Eight Techniques of PCB fabrication, Process, Types, and its Advantages
A Printed Circuit Board (PCB) is a thin board crafted from various laminate materials such as composite epoxy, fiberglass, or other materials. PCBs are fitted in different types of electrical and electronic components like computer systems, beepers, radars, radios, and many others.
PCB fabrication is the procedure that converts a design of the circuit board into a physical structure based on the specifications given in the design package. To know PCB fabrication and assembly process, follow the techniques given below:
- Designing a preferred layout on the copper-clad surface.
- Removing extra copper from inner layers to show traces and pads.
- Creation of the PCB layer stack up through lamination of board materials at high temperatures.
- Removing extra copper from outer layers to show traces and pads.
- For mounting holes, drill them using hole pins and vias.
- Plate pinholes and via holes.
- Either add a protective coat to the surface or do a solder mask.
- Finish the process by adding it to copper areas of the surface.
What are the Different Types of PCBs?
Mostly, PCBs are classified based on the frequency, several layers, and usage of a substrate. Some popular types of PCB’s are-
- Single-Sided PCBs
The basic type of circuit board is single-sided PCB’s. It consists of one layer of substrate or base material. The layer is coated with a thin layer of metal, for example – copper. It is a good conductor of electricity. Along with a silkscreen coat, the protective solder mask is applied on the top of the copper layer on the PCB. Some of the advantages of single-sided PCB’s are:
o Single-sided PCB’s are used for bulk production.
o They are low in cost.
o These PCBs are used in simple circuits like electronic toys, relays, power sensors, and sensors.
- Double-Sided PCBs
Double-sided PCBs contain two layers covered with the substrate. These are the metal conductive layer. Metal parts are attached from one side to the other with the help of holes in the circuit board. These PCBs are connected to the circuits on either side with the help of mounting schemes, such as through-hole technology and surface mount technology. The through-hole technology helps to fit the main components on the circuit board. The surface mount technology helps to directly place electrical components on the surface of the circuit boards.
Some of the Advantages of Double-Sided PCBs are:
o The surface mounting technique helps to attach more circuits to the board as compared to the through-hole mounting.
o Mobile phone systems, test equipment, power monitoring, and amplifiers are some of the applications in which these PCBs are used.
- Multi-layer PCBs
Multi-layer PCBs consist of more than two copper layers. Some of the advantages offered by multilayer PCBs are:
o Complex multiple layer PCBs provide a high level of design flexibility.
o These PCBs play a significant role in high-speed circuits. More space is offered for conductor pattern and power.
- Rigid PCBs
Rigid PCBs are comprised of a base material that is made from a solid material. Some of the advantages offered by Rigid PCBs are-
o Rigid PCBs are compact. It ensures the variety of complex circuitry is created around it.
o Repair and maintenance of these PCBs are quite easy because all the components are clearly marked.
- Flexible PCBs
These PCBs are fabricated on a flexible base material. They come in different formats, such as as- single-sided, double-sided, and multilayer formats. This helps to reduce the complexity.
Some of the advantages offered by Flexible PCBs are-
o A lot of space can be saved by using these PCBs.
o These PCBs reduce the overall board weight.
o Flexible PCBs helps to decrease the board size. This makes it suitable for different applications where high signal trace density is required.
o These PCBs are designed keeping in mind the working conditions, such as as- temperature and density.
Rigid-flex PCBs are a blend of rigid and flexible circuit boards. They consist of multiple layers of flexible circuits fitted to more than one rigid board.
o These PCBs are utilized in many medical and military applications.
o These PCBs are light-weight.
- High-Frequency PCBs:High-frequency PCBs are utilized in applications requiring a frequency range of 500MHz – 2GHz. Some examples of frequency critical applications in which they are used are – microwave PCBs, communication systems, microstrip PCBs, and many more.
- Aluminum backed PCBs:Aluminum backed PCBs are utilized in high power applications. These PCBs provide a high level of rigidity and a low level of thermal expansion. This makes it suitable for applications that require high mechanical tolerance. They are used in applications like LEDs and power supplies.
The demand for PCBs is increasing in different types of industrial sectors. It is always suggested to purchase PCBs for industrial and commercial use from leading manufacturers and suppliers.