With the development of laser welding technology, great breakthroughs have been made in the aspects of technology, process treatment and defect solution. False soldering of pack module often occurs in the process of laser welding, which not only affects the use of the whole battery, but also greatly affects the application of the company's image.

Faulty welding: that is, the welding strength between two (multi-layer) electrode lugs or between busbar and electrode lugs is insufficient, and even no penetration is formed. This form of defect mainly affects the stable performance of the battery, and the consequences are relatively serious.

The whole battery pack can not work normally because of the faulty soldering of a solder joint, and it is often an invisible defect that is exposed after the customer has used it for a period of time, which seriously damages the product quality image of the company.

What are the reasons for faulty soldering? Let's take a look at the following HGLASER laser series.

Welding conditions required for laser welding of lithium battery pack module:

1. Avoid short circuit during assembly or welding;

2. The influence of temperature on the body of the cell during welding should not exceed 60 ℃;

3. The oxidation area of the welding area is small, which does not affect the conductivity of the lug;

4. It can realize automatic mass production;

5. There is a structure of superimposed welding of multi-layer thin material lugs, and there may be welding of copper and aluminum dissimilar materials;

6. When welding a single layer, the depth of the welding layer should be controlled and cannot be penetrated.

Factors affecting the welding effect of laser welding pack module:

1. Material surface pollution

Generally speaking, when using laser welding machine for welding processing, pay attention to whether there is dirt on the material surface. If the material with dirt is put into the welding area, the surface of the material will not crystallize normally or not fully, which is one of the factors that directly affect the instability of the laser welding machine;

2. Welding speed is too fast

When using laser welding machine, users often mistakenly believe that the faster the welding speed is, the faster the production is, and the better the product is. In fact, when the laser welding machine acts on material processing, the longer the processing time between the laser and the workpiece, the more sufficient the welding is, not the faster the better; Otherwise, the faster.

3. Mismatch between material and welding power

The power of laser welding machine is not applicable to all materials. The power used for welding different materials is different. If the power used by the user is low, the welded material is not firm; For some high reaction materials, we can increase the welding power, slow down the welding speed and other welding process parameters.

4. Workbench and fixture

Workbench and fixture are used to fix materials. If the material is not fixed firmly enough, it may not be able to weld successfully, resulting in poor welding and missing welding. For example, nanosecond laser welding equipment will require the two weldments to be fully bonded, otherwise it is prone to false welding. And for those difficult to weld, we need to customize tooling fixtures to meet the welding needs.

To sum up, the welding effect of lithium battery pack module during welding will be affected by its own and the choice of laser welding process, so customers need to find experienced laser welding manufacturers when choosing laser welding equipment manufacturers. HGLASER set foot in the laser industry in 2004, and has rich experience in laser processing, and we can provide free sample testing. After being satisfied, we provide free overall laser welding scheme.