SZFitech

 SAC305 solder paste is a lead-free solder, specially developed to adapt to the environmental requirements and meet the RoHS and REACH requirements of the European Union. It is mainly composed of tin-silver-copper alloy (containing 96.5% tin, 3% silver and 0.5% copper) and flux, the melting temperature of the alloy is 217 degrees Celsius, and it is recommended for lead-free soldering by JEIDA (Japan Electronics Industry Development Association). SAC305 solder paste has a variety of features and advantages. First of all, its flux paste system is specially developed for lead-free solder (SnAgCu system), with moderate solder paste activity and good wettability, as opposed to medium and high temperature solder pastes, which have traditional rosin resin-based solder paste products. At the same time, our company has developed an epoxy resin or silicone resin instead of rosin resin epoxy-type solder paste, referred to as tin glue. The process of using this type of solder pa...

 Tin powder has a wide range of uses and is commonly used in powder metallurgy as an additive and porous material. Tin powder is also used as a high purity reagent in the electronics industry. The particle standard of tin powder is generally reflected by the particle size distribution, particle size, sphericity, chemical purity, surface finish, oxygen content and other indicators. Specific indicators are reflected: 1, particle size range According to the application requirements, the size range of tin powder particles can range from submicron to several hundred microns. For example, tin powder for welding generally requires a finer particle size to ensure good welding performance and uniform melting effect. 2、Morphology The morphology of tin powder can be spherical, irregular shape or other specific shapes. Standard specifications may require the morphology of tin powder to meet specific application requirements. 3、Particle Size/Particle Size Standards often specify m...

  Solder paste (solder paste) is a commonly used material in the electronic assembly process, and its storage and use methods are critical to ensuring soldering quality and performance. The following are the detailed storage and usage methods:   Storage method: It should be put into the refrigerator for storage as soon as possible after receipt, and the recommended storage temperature is 0~10℃. Too high a temperature will correspondingly shorten its service life and affect its characteristics; unopened solder paste in 0 ~ 10 ℃ under normal sealed storage conditions, the expiration date of 4 ~ 6 months; different types, batch numbers, manufacturers of solder paste should be stored separately; paste should follow the principle of first-in-first-out; storage, it should be kept sealed, to avoid oxidation of moisture; storage containers: the paste should be stored in a sealed form, to avoid external contamination and Oxidation. During storage, the packaging of solder paste should b...

  When selecting low-temperature solder paste, medium-temperature solder paste and high-temperature solder paste, you mainly need to consider factors such as soldering temperature, application scenarios and heat resistance of components. The following are recommendations for the selection of these three types of solder paste: 1. Use of temperature range Low-temperature solder paste: melting point is usually around 138 ° C, reflow peak temperature of 170 ~ 200 ° C, commonly used in temperature-sensitive components of the solder, such as plastic packaging components or other components sensitive to high temperature. Low-temperature solder paste mainly contains SnIn system / SnBi system / SnBiAg system and trace amounts of silver, copper, antimony and other micro-alloyed low-temperature high-reliability solder. Medium temperature solder paste: melting point is generally between 180 ° C to 220 ° C, peak reflow temperature of 210 ~ 260 ° C, commonly used in general welding of electronic...

 Flux and rosin each have their own characteristics and advantages in the soldering process, and the choice of which one is better to use needs to be decided according to the specific application scenario. Below are the main features and comparison of flux and rosin: Flux: Role: Flux is a chemical substance mainly used to reduce the surface tension between the soldered metals, to promote the soldering process, and to prevent oxidation reactions. It usually consists of active agents, solvents, etc. It can reduce the surface tension of the metal and promote fusion during welding. Advantages: Flux has excellent performance in soldering metals, especially suitable for occasions requiring high precision and strong corrosion resistance requirements. It has strong active performance and is widely used in high precision applications such as soldering circuit boards. Disadvantages: Some types of flux (such as flux containing rosin) will leave slag and residue after soldering, ...

 In order to protect human health and safety and to 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 solder (i.e., lead-based alloys with more than 85% lead) is not regulated by the directive and can be used in any application. The melting point of high-lead solder is up to 300°C or more, and the commonly used alloys are Sn5Pb92.5Ag2.5 and Sn5Pb95, which are widely used in high-temperature component connection, military manufacturing, medical devices and other specialized fields. These fields require high reliability and stability of the solder, which needs to be able to withstand high temperature, high pressure or high frequency of the working environment, while ensuring the performance and life of the components. High leaded solders are able to ...

 The production process for solder paste is a complex process involving several steps designed to ensure the production of high-quality products for use in surface mount technology (SMT) in the electronics manufacturing industry. The following is the detailed production process: 1. Raw material preparation: Preparation of the main raw materials required for solder paste production, including tin powder, resin and flux. Tin powder is the main component of solder paste, and its quality and proportion will directly affect the performance of the paste. Resin is used as an adhesive to bind the tin powder and flux together to form a homogeneous mixture. Flux is used to promote the soldering process of wetting, tinning, de-oxidizing and other processes. 2. Mixing: The prepared raw materials are put into the mixer according to a certain proportion for mixing. This process needs to ensure that all the raw materials are well mixed to ensure the performance and quality of the ...

 Creeping corrosion is a corrosion phenomenon on the surface of the circuit, which is generated by the reaction of corrosive gases such as sulfide or chloride in the environment in contact with bare copper. Creeping corrosion is characterized by solid corrosive material along the circuit and soldermask or encapsulation material surface migration growth, the formation of a structure similar to a spider's web, resulting in electrical shorts or impedance changes between adjacent pads or circuits, affecting the performance and reliability of electronic products. Creeping corrosion occurs from the exposed Cu surface, Cu surface in the role of sulfur-containing substances will generate a large number of black Cu sulfide, and in the exposed surface of Cu and its surrounding diffusion, buildup. The oxide of Cu is insoluble in water. However, the sulfides and chlorides of Cu are soluble in water and have high surface mobility driven by concentration gradients. The products wi...

 Solder powder is an indispensable connecting material in the electronics industry, mainly used to formulate solder paste for the soldering process of surface mount technology (SMT). The quality of the solder powder directly affects the performance of the solder paste and the welding quality of the circuit board, so the preparation process of the solder powder has high requirements. At present, the commonly used solder powder preparation process has a gas atomization method, rotating disk centrifugal atomization method and ultrasonic atomization method, etc., of which the ultrasonic atomization method has been used to produce high-quality solder powder used for soldering and solder paste, is currently the mainstream of the European and American countries to make the ultra-fine powder process. The principle of ultrasonic atomization method is the use of ultrasound vibration and cavitation effect, the molten metal droplets in the ultrasonic transducer atomized into tiny...

 Microelectromechanical systems (MEMS) are systems that integrate miniature mechanical and electronic components with sensing, control, and actuation functions.MEMS products are widely used in automotive, medical, communications, aerospace, and other fields. Due to the complex structure and tiny size of MEMS products, their packaging and interconnection technologies have an important impact on their performance and reliability, as shown in Figure 1. Figure 1. Integrated MEMS Traditional reflow soldering is widely used as a flux-based solder balling process for creating solder bumps and interconnects for microelectronic packages. An adhesive flux is applied to the metal pads prior to the reflow process to hold the solder balls in place after initial placement. In addition, the flux removes the oxide layer from the surface of the metal pads and promotes solder wetting during the reflow process. Figure 2. Conventional Ball Placement Soldering Process A chemical reaction...

  Flip chip (FC) technology is a packaging method in which the chip is directly attached to the substrate, which has the advantages of high density, high performance and low cost. However, due to the coefficient of thermal expansion (CTE) mismatch between the chip and the substrate, the solder joints are subjected to large thermal stresses when the temperature changes, leading to fatigue damage and failure. To improve the reliability of solder joints, a common method is to inject a polymer material, called underfill, between the chip and the substrate. Underfill improves the stress distribution in the solder joint, reduces the strain amplitude in the solder joint, and extends the thermal fatigue life of the solder joint.     Figure 1. Underfill process   Underfill is a liquid encapsulant, typically an epoxy resin heavily filled with SiO2, that is used between the chip and the substrate after flip chip interconnections. After curing, the hardened underfill has a high ...

 According to statistics, in the PCB design is correct, components and printed board quality is guaranteed under the premise of surface assembly quality problems in nearly 70% is out of the solder paste printing process. Printing position is correct or not (printing accuracy), the amount of solder paste, the amount of solder is uniform, whether the graphic of the paste is clear, there is no sticking, PCB surface is stained by the solder paste, etc., are directly affecting the quality of PCB assembly welding. There are many factors that affect the quality of printing, the main factors include: Stencil quality: stencil printing is contact printing, so the thickness and opening size of the stencil to determine the amount of solder paste printing. Too much solder paste will result in bridging, while too little paste will result in insufficient solder or false soldering. The shape of the stencil opening and the smoothness of the opening also affect the release quality. The...