Technology & Medicine › Atomic & space age › Electronic computer (Z3, Colossus, ENIAC)
Integrated circuit (microchip)
1958 (Kilby); 1959 (Noyce)· Invention or discovery· Communication & computing
Mostly agreedGood evidence; some details, dates or numbers uncertain.
A complete electronic circuit, with many transistors and other parts, built on one small piece of semiconductor.
See it on the Technology & Medicine map →How it works
In September 1958 Jack Kilby at Texas Instruments showed a working circuit made from one sliver of germanium, its parts joined by tiny gold wires. In 1959 Robert Noyce at Fairchild Semiconductor designed a better version in silicon, with metal connections laid on the surface using Jean Hoerni's flat 'planar' process, which could be mass-produced. In 1965 Gordon Moore noted chips were doubling in complexity at a steady pace; today's chips hold tens of billions of transistors.
Why it mattered
Chips made electronics small, cheap and reliable, putting computing into missiles, spacecraft, calculators, cars, phones and almost every modern device.
Think of it like
Like replacing hand-wired buildings with factory-made modules: the whole circuit is made in one process, so there are no hand-made joints to fail.
How we know
Kilby's dated 1958 lab notebook, both men's patents (Noyce's granted 1961, Kilby's 1964), surviving prototypes in museums, and chip industry production records.
Still unknown or debated
Credit is shared: Kilby built the first working chip, Noyce the practical kind. Kilby received the 2000 Nobel Prize in Physics; Noyce had died in 1990.
Connections (3)
▸Transistor was miniaturised into the Integrated circuit (microchip)Well documented
The connection
By the late 1950s, electronics needed thousands of transistors, each wired in by hand, and every solder joint could fail: engineers called it the 'tyranny of numbers.' Kilby and Noyce realised transistors, resistors and capacitors could all be made from the same semiconductor, so a whole circuit could be formed in one piece.
When and how
Kilby at Texas Instruments in Dallas, summer 1958; Noyce at Fairchild Semiconductor in what became Silicon Valley, 1959, using Jean Hoerni's flat 'planar' transistor process.
How we know
Kilby's dated lab notebook and Noyce's 1959 patent application describe transistors and other parts built together on one piece of semiconductor.
Debates and open questions
Whether the chip was a leap or an obvious next step is debated: British engineer Geoffrey Dummer proposed the idea in 1952, and several labs were close by 1958.
▸Integrated circuit (microchip) led to the Microprocessor (Intel 4004)Well documented
The connection
As chips held more transistors, roughly doubling every two years, engineers could fit an entire processor, with its arithmetic, logic and control, onto one chip. Intel's 4004 packed 2,300 transistors, made possible by the silicon-gate method that Federico Faggin had developed at Fairchild in 1968.
When and how
Intel in Mountain View, California, 1969–1971, designed by Federico Faggin, Ted Hoff and Stanley Mazor with Masatoshi Shima of the Japanese calculator firm Busicom.
How we know
Intel's design records and Faggin's accounts show the 4004 depended on denser chip-making; Gordon Moore's 1965 article had predicted such integration.
Debates and open questions
How long the doubling can continue is debated: features are now only a few dozen atoms wide, and gains increasingly come from stacking chips and specialised designs.
▸Integrated circuit (microchip) flew in the guidance computer of the Apollo 11 Moon landingWell documented
The connection
The Apollo Guidance Computer was one of the first computers built from integrated circuits: about 2,800 identical chips, each holding a few transistors. It steered the spacecraft and helped fly the landing. When it overloaded during descent, flashing '1202' alarms, its software dropped low-priority tasks and kept running.
When and how
MIT Instrumentation Laboratory in Cambridge, Massachusetts, 1961–1969, led by Charles Stark Draper, with software led by Margaret Hamilton; chips from Fairchild and Philco.
How we know
The computer's design documents and full software listings are public, and surviving units have been restored to working order.
Debates and open questions
How much Apollo and Minuteman missile purchases drove the early chip industry, versus commercial demand, is debated; claims that Apollo bought most US chips are disputed.