Abstract: A pallet for supporting a circuit board during a soldering process. The pallet has a thermal mass that is varied to offset a thermal mass of the circuit board so as to minimize the difference in temperatures across the circuit board during the soldering process. The thermal mass of the pallet is varied by build up or removal of material of the pallet in selected areas, and/or through the use of materials having varying thermal properties. In addition, the total thermal mass of the pallet and the circuit board is maintained to stay within a set range in order to allow a soldering process to accommodate more than one type of circuit board with minimal to no adjustments in the process settings between boards. Construction of the pallet is preferably performed in an iterative process wherein temperature variations in the circuit board are measured during heating cycles and the pallet is modified in response to the differences in temperature at different areas.