Welding and disassembly of components require the use of an electric soldering iron
Preparation before welding and dismantling
1. To remove the oxide layer, it is necessary to easily dip the soldering iron head into the soldering tin during welding. Before using an electric soldering iron, a small knife or file can be used to gently remove the oxide layer on the soldering iron head. After scraping off the oxide layer, it will reveal a metallic luster.
2. Dip in soldering flux. As shown in Figure B, after removing the oxide layer on the soldering iron head, apply electricity to the soldering iron to heat it up. Then, dip the soldering iron head in rosin (available in electronic markets, do not go to vegetable markets), and you will see rosin vapor emitting from the soldering iron head.
3. Hang tin. When the soldering iron head is dipped in rosin to reach a sufficient temperature, rosin vapor will emerge from the soldering iron head. Apply soldering tin to the head of the soldering iron head and apply a layer of soldering tin to the head of the soldering iron head.
The advantage of hanging tin on the soldering iron head is to protect it from oxidation and make it easier to solder components. Once the soldering iron head "burns out", that is, if the temperature of the soldering iron head is too high, the soldering tin on the soldering iron head evaporates, and the soldering iron head is burned black and oxidized, making it difficult to solder components. In this case, the oxide layer needs to be scraped off before hanging tin can be used. So when the electric soldering iron is not used for a long time, the power should be unplugged to prevent the iron from "burning".
4. Welding of components
When soldering components, first gently scrape off the oxide layer on the pins of the components to be soldered, then apply electricity to the soldering iron, heat it up, and dip it in rosin. When the temperature of the soldering iron head is sufficient, press the soldering iron head at a 45 ° angle onto the copper foil next to the pins of the components to be soldered on the printed circuit board, and then contact the soldering wire with the soldering iron head. The soldering wire melts into a liquid state, which will flow around the pins of the components. At this point, remove the soldering iron head, Solder cooling solders the component pins together with the copper foil of the printed circuit board.
When welding components, the soldering iron head should not contact the printed circuit board and components for too long to avoid damage to the printed circuit board and components. The welding process should be completed within 1.5-4s, and the solder joints should be smooth and evenly distributed during welding.
5. Disassembly of components
When disassembling components on a printed circuit board, use the tip of an electric soldering iron to contact the solder joint at the component pin. After the solder at the solder joint melts, pull out the component pin on the other side of the circuit board, and then solder the other pin using the same method. This method is convenient for disassembling components with less than 3 pins, but it is more difficult to disassemble components with more than 4 pins (such as integrated circuits).
