Introduction to the method of improving the welding quality of electric soldering iron
1. When using an electric soldering iron for welding, it is necessary to ensure that each solder joint is firmly welded and in good contact to ensure welding quality.
2. Good solder joints require bright tin spots, smooth and no burrs, and moderate tin content. Tin and solder are firmly fused. There should be no false welding and false welding.
3. Pay attention to prevent the problem of false welding and false welding: virtual welding means that only a small amount of tin is welded at the solder joint, resulting in poor contact, sometimes on and off. False welding means that it seems to be welded on the surface, but in fact it is not welded. Sometimes the lead wire will be pulled out from the solder joint when it is pulled out by hand.
Only after a large number of serious welding practices can these two major problems be avoided.
4. When soldering the circuit board, the time must be controlled. If the time is too long, the circuit board will be burnt, or the copper foil will fall off. When removing components from the circuit board, stick the tip of the electric soldering iron on the solder joint, and pull out the component after the tin on the solder joint melts.
5. Flux (rosin and soldering oil) is the key to welding. Fresh rosin and non-corrosive soldering oil are helpful for high-quality welding, and can make the surface clean and beautiful. Use multi-purpose flux.
The solution to the temperature out of control of the constant temperature electric soldering iron
A common failure with thermostatic soldering irons is temperature runaway, which results in overheating of the soldering iron. On the one hand, it leads to high-temperature oxidation of the soldering iron tip (solder is also oxidized at the same time); on the other hand, soldering at high temperature is also easy to burn out electronic components. When the electric soldering iron works at high temperature for a long time, it is also easy to cause damage to its internal circuit, resulting in permanent loss of control or even inability to use it. During the fault inspection, it will be found that the sliding contact of the temperature regulating resistor R2 is oxidized and has poor contact, which is equivalent to the temperature being adjusted to the maximum upper limit, so the temperature of the soldering iron is too high. There are two fundamental reasons: one is that when the electric soldering iron is working, a part of heat is transferred to the handle of the soldering iron (built-in circuit), which increases the temperature of the circuit working environment. After a period of time, it is easy to cause the movable contact of R2 to oxidize; the second is that the current-limiting resistor R1 in the rectifier filter circuit dissipates heat, which causes the temperature of the circuit working environment to rise and easily causes the movable contact of R2 to oxidize.
