How Integrated Circuits Are Created

How Integrated Circuits Are Created

Integrated circuits are essential to almost all of the electronic devices we use in our daily lives. They are in our TVs and smart phones, video games and computers; they control robots and factories; and they are the foundation of satellite, radar, radio, and mobile phone communication technology. Integrated circuits are also used in microwave ovens and air conditioners to control their functions.

The invention of the IC revolutionized electronics technology by dramatically reducing the size of components and making it possible to connect them in complex, sophisticated circuits that can perform many different tasks simultaneously. Integrated circuits, which are commonly called microchips or chips, are made up of miniature versions of all of the basic electronic components such as resistors, transistors, and diodes. An IC can be as simple as a collection of logic gates, or as complicated as a powerful computer processor.

Three American physicists, William Shockley, John Bardeen and Walter Brattain, invented the transistor in 1947. This made it possible to do things with electricity that were impossible or very difficult with vacuum tubes, such as amplification and switching. But even after this, most electronic circuits were a tangled mess of wires and components. Integrated circuits (ICs) solved this problem by creating an entire circuit in microscopic form on a piece of semiconductor material, such as silicon.

To create an IC, designers use a special type of software that builds the components in layers, similar to how a film is developed. Each layer has its own purpose, such as a transistor or memory device. When all of the layers are complete, they are etched onto a piece of glass or ceramic that is then covered with insulating material. Photons of a certain wavelength, typically ultraviolet, are then used to expose each layer, and the resulting pattern is the IC.

Each IC contains thousands, sometimes millions, of transistors, along with other electrical components such as diodes and capacitors. The transistors are all connected to one another using wires that run in and out of the chip and between it and other devices. The ICs can then be placed in printed circuit boards (PCBs), which are similar to the green one in this picture, with thin tracks linking the "legs" of each IC to other conventional electronic components on the board.

Integrated circuits come in all sorts of sizes, shapes and colors. This one, which we call a dual-inline package or DIP, is in a black plastic case with metal pins on each side for plugging into a bigger electronic circuit board. Most packaged ICs are large enough to contain identifying information, usually a manufacturer's name or logo, the part number and a four-digit date code that tells when it was manufactured. The smallest ICs are sometimes called surface-mount technology, and they do not have any identifying markings.

Tags:integrated circuits