What is a Printed Circuit Board?
The circuit board, also known as a printed circuit or board, is a plate made of an insulating material (e.g. epoxy resin) with wafer-thin conductor tracks made of copper. It is equipped with electronic components (circuits, diodes, resistors, etc.), which are either connected to the conductor tracks on one side through small holes through a soldered connection, or on both sides, i.e. the copper conductor tracks and components are located on both sides of the circuit board.
Areas of application are almost all electronic and electrical devices in the private and industrial sector: private applications include computers, radio and television sets (satellite receivers, DVD players ) as well as electrical household devices (drills, microwaves, razors, power supplies) Industrial applications include industrial controls, heaters, dimmable lamps, vacuum cleaners or washing machines (control unit).
Before the circuit board can be used, one must consider how the individual components are arranged and how they can be electrically connected. In the past, experts had to spend a large amount of time over complicated, large circuits. Fortunately, now, there are computer programs that do this for us.
Once the circuit board design is ready, holes for the individual components are drilled. The components are preferably inserted into the holes from one side, modern circuit boards also allow equipping on both sides. Now the electrical connections must be made between the points where the connections of the components will later look through the holes. Hobby electronics used to do this with an acid-resistant paint that simply covered the conductor tracks. The remaining, free-standing copper is etched away with an acid, the conductor tracks now remain.
Now you have to put the components through the holes according to the circuit board design (“layout”) and connect them electrically from below to the copper conductor tracks. This is done by soldering on the “soldering eyes”. The solder points on the connections not only create an electrical connection, but the components are also mechanically fixed. Modern, industrial processes are more complex, use photochemical processes to produce the conductor tracks, use both sides of the circuit board for assembly, use plated-through holes or use components whose connections are not inserted through the holes, but are soldered flat on one side of the circuit board.