Milestones:Manufacture of Transistors, 1951


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Allentown, PA, U.S.A.
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Lehigh Valley
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Manufacture of Transistors, 1951

Allentown, PA Dedicated April 1989 - IEEE Lehigh Valley Section

The commercial manufacture of transistors began here in October 1951. Smaller, more efficient, and more reliable than the vacuum tubes they replaced, transistors revolutionized the electronics industry.

The plaque can be viewed at AT&T, 555 Union Blvd., Allentown, PA, U.S.A.

At the end of World War II, a decision was made by Bell Labs' management to undertake an organized investigation to develop a smaller, more powerful, faster and more reliable device to replace the vacuum tube. This set the stage for the discovery of the transistor; an invention which revolutionized our electronic age. Three Bell System scientists, Walter H. Brattain, John Bardeen, and William Shockley, are credited with this invention which had a far-reaching impact on science, technology and society. Pooling their creativity, this notable trio evolved and tested their theories and hypotheses. They recognized the need for an interdisciplinary approach and recruited chemists and metallurgists as well as theoretical and experimental physicists to work on the project. The effort concentrated on producing what came to be the essential prerequisite for success: single-crystal semiconductor specimens of high purity to which very small amounts of specific impurities could be added in controlled quantities.

Invented at AT&T Bell Laboratories 23 December 1947, the transistor replaced the vacuum tube amplifier and provided a tiny, reliable, and relatively inexpensive substitute for the relays in electromechanical telephone exchanges. The transistor ushered in the "solid-state revolution," spawned today's worldwide semiconductor electronics industry and made possible dramatic changes in communications, computing, entertainment, medicine, space exploration and a host of other fields.

On 1 October 1951 the first line for the mass production of transistors was started at the Allentown Works. Throughout the 1950s, Allentown engineers and employees in development shops invented, designed and constructed the equipment needed to manufacture transistors. Since 1951, when 6,000 transistors were made, technology has continually evolved.

In 1947, the transistor had to be assembled manually by Bell Laboratories. Manual assembly was performed in volume quantities due to the minuteness of the components, rigid spacing requirements and changes made in specifications. Allentown Western Electric Company mechanized the process when they started transistor mass production in 1951. At that time, the transistor was only a few years old and mechanization was particularly difficult due to ongoing developmental efforts. The final product was a transistor made of crystalline perfection and remarkable purity. It was characterized by a long service life and inexpensive reproducibility. Changing from manual assembly to mechanized assembly was accomplished through the inventiveness, ingenuity and teamwork of engineers from Bell Labs and Western Electric.


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