Detailed explanation of the working principles of the four desoldering methods during welding
1. Desoldering method of tin absorber
Using the negative pressure of the built-in cavity of the tin suction device, the heated and molten solder is sucked into the cavity to separate the lead wire from the pad.
2. Desoldering method of tin suction rope
The soldering rope desoldering method is to use the tinning rope to suck away the molten solder to separate the lead wire from the pad.
Coat the part of the braided wire with rosin flux, then put it on the solder joint to be desoldered, then put the electric soldering iron on the braided wire to heat the solder joint, and when the solder in the solder joint melts, it will be absorbed by the copper braided wire.
If the spot solder is not sucked up once, it can be done for the second or third time until it is sucked up. When the braided rope is full of tin, it can no longer be used, and the place that is full of solder needs to be cut off.
3. Short pin desoldering method
The empty needle desoldering method is to use an empty needle (a syringe needle can also be used) of the same size (the aperture is slightly larger than the diameter of the lead) to be placed on the lead that needs to be desoldered. When the soldering iron heats the solder and melts, quickly rotate the needle until the soldering iron is removed. It can be stopped after the solder is solidified. At this time, the needle is pulled out and the lead wire has been separated.
4. Desolder with tin-absorbing soldering iron
Tin-absorbing soldering iron is a special desoldering iron, which can absorb tin into the inner cavity while heating the solder joints, thereby completing desoldering.
The problem of tin climbing on the tip of the electric soldering iron
The soldering iron tip has been used for a long time, and when the soldering iron tip is used again, the tin wire will run to the soldering iron tip, commonly known as running tin (scalding tin).
The upward run of tin is mainly related to the chrome plating layer. The function of chrome is to prevent the tin from running up. After the tip of the soldering iron is used for a period of time, the chromium layer will be wiped off. When the chrome layer is wiped off, the tin will run up. .
Climbing tin and running tin refer to the fact that the tinned layer of the soldering iron head has passed, and tin is also stuck to other parts. Therefore, the reason why the tip of the soldering iron runs up is directly related to the chromium layer, which is very common in solder.
The reason for the soldering iron head to climb tin
1. The reason of the product itself: the chrome plating on the outer layer of the soldering iron tip is too thin or the chrome layer is not handled well.
2. The rosin flux contained inside the tin wire has more impurities, and it is easy to corrode the chrome plating layer of the soldering iron tip at high temperature, which will lead to tin climbing.
Soldering iron head tin climbing treatment method
1. Return to the factory for a product with a thicker chrome plating layer or better disposal.
2. Replace the tin wire with better quality and less impurity content. Appropriately lowering the working temperature can improve the phenomenon of tin climbing;
3. Purchase an alloy soldering iron head, and the surface is treated with a special anti-tin corrosion layer, which can prevent tin from running out, the skin does not fall off, and prolongs the service life.
The role of chrome plating is only to prevent tin climbing. Tin crawling will appear on any electroplated soldering iron tip, and the original one is no exception, but it will appear sooner or later.
