?The printed circuit board has been a crucial part of nearly all manufactured electronic products since the 1950s, but there are not many people who really know what they are, what they do, or how they are made. This article should shed some light on these elusive elements that make up such an important part of our everyday lives. Printed circuit boards are lightweight, durable and rugged, serving as the backbone that keeps all various parts securely connected. Using printed circuit boards instead of hand-wiring has improved the quality, reliability and overall cost of electronics everywhere. While materials and manufacturing processes have improved over the years, the basic idea remains the same. Technicians use specialized software to create a layout from the electronic schematic every time a printed circuit board is tested and approved. The software maps out where the components will go on the printed circuit board and creates a pattern (a set of lines that electronically connects the components together). To keep electronic signals from interfering with each other, the lines must follow rules for width and spacing. Printed circuit boards are made of copper foils glued to a sturdy plastic base, usually formed from a 1.6 mm-thick fiberglass and epoxy composite. This material has a good combination of stiffness and strength, optimal electrical and radiofrequency characteristics, and is easily machined. In more demanding applications, other materials like Teflon could be used. To connect the electronic components during the manufacturing process, copper foil is printed with a masking substance in the design pattern. Then the board is dipped into a solution that etches the bare copper away, leaving only a pattern of lines. The mask is washed off, revealing traces in the copper. To allow for great circuit density and complexity, printed circuit board can also be made into a "sandwich" of many layers of board materials and copper. Everyday electronic items, such as cell phones or wristwatches, depend on high amounts of circuitry crammed into a small space. Each copper layer has a different pattern, interconnected by conducting pins. To make a working circuit, electronic parts are soldered onto the copper traces. Other parts come together to complete the board, allowing it to be connected to a chassis, power source and the remained of a finished product. Printed circuit boards aren't just for big companies. They can be created by you in your own home with the use of a kit and your home computer.
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