Process Enhancements for Dry Film Solder Mask
Original Publication Date: 1988-Jun-01
Included in the Prior Art Database: 2005-Feb-15
Utilizing dry film for solder mask applications in the construction of a printed circuit board (PCB) requires thorough cleaning of the PCB prior to the dry film application to ensure a good bond between the film and the PCB. A good bond is needed to protect circuitry from shorting during the tin and solder operation. A method of constructing a PCB through the applicable processing steps, including cleaning the raw board prior to resist apply, all the way through develop, eliminates several cleaning steps, two baking steps and eliminates two required holding steps. The above is accomplished by reducing the developing time. Several subsequent cleanings that were required to obtain the complete removal of the dry film to ensure solderability to the PCB are also eliminated. The improved process is described in the following.