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. 

At present, laser precision spot welding head is mainly used in the shell of electronic products, shielding case, USB interface, conductive patch, etc., with small thermal deformation, accurate and controllable action area and position, high welding quality, it can realize welding of heterogeneous materials, and is easy to realize automation and other advantages. However, when welding different materials, different welding methods need to be adopted. According to the experimental result of many times, laser welding engineers concluded that in the production and manufacturing process of consumer electronics, high reflective materials, metal sheets, what kind of laser precision spot welding head should be used for different materials such as heterogeneous materials to obtain better welding effect. Laser precision spot welding head method of high reflective material. When welding high reverse materials such as aluminum and copper, different welding waveform has a great influence on the welding quality. Using the waveform with a front spike, it can break through the high reflectivity barrier, and the instantaneous peak power can quickly change the state of the metal surface, so that the temperature rises to the melting point, thus reducing the reflectivity of the metal surface, improve energy utilization. In addition, due to the fast heat conduction speed of copper, aluminum and other materials, the appearance of solder joints can be optimized by using the slowly decreasing waveform.

The spot welding head process is to use solder joints to connect two or more sections of equal thickness or unequal thickness to form a joint. Spot welding heads generally use lap joint and flange joints.When designing the structure of a spot welding head, it is necessary to consider the reachability of the electrode, the margin, the amount of overlap, the assembly gap of the parts, the spot distance, the indentation and the indentation, the different plate thickness, the strength of the solder joint, etc.