In the development of modern electronic welding technology, the application advantages of laser soldering process

With the rapid development of modern electronic information technology, integrated circuit chip packaging forms are also emerging in an endless stream, and the package density is getting higher and higher, which greatly promotes the development of electronic products to multi-function, high performance, high reliability and low cost.

So far, through hole technology (THT) and surface mount technology (SMT) are common in the electronic assembly manufacturing industry. They have been widely used in PCBA processes and have their own advantages or technical areas.

With the increasing density of electronic assemblies, some through-hole inserts can no longer be welded with traditional wave soldering. The emergence of selective laser soldering technology seems to be a special form of selective soldering technology developed to meet the development requirements of through-hole components welding, and its process can be used as a substitute for wave soldering, which can optimize the process parameters of one solder spot by one to achieve the best welding quality.

Evolution of welding process for through-hole components

In the development process of modern electronic welding technology, it has experienced two historic changes:

The first is the change from through hole welding technology to surface mount welding technology; The second is that we are experiencing the transition from lead welding technology to lead-free welding technology.

The evolution of welding technology has directly led to two results:

First, fewer and fewer through-hole components need to be welded on the circuit board; The second is that the welding difficulty of through-hole components (especially large heat capacity or fine-pitch components) is becoming more and more difficult, especially for lead-free and high-reliability products.

Take a look at the new challenges facing the global electronics assembly industry:

Global competition forces manufacturers to bring products to market in less time to meet changing customer requirements. Seasonal changes in product demand require flexible manufacturing concepts; Global competition forces manufacturers to reduce operating costs while improving quality. Lead-free production is the trend of The Times.

The above challenges are naturally reflected in the choice of production methods and equipment, which is the main reason why selective laser tin welding has developed faster than other welding methods in recent years; Of course, the advent of the lead-free era is also another important factor to promote its development.

Laser tin welders are one of the process equipment used when manufacturing various electronic components, a process that involves welding specific electronic components to a printed circuit board without affecting other areas of the board, usually involving the board.

It is generally completed through three processes of wetting, diffusion and metallurgy, and the solder gradually diffuses to the pad metal on the circuit board, forming an alloy layer on the contact surface of the solder and the pad metal, so that the two are firmly combined. Through the programming device, the selective welding of each solder joint is completed in turn.

Advantages of laser soldering machine in electronic manufacturing

1. Non-contact processing, no stress, no pollution;
2. Laser solder high quality, high consistency, full solder joint, wuxi bead residue;
3. Laser soldering can be easily automated;
4. Low energy consumption, energy saving and environmental protection, low consumables cost, low maintenance cost;
5. Compatible with large pad and precision pad, the minimum pad size is up to 60um, easy to achieve precision welding;
6. The process is simple, and the welding is completed at one time, without the need to spray/print flux and the subsequent cleaning process.

Source: Zichen Laser