PCBA Tech - Matters needing attention in the SMT welding process

1. The PCB board must be processed well before SMT processing and soldering. It is necessary to ensure that the pads of the components and the circuit board are in a solderable state.

2. During SMT processing and welding, hair and wires should not be twisted together, especially for women with long hair. You should pay more attention to this. When performing SMT processing and welding operations, you must wear an anti-static hat and pull long hair. stand up.

3. Some employees with sweaty hands should wear gloves to avoid electric shock accidents.

4. The power plug of the soldering iron must be properly contacted with the socket to avoid loosening, damage and injury.

5. If the electric soldering iron is used every day, you should use the power socket switch to control the electric soldering iron on and off, or install a power switch on the electric soldering iron power line to avoid frequent plugging and unplugging which may cause loose plugs, poor contact, and finally cause accidents.

6. In SMT processing and welding, the soldering iron tip should not be immersed in the flux for a long time, and other highly corrosive chemical industrial products cannot be used as the flux.

7. Sometimes the low-power electric soldering iron can't reach the heat, and the soldering time is too long, and it is easy to burn the electronic components. You can choose a slightly larger electric soldering iron with sufficient heat to reduce the soldering time and the heat received by the solder joints. If it is less, it will not be damaged, so certain practical experience is also needed in choosing an electric soldering iron.

8. Choosing rosin as a flux can improve the wetting effect of electronic components and increase the solderability of components. The flux can be directly used as a block of rosin, or it can be configured as a rosin alcohol solution. Due to the volatility of alcohol, the bottle cap should be tightened after the rosin alcohol solution is used. You can also put a small piece of cotton in the bottle, and use tweezers to grab it and apply it to the printed circuit board or component leads.

9. Note that there is a kind of solder paste (also called soldering oil) on the market, which is corrosive and is used in industry, and is not suitable for welding electronic products. There is also rosin on the market, not the rosin alcohol solution mentioned in this book, so electronic enthusiasts must pay attention when choosing injections.

10. The integrated circuit should be carried out last in the welding of the entire electronic product, and an anti-static wristband must be worn when welding, and the electric soldering iron must be reliably grounded. Special sockets for integrated circuits can also be used, and the integrated circuits can be inserted after soldering the sockets. This method is convenient for the maintenance and replacement operations of frequently used and frequently damaged chips.

11. After SMT processing and welding are completed, wipe the residual flux on the circuit board with alcohol to prevent the carbonized flux from affecting the normal operation of the circuit.

12. After the welding is completed, you need to turn off the power and clean the desktop.

13. After the electric soldering iron is frequently used for a period of time, the power cord needs to be replaced to prevent the root of the power cord or the inside from breaking.