6 Fabrication
6.1 Film Generation

During this initial step, the board image is created on a film. One film is generated per layer. The film is generated from the Gerber files which are send to the manufacturer or the manufacturing unit where the negative image or mask is printed out on a plastic sheet. Generally, manufacturers use a photo plotter to make these films.

For the inner layers of PCB, black ink represents the conductive copper parts of the PCB. The remaining clear portion of the image denotes the areas of non-conductive material. The outer layers follow the opposite pattern: clear for copper and black for the area that will be etched away.