Invention of Integrated circuits – Behind the scene

Have you ever heard the story behind  invention of  integrated circuits or what made people work on it? Well, if your answer is ‘No’, continue reading to unveil the truth. This article takes you through the path of invention and developments of integrated circuits.

What are Integrated circuits?

An integrated circuit is just a small chip that performs multiple functions. It clubs together functions of many electronic components like an oscillator, an amplifier, a timer, a microprocessor and many others into a single chip.It has the capacity to hold any number of transistors, resistors and capacitors. Based on the manufacturing techniques, the integrated circuits are classified into two wide ranges. They are hybrid and monolithic circuits.

The need for invention

The need for smaller sized electronic units paved way for the invention of integrated circuits. People were forced to invent something new to replace big and costlier parts of electronic devices. Vacuum tubes were normally used before the invention of transistors. The size of a vacuum tube was its greatest drawback. Transistors, though much smaller than vacuum tube, was still bulky for some newer electronic devices. In addition the wiring part of circuit building was becoming more tedious with lots of transistors & components on a single board. This became a matter of concern for the scientists. They wanted to make a single block containing all the transistors and connecting wires.

The inventors 

People were really tired of working with the huge and complicated parts of the electronic machines and obtained great relief with the invention of ICs. It is truly amazing to know that two scientists invented integrated circuits at the same time. One among the two was Jack kilby, who worked for the Texas Instruments from 1958. He had a background in ceramic based silk screen circuit boards and transistor based hearing aids. The other one was Robert Noyce from California, who was the cofounder of the Fairchild Semiconductor Corporation. Both the scientists worked to fix the same problem during the years 1958 and 1959.

Jack Kilby - Copyright:- Texas Instruments and Wikimedia Foundation

Integrated circuits and the patents 

Jack kilby and Robert invented ICs that varied in their raw materials and construction. For the silicon based integrated circuit, Robert Noyce and the Fairchild Semiconductor Corporation received the US patent #2,981,877. For the miniaturized electronic circuits, Jack kilby and Texas Instruments received the US Patent #3,138,743. The two companies, Texas Instruments and Fairchild Semiconductor Corporation cross licensed their inventions after several years.

Kilby’s first chip  

During Kilby’s earlier days at the Texas instruments, he was appointed to work on the construction of smaller electrical circuits. As he worked, he found something odd in the ideas of the Texas Instruments in accordance with the miniature projects.

The First Integrated Circuit - Realized by Jack Kilby (Courtesy:- Texas Instruments & Wikimedia)

Jack Kilby started working on his idea for an integrated circuit during the summer of 1958. The company TI was shut down for 2 weeks (as part of annual vacation for its employees) during that time. Jack Kilby being a new employee of TI was not eligible for annual leave and was supposed to be at work. As Kilby was working alone in the company most of the time, he had many opportunities to work on the miniaturization method used in TI. He made good use of the time and started to inculcate his own ideas. He tried making transistors and the whole circuit components (resistors and capacitors) entirely of a single crystal. Kilby wanted to bring all the parts of the chip under one block of the semiconductor; as one monolithic unit. If that was possible, the transistors and the wires will be held in a single crystal. He proceeded with his idea after several discussions and approval from his seniors. He successfully developed his first integrated circuit in September 1958. After testing its performance, everyone was surprised to see that the IC worked perfectly without any disruption. Kilby’s first integrated circuit was considered to be a path breaking innovation though it had a few disadvantages.

He made the IC out of one material and the pieces were joined together using a metal wire. This helped to overcome the drawback of manually arranging all the components on the semiconductor. The first solid integrated circuit was showcased in March. This did not exceed the size of a pencil tip. For this breakthrough discovery, Jack kilby was awarded the Nobel Prize for physics in 2000. He then led to the invention of the hand calculator when he was continuing his work in the Texas Instruments.

Robert Noyce and his integrated circuit 

Robert Noyce - Copyright:- Wikimedia Foundation

Robert made his invention a half year later than that of Kilby. He had his own idea of an IC. The greatest advantage of Robert’s IC was that he solved almost all the complicated problems and issues that Kilby’s circuit had.  The major problem was linking all the components of the circuits together. Robert formulated a better way to connect all the components in a single crystal wafer, thus making a true integrated circuit possible. This facilitated mass production. Robert Noyce later quit Fairchild Semiconductors to start Intel with Gordon Moore.

The evolutionary stages of Integrated circuits

Long ago, a single computer occupied the entire space of a large room. This was only because of the vacuum tubes that were employed in the device. Later the vacuum tubes were replaced with transistors. The much sophisticated computerized society that we live in today is the result of the integrated circuits. Only when the bulky transistors were replaced with ICs, the smallest computers were made possible. One of the advantages of the integrated circuits is that they are highly reliable as well as smaller and inexpensive. This makes its range of applications wider too.



  1. thanks for this article…i would like to read such articles.

  2. Very interesting articles for our young’s and which also enrich our knowledge where the dead are speaking which are also changing the world of technologies. Thanks keep on this type of tracks.
    Regsrds sr from Mauritius