Semiconductor History

Small changes having a big impact. Introduced in 1960, Philco had by then improved their etching process to create the thin base layer of their germanium alloy junction transistors. They then replaced the indium electrodes making the emitter and collector junctions with cadmium, giving better thermal dissipation. Due to its speed and thermal performance, it became widely used in computers of the time. These were manufactured by Philco (later Philco-Ford) at their factory in Spring City, PA. One AI processor chip now has more transistors than the first 25 years at least of the semiconductor industry!  It works, hfe (gain) is 96, Vf=273mV (so germanium).

In 1962 Mullard (Philips) and GEC pooled their resources and facilities to create Associated Semiconductor Manufacturers. Mullard owned 2/3 of the combined business. GEC pulled out in 1969. This is a small signal diode CV7364/AAZ12, germanium, Vf=258mV.

Germanium transistors from 1955. In the early 1950s Sylvania established transistor and diode manufacturing at their tube (valve) facility in Emporium PA. Manufacturing was transferred to the Electronics Divsions in Woburn Mass. In 1957 it was divided into two new organizations, the Semiconductor Division and Special Tube Operations. Skyworks, one of the current world leaders in RF components for smartphones has its roots in Sylvania, Woburn.

Vintage Ediswan Mazda XB103 Germanium Transistor EDISWAN Germanium transistor originally from the late 1950s. The gain on this device is at the very top end of the gain spec @ 105. Edison and Swan merged in Britain in the late 1800s when Swan already held the dominant patents for the incadescent bulb. Ediswan were one of the original companies in the Associated Electrical Industries (AEI) merger from 1929 which included British Thomson Houston. Thomson Houston in the US became General Electric. Many British lamp companies moved into valves (tubes). Indeed the inventor of the first thermionic valve, Ambrose Fleming, worked at Edison Swan's factory at Ponders End in North London. Siemens Brothers (the other brothers) merged with Edison Swan in the early 1950s. It's not clear where Ediswan semiconductors were manufactured but may have been at Woolwich or Ponders End. Siemens Edison Swan had a research lab in West Road, Harlow in the late 1950s doing semiconductor res...