1) During preparing pcb soldering – clean the soldering iron.
1 Add tin to the tip and clean the tip to facilitate heat transfer.
2 Do not use a knife or other thing to scrape the oxide layer of the iron head.
2) Heating the weldments – the tip of the soldering iron is placed at the joint of the metal to be welded.
1 Place the tip on the connection point of the metal to be welded (where the heat capacity is the largest).
2 Start the heat flow – heat the surface of the metal to be welded.
3) Wetting tin is wet–adding tin wire, the tin wire is placed at the tip of the soldering iron.
1 Place the tin wire at the joint of the soldering iron tip and the soldered metal to form a thermal bridge.
2 Flux flows in the cold direction, soaking the pad–from the soldering iron tip to the entire pad, removing the oxide layer and promoting heat conduction.
3 Move the solder wire to the opposite side of the heat source, and the molten tin flows toward the hot direction, soaks the pad and the pin, and the capillary phenomenon, diffusion, dissolution, and metallurgical combination occur at the interface.
4 Push the flux residue toward the solder joint surface and edge.
4) Remove the solder – first remove the tin wire, then remove the soldering iron, otherwise the solder wire will solidify on the solder joint.
5) Stop heating – remove the soldering iron
1 Cooling, solidification, forming solder joints
2 Note that do not shake the components and PCB when the solder has not completely solidified, so as to avoid virtual soldering (disturbance).
3 Welding time of each solder joint is 2-3s (3-5s for lead-free soldering)
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