Hot gas soldering for interconnection of integrated electronic packages

A major problem facing users of integrated electronics has been the lack of high-speed automated processes for interconnection of fiat profile packages, in large quantities, into higher order subsystem assemblies. The hot gas soldering process employs jets of heated hydrogen which are scanned across the joint rows of planar package arrays. Joining speeds in excess of 100 leads per minute for each jet have been obtained, without causing thermal damage to package seals or wiring boards. This paper discusses in detail the process parameters of gas temperature, board feed rate, and joint mass as they effect soldering speed and joint quality. A multinozzle production machine which also positions microcircuit packages is described. Selection of printed wiring boards and materials for hot gas soldering is discussed.