According to the pulse heating principle of the hot press, due to the special design of the welding head surface, the resistance of the welding surface is very small, and the current will pass through the section with the lowest resistance. By constantly changing the voltage and adjusting the current level, the welding head can quickly heat up.

Hot press includes constant temperature hot press, pulse hot press, double station hot press, double indenter pulse hot press, desktop hot press, etc. As the pitch of PCB or FPC in consumer electronic products tends to be smaller, the traditional soldering process has been difficult to meet the requirements of ultra-fine hot pressing. ACF process has been gradually applied by mobile phone designers.