With the development of technology and the strong demand from the manufacturers for the industry, small-sized veneer-type placement machines are favored. In the SMT production line, it is placed after the dispenser or solder paste printing machine. The head surface mount component accurately places a device on the PCB pad. It is divided into manual and fully automatic. Now the mainstream is mainly automatic placement machine.
1. Generally, the temperature specified in the SMT workshop is 25 ± 3 °C.
2. When solder paste is printed, the materials and tools required for solder paste, steel plate, scraper, wiping paper, dust-free paper, cleaning agent, and mixing knife.
3. The commonly used solder paste alloy is Sn/Pb alloy with an alloy ratio of 63/37.
4. The main components of the solder paste are divided into two parts: tin powder and flux.
5. The main role of flux in soldering is to remove oxides, destroy the surface tension of molten tin, and prevent reoxidation.
6. The ratio of the volume of tin powder to Flux in the solder paste is about 1:1, and the weight ratio is about 9:1.
7. The principle of access to solder paste is FIFO.
8. When the solder paste is used in the opening, it must be warmed and stirred through two important processes.
9. Common manufacturing methods for steel plates are: etching, laser, electroforming.
10. The full name of SMT is Surface mount (or mounting) technology, which means surface adhesion (or placement) technology.
11. The full name of ESD is Electro-static discharge, which means electrostatic discharge.
12. When making an SMT device program, the program includes five parts, which are PCB data; Mark data; Feeder data; Nozzle data; Part data.
13. The melting point of lead-free solder Sn/Ag/Cu 96.5/3.0/0.5 is 217C.
14. The relative humidity and humidity of the parts drying oven is <10%.
15. Commonly used passive components (Passive Devices) are: resistors, capacitors, point sense (or diode), etc.
Active components are: transistors, ICs, etc.