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Browse Prior Art Database

Reduction of Bending and Stresses in Processing Diced Si Chips

IP.com Disclosure Number: IPCOM000108184D
Original Publication Date: 1992-Apr-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 72K

Publishing Venue

IBM

Related People

Krongelb, S: AUTHOR [+5]

Abstract

Cracks in quartz deposited on Si were found in the diced chips during the pick-up operation. A finite-element analysis showed that cracks are caused by chip bending as a result of vacuum sucking and a concentrated force imposed by a thin rod pusher. The purpose of the latter is to tear the chip away from the adhesive tape which is used to hold chip wafer during the dicing operation.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Reduction of Bending and Stresses in Processing Diced Si Chips

      Cracks in quartz deposited on Si were found in the diced chips
during the pick-up operation.  A finite-element analysis showed that
cracks are caused by chip bending as a result of vacuum sucking and a
concentrated force imposed by a thin rod pusher.  The purpose of the
latter is to tear the chip away from the adhesive tape which is used
to hold chip wafer during the dicing operation.

      Disclosed is a modified vacuum chuck for picking up diced chips
without causing quartz cracking.  Figure 1 shows the disclosed
configuration comprising an elastomeric cap 1 (put on a vacuum chuck
2) with a sleeve and plurality of protruded (short) tubings which are
uniformly distributed, and an universal joint, which is connected to
the wafer holder by a vertical slide, a rigid frame, and a set of X-Y
and rotation table, used to regulate the pick-up force to be always
in the direction normal to the diced wafer 5.  In such a way, it was
proved by a finite-element calculation that the bending and the
resulted stresses on the diced chip during the pick-up operation are
dramatically reduced so that the quartz cracking problem can be
eliminated.

      Disclosed anonymously.