A process for forming an encapsulating mold compound into a molded solder mask on a bottom surface of a PCB is provided that allows the molded solder mask to have a very precise, preselected thickness, or height, while also ensuring that no gaps between the solder mask and side walls of the electrical contact pads exist. A circuit board and circuit board assembly that incorporate the molded solder mask are also provided. The molded solder mask is fabricated in such a way that overlap between the molded solder mask and the electrical contact pads and gaps between the molded solder mask and the side walls of the electrical contact pads are avoided. In addition, the molded solder mask allows the pitch between adjacent electrical contact pads to be greatly reduced compared to the pitch that is possible using a traditional solder mask formed by the traditional photolithographic approach.