Abstract: A circuit board manufacturing method for manufacturing a printed circuit board with improved characteristics for machine soldering. The circuit board manufacturing method includes the addition of a polyimide "B" semicured material to a printed circuit board prior to preheating and then machine soldering the printed circuit board. The polyimide "B" semicured material retards heat and is used to eliminate the common "hot" and "cold" spots that occur with printed circuit boards during the preheat cycle prior to machine soldering of the printed circuit board. As a result of the heat retardation due to the polyimide "B" state material the circuit board is thoroughly and properly heated during the preheat cycle to eliminate hot and cold spots so that proper machine soldering can occur. A number of different methods are presented and in one method polyimide "B" stage material is used to prevent movement of thermal pads.