The rapid development of modern electronic information technology has led to the emergence of various packaging forms for integrated circuit chips, with increasing packaging density, greatly promoting the development of electronic products towards multifunctional, high-performance, high reliability, and low cost. So far, through-hole technology (THT) and surface mount technology (SMT) are very common in the electronic assembly manufacturing industry. They have been widely used in the PCBA process and have their own advantages or technical fields.
As electronic assembly components become increasingly dense, some through-hole plug-in components cannot be welded using traditional wave soldering. The emergence of selective laser soldering technology is like a special form of selective soldering technology developed to meet the development requirements of through-hole component welding. Its process can be used as a substitute for wave soldering, which can optimize the process parameters of each solder joint 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 undergone two historic changes:
The first time was a transition from through-hole welding technology to surface mount welding technology; The second time is the transition we are experiencing from lead-based soldering technology to lead-free soldering technology.
The evolution of welding technology has directly brought two results:
Firstly, the number of through-hole components that need to be welded on circuit boards is decreasing; The second is that the welding difficulty of through-hole components (especially those with large thermal capacity or fine spacing) is becoming increasingly difficult, especially for products with lead-free and high reliability requirements.
Let's take a look at the new challenges faced by the global electronic assembly industry:
Global competition forces manufacturers to push their products to the market in a shorter period of time to meet the constantly changing requirements of customers; The seasonal changes in product demand require flexible production and manufacturing concepts; Global competition forces manufacturers to reduce operating costs while improving quality; Lead free production has become a trend. The above challenges are naturally reflected in the selection of production methods and equipment, which is also the main reason why selective laser soldering has developed faster than other welding methods in recent years; Of course, the arrival of the lead-free era is also another important factor driving its development.
Laser soldering machine is one of the process equipment used in the manufacturing of various electronic components, which involves soldering specific electronic components onto printed circuit boards without affecting other areas of the circuit board, usually involving circuit boards. It is generally completed through three processes: wetting, diffusion, and metallurgy. The solder gradually diffuses towards the pad metal on the circuit board, forming an alloy layer on the contact surface between the solder and the pad metal, making the two firmly bonded. By using a device programming device, selective welding is performed on each solder joint in sequence.