Last edited 01 Mar 2021

Microchip

A microchip (also called a chip, integrated circuit or IC) comprises a series of electronic circuits on a small chip or semiconductor material that is typically made of silicon. It has almost completely replaced the use of the bulkier transistor and can be seen in the entire spectrum of electronic devices, including computers, mobile phones, TVs and radios, and a host of other domestic and industrial appliances.

Before the microchip, electronic components were huge: valves the size of domestic light bulbs and bigger. One of the first computers used by mathematician and codebreaker Alan Turing took up half a small room. The fact that today electronics can be compressed to the micro scale is largely due to the advent first of the transistor and more recently the microchip.

Traditionally, all the components of an electric circuit were placed on a board and joined together by wires or soldering. This created a very large, bulky circuit which resulted in correspondingly large appliances, whether radios, TV sets or computers.

In order to try and miniaturise the entire circuit, US-based electrical engineer Jack Kilby had the idea of replacing all the circuit components with a single material. He then hit on the idea of using a semi-conductor such as silicon which could act as required in various ways – either as a conductor of electricity or as an insulator.

Working at Texas Instruments in May 1958, Kilby experimented with slithers of silicon to create integrated circuits in which all the components were not conventional, single, freestanding entities but integrated into a whole. In the process, he invented the first monolithic integrated circuit – or microchip. In February 1959, he applied for a patent which was eventually granted five years later.

As with numerous other inventions where two inventors working independently claim to be the originators of an idea, another patent application for a very similar type of microchip was put in by Robert Noyce in 1959, very shortly after Kilby’s application. However, Kilby is regarded as the true inventor although some sources also credit Noyce.

Since Kilby’s invention, technical advances in the manufacture of metal-oxide-silicon (MOS) semiconductors have resulted in ever-increasing miniaturisation, accompanied by larger capacity chips working at much faster speeds. Modern microchips can have billions of MOS transistors in an area the size of a one-penny coin. The result is that today’s computer chips have capacities that are a million times greater and thousands of times faster than chips of the early 1970s.

Kilby went on to invent the first hand-held electronic calculator (1972) and became co-founder of Intel. He died in 1990 at the age of 62. In 2000, he was posthumously awarded the Nobel Prize for physics.