Common sense and standards for soldering iron use
1: Understand the electric soldering iron. The electric soldering iron is the most commonly used tool in welding.
1. Function: It converts electrical energy into thermal energy to heat and weld the welding point. Whether welding is successful depends largely on how well it is controlled. Generally speaking, the greater the power of the electric soldering iron, the greater the heat, and the higher the temperature of the soldering iron tip.
2. Commonly used powers of electric soldering irons are: 20W; 25W; 30W; 40W; 60W; 100W.
3. Heating mode of electric soldering iron: internal heating type; external heating type.
4. Commonly used soldering iron auxiliary supplies: soldering iron stand, solder absorber, tweezers, electrostatic bracelet, diagonal pliers, absorbent sponge.
2: Precautions for using soldering iron
1. Preparation before using the soldering iron.
The electric soldering iron must be tinned before use. The specific method is: heat the electric soldering iron. When the solder has just melted, use tin wire to evenly coat the soldering iron tip so that the soldering iron tip is evenly coated with a layer of tin. (Note: It is a normal reaction for a newly purchased soldering iron to emit smoke during the heating process)
2. Master the correct operating posture.
It can ensure the physical and mental health of operators and reduce labor injuries. In order to reduce the harm to humans caused by the volatile chemicals emitted when the solder is heated and reduce the amount of harmful gases inhaled, in general, the distance from the soldering iron to the nose should be no less than 20cm, usually 30cm is appropriate.
3. Before using the soldering iron, check whether the voltage used is consistent with the nominal voltage of the soldering iron.
4. The soldering iron must be grounded and well grounded.
5. Wear an electrostatic bracelet when using a soldering iron, and the electrostatic bracelet must be well grounded. (Note: The static electricity ground wire and the soldering iron ground wire must be separated)
6. Do not knock, disassemble or install the electric heating parts of the soldering iron at will after it is powered on.
7. The soldering iron should be kept dry and should not be used in excessively humid or rainy environments.
8. When removing the soldering iron tip, turn off the power.
9. After turning off the power, use the residual heat to put a layer of tin on the soldering iron tip to protect the soldering iron tip.
10. When there is a black oxide layer on the soldering iron tip, wipe off the oxide with an absorbent sponge and apply tin immediately. (Do not use a knife to scrape)
11. The sponge is used to collect tin slag, tin beads and oxides. It is appropriate to squeeze it with your hands just enough so that no water comes out.
12. The electric soldering iron should not be energized for a long time without being used. This will easily cause the soldering iron core to accelerate oxidation and burn out, shortening its life. At the same time, the soldering iron tip will be oxidized due to long-term heating, and may even be "burned to death" and no longer "eat". tin"
Three: Solder
Solder is a fusible metal that connects component leads to the connection points on a printed circuit board. Tin (Sn) is a soft, malleable silver-white metal with a melting point of 232°C. It has stable chemical properties at room temperature, is not easily oxidized, does not lose its metallic luster, and has strong resistance to atmospheric corrosion. Lead (Pb) is a soft, light blue-white metal with a melting point of 327°C. High-purity lead has strong resistance to atmospheric corrosion and good chemical stability, but it is harmful to the human body. Adding a certain proportion of lead and a small amount of other metals to tin can produce products with low melting point, good fluidity, strong adhesion to components and wires, high mechanical strength, good conductivity, not easy to oxidize, good corrosion resistance, and bright solder joints. Beautiful solder, generally called solder. Solder can be divided into 15 types according to the tin content. According to the tin content and impurities
The chemical composition is divided into three grades: S, A, and B. Wire soldering is commonly used in manual soldering. (There are also environmentally friendly lead-free solders that are commonly used today)
Four: Flux
Flux can generally be divided into inorganic flux, organic flux and resin flux, which can dissolve and remove oxides on the metal surface and cover them during welding and heating.
Surround the surface of the metal to isolate it from the air and prevent the metal from oxidizing when heated; it can reduce the surface tension of the melted solder and facilitate the wetting of the solder. (rosin, a natural resin flux)
