Operation of electric soldering iron
2.1 Pre-welding treatment:
Before soldering, the component pins or the soldering parts of the circuit board should be soldered. Generally, there are three steps: "scraping", "plating" and "testing".
1. "Scraping" is to clean the welding part before welding. The tools generally used are knives and fine sandpaper to clean the pins of integrated circuits and printed circuit boards, but the pins should be kept clean. For self-made printed circuit boards, the surface of the copper foil should be polished with fine sandpaper first, and the dirt on the printed circuit board should be cleaned, and then coated with rosin alcohol solution, flux or "HP-1" before use. For gold-plated silver alloy lead-out wires, the coating cannot be scraped off, and the surface dirt can be wiped off with an eraser.
2. "Plating" is tin plating on the scraped components. The specific method is to dip the rosin alcohol solution and apply it on the scraped component welding parts, then press the hot soldering iron head with tin on it, and turn the components to evenly coat a thin layer of tin layer. In the case of multi-strand wires, they should be twisted together after polishing, and then tinned.
3. "Testing" is to use a multimeter to check whether the quality of all tin-plated components is reliable after "plating". If there are unreliable or damaged components, they should be replaced with components of the same specification.
2.2 Five steps of operation
1. Prepare for welding: Check the condition of the electric soldering iron. After confirming that it is correct, determine the welding position and check the type of welding components
2. Plug in and preheat the welding position: power on the electric soldering iron, point the soldering iron head at the position to be welded, and preheat for 1-2 seconds (preheating time depends on the temperature of the soldering iron used and the temperature of the components to be welded
3. Add tin wire: After the welding position is preheated, hold the tin wire with your left hand and send it to the solder joint position
4. Disconnect the tin wire: When the tin wire melts to meet the requirements of the solder joint, remove the tin wire
5. The soldering iron tip leaves the solder joint: After completing the solder joint, remove the soldering iron tip and place the soldering iron safely on the soldering iron stand.
