Laser welding machine application and future development trend

Laser welding machine application and future development trend

With the development of science and technology, electronic, electrical and digital products are becoming more and more mature and popular in the world. From the main point of view, from the PCB board to the crystal oscillator, any component in the product covered by the field may involve the welding process. For components, most welding needs to be performed below 300°C.

Today, chip level packaging (IC packaging) and board assembly in the electronics industry mainly uses tin-based alloy filled metal welding to complete equipment packaging and card assembly. For example, during the inverted chip process, the welding material connects the chip directly to the substrate. In electronic assembly manufacturing, welding materials are used to weld equipment to the circuit board.

The welding process includes peak welding and reflow welding. Peak welding uses the peak surface of the molten solder to circulate and make it contact with the PCB welding surface connected to the component to complete the welding process. Reflow welding is a kind of welding process. Put the solder paste or pad together in advance after the PCB is heated, the melting of the solder paste or pad connects the component to the solder pad between the PCB.

Laser welding is a brazing method that uses laser as a heat source to melt tin and make the welds fit tightly. Compared with the traditional welding process, this method has the advantages of fast heating speed, less heat input and great heat influence. The welding position can be accurately controlled, the welding process is automatic, the welding amount is accurate, and the welding joint is consistent. It can greatly reduce the impact of volatile substances on the operator during the welding process, and non-contact heating is suitable for welding complex structural parts.

According to the state of the tin material, it can be divided into three main forms: tin line filling, tin paste filling and tin ball filling.

01: tin wire filling laser soldering applications

Laser welding is the main form of laser welding. The wire feeding mechanism is used in conjunction with the automatic work table to realize automatic wire feeding and light output through modular control. Welding has the characteristics of compact structure and one-time operation. Compared with several other welding methods, its obvious advantages are disposable clamping materials and automatic welding, and wide applicability.

The main application areas are PCB welding circuit boards, optical components, acoustic components, semiconductor refrigeration components and other electronic components. The solder joint is full, and the pad is wettable.

02: Application of solder paste filling laser solder

Solder paste laser welding is usually used for parts reinforcement or pre-tinning, such as high temperature melting reinforced shielding cover corners, magnetic head contact tin melting; It is also suitable for circuit conduction welding, for flexible circuit boards (such as plastic antenna mounting base), the welding effect is very good, because there is no complex circuit, so solder paste welding usually achieves good results. For precision and miniature workpieces, solder paste filling welding can fully reflect its advantages.

Because the solder paste has good thermal uniformity and a fairly small equivalent diameter, the number of tin points can be precisely controlled with precision dispensing equipment. The welding paste is not easy to splash, and the welding effect is good.

Due to the high concentration of laser energy, the welding paste heating is not uniform, the rupture and splashing, and the splashing welding ball is easy to cause short circuit. Therefore, the quality of the solder paste is high, and splash-proof solder paste can be used to avoid splashing.

03: tin ball filling laser soldering application

Laser tin ball welding is a kind of welding method in which the tin ball is put into the nozzle of the tin ball, melted by the laser, and then dropped onto the pad, and the pad is wet.

Tin balls are small particles of pure tin that are not dispersed. Laser heating melts without causing splashes. It will be full and smooth after curing. No other processes, such as subsequent cleaning or surface treatment of gaskets.

Through this welding method, the welding of small pad and enamelled wire can achieve a good welding effect.

04: Laser soldering technology is difficult to apply

Traditional welding, including peak welding, reflow welding and manual welding, can solve problems in the welding process. Laser welding can be replaced gradually, but just like patch welding (mainly used for reflow welding), the current laser welding process is not suitable. Due to some characteristics of the laser itself, the laser welding process is more complex, which can be summarized as follows:

1) For precise and fine welding, it is difficult to find and clamp the workpiece;

2) For flexible wire, the consistency of clamping positioning is not good, and the fullness and appearance of welding samples are very different;

05: Overview of laser solder market demand

After years of development, the market demand for laser solder at home and abroad is constantly changing. Under the guidance of the welding process requirements for electronic and digital products, not only the number of vertical increases, but also the horizontal application field is expanding.

Covers welding process requirements for other components in various industries, including automotive electronics, optical components, acoustic components, semiconductor refrigeration equipment, security products, LED lighting, precision connectors, disk storage components, and more. ; In terms of customer base, the company has been looking for laser welding process solutions, mainly related welding process requirements derived from the relevant components of Apple customers' products (including the upstream industry chain). In general, laser welding will last a long time. There will be amazing explosive growth and relatively large market volume.

In the current weak global economy, Apple is thriving. Its large market share in digital electronics and large-scale global sourcing have driven business growth for many companies. The main products of these companies are electronic components and welding. This is an indispensable part of its production process.

06: Process breakthrough requirements

The products produced by companies including Apple, including suppliers, are the latest and most high-end designs, which will encounter difficult process problems during mass production and need to be improved and perfected.

A very typical area is the storage component industry. Magnetic head is a storage component with high precision and high technical requirements. The data line of the magnetic head is usually a flexible PCB, attached to one end of the steel structure. The small spots of the array arrangement need to be tinned in advance, and the trace tin can only be completed under the microscope, and the welding effect is extremely strict.

The traditional welding method is manual welding, which requires the operator to have a high level of welding. The scarcity and mobility of labor resources bring great uncertainty to production. In addition, it is impossible to quantify the process standard (there are no process parameters, and it is entirely dependent on the human feeling to judge the effect after welding), so the laser welding process is needed to overcome the technical obstacles.

07: Process upgrade expansion requirements

Laser soldering can stimulate the process parameters, increase production, reduce costs, and ensure the standardization of production operations.