METHOD FOR MANUFACTURING INDIUM MICROSPHERES FOR ASSEMBLING INTEGRATED CIRCUITS Russian patent published in 2005 - IPC

FIELD: producing microassemblies of integrated circuits using, for instance, flip-chip technique for infrared photodetectors with aid of indium microspheres.

SUBSTANCE: proposed method for manufacturing microspheres to assemble integrated circuits includes application of adhesive layer onto wafer carrying integrated circuits with contact pads, formation of barrier-adhesive layer above contact pads, electrochemical deposition of metal, and removal of adhesive layer beyond microsphere forming areas; adhesive layer is oxidized prior to electrochemical deposition and barrier-adhesive layer is activated, this being followed by electrochemical deposition of indium; adhesive layer is removed together with oxide layer formed thereon. Electrochemical deposition of indium is conducted in acetamide melt at temperature higher than indium melting point as indium being deposited is in liquid state, and fused microspheres are formed due to surface tensioning forces. It will be good practice to apply indium layer, 1-3 μm thick, by electrochemical deposition in acetamide melt at temperature below indium melting point prior to deposition of microspheres.

EFFECT: reduced labor consumption.

4 cl, 4 dwg