Solder bump production on substrate - by immersing cooled substrate in molten solder bath.

: Oppermann, H.H.

Abstract
In a method of producing solder bumps on a substrate by contact with a molten solder bath, at least part of the substrate is cooled during contact with (preferably immersion in) the solder bath. Preferably, the substrate is a chip or wafer and is briefly dipped into the solder bath or wetted by a solder wave. ADVANTAGE - The method has lower equipment and material costs than prior art deposition methods, employs short and simple process steps and provides a copious solder supply for forming solder bumps of satisfactory height on the substrate.