A PCB is a printed circuit board. It is a flat piece of plastic or metal with lines on it that are connected to electronic components like chips, resistors, capacitors and other pieces.
A printed circuit board (PCB) is an insulating material with metallic patterns on it. Components are connected to the metal traces. The PCB has holes or pads to connect components mechanically, and connections where leads can be inserted for electrical connections. The components are mounted on the PCB by placing parts in holes or pads.
What is the purpose of a PCB / what is it for?
The main purpose is to connect electronic components together in an organised way so they can work as part of an assembly or system. The board pattern or circuit design is considered during the initial stages of product development so the components are placed in an effective way.
A PCB can also hold micro-machined devices such as accelerometers, gyroscopes and pressure sensors that are used to monitor physical movements or conditions.
How does a PCB work?
PCBs have copper tracks or “conductors” that are etched on them in specific patterns. These conductors connect various components by placing the components on pads on the PCB and soldering them together. The component is usually placed with its pins through the board holes, then solder paste is applied to each hole, then the part is placed on top of that and heated to melt the solder paste and bond it. The component is left firmly attached to the board so it does not move out of place during any subsequent processes.
What is the process behind designing a circuit board? How does it work?
It starts by putting together an electronic schematic of what you want. This involves drawing electrical connections between components like resistors, processors and chips with labelled lines to tell you how much electricity it will let through. Once this is done, you have to send the schematic to a professional who can turn it into something you can physically use. The next step is called the fabrication process where the board pattern or circuit design has to be laid out according to the schematic. This involves finding where each electronic component needs to go, so it should be decided on first before designing the PCB because this, in turn, affects the components to be placed there.
What is a PCB footprint?
PCBs have specific patterns for different electronic parts and holes and pads where the connections go. These footprints represent how an electrical component will fit on a PCB, including its dimensions and connectors. Many manufacturers provide libraries of footprints that can be used to ensure the components are compatible with the board pattern or circuit design.
Here are some common examples that use footprints
- IC (Integrated Circuit) – A footprint that is designed to hold an integrated circuit, which is a small semiconductor chip made up of many electronic components within it. They are used for all sorts of things like amplifying or switching electronic signals, converting sound to digital data, etc.
- Resistor – A footprint that holds a component called a resistor. Resistors are used in all sorts of electronic circuits to control the amount of current flowing through them. They work by resisting the flow of electricity.
- LED (Light Emitting Diode) – An LED footprint is used to hold an LED. LEDs are very commonly used in products as light sources, but they can also be used for optical communication and data transmission.
- Transistor – A transistor footprint holds small components that amplify or switch electronic signals. They have three pins that connect to the circuit board with solder pads using a specific pattern.
- Connector – A connector footprint contains a set of two or more round pinholes with a certain pitch spacing between them. The pins are designed to sit in the holes and join components together, usually ones that have been manufactured separately.