Knowledge of using electric soldering irons and operating standards for electric soldering irons
1： Understand electric soldering iron, which is the most commonly used tool in welding.
1. Function: It converts electrical energy into thermal energy to heat and weld the welding points. The success of welding largely depends on how well one handles it. Generally speaking, the higher the power and heat of an electric soldering iron, the higher the temperature of the soldering iron tip.
2. The commonly used power of electric soldering irons is 20W; 25W; 30W; 40W; 60W; 100W
3. Heating form of electric soldering iron: internal heating type; Externally heated.
4. Common soldering iron accessories: soldering iron holder, tin absorber, tweezers, electrostatic bracelet, diagonal pliers, absorbent sponge.
2： Precautions for using electric soldering iron
1. Preparation work before using the soldering iron.
Before using an electric soldering iron, tin should be applied. The specific method is to heat the soldering iron, and when it can just melt the solder, evenly coat the soldering iron head with a tin wire, so that the soldering iron head can eat a layer of tin evenly. (Note: Smoking from newly purchased soldering iron during heating is a normal reaction)
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 chemicals emitted by welding flux during heating to humans and reduce the inhalation of harmful gases, the distance from the soldering iron to the nose should generally not be less than 20cm, and 30cm is usually recommended.
Before using an electric soldering iron, check whether the voltage used matches the nominal voltage of the soldering iron.
4. The soldering iron should be grounded and well grounded.
5. When using a soldering iron, wear an electrostatic wristband and ensure that it is well grounded. (Note: The static grounding wire and the soldering iron grounding wire must be separated)
6. After the electric soldering iron is powered on, it should not be knocked, disassembled, or installed with any electric heating parts.
7. Electric soldering irons should be kept dry and should not be used in excessively humid or rainy environments.
When disassembling the soldering iron head, turn off the power.
9. After turning off the power, use the remaining heat to apply a layer of tin on the soldering iron head to protect it.
10. When there is a black oxide layer on the soldering iron head, the oxide can be wiped off on a water absorbing sponge and immediately tinned. (Cannot be scraped with a knife)
11. Sponges are used to collect tin slag, tin beads, and oxides, and it is advisable to pinch them with your hands just enough not to release water.
12. Electric soldering irons should not be powered on for a long time without use, as this can easily accelerate the oxidation of the soldering iron core and burn it out, shorten its lifespan. At the same time, it can also cause the soldering iron tip to oxidize due to prolonged heating, and even be "burned" and no longer "eat tin"
3： Solder
Solder is a fusible metal that can connect component leads to the connection points of printed circuit boards. Tin (Sn) is a soft and ductile silver white metal with a melting point of 232 ℃. 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 relatively soft light blue white metal with a melting point of 327 ℃. High purity lead has strong resistance to atmospheric corrosion and good chemical stability, but it is harmful to human health. Adding a certain proportion of lead and a small amount of other metals to tin can make solder with low melting point, good fluidity, strong adhesion to components and wires, high mechanical strength, good conductivity, low oxidation resistance, good corrosion resistance, and bright and beautiful solder joints. It is generally called solder. Solder can be divided into 15 types based on its tin content and impurities
The chemical composition of is divided into three levels: S, A, and B. Manual welding commonly uses wire solder. (There are also commonly used environmentally friendly lead-free solder nowadays)
