Thermal Analysis of Printed Circuit Boards for Infrared Reflow Soldering

The method of calculating radiation heat transfer was examined for use in the thermal analysis of printed circuit boards (PCBs) during infrared reflow soldering. The results confirmed that the heater and PCBs must be regarded as non-gray bodies. In addition, wavelength intervals must be set at two microns or less to accommodate both radiation characteristics of the heater and absorption characteristics of the PCBs. We developed the reflow soldering simulation system using the radiation calculation method. The results of the transient analysis of a PCB on the simulation system correspond to the experimental values and were proven to be accurate. A detailed understanding of the heating process of a PCB, including components mounting the PCB, during infrared reflow soldering can be acquired by using the simulation system.