SMT生产注意事项（SMT production precautions）.doc

SMT生产注意事项（SMT production precautions） General knowledge about SMT 1. In general, the temperature of the SMT workshop rules of 25 + / - 3 ℃. 2. The preparation materials and tools for the printing of solder paste, steel plate, scraper, wiping paper, dust free paper, cleaning agent and stirring knife. 3. The commonly used alloy composition is Sn/Pb alloy, and the proportion of alloy is 63/37. 4. The main components of solder paste are divided into two parts, tin powder and flux. 5. The main role of flux in welding is to remove oxides, destroy the surface tension of solder and prevent reoxidation. 6. The volume ratio of tin powder in tin paste to Flux (Flux) is approximately 1:1, and the ratio of weight is about 9:1. The principle of the use of solder paste is advanced first. 8. When used in kaifeng, the solder paste must go through two important processes for tempering and stirring. 9. Common production methods of steel plates are: etching, laser and electroforming. 10. Is the full name of SMT Surface mount technology (or mounting), the Chinese meaning for the Surface adhesion (or SMT) technology. 11. The full name of ESD is electro-static discharge, which means electrostatic discharge in Chinese. 12. When making SMT equipment, the program includes five parts, the five parts are PCB data; Mark the data; Feeder data; Nozzle data; Part of the data. 13. Lead-free solder Sn/Ag/Cu 96.5/3.0/0.5 has a melting point of 217C. The relative humidity of the parts drying box is 10%. 15. Passive Devices (Passive Devices) include: resistance, capacitance, point sense (or diodes); Active components Devices: transistors, IC, etc. 16. Commonly used SMT steel is made of stainless steel. 17. The thickness of the commonly used SMT plates is 0.15mm (or 0.12mm). 18. The types of electrostatic charge generation include friction, separation, induction, electrostatic conduction, etc. The effect of electrostatic charge on electronic industry is: ESD failure, electrostatic pollution; The three