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Ultrasonic Wire Bond Protector

IP.com Disclosure Number: IPCOM000110905D
Original Publication Date: 1994-Jan-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Cutting, L: AUTHOR [+4]

Abstract

In ultrasonic wire bonding process, the wire bond suffers pull-off during the table tear stage of some autobonders, resulting in tremendous loss of yield. This article describes a mechanism or a device which protects the bond from pull-off and improves the yield.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 60% of the total text.

Ultrasonic Wire Bond Protector

      In ultrasonic wire bonding process, the wire bond suffers
pull-off during the table tear stage of some autobonders, resulting
in tremendous loss of yield.  This article describes a mechanism or a
device which protects the bond from pull-off and improves the yield.

      This device, called "The Bond Protector", is an attachment
which can be mounted on the existing autobonder and does not
interfere with its automatic operation.  As shown in the figure, a
small DC solenoid is mounted in a bracket which is attached to the
frame surrounding the transducer-wedge assembly.  The solenoid can be
oriented to aim the plunger at the exact position of the wire bond.
The plunger tip is rounded to let it slide easily over the bond under
the pressure when the table moves.  After forming the bond, when the
wedge is lifted up, the solenoid is energized and the plunger is
pushed against the bond to exert the pressure on the bond while the
table moves to terminate the wire.  This way the upward lifting force
of the wire pull is counteracted by the pressure of the plunger and
thus the bond is protected against the "pull-off".  When the wire is
terminated, the solenoid is de-energized to retract the plunger and
the wedge along with the plunger moves to the next bond site.  This
cycle repeats for every bond made, thus protecting all bonds from
pull-off.  These steps and forces acting during the wire termination
are shown in the lower half of...