The power supply selected to perform reflow soldering/hot bar bonding provides temperature and time control to the process; it generates a controlled electrical current which is passed through the thermode. A typical bonding profile consists of a 'preheat' cycle, 'rise,' 'reflow' and 'cool.'

Heating a thermode for hot bar bonding takes about 2 seconds. During this time, the flux is activated and promotes wetting by removing the oxide layer from the parts to be joined. Preheat is only used when the thermode is affected by excessive heat sinks, or the application has very delicate substrates, like ceramic, which need more controlled heating to avoide cracking.

Time and temperature may be programmed for the rise and reflow stage of the process, ideally in 0.1 second and one-degree increments. Typical temperature settings range from 280 to 400 degrees Celcius. Although normal solder will reflow at 180 degrees Fahrenheit, the temperature must be set higher to allowo for thermal transfer losses in the thermode.

'Cool' is a programmable temperature at which the power supply will send a signal to the head to move to the 'up' position. This temperature is usually set just below the solder solidification temperature. As soon as the solder is once again solid, the joint is formed, and the process is ended. Forced air cooling may also be used. The power supply may be programmed to switch a relay that controls the flow of air over the thermode to cool it and the joint more rapidly. Release temperature can normally be set to 180 degrees Celcius.