Subtractive tech­nology is the most commonly used PWB manufacturing process. The processing sequence of a usual subtractive technology can be studied by using the animation below. The sequence contains many processes, which can be grouped into three categories.

 

Process steps of subtractive PWB technology

(click the right hand bars to see the process)

 

 

 

 

The main groups of basic processes of PWB fabrication

 

 

Before starting PWB production, the designer (or the customer) provides the PWB contract manufacturer with all necessary documen­ts, usually in standard electronic file formats. The documents include the CNC drill program, the working films (photo masks) of all layers (i.e. the pattern, or drawing, or artwork of the layers, resulted by the CAD design process), solder resist film, solder mask film, manufacturing specifica­tions, etc. All the documentation must be reviewed for completeness and accuracy.