Lead-free solder sheet solder ring SAC305 preformed solder sheet Sn96.5Ag3.0Cu0.5 tin silver copper soft soldering

Preform Solder performs     In today's SMT process, due to the limitation of the thickness of the solder paste printed on the stencil, there may be insufficient amount of solder in the local solder joints, and the solder joints may not be full. Such as: mobile phone jack sockets, connectors, network cable jacks, etc. These parts still need a certain amount of solder to ensure the strength and quality of their welding. In order to solve this problem, you can paste the solder paste on the solder paste after printing. The preformed solder is placed on the sheet, and the solder is supplemented quantitatively, so that the solder joints are full and the strength and reliability are improved. At present, the mainstream soldering process in the industry is solder paste + SMT reflow soldering and other equipment soldering. The flux content of solder paste is about 10%, resulting in a large void rate of about 20% in the solder layer and more flux residues. However, for some high-demand soldering fields, such as semiconductor packaging, power equipment, automotive products, train control, aerospace systems, etc., which require high reliability of circuits, it is necessary to eliminate or reduce the voids and oxidation of soldering materials and flux residues. . How to effectively solve the above problems, a new process is urgently needed. Dimensions and Specifications Preformed solder can usually be made into any shape and size to meet specific needs. Common shapes include ring gasket, disc, rectangle and frame. Customization: Flux type, content, shape and size of solder preforms can be produced according to customer requirements; our company also prepares solder preforms with other alloy components, welcome to consult. About the welding process (1). High-clean solder sheet: refers to the surface of the solder sheet without flux, bright surface, low oxidation rate, generally used in the formic acid-vacuum furnace process, and a flow-controlled reducing gas (formic acid) is introduced into the vacuum furnace. /Hydrogen/Nitrogen+Hydrogen N2/H2--95%/5%); let the reducing gas fully remove the oxide on the metal surface to replace the traditional flux, zero residue. Reduce the voids in the solder layer. (2) Flux-coated solder sheet: It means that the surface of the solder sheet is coated with 2% flux, and it is soldered by SMT reflow soldering or other heating equipment. Generally, the void rate can be controlled at about 10%, which is lower than that of solder paste soldering. The void rate is 20%-30%. Be applicable: It is used for PCB circuit boards, metal shells, metal-glass packages, semiconductor integrated circuits, filter devices, microwave devices, high-power devices, connectors, sensors, and metal shells or ceramic shells for hermetically sealed packaging of optoelectronic devices. Advantage 1Using high clean solder tabs, vacuum furnace process to achieve zero residue, eliminate or low voids 2 Good solderability, reducing flux spatter and residue; 3 Use with solder paste to increase the metal content of the solder; 4 When used alone, the metal content can be controlled, and the surface can be coated with uniform flux to maintain the consistency of welding and low residue; 5. Standard SMT tape and reel packaging (SMD carrier tape 7 inch/13 inch) can be realized, which is convenient for mass production and assembly, and SMT placement machine can be used to place parts to save manpower or avoid personnel errors. Can produce standard 1206, 0805, 0603, 0402, 0201 and other SMT application solder lugs. Preforms of various sizes/alloys can also be customized, Typical Specifications for SMD Application SAC305 Solder Sheet: SMD solder sheet 1406 (length, width and height 3.56*1.52*0.77mm) 3000 pieces/reel (SMD carrier tape reel) SMD solder sheet 0805 (length, width and height 2.03*1.27*0.76mm) 3000 pieces/reel (SMD carrier tape reel) SMD solder sheet 0603 (length, width and height 1.6*0.8*0.8mm) 4000 pieces/reel (SMD carrier tape reel) SMD solder sheet 0402 (length, width and height 1.0*0.5*0.5mm) 10000 pieces/reel (SMD carrier tape reel) SMD solder sheet 0201 (length, width and height 0.6*0.3*0.3mm) 10000 pieces/reel (SMD carrier tape reel) Tin silver copper SAC305 Sn-Ag-Cu(SAC) is a lead-free solder alloy system for electronic soldering. Such as SAC105 (Sn98.5Ag1Cu0.5), SAC305 (Sn96.5Ag3Cu0.5), SAC387 (Sn95.5Ag3.8Cu0.7) and SAC405 (Sn95.5Ag4Cu0.5) are usually used for reflow soldering, wave soldering and manual Soldering, the melting point is around 217°C. Among these solders, SAC305 is widely used and supported by IPC. For SAC305 (Sn96.5Ag3Cu0.5) solder, its hardness, tensile strength, yield strength, shear strength, impact strength and creep strength are higher than those of eutectic Sn63Pb37. Wetting properties are also better than Sn-Cu and Sn-Ag solders. Tin silver Sn96.5Ag3.5 Tin-silver based solders have been used in the electronics industry for many years as a tin-lead substitute. It provides good adhesion for a long time. No nitrogen protection is required during reflow soldering, and its wettability and diffusivity are similar to those of tin-lead solders. The electrical conductivity, thermal conductivity and surface tension of the alloy are comparable to those of the tin-lead alloy. The melting point of Sn96.5Ag3.5 solder is higher than that of traditional tin-lead eutectic solder, and its wetting performance on Cu matrix is also slightly worse than that of tin-lead, but its tensile strength, shear strength, fatigue strength and creep resistance are all Better than Sn63Pb37 solder.