Integrated Circuit

The integrated circuit (IC or chip) is a miniaturized electronic circuit.

An integrated circuit is an assembly of interconnected components on a small semiconductor chip, usually made of silicon. One chip can contain millions of microscopic components and perform many functions. These components are fabricated together on a slice of silicon crystal (known as a wafer) that contains many ICs arranged in rows. Manufacture of ICs involves a succession of processes, including photolithography, high-temperature diffusion, oxidation, and metallisation. The wafer is then separated into chips, which are individually packaged.

The IC was invented independently by two researchers.

The integrated circuit was invented in different forms in the United States by Jack Kilby of Texas Instruments and Robert Noyce at Fairchild Semiconductor. With this new semiconductor technology, computers, communications devices, and all sorts of consumer electronics became possible.

The integrated circuit controls the functions of the quartz watch.

In all quartz watches, the IC makes the quartz crystal oscillate, divides the quartz frequency down to one pulse per second, and drives the display. Many more functions can be added using a microprocessor, making today's quartz watches more like dedicated microcomputers.

Both Swiss and Japanese watch companies were involved in developing ICs suitable for use in watches.

The first IC used in a watch was developed in the 1960s in a Swiss laboratory, CEH. The chip's power consumption had to be drastically reduced in order to allow battery life of at least one year. In the first quartz watch, the Beta 21, a single IC containing about 110 components managed all electronic functions of the watch, including quartz crystal excitation, frequency division, and motor drive.

In 1970 the Seiko 36SQC was introduced and was the first quartz watch to use a CMOS chip (a low energy integrated circuit invented at Fairchild in 1963). Today's quartz watches all use CMOS technology, with chips containing 100,000 components and more. They combine microprocessor, memory, and analog functions, and act like dedicated microcomputers.