Browse Prior Art Database

Ultrasonic Bond Automated Quality Inspection System

IP.com Disclosure Number: IPCOM000103305D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 46K

Publishing Venue

IBM

Related People

Brooks, WW: AUTHOR [+5]

Abstract

Disclosed is the use of a simple machine vision system to assess ultrasonic bond quality. Essentially this is done by determining, through the use of suitable optics, electronics and programming, whether a velocity-controlled jet of air or other suitable gas can move the wire in the vicinity of the ultrasonic bond.

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Ultrasonic Bond Automated Quality Inspection System

      Disclosed is the use of a simple machine vision system to
assess ultrasonic bond quality.  Essentially this is done by
determining, through the use of suitable optics, electronics and
programming, whether a velocity-controlled jet of air or other
suitable gas can move the wire in the vicinity of the ultrasonic
bond.

      The following describes the fundamentals of the inspection
system. The system would take a TV/microscope picture of the
immediate vicinity of the wire/pad ultrasonic bond to be checked.
The gray scale information for all of the pixels in the view would be
saved in computer memory. Next, the system would apply a brief pulse
of gas to the area of the bond.  During the time the gas jet is
on, a second image of the wire bond area would be taken.  A
comparison of the two frames on a pixel by pixel basis, using a
suitable algorithm, would indicate whether the wire moved
significantly when the gas jet was on. Significant movement would be
taken to mean a bad bond.

      This inspection system could be used where the wire bonds are
performed.  In this application, the system would only detect wire
bonds which had extremely low bond strengths such as would happen if
an unbondable layer were present on the bonding pads, or if the
bonder was not functioning.

      This inspection system could also be used where the excess wire
scrap is removed from the bond area.  As the excess wire is...