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INVENTION SUMMARY: AUTOMATION OF THE WAFER DEMOUNT PROCESS

IP.com Disclosure Number: IPCOM000007228D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2002-Mar-06

Publishing Venue

Motorola

Related People

Authors:
Anthony R. Weeks James Lee Stephen Switzer

Abstract

The wafer thinning process requires the front side of each wafer to be submerged in wax, wherein, the wax mechanically affixes the wafer to the stain- less steel carrier. Next, the carrier is turned wafer side down and spun on a stainless steel table. A mixture of grit (aluminum oxide) and water are dis- pensed onto the table to aid in the wafer thinning process and to eliminate wafer to table contact. The lapping process continues until the wafers are approx- imately 7 mils thick. At this point, the carriers and attached wafers are submerged in a 5:l:l acid bath to etch the wafers to a final thickness of 5 mils. Finally, the carrier is placed on a hot plate for 10 minutes in an attempt to melt the wax bond be- tween the wafer and the carrier. At the end of this time, an operator attempts to peel (like the skin off a banana) the wafers from the carrier with a hand held vacuum wand by placing the vacuum on the back side ofthe wafer and lifting in an upward motion (Figure 1).