Mated-film memory production--A progress report

Between April 1, 1970 and November 1, 1971, 32 500 acceptable arrays of Mated-Film^TMelements were produced. These 35 million bits were produced at an average rate of 1.75 and a maximum rate of 5.5 megabits per month. The results of this pilot run were to point out, first, that film memories can be produced for high-performance military systems at lower cost and with better reliability than core; and secondly, that the four metallic layers can be deposited with an overall yield of 60%. However, maximum cost effectiveness can probably be obtained by placing the greater priority on product through-put. The continuous deposition system is most compatible with the NiFe film because of the 1% NiFe ratio control needed for zero magnetrostriction. This is easily achieved by a steady-state electronically controlled source. Limitations in speed, start-up, and stabilization time, and machine reliability were all noted in the continuous coater during this run. The equipment for the expanded facility, designed according to these findings, is expected to at least double the output and to halve the production costs. The new equipment cost is approximately 5 kilobucks per megabit per year.