PCB Manufacturing Process
Did we know that any electronic item we use in our homes have electronic circuits? Did we know that the electronic circuits are created by a process by mounting electronic components on a board which is a bad conductor? If you answered negative to both these questions, it is time that you knew something about Printed Circuit Boards and PCB Manufacturing Process.
Before we look at the process elements of a PCB Manufacturing process, it is important that we know the materials/elements used in the production process. Copper is used for the conductive circuits with aluminum, nickel and chrome offering suitable alternatives. Printed Circuit Boards are manufactured in three different varieties. The different varieties are Single-Sided PCB, Double-sided PCB, Multi-layered PCB.
What are the steps of a PCB Manufacturing Process?
The basic requirement of production of a PCB is to plate and etch off flat circuits of copper which are supported on a non-conducting sheet of plastic. The raw material required for PCB manufacturing is a sheet of plastic which is laminated with a thin layer of copper foil.
- A drilling machine is used to drill holes through the board. The holes are drilled symmetrically on to the board. The drilling process pollutes the board by leaving some particles on the surface of the board.
- These particles are cleared off before mounting any electrical components as they interfere with the conduction process. A scrubber is used to clear off copper wastes from the board. The rinse-water from the scrubber is a valuable source of copper waste which is then fed on to copper treatment plants.
- After scrubbing the board, the manufacturer cleans the board and etches them that ensure good adhesion to the board. The board is then plated with an electroless copper plating providing a continuous conductive surface overt he board. Please note that the holes that have been drilled on to the board are non-conductive.
- Chelating agents which keep the copper in an electrolytic solution at an Alkaline Ph are used for electroless copper plating. After the electroless plating, the manufacturer applies a plating-resist to the panel and photo-image it to create the circuit design.
- Copper is used for electroplating the final board which is added by a tin solder plated over it. The plating resist is removed by the manufacturers to expose the copper which does not play a role in the final circuit pattern.
- To reveal the circuit pattern, exposed copper is removed with the help of etching solution. Most commonly used etching solutions are Ammonia - based.
The PCB Manufacturing Process is a highly technical one and the manufacturers indeed have to pay deep attention to pollutants and pollution control to ensure high quality PCBs are printed.