Charles W. Mueller


Biograhic Note


Dr. Charles W. Mueller was instrumental in the development of the alloy junction transistor at the RCA Princeton laboratories.  He co-authored several fundamental papers on alloy junction technology in 1952 and 1953, and was primarily responsible for moving transistor manufacturing from the lab environment at Princeton to the manufacturing facility at Harrison NJ. The following oral history was taken in November, 1998.




This photo shows examples of the first RCA junction transistors, which were made by Dr. Mueller at the RCA Labs at Princeton in late 1952, early 1953.  The TA153 is a PNP type, as described in the Oral History.  The TA154 is an NPN.  The “TA” designation was used on early developmental transistors at RCA, and is a designation for “Transistor Amplifier”.  These early units were hand labeled and serialized.  Red ink was used for PNP and green ink for NPN.   These first units have a handmade appearance and are (approx)  ¼” by ½” for the white epoxy region.


Oral History – Early Production of Junction Transistors at RCA


How the early production of transistors at RCA came into being can best be described by my giving an account of our early transistor work as I remember it at RCA.  The first transistor experiments in our laboratory was the point contact type.  These transistors were not rugged enough to really interest our radio circuit designers.  It was only when we appreciated the real advance of p-n-p junction devices that progress was rapidly made.


In my laboratory in the early 1950’s we were constantly building transistors one junction at a time.  The base was a thin .001 to .002 inch thick strip of single-crystal germanium.  The collector was a .015 round ball of indium which was heated to about 450 degrees C. in a hydrogen furnace to melt and alloy this dot with the germanium.  On cooling and hardening the collector junction was formed.  The wafer was then turned over and a slightly smaller emitter junction alloyed to germanium on the opposite side.  After attaching the base and the 2 dots of indium to a suitable glass stem and carefully enclosing the parts in plastic we would have a sturdy transistor.


 Then, of course, we made jigs holding six transistors for the alloying in the hydrogen furnaces.  When we got to making six measurable transistors, we were all very happy.  This was “mass” production.  (Editor’s Note:  The model number TA-153 was assigned to this earliest pnp alloy junction developmental transistor type.)


Go To Mueller Oral History, Page 2



COPYRIGHT © 2001 by Jack Ward.  All Rights Reserved.  http://www.transistormuseum.com/