Specification for the use of soldering iron

First, understand the electric iron, electric iron is the most commonly used tool in welding.

1. Function: It is to convert electric energy into heat energy to heat weld the welding point. A big part of welding is how to control it. In general, the greater the power of the soldering iron, the greater the heat and the higher the temperature of the tip.

2. Common power of electric soldering iron: 20W; 25W; 30W; 40W; 60W; 100W.

3. Electric iron heating form: internal heat type; external heat type.

4. Commonly used soldering iron accessories: iron frame, suction tin, tweezers, electrostatic bracelet, diagonal pliers, absorbent sponge.

Second, the use of soldering iron notes

1. Preparation before using the soldering iron.

The soldering iron should be tinned before use. The specific method is: heat the soldering iron. When the solder can be melted, apply the tin wire evenly on the soldering iron tip to make the soldering iron evenly eat a layer of tin. (Note: The newly purchased soldering iron emits a normal reaction during the heating process)

2. Master the correct operating posture.

It can ensure the physical and mental health of the operator and reduce labor injuries. In order to reduce the harm of chemical substances volatilized by the flux during heating and reduce the inhalation of harmful gases, in general, the distance from the soldering iron to the nose should be no less than 20cm, usually 30cm.

3. Before using the soldering iron, check whether the voltage used matches the nominal voltage of the soldering iron.

4. The soldering iron should be grounded and grounded.

5. Use an electrostatic bracelet when using the soldering iron, and the electrostatic bracelet should be well grounded. (Note: The electrostatic ground wire must be separated from the soldering iron ground wire)

6. After the electric iron is energized, it is not allowed to knock, disassemble and install the electric heating parts.

7. The soldering iron should be kept dry and should not be used in excessively humid or rainy environments.

8. Turn off the power when removing the soldering iron.

9. After turning off the power, use a layer of tin on the soldering iron to protect the soldering iron tip.

10. When there is a black oxide layer on the tip, wipe off the oxide on the sponge and immediately apply tin. (not available with knife scraping)

11. Sponge is used to collect tin slag and tin beads and oxides. It is advisable to pinch just enough water.

12. The soldering iron should not be energized for a long time without using it. This makes it easy for the iron core to accelerate oxidation and burn, shortening its life, and also causing the soldering iron to oxidize due to prolonged heating, even being "burned out" and no longer "eaten". tin"

Third, the solder

Solder is a fusible metal that connects the component leads to the printed circuit board connection point. Tin (Sn) is a silvery white metal with soft texture and high ductility. Its melting point is 232 °C. It has stable chemical properties at normal temperature, is not easy to oxidize, 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 is resistant to atmospheric corrosion and has good chemical stability, but is harmful to humans. A certain proportion of lead and a small amount of other metals in tin can be made into a low melting point, good fluidity, strong adhesion to components and wires, high mechanical strength, good electrical conductivity, low oxidation resistance, good corrosion resistance, and bright solder joints. Beautiful solder, generally called solder. Solder can be divided into 15 kinds according to the amount of tin. According to the chemical composition of tin content and impurities, it can be divided into three grades: S, A and B. Hand soldering commonly used wire solder. (There are also environmentally friendly lead-free solders that are commonly used now)

Fourth, flux

Flux can be generally classified into an inorganic flux, an organic flux and flux resins can dissolve the metal surface oxide is removed, and heating the welding surface of the metal surrounded, so that air separation and, to prevent oxidation of the metal upon heating ; can reduce the surface tension of the solder after melting, which is beneficial to the solder wet. (rosin a natural resin flux)