What were the technical
aspects of the early Motorola silicon transistors?
was first out with planar silicon, which rapidly followed the mesa silicon.
Their devices 2N1613, NPN, and 2N1132 PNP, rapidly became the standards.
Motorola followed a strategy of being all epitaxial, both silicon and germanium.
In 1962 I was given the Silicon Transistor division Job (at Motorola). We
introduced the 2N2219 and 2N2218, which were epitaxial versions of the
Fairchild 2N1613. These devices rapidly supplanted the Fairchild devices,
as volume leaders. Later that year we brought out the PNP versions. Fairchild
only had a Mesa PNP product. This was accomplished using an “annular
ring”. By mid 60’s Moto had passed both Fairchild and TI in silicon transistors.
2N2218 and 2N2219 were beta sorts (Gain) - 2218 was low beta, 2219 high
beta. These devices were in the TO5 package (hermetic). As we didn’t have
probe sorting at that time, they were sorted into three ranges by Lehner’s automated
test machines. The low range 2N2217 was regarded as junk. However the
testers sorted to specific customer specs also. The 2N2221 and 2N2222 were
the same specifications as the 2218 and 2219 in the smaller TO18 package.
These devices used the STAR geometry the PNP equivalents were
the 2N2904, 2905 and in TO18 2N2906 and 2907. There were “A” versions of
all these 2N numbers, A’s were a tighter sort, and were priced higher.