A 4 kword DRO fine striped memory

The fine striped memory completely satisfies the conditions required on magnetic random access memory such as high speed, small size, and low cost. Adoptions of the formation of complete flux path closure on the digit lines, the introduction of the batch fabrication technique, and the use of a flux keeper on the word lines allow this memory to accomplish outstanding performance. At present, however, size and cost of peripheral parts are not practical. A problem which still remains is to design the entire system more compactly and economically. This paper introduces an approach to a 4 kword 32 bit DRO fine striped memory for this purpose. The memory stack consists of memory planes (1.6 × 120 × 310 mm). Each plane has one digit sheet sandwiched between two word sheets. A group of digit lines (70 μm wide, 100 μm pitch) is batch fabricated on a glass substrate (1 × 40 × 120 mm). The development of the heat ray soldering technique ensured the connection of digit lines in a short time and high reliability. On a word sheet, 64 IC modules are mounted and four sponge buffer backed ferrite flux keepers are glued. The word lines (100 μm diameter, 350 μm pitch) are inserted in the grooves of the flux keeper. Under 300 mA word current (30 ns rise time) and ± 15 mA digit current, output in the worst condition was minimum ± 1.5 mV.