Every electronic device has at least one printed circuit board (PCB). These are the circuit boards that include numerous components and connect to other boards. These plastic boards and the components soldered to them provide the basic electric technology that runs everything from complicated computers and smartphones to basic home appliances, like microwaves and coffee makers.
What is a Printed Circuit Board or Circuit Board?
Stated by a PCB manufactruting company a Printed circuit boards (PCBs) are thin boards made of an insulating material coated in metal, often on both the top and bottom. The board is the basic building block of any electronic design – think of the flat boards that children use to build their Lego creations.
Instead of piling Legos on top of them, printed circuit boards are etched with acid to give electric currents a route to travel to move through the attached components. When the components are soldered, the board eventually becomes green from the solder mask. Many PCBs also have holes drilled into them so manufacturers can attach components and attach other circuit boards to them. A plain circuit board does not look like much, but once components are attached, they look artistically sophisticated.
What Does a Circuit Board do?
Circuit boards look like they don’t do much. They’re just thin boards made of fiberglass, epoxy resin, and copper foil. Some less expensive ones are made of reinforced paper covered in phenolic resin with copper foil. But once components are added and routes are printed, they become rather amazing.
The job of a circuit board is to integrate electronics into a compact space. The board insulates the electronic components, so our electronic devices are safe to use. Circuit boards are inexpensive tools that can be designed in infinite ways. Manufacturers have developed automated methods to create them in high volume so they can be efficiently placed into millions of smartphones or coffee makers.
What are the Components of a Circuit Board?
Printed circuit boards on their own do not do much. But, once components are added, they do rather amazing things. There are several components that can be added to a circuit board. They do not all need to be placed on every circuit board, but most circuit boards have numerous components used on both the top and bottom.
Battery
Circuit boards need batteries for power. They are often attached via a dual-terminal device for voltage at two points through the circuit.
Capacitor
This is another component that provides power. Instead of providing it directly, the capacitor captures the power and releases it when an electrical charge is needed. These look like little gumdrops or they can be large cylinders. Some will have numbers or other bits of information printed on them. There are several types of capacitors, like the diverse polymer capacitor and the ceramic disc capacitor. After the resistor, these are the second most common component on PCBs.
Connectors
These are useful for circuit boards that connect to other boards and devices. They usually include plastic shells, pins, and links so the devices can connect with the appropriate cables.
Diode
A diode is a directional component that sends the current in a preset direction. Diodes often have their specs listed on their shells, and some are made with LEDs. When looking at the design of a PCB, the diagram will have an arrowhead and bar to show where the diode goes based on the direction of the current.
Inductor
This is another power component that stores the electrical current as magnetic energy. These are complicated looking loops of wire that are often color-coded. Inductors can have different numbers of windings, and those with more have greater magnetic fields. It is important to test these before permanently attaching them to a PCB.
Integrated Circuit (IC)
This is a complicated chip that often includes numerous circuits and components that are miniaturized. It is specifically designed to do a preset function. These are often called “circuits on a chip.” If you receive several of them in a shipment, it can be tough to tell the difference between them. Many come with explanatory datasheets. On a circuit diagram, the IC is marked by a rectangular block.
Light Emitting Diode (LED)
These are small lights that circuit boards use to provide visual feedback. These lights come in various colors. And some have several colors that send specific messages. Some are high-powered and others need very little power to emit light.
Single-color LEDs have two terminals: the cathode and anode. If the LED has several colors, there will be two terminals for each color. If the LED is large, it will have a metal casing that reduces the heat that comes from the light.
Resistor
This component regulates the flow of electric current by resisting it. These are little cylinders that usually have stripes that explain their resistance and tolerance. The most common shape is known as an axial, with the cylinder in the middle with long “legs” hanging out of each end. If they are large enough for writing, the writing will explain how they function. These are the most common components found on a PCB.
Relays
These are electronic switches. They usually have shells with their specs. When the relays are open, the electricity moves through them. When they are disconnected, the flow stops.
Switch
This component is like an on-off switch that either blocks the flow of the current or allows it to flow.
Transistor
This is another switch that controls the electrical signals as they travel through the boards. These will have three terminals and are D-shaped. On the diagram, transistor locations are marked with circles with three leads. Some circuit boards will have a Q to show their locations.
Printed circuit boards, also known as PCB, are a necessity in an electronic device. They are used to connect many electronic components inside the devices we use each day, like smartphones, cameras, televisions, and computers. The boards might not look complicated at first, but once components are attached, they do some amazing things.