New way to use the soldering iron
1. Preheating
The soldering iron tip is angled at a 45 degree angle and pressed against the solder pad and component pins. Preheat the component pins and solder pads in advance. The tip of the soldering iron should not be pressed against the copper free position on the PCB board, as this may burn a mark on the board; It is best to keep the soldering iron tip in the direction of the circuit: the soldering iron tip should not be plugged into the via hole: the preheating time is 1-2 seconds.
2. Tin plating
Introduce the tin wire from the contact surface between the component pin and the soldering iron; When the tin wire melts, control the incoming wire speed; When the tin is scattered throughout the entire solder pad, remove the tin wire; Tin wire should not be directly placed on the soldering iron tip to prevent the flux from burning black; The entire soldering time is approximately 1-2 seconds.
3. Remove the tin wire
Remove the tin wire and place the furnace on the solder pad; The time is approximately 1-2 seconds.
4. Remove the soldering iron
When only a slight smoke is emitted from the soldering iron, the soldering iron can be removed: the solder joint solidifies.
Precautions for using a new soldering iron
1. Suitable soldering materials should be selected, such as low melting spot welding tin wires used for soldering electronic components.
2. Flux, using 25% rosin dissolved in 75% alcohol (by weight) as the flux.
3. Before using the soldering iron, it is necessary to tin it. The specific method is to heat the soldering iron until it can just melt the solder, apply the flux, and then evenly apply the solder to the tip of the soldering iron, so that the tip of the soldering iron is evenly coated with a layer of tin.
4. Welding method: Clean the solder pads and pins of the components with fine sandpaper and apply soldering flux. Dip an appropriate amount of solder with a soldering iron tip, touch the solder joint, and wait for all the solder on the solder joint to melt and submerge the component lead. Then, gently lift the soldering iron tip up along the pins of the component and leave the solder joint.
5. The welding time should not be too long, otherwise it is easy to burn the components. If necessary, tweezers can be used to clamp the pins to help dissipate heat. However, for wires with a cross-sectional area of 2.5mm2 or more, chassis solder joints and metal products of electrical components, the heating time should be sufficient to avoid "virtual soldering".
6. The solder joint should have a sine wave peak shape, with a bright and smooth surface, no burrs, and a moderate amount of tin.
7. Various fluxes have varying degrees of corrosive effects. After soldering, residual fluxes on the circuit board should be cleaned with alcohol to prevent carbonization from affecting the normal operation of the circuit.
8. The integrated circuit should be soldered last, and the soldering iron should be reliably grounded or soldered using residual heat after power failure. Alternatively, use a dedicated socket for integrated circuits, solder the socket, and then plug in the integrated circuit.
9. Electric soldering iron should be placed on the soldering iron holder.
10. After welding, it is necessary to promptly clean up the tin slag that falls off during the welding process.
