Batch fabricated matrix memories

Abstract

Present-day matrix memory fabrication techniques are relatively expensive since discrete binary memory elements are individually made and then assembled into a matrix array by means of manual or semimanual wiring. The assembly of individual matrix planes is usually followed by another expensive step wherein the planes of a memory stack are interconnected. The key to low cost matrix memories lies in integrated or batch fabrication of the memory elements and wiring structure of a plane, and also batch forming the interconnections between planes in a memory stack. Additional economy results from making the bit capacity of a plane as large as possible. The need for batch fabricated memory planes appears to be generally recognized, considering the number of suggestions that have been made for achieving the goal. Thin magnetic film memory elements were initially of interest because of their high switching speed, which made very fast memories possible, but today thin magnetic film memories are of interest principally because they offer one approach to batch fabrication, since in the meantime ways have been found for achieving high speed with ferrites.