Overview of the basic operation of manual electric soldering iron welding
In the small-scale production of electronic small products, manual welding is indispensable for electrical maintenance personnel to carry out maintenance work and for electronic enthusiasts to learn and experiment. Manual welding, as a basic skill that electronic enthusiasts must master, may seem simple, but the correct welding steps are often overlooked. Incorrect operation methods will directly affect the welding quality, leaving hidden dangers such as virtual welding for products. Therefore, electronic enthusiasts must master the correct welding methods in the process of learning and practice, while paying attention to safety during welding operations.
1, Welding operation posture and hygiene
The chemical substances emitted by the heating of flux are harmful to the human body. If the nose is too close to the soldering iron head during operation, it is easy to inhale harmful gases. The distance between the soldering iron and the nose should generally not be less than 30cm, and it is usually advisable to use 40cm.
There are three ways to hold an electric soldering iron, as shown in Figure 1. The reverse grip method has stable movements and should not be fatigued during long-term operation, making it suitable for high-power soldering iron operation. The positive grip method is suitable for operating medium power soldering irons or electric soldering irons with elbows. Generally, when soldering printed circuit boards and other components on the control panel, the pen grip method is often used.
Introduction to how to solder SMT components
SMT components are difficult to solder with an electric soldering iron due to their extremely small size, just like ordinary components. And special solder paste is needed for welding. Under amateur conditions, soldering SMT components can be purchased from the market with SMT solder paste. There are two common types in the market now: one is pre mixed solder paste, with the trademark Shenzhen, and the other is solder paste made by mixing solder paste and blending agent, with the trademark Dayan.
The welding method is to place the SMD component on the solder pad, then apply the adjusted SMD solder paste to the contact between the component pins and the solder pad (note not to apply too much to prevent short circuits), and then use a 20W internal heating electric soldering iron to heat the connection between the solder pad and the SMD component (the temperature should be between 220-230 ℃). After seeing the solder melt, remove the soldering iron and wait for the solder to solidify before welding is completed. After welding, a pair of tweezers can be used to clamp the soldered SMT component to check for any looseness. If there is no looseness (it should be very sturdy), it indicates good welding. If there is looseness, apply some SMT solder paste again and re weld according to the above method.
