transistor. Consequently, specific values of the electrical
characteristics of individual transistors are highly unpre-
dictable and can at best be expected to fall within a broad
range. The customer, on the other hand, is not satisfied
with just any transistor; he is asking for a product with
electrical characteristics clearly defined and frequently
limited to a narrow range, that is, a device.
The conversion of a transistor into a device is done in
the last phase of the manufacturing process called testing.
However, the main purpose of testing is not to ascertain
compliance with predetermined standards but rather to select
from the available supply those transistors which match the
customer's specific requirements. Since there are several
alternative ways of converting a given transistor into a
device, the manufacturer is extremely interested in using the
best method because this optimizes customer satisfaction and .
increases profits.
Statement of the Problem
Because of the transistor's potentiality, the testing and
conversion phase is receiving considerable attention with
more effective testing methods constantly being sought.
Several systems are now available, and each is considered
optimal by its designer. However, all these systems have a
common conceptual weakness; they are device-oriented'because
they seek to identify &nd measure in each transistor only