Printed circuit boards are one of the key components of electronics equipment to function. They offer mechanical support and electrically connectivity to the components such as resistors, capacitors, inductors, microcontrollers, and others that are required to operate any electronic device. A PCB provides the conductive pathways to connect various components and allows electrical current to complete a circuit as per the required design. These components are soldered mechanically onto a printed circuit board as per the schematic design to complete the electrical connectivity.
A PCB is a flat and rigid board with thin conductive structures printed on it using an insulating material such as copper. It comprises layers of different materials laminated together in the form of a single object to provide support and conductivity altogether. These layers are categorized as:
- Substrate (FR4): It is the base of any printed circuit board that is usually made of fiberglass. It gives a flat and rigid structure to printed circuit boards.
- Copper: A PCB comprises a thin layer of copper as the next layer to provide the conductivity to connect various components electrically. It is laminated using heat and adhesive on the substrate.
- Soldermask: It is the next layer that is mounted on the top of the copper layer that gives printed circuit boards its green color. It works as an insulation layer to prevent solder jumpers while soldering components on the board. It ensures the proper conducting path as per the schematic design.
- Silkscreen: On the top of the solder mask layer, a white silkscreen layer is applied to represent letters, numbers, and symbols on the PCB. It helps in understanding the conductive path to allow easier assembly of the electronic circuit.
Types of Printed Circuit Boards
PCBs are mainly classified as single-sided, double-sided, and multilayer PCBs based on the copper layer composition.
Single-Sided PCB: A single-sided PCB consists of a single copper layer laminated on one side of the substrate. These are the simplest form of printed circuit boards available in the market to design simple electronics circuits. It doesn’t require plating through holes for conductive paths.
Double-Sided PCB: In a double-sided PCB, the copper layer is laminated on both sides of the substrate layer for complex circuit designs. Through-holes are fabricated between the top and bottom pads connected with special copper plating known as Plated Through Hole (PTH). It allows reconnection between layers for complex circuit designing.
Multiplayer PCB: Multilayer PCBs consist of four or more copper layers laminated on the substrate. Each copper layer is bonded together and separated by an insulating material to allow much higher component density.
PCB fabrication and designing is a complex process and requires a high level of skills and technical knowledge. If you are into the electronic equipment industry and looking for quality Printed Circuit Board Manufacturers for circuit assembly, make sure to find a manufacturer that uses advanced engineering processes and the latest technologies in the fabrication of PCBs.