Tuesday, December 16, 2008

Integrated Circuit Chips (IC)

rcuits are made up of different electronic components (capacitors, resistors, transistors, etc.) wired together in a manner that performs a specific electronic function. . These components are hooked together on fiberglass boards called circuit boards. You can see the small thin copper or metal lines (wires) on a circuit board that connect the different components together. These are called traces.

If you could find an old 7 or 10-transistor radio from the sixties, you could open it up and see the peanut sized transistors on the circuit board. They looked like little water towers with their 3 legs going down to the circuit board where they were soldered in place. Now, imagine that circuit board and all of its transistors, shrunk down to about the size of your little fingernail and put into a small plastic case for protection. In other words, the entire circuit would be integrated into that one small chip. Hence the name, Integrated Circuit (IC).

With today's technology, these circuits and transistors can be etched into small wafers of silicon and sandwiched into a small plastic package or chip. There are small metal pins coming out of the chip that are connected to the silicon wafer inside with microscopic wiring. The most amazing thing is, today's small integrated circuits now contain millions of transistors, not just 7 or 10. These IC chips are then placed on a circuit board connecting them to other components and IC chips.

One technology for producing ICs is called TTL (Transistor Transistor Logic). These chips are actually more tolerant of ESD (Electrostatic Discharge) and even faster than the newer technology. However, they're also larger, use more electricity or power, and their resistance causes them to run very hot. As computer technology advanced and the number of transistors in the chips increased, heat and power consumption became a huge problem.

TTL ICs are still used in computers today, but the newer CMOS chips (Complimentary Metal-Oxide Semiconductor) have all but replaced them entirely. These chips have a semi-conductive metal oxide layer that allows for less resistance, reducing the power consumption and the generated heat. Unfortunately, the very technology that makes these CMOS chips more efficient also makes them very susceptible to electrostatic discharge.

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