Experience skills to prevent poor welding of electric soldering iron
1. Choose suitable solder, it is recommended to use low melting point solder wire for welding electronic components.
2. Flux, use 25% rosin dissolved in 75% alcohol (by weight) as flux.
3. The soldering iron should be tinned before use. Method: heat the soldering iron, and when the solder is just melted, apply flux, and then apply solder evenly on the soldering iron tip, so that the soldering iron tip can evenly eat a layer tin.
4. Welding method: Polish the pads and component pins with fine sandpaper, and apply flux. Dip an appropriate amount of solder with the tip of the soldering iron and touch the solder joint. After the solder on the solder joint is completely melted and immersed in the component lead, the soldering iron tip gently picks up along the lead of the component and leaves the solder joint.
5. The welding time should not be too long, otherwise it is easy to burn the components, and the pins can be clamped with tweezers to help dissipate heat.
6. The solder joints should be in the shape of sine wave peaks, the surface should be bright and smooth, without tin thorns, and the amount of tin should be moderate.
7. After the soldering is completed, use alcohol to clean the residual flux on the circuit board to prevent the carbonized flux from affecting the normal operation of the circuit.
8. Finally, solder the integrated circuit to ensure reliable grounding of the electric soldering iron, or use residual heat to solder after power failure. It is also possible to use a dedicated socket for integrated circuits. After the socket is soldered, the integrated circuit is plugged in.
9. When the soldering iron is not in use, it needs to be placed on the soldering iron stand.
Soldering iron pre-soldering work
1. Remove the oxide layer on the welding part
Use a broken saw blade to make a knife to scrape off the oxide layer on the surface of the metal lead to expose the metal luster of the lead.
After polishing the printed circuit board with copper foil with fine gauze paper, apply a layer of rosin alcohol solution.
2. Component tin plating
Tin the scraped lead, dip the lead in the rosin alcohol solution, press the tinned hot soldering iron tip on the lead, and turn the lead, so that the lead can be evenly coated with a thin layer of tin.
Before the wire is welded, the insulation sheath needs to be peeled off, and the formal welding can only be done after the above two treatments. For multi-wire wires, they are polished and twisted together before tinning.
