The U.S. patent number for Jack Kilby’s first integrated circuit is 3,138,743.
The patent, titled “Miniaturized Electronic Circuits,” describes putting multiple circuit elements into a single semiconductor body. Kilby filed the application on February 6, 1959, while working at Texas Instruments, and the patent was issued on June 23, 1964. Its claims covered an integrated arrangement of components such as transistors and resistive regions.
Kilby’s breakthrough addressed a major problem in electronics: conventional circuits required many separately manufactured components and connections. Combining them in one piece of semiconductor material made circuits smaller, more reliable, and easier to mass-produce. Robert Noyce independently developed a related planar approach at Fairchild Semiconductor, so the integrated circuit’s history is associated with both inventors.
The patent number is sometimes confused with later semiconductor patents or with Kilby’s other inventions. Kilby shared the 2000 Nobel Prize in Physics for foundational work on the integrated circuit.