SZFitech

 Lead-free solder pastes are soldering materials that are most commonly used by packaging manufacturers and can be used for chip soldering and other purposes. One of the most common lead-free solder pastes is the SnAgCu series, including SAC0307, SAC305 and etc. The excellent mechanical strength and conductivity of solder joints made of SAC solder pastes have attracted much attention. However, due to the high content of Sn in this type of solder paste, it is easy to cause tin whisker growth in highly corrosive environments. Tin whiskers are surface defects on pure tin or objects with high tin content, which may cause short circuits between component leads. Generally, solder alloys with low Ag content, such as SAC0307, are more sensitive to whisker growth. Therefore, it is necessary to inhibit the growth of tin whiskers through some means. Nanocomposite solder paste experiment Numerous reports have shown that adding specific metals to solder alloys can hinder the appea...

  Wire-bonding LED chips, vertical LED chips, and flip-chip LEDs are three different structures of LED chips. Different structures of LED chips influence the selection of lead-free solder pastes.     1. LED Chip Definition The LED chip is a semiconductor device that realizes the photoelectric conversion function. It is made by processing semiconductor chips on epitaxial wafers. This semiconductor chip fabrication process is to transfer metallic organic compounds to a homogeneous or heterogeneous substrate at a suitable temperature and to grow semiconductor thin film materials with specific photoelectric properties through chemical reactions.   2. LED Chip Lighting Principle Each pixel of the LED display screen is composed of a set of RGB (red, green, and blue) chips, which belongs to the self-luminous display technology. RGB LED luminescent materials are different according to the various sizes of the band gaps between the conduction bands and the valence bands of th...

  The traditional solder flux is formulated with rosin or epoxy resin as the base material, mixing with an active agent, thixotropic agent, solvent, and other substances. At present, two major factions of no-clean solder paste and water-soluble solder paste have been derived based on flux compositions. No-clean solder paste, as the name suggests, produces a tiny amount of residue after soldering and is unnecessary to clean. Although no-clean solder paste has less activity, it can still meet most consumer electronics soldering needs. Currently, no-clean solder paste is adopted by the majority of companies because of its good stability and simple use process. However, some solders require higher flux activity, and the residue level is unacceptable, which needs to be removed by using cleaning agents.   Features of Water-Soluble Solder Paste The water-soluble solder paste is still made by mixing alloy solder powder and flux but using water-soluble flux components. Water-solu...

International annealed copper standard: % of IACS=0.017241/ ρ*100% Notes: 1. 1MPa=145psi   1psi=6.895kPa  1kPa=0.0102 kgf/cm²  1psi=0.0703 kg f/cm² 2. Electrical conductivity and resistance：Electrical conductivity（%IACS）=0.017241/ρ*100%.      Electrical conductivity and conductance: Electrical conductivity（%IACS）=σ/58.0*100%.     58MS/m=100%IACS;  1%IACS=0.58MS/m;  1MS/m=1.7241%IACS 3. “-” represents no data available 4. 1W/(m·K) =1W/(m·℃) 5. Data with light blue color is only for reference 6 *27 represents the temperature of 20℃. The shear strength is 27MPa if the elongation rate is 0.1mm/min. In most cases, the shear strength decreases with temperature.   

 Solder paste printing needs to be realized through a stencil. The stencil opening needs to be aligned with the substrate pad to achieve accurate printing. It can be said that the stencil quality has a significant impact on the printing effect. The influences of the stencil opening on the printability and release of solder paste cannot be ignored. If the apertures have burrs, the smooth printing of solder paste will be blocked. If the aperture walls are rough, the solder paste sticks to the wall during release, which makes the solder pad have insufficient solder volume and uneven solder shape. After reflow, it will lead to the thermal slump of solder joints and uneven solder joints. Different stencil manufacturing processes will bring different aperture wall quality. At present, the most common stencil manufacturing processes include chemical etching, laser cutting, and electroforming. The stencil is mainly made of nickel and stainless steel. Nickel can provide bett...

 PCB surface treatment is to cover the PCB surface with a protective layer to prevent copper oxidation, corrosion and to improve solderability, reliability and aesthetics. there are various PCB surface treatment processes, such as tin spraying, gold sinking, silver sinking, etc., of which OSP is an environmentally friendly process that meets the requirements of the RoHS directive. What is OSP? OSP is the abbreviation for Organic Solderability Preservatives, also known as bare copper, Entek. simply put, OSP is an organic skin film that grows chemically on a clean bare copper surface. This film is resistant to oxidation, thermal shock and humidity and protects the copper surface from further rusting (oxidation or sulphidation etc.) in the normal environment; however, in the subsequent high soldering temperatures, the film must be easily and quickly removed by the flux so that the exposed clean copper surface can be immediately bonded to the molten solder in a very sh...

  Solder paste is a mixture used to connect electronic components to printed circuit boards (PCBs) and is mainly composed of tin powder and flux. There are mainly the following solder heating methods for solder paste:   Reflow Soldering Reflow soldering is a soldering technique that uses heat such as hot air or infrared rays to heat the solder paste printed or dotted on the printed circuit board until it melts, forming a metallurgical connection with the components and pads. The tool for reflow soldering is usually a reflow oven consisting of a heating element and a fan. The reflow oven can be controlled according to different temperature profiles to accommodate different solder paste and component characteristics. The advantage of reflow soldering is that it can achieve large-area, high-density and high-precision soldering, which is suitable for soldering surface-mounted components (SMC/SMD) in SMT. Figure 1. Reflow oven appearance   Laser Soldering Laser soldering is a ...

  The problem of insufficient solder in the solder paste printing process is mainly attributed to the following reasons:   (1) Inappropriate stencil thickness For square and rectangular apertures, the aperture area can be simply calculated by length times width (L x W).   Hole wall area=2T(L+W)   For circular aperture structure:LW/(2T(L+W))   In process of solder paste printing, four forces are mainly considered, including the downward pull of the PCB pad on solder paste, the gravity of solder paste, the tackiness of the aperture wall to solder paste, and the tackiness of residual solder paste on the stencil to solder paste in apertures. The force that plays a leading role in printing quality is the downward pull of the PCB pad on the solder paste and the gravity of the solder paste. The sum of these two forces must be greater than the tackiness of the aperture wall to the solder paste to ensure smooth solder release. The greater the stencil thickness, the ...

  Solder Paste and Ultra-Fine Solder Manufacturer-Shenzhen Fitech is a comprehensive solder paste supplier integrating production, sales, research, and service of solder paste, epoxy solder paste, and solder powder. Fitech is the leading unit for the formulation of solder powder standards of the Ministry of Industry and Information Technology. Fitech's products include ultra-fine lead-free printing solder paste, ultra-fine lead-free dispensing solder paste, ultra-fine lead-free jetting solder paste, ultra-fine lead-free pin transfer solder paste, no-clean solder paste, water-soluble solder paste, high-temperature solder paste, medium-temperature solder paste, low-temperature solder paste, etc. Fitech can manufacture electronic-grade packaging solder powders with particle sizes from T2-T10. Consulting firm Gartner recently released a report summarizing five technology trends to focus on in the automotive industry in 2023. Trend 1: Automakers revisit their approaches t...

 Solder paste is a material used for electronic soldering, mainly composed of metal powder, flux carrier. Solder paste according to the cleaning method can be divided into two categories of no-wash type and cleaning type solder paste. Currently, the industry mostly uses the no-wash process. No-clean solder paste, as the name suggests, is the product production is completed after the residual flux activity on the product is limited, will not corrode the solder joints or components leading to abnormal product performance and functionality, so there is no need to clean. And cleaning type solder paste in the flux component activity is stronger, conducive to solder paste wetting solder interface, effectively remove the solder interface oxidation layer and the formation of normal solder joints; but the flux residue is easy to corrode the solder joints and metal parts, resulting in an open or short circuit, so after the completion of the soldering to be thoroughly cleaned. ...

  With the increasing demand and miniaturization of electronic devices, electromigration poses a challenge not only to the reliability of integrated circuits, but also to the reliability of electronic packaging. Electromigration is one of the factors that affects the reliability of solder joints. When the electronic equipment is operated, current stress will be generated to form a certain current density at the solder joints. As the number of I/Os increases, the current density also increases. The current density is the driving force for the atom migration and the growth of intermetallic compounds (IMC). Continuous current stress can lead to open circuit issues over time.   Electromigration is the diffusion of metal ions caused by the momentum transfer of mobile electrons. Electromigration occurs when an anode and a cathode are present in the element. Under current stress, the directional atomic transport in the interconnected solder joints accelerates the UBM depletion and as...