A New Set of Printed-Circuit Technologies for the IBM 3081 Processor Unit
by D. P. Seraphim
A new set of printed-circuit technologies have been developed which permit construction of printed-circuit panels with several kilometers of controlled-impedance interconnections. Communications between internal layers of signal planes are achieved through small plated vias (drilled with a laser), while plated through-holes are used for the logic service terminals for cable terminations and module terminals. The panels are the largest currently known in the industry, 600 × 700 mm, and have the most layers, 20. This paper describes new LSI package designs which are achievable with the exceptional versatility that the new technologies provide. These technologies encompass vacuum lamination, electroless plating, photosensitive dielectric, laser drilling, automatic twisted-pair wire bonding, and other new approaches to printed circuits.