SZFitech

 With the development of surface assembly technology in the direction of high density and small size, traditional reflow welding process may cause damage to heat-sensitive devices, so a process that can heat welding devices in a specific area is needed. Laser welding is a new welding process, the technology can be local non-contact heating and heating time is very short, can quickly form a reliable solder joint. However, there is still a disturbing phenomenon in the process of laser welding, that is, the random burning of thermal elements around the solder joint. This situation is mainly caused by the laser reflection (LR) of the pad and the ball during the laser jet welding ball bonding process. Therefore, it is necessary to understand the relationship between laser reflectivity and solder. Experimental design Zhao et al. (2022) used a 60×60 FR4 coppered plate and a green oil plate. The surface of the plate was cleaned with anhydrous alcohol before the experiment. T...

 Nowadays, with the development of integrated circuits, more and more welding technologies have been developed to meet the welding needs of small components. The emergence of laser welding makes the welding of small components more efficient and accurate. The rapid development of laser welding has been gradually adopted by more and more semiconductor manufacturers. During MEMS packaging, the chip can be planted to make micro-convex points, and the chip and the substrate can be welded. Current MEMS processes include reflow welding and laser welding. Both are widely used in semiconductor package welding technologies. As shown in the figure below, when the MEMS inverted planting ball is installed, the welding ball is sprayed by the laser transmitter and forms a micro-convex point on the chip. Compared with the slow heat transfer heating of reflow welding, laser welding can be used as a local heating method for rapid local heating of a specific welding area. After the las...

 Tin whiskers are slender, needle-shaped tin whiskers that form spontaneously on the surface of pure tin (Sn) or of a tin-containing alloy. These whiskers are usually only a few micrometers in diameter, but can be several millimeters long or even more than 10 millimeters long, which can cause serious reliability problems. The following is a comprehensive explanation of tin whisker growth mechanism, influencing factors and inhibition measures: Tin whisker growth mechanism 1. Driving force: The driving force for the growth of tin It was mainly derived from the Cu₆Sn₅ intermetallic compound formed by the reaction between Sn and Cu at room temperature. This reaction creates compressive stress within Sn. 2. Release of compressive stress: Due to the high homogenization temperature of Sn at room temperature, Sn atoms diffuse rapidly along grain boundaries. The compressive stress is released through atomic diffusion and rearrangement, which leads to the migration of Sn atomic ...

 In recent years, with the rapid development of new energy vehicles, IGBT, as the main cost component of the controller for new energy vehicles, has also ushered in an outbreak. It is expected that by 2025, China's IGBT market will reach 52.2 billion yuan, with a compound annual growth rate of nearly 20%. However, from the perspective of design and manufacturing, looking at the status quo of the global automotive IGBT industry, almost 70% of the current market share has been scraped by Europe, the United States, Japan and other countries. The development of domestic IGBT design and manufacturing capacity is uneven, of course, there are many of them to keep up with the pace, continuous technological innovation, and obtain their own value and self-breakthrough national enterprises, Shenzhen Fuyingda is one of them. What is car grade IGBT Package? It is defined as a power electronic device specifically used in the field of new energy vehicles. It has the characteristic...

 Sn42Bi58 eutectic solder is a widely used low-temperature lead-free solder with excellent creep resistance and low melting point, which is suitable for poor heat-resistant components. In addition, it can be used in multiple reflow soldering. Sn42Bi58 eutectic solder contains a large amount of Bi, resulting in the formation of a Bi-rich layer during soldering and reliability issues such as brittleness, low conductivity, and low thermal conductivity. One of the methods to improve the reliability of Sn42Bi58 solder is to add a small amount of Ag element. Another relatively new technology is to add silver-coated copper particles to Sn42Bi58 eutectic solder (Cu@Ag). Since Ag and Ag3Sn IMCs have excellent electrical and thermal properties, adding Sn42Bi58 solder can improve the function of the solder. However, Ag is more expensive, so Cu@Ag can be chosen instead. To verify the influence of Cu@Ag on various properties of solder joints, Li et al. conducted a series of exper...

  Surface mount technology (SMT) and through-hole insert technology (THT) are the two main methods for mounting electronic components on printed circuit boards (PCBS). While they all play an important role in electronics manufacturing, there are significant differences in technology and application.   Surface mount technology (SMT) : In a narrow sense, SMT is to paste surface components onto the PCB, and realize the interconnection of electronic components through integral heating. However, in a broad sense, it includes many aspects, such as chip components, surface assembly circuit boards and their process design, surface assembly equipment (such as printing presses, dispensing machines, reflow welding equipment) and assembly materials (such as solder paste, flux).   Through hole insertion technology (THT) : A traditional installation technology that uses THC (perforated mounting components) and THD (perforated mounting devices) to complete the installation and welding o...

 At present, SAC305 is the main alloy component of solder paste, its melting point is 217℃, has good wettability and thermal fatigue strength and solder joint reliability, is the first choice of lead-free welding alloy. The disadvantage of SAC305 alloy is that the price of silver is higher, which increases the welding cost, and the thermal expansion coefficient of SAC305 is higher, which may lead to thermal cycle fatigue and cracking of the solder joint. As a result, some researchers have proposed ways to reduce silver content or substitute silver to reduce costs and improve reliability. For example, SAC0307 alloy is a low silver content (0.3%wt) tin-silver-copper alloy with a melting point of 217 to 226 ° C, slightly lower wettability and heat resistance fatigue than SAC305, but better creep and lower cost. The silver-free tin-copper series alloys are mainly used in the production of wave soldering strips and tin wires, as well as the production of lead-free tin-spr...

 In order to protect human health and safety and improve the environmental performance of electronic equipment, the European Union adopted the Restriction of Hazardous Substances (RoHS) Directive in 2006, which prohibits the use of certain hazardous substances, including lead, in electronic equipment. However, high lead solders (that is, lead-based alloys with a lead content of more than 85%) are not covered by the Directive and can be used in any situation. The melting point of high lead solder is above 300°C, and the common alloys are Sn5Pb92.5Ag2.5 and Sn5Pb95, which are widely used in high temperature component connection, military manufacturing, medical equipment and other special fields. These areas have high requirements for solder reliability and stability, requiring solder to withstand high temperature, high pressure or high frequency operating environments, while ensuring component performance and life. High lead solder can meet the needs of these fields due...

 With the continuous development of LED technology, the luminous efficiency and brightness of LED are also improving, especially in the field of solid-state lighting, and the market demand for high-power LED continues to grow. High-power LED devices have the advantages of high brightness, high efficiency, long life and environmental protection, but they also face challenges in heat dissipation and reliability. In order to solve these problems, gold solder as a high-performance brazing material, with its high strength, high thermal conductivity, no flux and other characteristics, has become the ideal choice for high-power LED device packaging and connection. This paper will introduce the physical properties of gold tin solder, as well as its application and advantages in high-power LED devices. LED chip package form At present, there are two main packaging forms of LED chips: formal (welded wire) LED and flip chip (FC) LED. Compared with welded wire LED, flip-chip LED ...

  Surface mount technology (SMT) and through-hole insertion technology (THT) are the two main methods of mounting electronic components on printed circuit boards (PCBs). Although they both play an important role in electronics manufacturing, there are significant differences in technology and applications. Surface Mount Technology  (SMT): In a narrow sense, SMT is the process of pasting surface components onto a PCB and realizing the interconnection of electronic components through integral heating. However, in a broader sense, it includes a number of aspects, such as chip components, surface assembled circuit boards and their process design, surface assembly equipment (such as printers, dispensers, reflow soldering equipment), as well as assembly materials (such as solder paste, flux) and so on. Through-Hole Technology (THT): the use of THC (through-hole mounted components) and THD (through-hole mounted devices) to hand soldering, dip soldering and wave soldering and other wa...

  Tin bead is one of the common defects in reflow welding, which has many reasons, not only affects the appearance of solder joints but also causes bridging. Tin beads can be divided into two categories, one appears on the side of the chip component, often an independent large ball; The other type appears around the IC pin in a scattered bead shape.         The main reasons for the production of tin beads are:   The temperature curve is incorrect   The reflow curve can be divided into four stages, namely preheating, constant temperature, reflow and cooling. The purpose of preheating and constant temperature is to make the PCB surface temperature rise to 150 ° C within 60~90s, and the constant temperature is about 90s, which can not only reduce the thermal shock of PCB and components, but also ensure that the solvent of the solder paste can be partially volatilized, and avoid splashing caused by too much solvent during reflow welding, causing the solder...

 Ultrafine tin powder is ultrafine solder powder with particle size model above T6 (5~15μm), including T6 (5~15μm), T 7 (2~11μm), T 8 (2~8μm), T 9 (1~5μm), T 10 (1~3μm) and other models of ultrafine tin powder. Ultra micro tin powder is the key material for microelectronics and semiconductor packaging, precision device packaging. The advantages of ultra-micro tin powder are mainly reflected in the following aspects: Fine particle size and uniform distribution: ① The average particle size of ultra-micro tin powder is usually between a few microns and ten microns, compared with the traditional solder powder has a smaller particle size. ② As a result of the use of advanced ultra-micro-grinding technology, the particle size distribution of ultra-micro tin powder is uniform, making its physical and chemical properties more stable. Large specific surface area: The reduced particle size of ultrafine tin powder directly leads to a significant increase in its specific surface a...

 Solder paste printing is a key process step in SMT, and its quality directly affects the reliability of welding and the performance of electronic products. In the process of solder paste printing, the adjustment of the technical parameters of the scraper is very important. First, the properties of the solder paste need to be considered. Solder paste is a thixotropic fluid with a certain viscosity. When the scraper moves at a specific speed and Angle, pressure is applied to the solder paste, pushing the solder paste to roll in front of the scraper in order to inject the solder paste into the mesh or leak. The shear force reduces the viscosity of the solder paste, which is conducive to the smooth injection of the solder paste into the mesh or leak hole. Therefore, there are complex constraints between the speed of the scraper, the pressure of the scraper, the Angle of the scraper and the solder paste viscosity, and these parameters need to be precisely controlled to e...