Elenco Electronic Component Kit - Manual (Page 20)

-19-
SEMICONDUCTORS
THE INTEGRATED CIRCUIT
If the water pipe analogies of the resistor, diode,
transistor, and very small capacitors could be
etched into a single block of steel you would have
the equivalent of the Integrated Circuit in
Electronics. Figure 31 represents such a device.
This block of steel would have to be very large to
include all the mechanical parts needed. In
electronics, the actual size of a diode or transistor is
extremely small. In fact, millions can be fabricated on a piece of silicon no larger than the head of a pin.
Photographic reduction techniques are used to
generate the masking needed to isolate each part.
These masks are then stepped and repeated in
order to make many separate integrated circuits at
the same time on a single substrate. Using mass
production techniques, these circuits are
manufactured, packaged, and sold at prices much
lower than the equivalent discreet circuit would cost.
SEMICONDUCTOR SYMBOLS
Figure 32 shows the common symbols used
in electronics to represent the basic
components. Integrated Circuits are usually
drawn as blocks with leads or as a triangle
for operational amplifiers. The Zener diode
(voltage reference diode) is used in the
reverse direction at the point of breakdown.
Figure 32
Diode LED Zener
Diode
PNP NPN FET
Figure 31
The Integrated Circuit
8
7
14
1