Technological advantages of button battery, laser welding and pulse welding technology

With the development of electronics, 5g and artificial intelligence, global electronic products tend to be intelligent, lightweight, wireless interconnection and entertainment. The emergence of TWS earphones, smart watches, smart speakers and other products has created a new round of demand climax for electronic consumption. TWS headphones are undoubtedly the most concerned consumer electronics in recent years.

Technological advantages of button battery, laser welding and pulse welding technology (1)
Technological advantages of button battery, laser welding and pulse welding technology (2)

TWS headphones are usually composed of main chip, battery, flexible circuit board and audio controller, in which the battery cost is about 10% ~ 20%. Take airpodspro as an example. It has three batteries: two headphones and a charging warehouse. The battery in the headphones is a new type of button charging battery. Compared with other electronic products, the button battery in TWS headset is more difficult to process. It is a new type of rechargeable battery. Due to its small volume and energy storage, it is widely used in consumer electronics, computers and peripherals, communication, vehicle mounted, medical treatment, home, IOT and other fields.

In daily life, most of the button batteries commonly used in various small electronic products are traditional disposable batteries, which are cheap and simple in processing technology. In order to meet the needs of consumers for high durability, high safety and personalized electronic products, battery manufacturers have developed rechargeable button batteries. The traditional processing technology touches the pain point of the upgrading of the processing technology of the new button battery, which makes the processing difficulty and process level of the button battery continuously improve.

The traditional button battery pack process uses the thermal effect of resistance to melt arc welding into arc welding. Although this welding process is simple and low cost, its disadvantages are also obvious. If only a single material can be used for welding, the welding trace is not beautiful, the size of the welding spot is not accurate, and the equipment and personnel are prone to oxidation, black, large cloak and other problems during operation, which is easy to cause safety problems such as falling off of the welding strip and drop of the battery voltage of the welding foot. Resistance welding is no longer suitable for the processing quality requirements of new button battery.

Many button batteries are usually used in circuit boards, and solder pins need to be welded on their surfaces. Due to different circuit boards, there are many forms of welding feet. At the same time, the welding leg of button battery is complex and the resistance welding process is not professional.

Because the existing resistance welding technology can not meet the high-quality welding requirements of steel shell battery, many button battery manufacturers are committed to laser welding and pulse welding technology.

It can meet the welding of various materials (stainless steel, aluminum alloy and nickel). The welding track is irregular, the welding shape is good, the welding performance is good, the welding spot is fine, and the welding area is more accurate. It can also make the products highly consistent, reduce the damage to the battery and avoid the waste of raw materials.

Process advantages:

1. High energy density, easy to reach the absorption threshold of materials (especially highly reactive materials);

2. Various welding trace diagrams can be realized. There are sine type, spiral type, spiral type, etc;

3. The smaller the welding spot, the greater the welding depth. Under the same welding size, the larger the contact area, the greater the weld strength and tensile force;

4. High energy density. Its welding principle is different from the traditional welding principle based on large molten pool. It is closer to inlay welding, which can obtain higher welding strength. Especially for the welding of different materials, it can reduce the generation of brittle compounds.

It can meet the welding of different welding materials and different material thickness. If the material of the pole lug is nickel, the steel shell is stainless steel, the thickness of the pole lug is 0.15mm, and the thickness of the steel shell is 0.15 or 0.2mm, which can meet all kinds of solder joints at the same time. The solder joint is very small, the solder joint is very small, and the welding requirements must reach 30n.

During spot welding, pay attention to spot welding parameters: pre welding current, welding time, welding current, etc. adjust appropriate parameters according to different nickel sheets.


Post time: Nov-16-2021