Feature

Micrologic elements being developed

By Staff -- EDN, 10/1/1960

Editor's note: EDN posted this article in 2006 as part of its 50th Anniversary celebration . For present-day analysis, see "Milestones That Mattered: The planar IC—revolution underestimated."

MOUNTAIN VIEW, CALIF.—High-speed, low power digital computer logic building blocks are under development at Fairchild Semiconductor Corp. To be available early next year, the family of solid-state micrologic elements will handle all the logic function requirements of a digital machine, no other components being required.

The micrologic elements are made by diffusing planar transistors and resistors into a solid continuum of silicon; element intraconnections are then deposited on the surface. The low cost resulting from batch-processing will mean lower first cost of a computer logic section. It is expected that reliability of the micrologic elements will be atleast as good as that of a well-engineered contemporary logic circuit performing the same function.

Micrologic elements will operate at bit rates in excess of 1 mc, a significant advance in the speed of such units. Typical power dissipations of 30mW per unit will permit high density packaging without extraordinary thermal problems (elements will have a temperature range of -55C to +125C0. The first units will be packages in 8-lead JEDEC TO-5 transistor cases suitable fro printed circuit board interconnections and elements will also be available in the smaller TO-18 packages for welded wire construction. Although these cases do not represent the smallest possible size, they are a convenient compromise between size and ease of interconnection.

Emphasis is placed on the logic function to be performed in both development and use of these building blocks. The following micrologic elements comprise the family:

"F" Element – Flip-flop	"B: Element – Buffer
"S" Element – Half-shift Register	"H" Element – Half Adder
"G" Element – Gate	"C" Element – Counter Adapter

These are all the building blocks needed for logic functions.

Each micrologic element is capable of driving up to four others in parallel. Any micrologic element can be driven by any other element. Output coupler elements, to be made available later, will accept micrologic inputs and drive high voltageor high current loads (of the order of 100v, 1 amp).

The basic objectives of the micrologic development program at Fairchild Semiconductor call for a set of building blocks which as a product line are reliable, economical, and useful. The elements will have adequate performance to satisfy most system requirements. A paper entitles "Applications of Micrologic Elements" will be presented by D. Farina and J. Nall of Fairchild Semiconductor at the National Electronics Conferences in Chicago on Tues., Oct 11.

Small Size is Not the Big Thing

The weight and size of batteries and solar cells is the main problem in missile and space electronics – not the size of the electronics package. This comment was heard by EDN editors while sampling industry opinion concerning trends in miniaturization. According to E. O. Johnson, Chief Engineer of RCA's Semiconductor Materials Div., present satellites contain a great deal of empty space; micro electronic systems are going to have to make their own way on the basis of lower cost and reliability. Systems engineers will not tolerate any less degree of performance just to have miniaturization.

Modules – Yes or No?

Whether standard modules are practical or not is still a point of controversy within the industry. During a discussion period at the First Electronics Packaging Symposium in Boulder, Colo., Charles Dunaief of RCA's Defenses Electronic Products described an effort by industry and government to develop standard packages for airborne equipment. The hope was that new types of aircraft could be equipped by aseembing a group of standard components into a new configuration. The results of an investigation into this possibility was that in view of rapid advances in the electronic arts, no one wished to be restricted by a prescribed set of modules.

Computers represent the more likely field for the widespread use of modules because of the great quantities of identical circuits used. The Fiarchild Micrologic Elements and the earlier Texas Instruments' "Solid Circuits" are intended for this field. Even so, Dr. Peter B. Meyers of motorola's Semiconductor Products Div. is firm in his belief that circuit modules will have to be built to order to fit various customers' demands. He envisages an automatic production line for making solid-state integrated circuits, but the line will be computer-controlled so that circuit parameters can be modified as required. The Fairchild concept is to supply modules which have sufficient built-in flexibility.

Biggest Need for Miniaturization

Memory devices are most in need of miniaturization in tomorrow's computers are ever to be built – this from Dr. John Salzer, Director of Ramo-Wooldridge's Intellectronic lab who spoke of the enormous storage capacity required by self-learning machines. In a lecture sponser by EDN in Los Angeles last month, Dr. Salzer said that in moving toward this goal, some thought is being given to adapting molecular phenomena, such as molecular spin, for memory use.

Standard Components Persist

Apart from developments in new ways to build circuits, interest in standard components still runs high as evidenced by the favorable reaction to a new high-density packaging technique using standard components. Disclosed at the First International Electronic Circuit Packaging Symposium in Boulder, COLO., the method uses small printed circuit boards especially notched on the edges for holding component leads in place. Besides use of standard components, features of this method include fast assembly and ease of testing and modifying completed modules. Interest in this technique was stimulated by the fact that only a few simple tools are required; any electronics lab can try it out without heavy investment in equipment or training.

The method is described in a paper entitled "Evaluation of a High Density Approach to Electronic Packaging" by James Kuller and Theodore Knight of Bendix Radio Div., Baltimore, MD. An abstract of this paper appears in the special supplement of this issue of EDN.