D.D. McBride


Biographic Note


D. D. “Mac” McBride worked at Texas Instruments from July 1953 until early retirement in April 1975.  This 20+ year career spanned the critical early years in transistor technology and his Oral History provides insight into the tremendous changes that occurred during this time.  It is interesting to note that Mr. McBride’s first assignment at TI was that of assembler of point contact transistors, and that his earlier training as a watchmaker provided the essential skills for this job.  As you’ll discover in the following text, the performance of these early transistors was quite unpredictable and largely dependent on the precise mechanical placement and adjustment of sharpened electrodes that were held in place with glue!  It would have been difficult at that time to even imagine the increase in complexity in semiconductor technology that now supports the large scale manufacture of microprocessor chips containing millions of transistors in a device of similar size as these first point contact transistors.

















Oral History – D. D. McBride


 This Oral History was taken in Jan 2002




I started at TI in July of 1953 and took early retirement on April 11, 1975, having reached the age of 60 with 20 years of service.  I worked on the point contact transistors, PNP and NPN junction transistors, silicon and germanium diodes, and 10 amp power transistors.  I operated vacuum systems and, with a very good friend (Charlie Earhart), I worked on switching plates.  I worked with the group that built the transistors for the Regency radio – now that was a big deal!  We worked late every night.  If I remember correctly, they had to have two transistors with the same readings.  I also worked in wafer processing and in research.


Building Point Contact Transistors


My first job was point contact transistors.  I can’t remember just when I built my first one, but I’m sure it was sometime in August of 1953.  It was quite a deal to build them.  

Here are the basic steps, as I remember:

1) First was to get the material to make the points.  A strip of fiber about 3” long, ¼ “ wide and 1/8” thick.  Then you needed strips of phosphorous bronze and beryllium copper.  These strips were 10 Mils.  The metal strips were cleaned and stuck on the fiber lengthwise on either side with about 1/16” separation.  Next, the strips were put in a press and then baked at 300 degrees for about four hours.


McBride Oral History, Page 2

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