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U.S. Department of Energy
Office of Scientific and Technical Information

Vacuum die attach for integrated circuits

Patent ·
OSTI ID:867973

A thin film eutectic bond for attaching an integrated circuit die to a circuit substrate is formed by coating at least one bonding surface on the die and substrate with an alloying metal, assembling the die and substrate under compression loading, and heating the assembly to an alloying temperature in a vacuum. A very thin bond, 10 microns or less, which is substantially void free, is produced. These bonds have high reliability, good heat and electrical conduction, and high temperature tolerance. The bonds are formed in a vacuum chamber, using a positioning and loading fixture to compression load the die, and an IR lamp or other heat source. For bonding a silicon die to a silicon substrate, a gold silicon alloy bond is used. Multiple dies can be bonded simultaneously. No scrubbing is required.

Research Organization:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA
DOE Contract Number:
W-7405-ENG-48
Assignee:
Regents of University of California (Oakland, CA)
Patent Number(s):
US 5046656
OSTI ID:
867973
Country of Publication:
United States
Language:
English