Electronics

• 1. Introduction

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  Electronics is the discipline of bending physics to a single purpose: controlling the movement of electrons and other charged particles. It studies and applies the principles of physics to design, create, and operate devices that do exactly that. The numbers it commands are hard to picture. The semiconductor industry, the engine driving it forward, brought in annual revenues exceeding 481 billion dollars in 2018. One branch alone, e-commerce, generated over 29 trillion dollars in online sales in 2017. How did a field built on something invisible come to shape telecommunications, entertainment, education, health care, industry, and security? Why did the glowing glass tubes that started it all give way to slivers of silicon? And how did the place where these devices are made drift halfway around the world?

• 2. From Crystal To Vacuum

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  Karl Ferdinand Braun built the crystal detector in 1874, the first semiconductor device. The field had its starting point before anyone could name the particle at its heart. In 1897, Sir Joseph John Thomson identified the electron itself. The vacuum tube followed, able to amplify and rectify small electrical signals, and the electron age was underway. Ambrose Fleming invented the diode and Lee De Forest invented the triode in the early 1900s. These made the detection of small electrical voltages practicable, including radio signals pulled from a radio antenna. Vacuum tubes, also called thermionic valves, were the first active electronic components to control current by influencing the flow of individual electrons. They gave the world radio, television, radar, long-distance telephony, and much more. By the 1920s, commercial radio broadcasting and telecommunications were spreading, and electronic amplifiers were at work in long-distance telephony and the music recording industry. The glowing tube would not surrender its place for decades, holding on in microwave and high power transmission and in television receivers until the middle of the 1980s.

• 3. The Solid-State Turn

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  John Bardeen and Walter Houser Brattain built the first working point-contact transistor at Bell Labs in 1947. The next big technological step had taken several decades to arrive. In April 1955, the IBM 608 became the first IBM product to use transistor circuits with no vacuum tubes at all, believed to be the first all-transistorized calculator made for the commercial market. The 608 held more than 3,000 germanium transistors. Thomas J. Watson Jr. ordered all future IBM products to be designed with transistors. From that point, transistors were used almost exclusively for computer logic circuits and peripheral devices. Early junction transistors carried a flaw. They were relatively bulky and hard to manufacture on a mass-production basis, which confined them to a handful of specialised applications. The answer came from the MOSFET, invented at Bell Labs between 1955 and 1960. It was the first truly compact transistor that could be miniaturised and mass-produced for a wide range of uses. Its advantages were high scalability, affordability, low power consumption, and high density. It became the most widely used electronic device in the world and the basic element in most modern electronic equipment. Solid-state devices have all but completely taken over, though vacuum tubes still serve in high power RF amplifiers, cathode-ray tubes, specialist audio equipment, guitar amplifiers, and some microwave devices.

• 4. Shrinking The Circuit

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  Speed was the trap. A complex circuit like a computer depended on it, and as circuits grew, their size became the enemy. Large components meant long interconnecting wires, and electric signals took time to travel through them, slowing the machine. Jack Kilby and Robert Noyce invented the integrated circuit and broke the trap. They made all the components and the chip from the same block, a monolith, of semiconductor material. Circuits could be made smaller, and the manufacturing process could be automated. The idea of integrating every component on a single-crystal silicon wafer led to small-scale integration, or SSI, in the early 1960s. Medium-scale integration, MSI, came in the late 1960s, followed by VLSI. The shrinking did not stop. In 2008, billion-transistor processors became commercially available.

• 5. Analog And Digital

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  Analog circuits use a continuous range of voltage or current for signal processing, unlike the discrete levels of digital circuits. They were common in the early years, in radio receivers and transmitters, and analog electronic computers were valuable for solving problems with continuous variables until digital processing advanced. Digital circuits rest on discrete voltage levels and use Boolean algebra, forming the basis of all digital computers and microprocessor devices. They run from simple logic gates to large integrated circuits employing millions of such gates. The digital world uses a binary system with two voltage levels labelled 0 and 1 to mark logical status. Often logic 0 is a lower voltage called Low and logic 1 is called High, though some systems reverse this or work from current. The definition of the levels as 0 or 1 is arbitrary, and a logic designer may flip it from one circuit to the next to suit the design. The line between the two worlds can blur. A voltage comparator receives a continuous range of voltage but outputs only one of two levels, like a digital circuit. An overdriven transistor amplifier can behave like a controlled switch with essentially two output levels. Ternary logic, with three states, has been studied and built into a few prototype computers, but it has never gained significant practical acceptance. As semiconductor technology developed, digital circuits took over many analog functions, and entirely analog circuits grew less common. A hybrid approach now handles much of the work, using analog circuits at the front end to receive an analog signal, then digital processing through microprocessor techniques. Analog circuits remain widely used for signal amplification, such as in the entertainment industry, and for conditioning signals from analog sensors in industrial measurement and control.

• 6. Building And Cooling

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  Passive and active components are the raw vocabulary of every electronic system. Capacitors, inductors, and resistors are passive. Active components are semiconductor devices such as transistors and thyristors, which control current flow at the electron level. Components are usually soldered to a printed circuit board to create a circuit with a particular function, packaged singly or grouped into integrated circuits. The ways of connecting them have changed over the years. Early electronics often used point to point wiring, with components attached to wooden breadboards. Cordwood construction and wire wrap were other methods. Most modern electronics use printed circuit boards made of materials such as FR-4 and FR-2, with electrical components mounted through-hole or by surface mount. Heat is the quiet adversary of every working circuit. It must be dissipated to prevent immediate failure and to improve long-term reliability, mostly through passive conduction and convection. Heat sinks and fans handle air cooling, and other methods such as water cooling rely on convection, conduction, and radiation of heat energy. Noise is a separate trouble, defined as unwanted disturbances laid over a useful signal that obscure its information content. It is not the same as signal distortion caused by a circuit, and it accompanies all electronic circuits. Some noise is electromagnetically or thermally generated and can be reduced by lowering the operating temperature. Other kinds, such as shot noise, cannot be removed because they arise from limitations in physical properties.

• 7. Where Chips Are Made

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  The most widely manufactured electronic device on Earth is the MOSFET, with an estimated 13 sextillion of them made between 1960 and 2018. The map of who makes such devices has been redrawn more than once. In the 1960s, U.S. manufacturers could not compete with Japanese companies such as Sony and Hitachi, who produced high-quality goods at lower prices. By the 1980s, U.S. manufacturers had become the world leaders in semiconductor development and assembly. The 1990s reversed the current. The industry shifted overwhelmingly to East Asia, a process that began when microchip mass-production first moved there in the 1970s, as cheap, plentiful labor and rising technological sophistication became available. The United States' global share of semiconductor manufacturing capacity fell from 37 percent in 1990 to 12 percent in 2022. Intel Corporation, America's pre-eminent semiconductor manufacturer, fell far behind its own subcontractor, Taiwan Semiconductor Manufacturing Company, in manufacturing technology. Taiwan became the world's leading source of advanced semiconductors, followed by South Korea, the United States, Japan, Singapore, and China. Important facilities, often subsidiaries of a leading producer based elsewhere, also operate in Europe, notably the Netherlands, along with Southeast Asia, South America, and Israel.