PCB News - About SMT new technology and environmental protection

The SMT placement machine industry is a relatively high-tech industry. Its core equipment, the SMT placement machine, has high accuracy, repeat positioning and fast accuracy. SMT is the abbreviation of Surface Mounted Technology: its technology (Surface Mounted Technology) It is the most popular and efficient technology and process in the electronic assembly industry at present!

As a new generation of electronic assembly technology, SMT has developed rapidly in the past 20 years and has a wide range of applications. It has penetrated most of the electronic industry fields and has partially or completely replaced the traditional circuit board through holes in many fields. Insertion technology, especially since 2017, my country’s key breakthroughs in chip technology, localization of CPU processors, etc., China’s electronic information product manufacturing industry has been growing rapidly every year, and the scale of the electronics industry has been in the world for three consecutive years since 2010. The first one.

Driven by the rapid development of China's electronic information industry, China's surface mount technology (SMT) and production lines have also gained a larger scale. The key equipment of the surface mount production line-the number of automatic placement machines is already in place in China. In the forefront of the world.

According to official statistics: China's imported automatic placement machines rank first with more than 30% in Guangdong Province, followed by Jiangsu, Shanghai and Beijing. Demand will maintain steady growth. With the strong rise of my country's smart phones, notebook computers and related digital products, etc. IT products account for more than 70% of the world's total output, and the domestic SMT placement machine industry has also become the world's largest market.

Domestic SMT equipment companies have basically achieved localization in SMT equipment such as printing presses, welding, and testing, and occupy 70% to 80% of the domestic market share by virtue of their market price advantages. The placement machine is basically 90% imported, and Japan's exports to my country account for more than 50%.

Jingguan placement machine equipment, domestic products with very high precision are still rare, because as far as placement machine is concerned, it is a highly intelligent mechatronics equipment and an information product. The research and development of placement machines can move related basic industries, such as fine mechanical production and related skills; various high-precision sensing skills; various high-performance motor production skills; image processing and sensing skills; XY servo control System; messy software skills, etc. Although we have caught up in many industries, the R&D of SMT placement machines still needs to be continuously strengthened. The main reasons are summarized as follows:

First, the placement machine has a complex structure, high technical content, and insufficient domestic basic industry accumulation.

The placement machine is a multi-disciplinary integration of high-tech precision equipment such as electromechanics and optics. There are 10,000 to 20,000 components. Foreign placement machine companies generally purchase 70% of them, and the other 30% are customized by the company. These 30% of domestic companies are unable to produce components due to lack of basic technical talents.

Second, the development cost of the placement machine is high, and the investment risk is high, and private enterprises cannot guarantee continuous capital investment.

At present, the production of placement machines has not received enough attention from the government. In the past, state-owned enterprises developed placement machines, usually the government allocated special funds to set up projects to tackle key problems. The enterprises produced prototypes and organized appraisals, and then the project ended, lacking the motivation for continuous innovation. Private enterprises have strong innovation vitality and are currently the main force in the development of placement machines (there are hundreds of domestic manufacturers engaged in SMT equipment manufacturing, almost all of which are private enterprises), but they are small in scale and limited in strength, and lack of prototypes for further development and improvement Capital investment. At the same time, once domestic companies successfully develop new products, foreign companies will immediately cut prices to suppress domestic companies, causing domestic companies to break the R&D capital chain and fail to survive the ever-changing performance of the placement machine market.

Third, the SMT industry standard system is not perfect.

The standard system is the key to integrating the supply chain. The rapid changes in SMT technology, new materials and new processes, as well as the dual pressures of cost and environmental protection, have forced frequent changes in product specifications and new requirements for the formulation of SMT standards. For a long time, my country's SMT industry has overly relied on foreign IPC standards and has not formulated a complete standard system based on the actual conditions of China's SMT industry. Although domestic standards such as GB19247, GB3131, and QJ165 have been formulated, there are problems such as complex standards and unsystematic standards.

The process flow of SMT patch processing can be roughly divided into: printing, patching, welding and testing (testing links can be added to each process to control quality). With its own characteristics and advantages, SMT technology has caused fundamental and revolutionary changes in electronic assembly technology.

High-precision solder paste printing is one of the important processes in SMT production.

SMT printing is the first process of a surface mount production line, and the quality of it has an extremely significant impact on the pass rate of SMT products. An important factor affecting the quality of solder paste printing is the motion control accuracy of each part of the printing machine. At present, the production of SMT products is developing in the direction of high yield and "zero defect". In production, the printing machine needs to be stable and uninterrupted for a long time. High-speed operation puts high demands on the speed, stability and reliability of its motion control system. The innovative technologies of large printing and assembly factories are constantly challenging the limits of quality and production efficiency.

Compared with all configuration equipment in the SMT production line, the SMT placement machine has the highest integration level, accounting for 70% of the production line configuration.

The placement machine is a device used to achieve high-speed, high-precision, and fully automatic placement of components. It is related to the efficiency and accuracy of the SMT production line. It is the most critical equipment for the SMT production line and the highest technical and stability requirements. It often accounts for the entire More than half of the investment in the production line, its development trend can be summarized by the "three highs and four modernizations", that is, high performance, high efficiency, high integration, flexibility, intelligence, green, and diversification.

Specifically, the SMT placement machine has undergone three generations of development, and has evolved from the early low speed (1-1.5 seconds/piece) and low precision (mechanical centering) to high speed (0.08 seconds/piece) and high precision (optical Automatic placement machine with centering and placement accuracy of ±60um/4q). The first-generation placement machine does not have the functions of visual identification devices, precise servo system, automatic feeding and automatic nozzle change, but only a stepping multi-axis system with low precision; the second-generation placement machine has the function of visual identification, placement The number of heads has also been expanded from 2 to more. Automatic transmission and imported servo technology XY-axis system can also be imported; the third-generation placement machine has higher-level upgrades, such as device identification and placement optimization functions, and the Z-axis height is adopted. Precise servo technology meets the requirements for thickness detection and replenishment of different devices and ICs, and high-precision placement. The third-generation placement machine is actually a precision industrial robot, composed of computers, optics, precision machinery, and ball screws., Linear guide, linear motor, harmonic drive, vacuum system and various sensors constitute mechatronics high-tech equipment.

High quality and green counterparts, SMT reflow soldering pays more attention to energy saving and environmental protection. SMT reflow soldering is a soldering method that forms solder joints by remelting the solder surface placed in advance, and does not add any additional solder during the soldering process. The heating circuit heats air or nitrogen to a high enough temperature and blows it to the circuit board where the component is already attached, so that the solder on both sides of the component is melted and then bonded to the motherboard. This has become the mainstream process of SMT. Most of the components on the board are soldered to the circuit board through this process.