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Auto Adjust Probe Deflection

IP.com Disclosure Number: IPCOM000107182D
Original Publication Date: 1992-Jan-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Balas Jr, RF: AUTHOR

Abstract

Auto Adjust Probe Deflection is a method of changing probe pressure "on the fly". This method would be useful on testing systems which test substrate open and shorts or any similar test equipment. (Image Omitted)

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Auto Adjust Probe Deflection

       Auto Adjust Probe Deflection is a method of changing
probe pressure "on the fly".  This method would be useful on testing
systems which test substrate open and shorts or any similar test
equipment.

                            (Image Omitted)

      A capacitor sensor integral to the probe heads coupled with
sense logic scans for variation in substrate thickness while the test
heads index back and forth across the part. This scanning sensor
eliminates manual adjustment of two micrometer spindle settings for
substrate thickness variation.  Ordinarily, these micrometers must be
set for almost every part placed on the tool and are constant until
manually changed again.  If the proper probe pressure is not achieved
failures may occur either in the form of an "open" or a "short".  An
"open" is indicative of too little probe pressure being applied while
a shorts indicates too much pressure.

      The sensor as mounted between the metal frame of the probe and
the plastic dies of the probe heads.  The test system is configured
as the device under test remains stationary while two sets of probes
index above it in X, Y and Z movement.  While both sets of probes
hover above the device under test, they are in a state called Z test
up. When the command comes over to make contact, the probes go to the
Z test down state.  When an End of Test is received, the probes are
commanded to Z test up state.

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