Global Challenges in Focus

Semiconductors have revolutionized our day-to-day lives, paving the way for ground-breaking innovations as diverse as smart phones, electric cars and renewable energy. Infineon Technologies, continuing in the tradition of Siemens, plays a defining role in advancing today’s semiconductor technologies. Join us on a journey through our company history. It all started out in a castle in Upper Franconia.

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Once upon a time at a small castle in Pretzfeld...

In 1946, the Siemens Executive Board establishes a lab dedicated to basic semiconductor research at a small castle in the village of Pretzfeld. In the summer of 1946, a small group of researchers starts work there, laying the foundations of Infineon Technologies as we know it today. The group is headed by Eberhard Spenke and includes Walter Schottky as a scientific consultant – two pioneers in semiconductor research.


Eric Lidow and his father, Leon Lidow, found International Rectifier in August 1947 with just six employees at the facility in Inglewood, CA.


IR introduces selenium plates 50% larger than existing plates.


IR introduces selenium photo cells and selenium diodes and selenium cartridge rectifiers.


IR installs new process techniques based on single crystal P-N junction technology that allows rectifiers to be made smaller and withstand greater temperature extremes.


The fruits of basic research:
Heinrich Welker registers patents for III-V semiconductors

In 1951, Heinrich Welker registers a patent for DE970420B, an electronic semiconductor device that forms the basis of all III-V semiconductors. This class of semiconductors includes gallium and arsenide and is used in a wide range of components, including light emitting diodes (LEDs). Today, lighting remains a key application area for semiconductor modules from Infineon.

IR introduces selenium stack rectifiers for battery charging. IR relocates from original facility on Victoria St. In Inglewood to1521 Grand Ave. in El Segundo.


Semiconductors take center stage as Siemens establishes semiconductor fabrication facility

April 1, 1951, an internal memo announces Siemens’ plans to open a semiconductor fabrication facility. In the letter, Ernst von Siemens writes: “semiconductors such as transistors, thermistors, varistors and diodes (crystal diodes) are becoming increasingly important in communications engineering. This is an extremely important area and it is therefore vital that we establish a strong presence across the entire field.” Today, Infineon has a dozen fabrication sites worldwide. Half of these are located in Europe.

IR introduces line of sub-miniature selenium diodes for bias supplies, sensitive relays, hearing aids and many space-restricted applications.


IR begins production of selenium rectifiers for the new color TV. New products include germanium diodes and world’s largest single selenium rectifier stack.


IR offers tiny silicon diodes. IR opens new facility at 201 Nevada St. El Segundo to produce selenium rectifiers for radio and television industry. IR offers selenium cartridge rectifier for use in Geiger counters.


IR introduces sub-miniature selenium diodes for applications that must withstand severe environmental conditions. IR is the first company to introduce space-saving silicon cartridge rectifier.


Operations begin at IR Turin, a joint venture with Fiat. Dallons manufactures the ground support equipment used to monitor Alan Shepard’s heart during his historic space flight. IR purchases Honolulu’s Industrial Research laboratories. IR acquires Xaloy Inc., the world's largest manufacturer of bimetallic extruder cylinders for industrial equipment.


IR establishes Rachelle Laboratories Italia, S.p.A.


IR intensifies its research and development of high power thyristor.