Knowledge of the use of soldering iron and soldering iron operating standards
A: understand the soldering iron, soldering iron is the most commonly used tools in welding.
1. Role: is the conversion of electrical energy into heat on the welding point part of the heating welding. Whether the welding is a large part of the work is to see how the control of it. Generally speaking, the greater the power of the soldering iron, the greater the heat, the higher the temperature of the soldering iron head.
2. The common power of soldering iron: 20W; 25W; 30W; 40W; 60W; 100W.
3. Soldering iron heating form: endothermic; external heat.
4. Commonly used soldering iron auxiliary supplies: soldering iron stand, tin sucker, tweezers, electrostatic hand ring, diagonal pliers, absorbent sponge.
Second: the use of soldering iron precautions
1. The preparatory work before using the soldering iron.
Soldering iron to use before the tin, specific method is: the soldering iron will burn hot, to be just able to melt the solder when the tin line evenly coated in the head of the soldering iron, so that the head of the soldering iron uniformly ate on a layer of tin. (Note: the newly purchased soldering iron in the heating process smoke is a normal reaction)
2. Master the correct operation posture.
Can ensure the physical and mental health of the operator, reduce labor injury. In order to reduce the solder heating volatile chemical substances on the harm, reduce the inhalation of harmful gases, in general, the soldering iron to the nose distance should be not less than 20cm, usually 30cm is appropriate.
3. Before using the soldering iron, you should check whether the voltage is consistent with the nominal voltage of the soldering iron.
4. The soldering iron should be grounded and well grounded.
5. Use the soldering iron with electrostatic hand ring, and electrostatic hand ring to be well grounded. (Note: static grounding line and iron grounding line must be separated)
6. After the soldering iron is energized, it can not be knocked, disassembled and installed its electric heating part of the parts.
7. The soldering iron should be kept dry and should not be used in excessively humid or rainy environment.
8. When removing the head of the soldering iron, turn off the power.
9. After turning off the power, use the residual heat to put a layer of tin on the head of the soldering iron to protect the head of the soldering iron.
10. When there is a black oxide layer on the soldering iron head, you can wipe off the oxide on the absorbent sponge, and immediately on the tin. (Do not scrape with a knife)
11. The sponge is used to collect the tin slag and tin beads and oxides, and it is appropriate to pinch the sponge with your hand just without water.
12. Soldering iron should not be energized for a long time without using, this is easy to make the soldering iron core to accelerate the oxidation and burn off, shorten its life, but also make the soldering iron head due to prolonged heating and oxidation, and even be " burned to death " no longer " eat tin "!
Third: solder
Solder is a kind of fusible metal, it can make component leads and printed circuit board connection points connected together. Tin (Sn) is a soft, malleable silver-white metal, melting point of 232 ℃, stable chemical properties at room temperature, not easy to oxidize, no loss of metallic luster, strong resistance to atmospheric corrosion. Lead (Pb) is a softer light greenish-white metal, melting point of 327 ℃, high purity lead atmospheric corrosion resistance, chemical stability, but harmful to humans. Tin in a certain percentage of lead and a small number of other metals can be made into a low melting point, good mobility, strong adhesion to the components and wires, high mechanical strength, good electrical conductivity, not easy to oxidize, corrosion resistance, good, bright and beautiful solder joints solder, generally referred to as solder. Solder according to the amount of tin can be divided into 15 kinds, according to the amount of tin and impurities
The chemical composition of the tin content and impurities are divided into S, A, B three levels. Hand soldering commonly used wire solder. (There are also now commonly used environmentally friendly lead-free solder)
Four: flux
Flux can generally be divided into inorganic flux, organic flux and resin flux, can dissolve the removal of oxides on the surface of the metal, and in the welding heating package
Surrounding the surface of the metal, so that it is isolated from the air, to prevent oxidation of the metal when heated; can reduce the surface tension of the melted solder, which is conducive to the wetting of the solder. (Rosin is a natural resin flux)
