Printed Circuit Board Construction

Printed circuit boards are constructed using a variety of methods. Discussed here is one (of many) of the methods: print and etch (subtractive) method

Print and Etch Method.

The first step in this process uses a single or double-sided circuit board coated (in this example) with copper.

The second step is to coat the board with a photoreactive polymer film.

The coated circuit board is then exposed to an imaging light source, selectively inducing crosslinking of the polymer film into an 'etch resist.'

The circuit board is then exposed to an acid solution that dissolves away (etches) the copper from the uncrosslinked sections.

The crosslinked polymer is then removed to expose the printed circuit board traces.