Application of BGA solder balls

In the CPU chip of each computer, nearly 1,000 solder balls with a diameter of only 0.3 mm are silently supporting the high-speed flow of data. In the battery management system of new energy vehicles, the welding points of ultra-fine tin wire ensure the stable transmission of current; Behind each panel of a photovoltaic module, the precise connection of low-temperature solder determines the level of power generation efficiency...... These seemingly insignificant tin-based materials, like the "neural network" of the industrial system, not only penetrate all aspects of daily life, but also support the development of national strategic emerging industries. Tin, a metal known as "industrial monosodium glutamate", is being upgraded from a traditional industrial raw material to a strategic new material with high added value through breakthroughs in deep processing technology.

1. Ultra-fine tin wire: a welding revolution with hair-level precision

In a clean workshop with a constant temperature of 25°C and a humidity of 50%, a bundle of tin wire with a diameter of only 0.1 mm is continuously being ejected from the precision drawing equipment – a metal wire that is thinner than a human hair (about 0.07-0.1 mm in diameter) and requires ten processes of precision forging to form. Starting from the ratio of solder alloy, the ratio of tin to silver, copper and other elements should be controlled within the error range of ±0.01% to ensure the stability of subsequent soldering performance. The ingot casting process adopts vacuum melting technology to control the gas impurity content below 5ppm to avoid wire drawing fracture caused by internal pores; In the final ultra-fine drawing process, the deformation of each pass is accurately controlled between 8% and 10%, and through more than 20 times of progressive stretching, the wire is gradually reduced from the initial diameter of 5 mm to the target size, and its processing accuracy is comparable to the meshing tolerance of clock gears. The birth of this φ0.1mm ultra-fine solder wire broke the size barrier in the field of electronic soldering. In the fingerprint recognition module of smartphones, it can achieve precise connection of 0.05 mm pitch solder joints, reducing the risk of solder bead splashing by 30% compared to traditional wires. In the gyroscope assembly of space satellites, its uniform composition distribution keeps the solder joints stable over temperature cycles from -50°C to 120°C, increasing connection reliability to 99.9%. Zhang Chenghai, head of the company's business department, pointed out: "The technical difficulty of ultra-fine tin wire is not only in size control, but also in maintaining the mechanical properties under small diameters - our products can withstand more than 50 repeated bends in the 180-degree bending test, while ordinary tin wires will crack about 10 times. "

The industrial application of this technology has formed significant economic benefits. In 2023, the sales volume of ultra-fine solder wire alone will exceed 500 tons, and the new sales revenue will exceed 80 million yuan. More importantly, it has led to the technological upgrade of the entire product line, and the company has launched a series of high-reliability solder wires, which has replaced imported products in the welding of motor controllers of new energy vehicles, reducing the procurement cost of similar components by 40%.

2. BGA solder balls: a precision world of one in five million

In a glass jar the size of a household seasoning bottle, about 5 million solder balls are neatly arranged - these metal spheres with a diameter of 0.3-1.2 mm, each of which has undergone triple inspection of roundness, diameter, and surface finish, can be called the "standard parts" of the microscopic world. As the core material of ball grid array packaging (BGA) technology, BGA solder balls play a key role in replacing traditional pins, building hundreds or even thousands of electrical interconnect channels between the chip and the substrate, and its performance directly determines the signal transmission speed and heat dissipation efficiency of integrated circuits. The production process of BGA solder balls is a protracted battle against microscopic defects. Due to the lack of mature production experience in China, Zhang Xianli, the company's equipment team leader, led the team to complete the process breakthrough in three years: the self-developed automatic roundness screening machine detects each solder ball 360 degrees through laser scanning technology, and all products with a roundness error of more than 0.002 mm are eliminated, and the pass rate has increased from 75% to 99.5% in the initial stage; The introduced precision drop casting equipment adopts the constant temperature liquid tin drop ball process under nitrogen protection, so that the oxide layer thickness on the surface of the solder ball is controlled within 5 nanometers, which is far lower than the industry standard of 20 nanometers, and significantly improves the wettability during welding. Intelligent transformation further releases production capacity potential. After replacing the high-cost imported ultrasonic power supply, the cleaning efficiency of the solder balls is increased by 40%, and the energy consumption of a single equipment is reduced by 25%. The newly launched fully automatic production line realizes the unmanned whole process from raw material input to finished product packaging, shortening the production cycle from the original 48 hours to 12 hours. These process optimizations bring more than just efficiency gains – in the core chip packaging of 5G base stations, using the company's BGA solder balls, the solder joint void rate has been reduced from the industry average of 8% to 2.3%, resulting in a 15% improvement in the base station's communication stability.

3. Innovation matrix: seamless connection from the laboratory to the production line

At the company's R&D center, the flame retardant team is making its 37th formulation adjustment – a tin-based flame retardant that needs to maintain flame retardant efficiency while keeping the material's dielectric constant below 3.0 to meet the signal transmission requirements of 5G communication devices. This kind of tackling of the "stuck neck" problem is a normal portrayal of the company's innovation system. Focusing on the industrial chain of tin-based new materials, the company has built a professional R&D team covering alloys, tin chemistry, solder chemicals, flame retardants, high-purity materials and other fields, forming a full-chain innovation capability of "basic research, pilot incubation, and industrial transformation". In 2023, R&D investment increased by 28.2% year-on-year, and this continuous technical investment has yielded fruitful results: aluminum-based solder wire uses flux to solve the oxidation problem during aluminum soldering, increasing the welding efficiency of photovoltaic busbars by 50%; By adding 0.1% nickel element, the high-temperature strength of the solder joint is increased to 1.8 times that of traditional products, meeting the high-temperature resistance requirements of electric vehicle battery packs. Organotin compounds such as dioctyl tin dichloride and dioctyl tin oxide have replaced toxic lead stabilizers in the production of medical PVC materials, promoting the green upgrading of medical packaging. The collaborative innovation system of "government, industry, academia, research and application" accelerates the transformation of achievements. The low-temperature solder for photovoltaic soldering tapes developed by it reduces the soldering temperature from 220°C to 180°C, reducing the thermal damage of solar cells and increasing the conversion efficiency by 0.5 percentage points. The market advantages brought by this technological innovation are emerging: in 2023, the company's new product sales will reach more than 3,700 tons, and the new sales revenue will be 480 million yuan, of which more than 80% of the products will be imported substitution.

4. New quality productivity: the "chemical reaction" of the talent echelon

On the whiteboard of the flame retardant laboratory, various chemical reaction equations are densely written - this is the trace of Yuan Yingjie's team brainstorming on market application problems. As the leader of the flame retardant team, he led a team of 12 people, including doctors with deep knowledge of materials science and engineers with rich production experience. The hierarchical training system established by the company provides customized growth paths for talents at different stages: for fresh graduates who have just joined the company, the implementation of the "mentorship system" training, the arrangement to participate in the process optimization of specific projects, and the mastery of core technologies in practice; For technical backbones with certain experience, they are selected to exchange and learn from leading enterprises in Germany, Japan and other countries, and track international cutting-edge technologies; For leading talents, independent decision-making power for R&D projects is given, and special financial support is provided to encourage disruptive innovation. This talent training model has borne fruit. The octyl tin product team in the tin chemical sector is composed of young engineers with an average age of 32 years old, and the environmentally friendly octyl tin heat stabilizer they developed solves the odor problem of traditional products through molecular structure design, and successfully enters the supply chain of international retail giants such as IKEA and Wal-Mart; The analysis and testing team has established a testing system covering more than 80 indicators, and its test reports have been mutually recognized by the International Laboratory Accreditation Cooperation Organization (ILAC), clearing technical barriers for product exports.

epilogue

From φ0.1mm ultra-fine tin wire to BGA solder balls of 1 part of 5 million, from laboratory formula research and development to intelligent manufacturing of production lines, every technological breakthrough of tin-based new materials reflects the hardships and glory of the transformation of traditional industries to high-end manufacturing. In this process, "new product development" is like the rearrangement of atoms, "new process optimization" is like the densification of crystal structure, and "new talent training" is like the role of a catalyst - the synergy of the three is producing a "chemical reaction" that promotes industrial upgrading. When these micro-scale innovations accumulate to a certain extent, it triggers qualitative changes in the industrial energy level. Today, the company's tin deep processing products not only meet the needs of the domestic market, but also export to developed countries such as Japan, South Korea, Europe and the United States, occupying a place in the global electronics manufacturing supply chain. This identity change from "industrial monosodium glutamate" to "strategic materials" confirms a simple truth: real core technologies cannot be introduced, and independent innovation must be relied upon; The cultivation of new quality productivity must eventually return to the coordinated development of the three fundamental elements of materials, technology and talents.

In the future, with the rapid development of 5G, new energy, artificial intelligence and other industries, tin-based new materials will usher in a broader application space. Those seemingly small technological improvements may be laying the groundwork for the next generation of electronic manufacturing technology - just as solder balls silently support the data torrent in chips, innovations in these basic materials are supporting the high-quality development of China's manufacturing industry.