Butt spot welding heads Is it divided into upper and lower parts. When welding, the welded object is located in the center of the upper and lower parts. Current passes through the welded object and generates heat on the welded object, Sometimes heat occurs primarily through the contact surface of the welded object and the welding head. This depends on which part of the current loop has a large resistance. Micro spot welding head The micro spot welding head is the welding head corresponding to the microelectronic spot welding machine. Its characteristic is that the welding head and the welding machine have now formed a loop. After the current passes through this loop, the heat is generated at the high end of the welding head. The welding head actively generates heat, while the welded object does not actively generate heat.

The molybdenum spot welding head is composed of two pieces of conductive metal bonded together. The centers of the two pieces of metal are insulated. As long as there is a contact at the tip, this contact constitutes a small resistance. The bottom of the welding head is flat and lubricated. When operating the machine, when the molybdenum spot welding head is pressed on the enameled wire by pneumatic means or with a foot pedal, the pressure will continue to increase. When the reaction force of the enameled wire on the welding head reaches the set welding pressure, it will Trigger a pulse current, the current time is very short, generally between a few milliseconds to ten milliseconds, about tens to more than one hundred amperes, the current flows from the bottom of the welding head, and there is a contact resistance at the tip of the welding head. The contact resistance will generate heat and sparks, this heat can remove the varnish of the enameled wire and a large amount of the heat will be transferred to the copper wire inside the enameled wire superior, a part of the current will from the bottom end of the welding head through the burned-out copper wire, the copper wire itself also heating, the copper wire in a short period of time before the temperature reaches the melting point of the melting state, under the action of pressure and metal underneath to from a new nugget, so that the enameled wire is connected with the metal.

2.Features of fine spot welding process The fine spot welding soft tin welding process has the following characteristics that other connection methods do not have: ①Able to weld multiple solder joints at the same time (that is, group soldering can be implemented) ②It can be welded at a lower temperature, and the thermal damage to the PCB and electronic components is small ③Good electrical conductivity at the junction; ④High-reliability joints can be completed ⑤The joints are reworked and repaired easily ⑥Suitable for various soldering methods such as soldering iron soldering, dip soldering, wave soldering, and reflow soldering ⑦The welding materials and equipment used are cheaper and therefore economical