Here is a look at the process of manufacturing PCBs or Printed Circuit Boards. The steps outlined below apply in most custom electronic design.
Setting up the process which includes choosing processes, material and how to meet custom circuit board customer's specific needs for the design of the board.
This is the imaging stage where the data is transferred onto etch resist film that then gets put on the copper conductive layer.
Now is the time for the process of etching. The traditional method would expose the unprotected areas and the copper to a chemical leaving behind just the protected copper pads. More modern methods in this process of making a custom circuit board use lasers or plasma etching rather than the chemicals as they give a better definition in the lines.
Aligning the insulating dielectric layers and conductive copper under heat which are then pressed to turn the board into a solid material.
Drilling holes for plated through applications. The second drilling for holes that are not going to have plating happens in step seven.
Applying copper plating to the traces and the pads and holes. A bath of copper that is electrically charged holds the boards.
Now is the time for the second drilling of holes through an area of copper that is not going to be plated through. This does add extra cost to the process of custom electronic design boards.
Now is time for the process of masking. Apply a material over the traces of bare copper and where there are thin amounts of solder over copper too. This protects them from damage and gives it better insulation and less likely to have problems with solder shorts.
At this stage of finishing it is time to apply a coating to the pad areas along with a fine layer of solder. This gets it ready for the reflow soldering or wave soldering that comes later once the components are in place.
Silk screening time which you can apply to both sides if both sides will have components or just the top side. The markings that designate components and the outlines of those components are applied.
The routing step is where the separation of multiple boards occurs, and slots or notches are cut into them should that be a requirement.
The boards need to have a visual inspection and checked for quality.
Time to test them. With electrical testing, the boards are checked for shorted connections by applying a volt to different points and making sure there is a flow of current. Some more complex boards need test programs and fixtures specifically designed to test them.