SIXTH INTERIM DEVELOPMENT REPORT FOR A POROUS SUBSTRATE RESISTOR AIMED AT MINIATURIZATION OF METAL-FILM RESISTORS

摘要

In order to increase the wattage limits established in Phase I, ceramics with higher thermal conductivity than quartz were investigated. Specifically, alumina was reconsidered for substrate use because of thermal conductivity, availability and cost. Defects in the substrate structure (fused areas, vacancies and non-intercommunication of pores) were analyzed with respect to the parameters of weight-to-volume ratio and flow. The results have showa significant improvement in structure. Individual brazing of the end cap to the substrate replaced "strip brazing'' used The new method eliminated the need for deburring and refluxing and was superior in strength. The end cap was redesigned to permit the mechanical adjustment of the four surfaces of the substrate and solution penetration was enhanced.