UNIVAC Defense Systems in St. Paul was one of the first systems manufacturers to actively investigate
the use of monolithic integrated circuits. The use of a monolithic silicon integrated circuit design allowed
the integration of dozens of circuit elements on a single piece of epitaxial silicon, a pure layer of silicon
grown on top of a silicon wafer substrate. These devices used a gold-doped bipolar diode-transistor-logic (DTL) process and allowed simple logic gate elements to be contained in a single 10-lead metal/ceramic flat pack measuring no more than 1/4x1/4 inch on a side and 1/10 inch thick. The silicon chip (or die) inside was only about 0.050 inches on a side. These circuits were designed for minimal power dissipation, maximum noise margin, maximum reliability, and minimum parts count. These aerospace programs were short term with low part volumes.
Each semiconductor manufacturer known to have capability in the integrated circuit field was given an opportunity to participate in the early phases of negotiations.
Although UNIVAC provided the initial equivalent circuit design, suppliers were allowed to come up with
their own circuit and silicon implementation which would meet the requirements. Five suppliers were
selected for continued development based on past performance, long range pricing, supplier interest, and
UNIVAC’s perception of their capabilities.
Development orders were placed in December of 1964 to
Westinghouse, Motorola, Signetics, Texas Instruments, and Fairchild. The prime semiconductor process
being used at that time was a gold-doped bipolar process on about a 1-1/2 inch diameter wafer.
Samples were built and obtained from each potential supplier in 1965. These samples were technically scrutinized by UNIVAC technology experts and electrically tested. Each supplier had a unique implementation: some had advantages, some had disadvantages. Differences in the package used by each supplier were also noted.
Both Texas Instruments and Fairchild failed to meet the electrical specifications or had an unacceptable
design. The initial Signetics and Motorola parts were marginal but Motorola later delivered an acceptable
product. The Westinghouse devices were acceptable. The acceptable devices were subsequently electrically evaluated in more detail. Westinghouse was qualified as an initial sole source. The 10 and 14 pin flat packs had 1/4 inch by 1/4 inch by 0.100 inch thick bodies. They were hermetically sealed kovar and glass with a hollow interior. Flat kovar leads (pins) extended through the glass walls on opposite edges of the package. All kovar was gold plated.
Larry Bolton
Edited (Shortened, Parsed, Chopped-up and Mutilated) by Todd J. Thomas
External Link to original PDF file on VIPCLUBMN