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A Brief Overview On PCB Fabrication Process

 The backbone for any electronic device is its printed circuit board to PCB. PCBs act by routing the electrical signal to the electronics of the device to meet their electrical and mechanical circuit requirements. This routing of electrical impulse is done by network of copper pathways which determines the unique role of each part printed on the circuit board.
Types and variation
PBCs although in general serves similar purposes, however the PCB fabrication process slightly varies according to the type of circuit board that is to be manufactured. Generally there are three main types:
  •          Single Sided Circuit Boards
  •         Double Sided Circuit Boards
  •          Multi Layered Circuit Board


A brief manufacturing process
The PCB fabrication process introduced by leading manufacturers is elaborate and intensive. A concise account is given below
Design: Any manufacturing process begins with a design. The most commonly used software for PCB designs are Altium Designer, OrCAD, Pads, KiCad, Eagle etc.
Printing: After the design has been finalized the design is printed on a special plotter printer. This is essentially a photo negative version of the real PCB.
Printing of copper layers: the basic PCB comprises of a laminate board. This laminate board serves as the body for receiving the copper. This process whittling away of copper for the film design
Removing of extra copper: An alkaline solution is used to eat away the extra copper that is not covered by photo resist.
Inspection and alignment: After cleaning, the holes from the earlier are used to align the inner and outer layers. For alignment the layers are place on optical punch where the punch drives pin down through the holes to layer up PCB. Another optical punch is performs the optical inspection.
Laminating: Once the layers are detected defect free they are laminated and sandwiched which is done by metal clamps.
Drilling: A computer guided drill is utilized for making the holes
PCB plating: After the drilling a chemical solution is used to fuse different layers of PCB together.
Imaging the outer layers: A photo resist is applied on the outer layer to make it more resistant.
Etching: Any unwanted copper is removed by etching, tin guard is sued to protect the copper layer during etching.
Solder Mask: After etching and cleaning soldering ink along with solder mask is applied. and the boards are blasted under UV rays. Then baked for the mask to be cured.
Finishing: For silkscreening or finishing PCBs are plated with gold silver or HASL so that components are able to solder to pads and protect the copper.
Testing: After finishing touch a battery of electrical test is run for testing different areas of the circuit.
Cutting and profiling: After the piece tests defect free they are cut into different pieces as per profiling and purposes.
End note
The entire process of PCB manufacture is elaborate and highly complex requiring a mixture of lot of chemical and high end precision techniques. Industry experts in PCB fabrication can provide different high end PCB circuits as per the specifications of your device needs.



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