PRODUCTION ENGINEERING MEASURE ON SILICON ALLOY TRANSISTORS.
Quarterly rept. no. 4, 1 Apr-30 June 63.
RAYTHEON CO LEWISTON MAINE
Pagination or Media Count:
Efforts were continued on the establishment of a PEM to improve the reliability of silicon alloy transistors. Dimensional control of the chip is complete and in production. Float zone silicon crystal was put into full production use with specified controls on all bulk parameters. Electrical evaluation of subassembly basewidth was incorporated into production. A modified heat sink stem was investigated and the thermal resistance of three stem designs measured. An optimum basecoat curing cycle was evaluated and made part of the production process. Investigation of the effect of packaging ambients continues. An optimum post seal stress cycle was incorporated into production. Step-stress experiments were initiated and confirmed the existence of an alternate failure mode. Author