PATENT COVER GRAPHIC


United States Patent 3,495,322
February 17, 1970

Process For Bonding A Silicon Wafer To A Ceramic Substrate
Marcy B. Goldstein

Filed July 20, 1967
Image of US PATENT 3,495,322

Abstract of the Disclosure

An integrated circuit die is bonded to a ceramic substrate by a series of steps including the application of a molybdenum-manganese paint to the ceramic base by silk screening techniques. The paint is characterized by a ratio of manganese to molybdenum not greater than 1:4.5 and includes 1% to 10% by weight silica based on total solids. After drying and sintering the metallic powders in a wet hydrogen atmosphere, the metallized surface is cleaned with a 50% aqueous solution of hydrogen fluoride to remove any film of glass or ceramic formed on the metallized surface. A gold-germanium alloy preform is placed on the metallized surface and the parts are heated to at least 600 C. in a nonoxidizing atmosphere to provide intimate contact of the molten alloy with the metallized surface. Subsequently, at a temperature no greater than 450 C., the silicon die is placed in contact with the alloy phase whereby a metallurgical bond is formed.
Figure descriptions: cover graphic

  • Figures 1 and 4 through 6 are plan views showing a metallized ceramic plate in the various processing stages of the invention.
  • Figure 2 is a separate view of a gold-germanium alloy preform used in the process of the invention.
  • Figure 3 is a separate view of the integrated circuit die to be bonded to the ceramic plate as shown in Figure 6.
  • Figure 7 is an isometric view of a ceramic-glass flat package prepared in accordance with one embodiment of the invention.

 Citations [54]:
  
2,902,756 09/1959 Cavanaugh 540,991 11/1941 Great Britain
National Museum of American History
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