Welding of Electronic Modules for the Polaris Missile

Some time ago the potential value of welding electronic modules was recognized. An investigation was authorized to locate and solve the problems which would be encountered Jf this technique were to be applied to the electronic modules. This paper summarizes the status of findings to date, the number of problems still under investigation, and other subjects requiring study. Preparations have been made for the first production application of welding electronic modules. A welding specification OS 11889 has been released. This specification states the requirements of suitable welding machines and the criteria for certifying weld schedules and in-process and final inspection. Preliminary weld schedules have been developed which meet the broad requirements of the specification. The thousands of welds made and tested during the development of these schedules have served to field test the requirements and related conditions to current experience in industry. The investigations offer evidence that nickel, Dumet, and Kovar are weldable lead materials to nickel interconnecting media. To meet standards, separate weld schedules are required for each material size; moreover, variations in material composition and temper must be limited. Continuing study of other essential aspects of the problems are being pursued.