Circuit board with solder mask on internal copper pad

A method of fabricating a primed circuit board, the method comprising:

• providing a first stack-up, wherein the first stack-up includes one or more electrically conductive layers and one or more electrically non-conductive layers;
• placing solder mask material on at least one copper pad of the first stack-up, wherein the at least one copper pad is exposed on a first surface of the first stack-up;
• placing a prepreg layer on the first surface of the first stack-up over the at least one copper pad;
• forming at least one cavity through the prepreg layer and the solder mask material to expose the at least one copper pad;
• placing conductive paste in the at least one cavity;
• aligning a second stack-up with the first stack-up, wherein the second stack-up includes one or more electrically conductive layers and one or more electrically non-conductive layers, such that the conductive paste aligns with a second copper pad of the second stack-up;
• and
• laminating the second stack-up to the first stack-up.