holding forces can be applied on small objects from several directions simultaneously. One application where reduction to practice has been demonstrated is the holding of a very small chip (approximately 2mm x 2mm) for thermosonic bonding. In this case, the simultaneously applied forces are perpendicular to each other. This application is described in detail below.

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Multi-Directional Vacuum Chuck for Holding Very Small Objects

      Disclosed is a multi-directional vacuum chuck where holding
forces can be applied on small objects from several directions
simultaneously.   One application where reduction to practice has
been demonstrated is the holding of a very small chip (approximately
2mm x 2mm) for thermosonic bonding.   In this case, the
simultaneously applied forces are perpendicular to each other.  This
application is described in detail below.

      Single-point Inner-Lead-Bonding (ILB) of chips to TAB flex
circuits or leadframes is done by thermosonic bonding.  In order to
obtain good bonding conditions, it is necessary to couple the
ultrasonic energy very efficiently and consistently into the bonding
area.  This is difficult to achieve when dealing with very small
chips where conventional mechanical means for holding chips during
bonding are not suitable.  The ultrasonic energy applies high
vibratory and motion forces on the chip, which create unstable
bonding conditions.  To solve this problem, a chip-holding technique
specially suitable for very small objects has been applied.  As shown
in the Figure, the technique is based on the simultaneous application
of vertical and side forces on the chip by vacuum.  The vertical
suction force is provided by a vacuum hole which is totally covered
by the underside of the chip.  The horizontal side force is provided
by a plate that presses the side of the chip.  This...