Laser precision spot welding head of high reflective material

In recent years, with the increasingly fierce competition in the consumer electronics markets, the electronic product manufacturing industry has also put forward higher requirements for products. Traditional processing methods easily lead to unstable product quality, parts melting, difficulty in forming normal nuggets, and low yield. The emergence of laser processing technology can quickly solve these problems for electronic product manufacturers. In the production process of high-end electronic products, laser processing plays an important role in the volume optimization and quality improvement if of products, making the products lighter, thinner and more stable. It is reported that about 70% of the processing and manufacturing links of electronic products are applied to laser technology ( more than 20 different processes) and related manufacturing equipment.

At present, laser precision spot welding head is mainly used the shell of electronic products, shielding case, USB interface, conductive patch, etc, with small thermal deformation, precise 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.

Based on the results of many experiments, Chuangxin Laser Welding Engineers summarized in the manufacturing process of consumer electronics, which method should be used for laser precision spot welding of different materials such as high-reflective materials, metal sheets, and dissimilar material. Get a better welding effect.

Laser precision spot welding head method for high reflective materials

When welding high-reflection materials such as aluminum ans copper, different welding waveforms have a great influence on the welding quality. Using the laser waveform with pre-spike, it can break through the high reflectivity barrier. The instant high peak power can quickly change the state of the metal surface and increase the temperature to the melting point, thereby reducing the reflectivity of the metal surface and increase the temperature to the melting point. In addition, due to the fast propagation speed of materials such as copper and aluminum, cooling can be used to optimize the appearance of solder joints.

On the other hand, the absorptivity of gold, silver, copper, steel and other materials decreases with increasing wavelength. For copper, when the laser wavelength is 532nm, the absorptivity of copper is close to 40%. A comparative analysis of the characteristics of infrared lasers and green laser shows that infrared laser have larger spot sizes and short focal depths, and copper had low absotption; green lasers have small spot sizes and long focal depths, and copper has high absorption. The infrared laser and the green laser were used to pulse spot welding on copper. It can be found that the size of the solder joints after the infrared laser welding is inconsistent, while the size of the solder joints of the green laser is more uniform, the depth is consistent, and the surface is smooth. The welding effect of the green laser is more stable, and the required peak power will be more than half lower than that of the infrared laser.