Browse Prior Art Database

Method for Removing Flip Chips

IP.com Disclosure Number: IPCOM000087057D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Angelone, PA: AUTHOR

Abstract

This chip removal technique allows flip chip, or face-side-down, mounted semiconductor chips to be quickly and safely removed from substrates for evaluation of failures or other purposes.

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Method for Removing Flip Chips

This chip removal technique allows flip chip, or face-side-down, mounted semiconductor chips to be quickly and safely removed from substrates for evaluation of failures or other purposes.

In the past when chips, having been soldered face down to a substrate, required removal, heating of the chips to a temperature above the melting point of the solder or chemical etching have been used. Both of these techniques may damage the chips to the point that removed chips could provide little failure analysis information.

In addition, as circuit densities have increased, the number of solder pads per chip has increased to further reduce the effectiveness of thermal or chemical removal.

In this method, solder pads are physically cut or severed by a microscalpel easily fabricated from a dental probe. The tip of the probe is shaped to form a cutting surface narrow enough to fit between adjacent solder pads such that horizontal movement of the probe severs chip pads one at a time. The blade portion of the probe should be formed to a suitable angle with respect to the handle to enable convenient handling of the removal tool.

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