The micro-spot welding head is the corresponding welding head of the microelectronic spot welding machine. Its characteristic is that the welding head and the welding machine form a loop.

Tungsten carbide has high hardness, wear resistance and refractory properties. These alloys contain 85%-95% tungsten carbide and 5%-14% cobalt. Cobalt is used as a binder metal, which gives the alloy a certain strength. Some alloy mainly used for processing steel also contain carbides of titanium, tantalum and niobium. All these alloys are manufactured by powder metallurgy. When heated to 1000-1100℃, they still have high hardness and wear resistance. The cutting speed of cemented carbide tools far exceeds the cutting speed of tool steel tools. Cemented carbide is mainly used for cutting tools, mining tools and wire drawing dies.

There are two shapes of precision spot welding tips: sector and conical. The conical shape can imporve the rigidity of the bumps  and prevent premature crushing when the electrode pressure is high; It can be also reduce the splash caused by excessive current density. But sector shape bumps are usually used. In order to prevent the extruded metal from remaining around the bumps and forming gaps between the plates, bumps with annular overflow grooves are sometimes used. In multi-point projection welding, the inconsistent height of the bumps will cause the imbalance of the current at each point and make the joint strength unstable. Therefore, the height error of the bump should not exceed ±0.12mm. If the preheat current is used, the error can be increased.