Related methods of SMT SMT com
The first method is to use the special soldering iron head disassembly method to select a special "n" shaped soldering iron head. The width (W) and length (L) of the notch at the end can be determined according to the size of the part to be disassembled. The special soldering iron head can melt the solder of lead pins on both sides of the disassembled part at the same time, which is convenient to remove the components to be removed. The self-made method of this kind of soldering iron head is as follows: select a section of copper tube with inner diameter matching with the outside of the soldering iron head, clamp (or hammer) one end with a vise, and drill a small hole. Then two pieces of copper plate (or copper tube longitudinally split and flattened) are processed into the same size as the disassembled part, and small holes are drilled. File the end face of the copper plate, grind it clean, and finally assemble it with bolts and put it on the soldering iron head. The soldering head can be used after being heated and stained with tin. For the rectangular chip element device with two solder joints, as long as the soldering iron head is knocked into a flat shape so that the end face width is equal to the length of the component, the two solder joints can be heated and melted at the same time, and the chip meta device can be removed.
The second method is tin absorbing copper mesh method. The tin absorbing copper mesh is woven into mesh belt with fine copper wire, which can be replaced by metal shielding wire or multi strand flexible wire of cable. When in use, the wire is covered on multiple pins and coated with rosin alcohol flux. Heating with a soldering iron and pulling the wire, the solder on each foot is absorbed by the wire. Cut off the wire with solder and heat the solder for several times. The solder on the pin gradually decreases. Finally, the component pin is separated from the PCB.
The third method is to clean the solder. When the multi pin components are heated with anti-static soldering iron, the solder can be cleaned with toothbrush (or oil brush, paint brush, etc.) and the components can be removed quickly. After the components are removed, the printed board should be cleaned in time to prevent short circuit of other parts caused by residual tin.
The fourth method is the method of lead pulling and dismantling, which is suitable for the disassembly of chip integrated circuit. A piece of enameled wire with appropriate thickness and certain strength is used to penetrate the gap inside the pin of integrated circuit. One end of the enameled wire is fixed in a proper position, and the other end is held by hand. When the solder on the IC pin melts. Pull the enameled wire to "cut" the solder joint, and the IC pin will be separated from the printed circuit board.
The fifth is the method of removing the solder sucking device. There are two kinds of tin absorbers: ordinary tin absorbers and tin absorbing electric soldering irons. Press down the piston rod of the solder sucking device when using the ordinary tin absorber. When the solder joint of the disassembled part is melted by the electric soldering iron, press the solder sucking nozzle close to the melting point, press the release button of the solder sucking device, and the piston rod of the tin absorber will bounce back to absorb the molten tin. After repeated several times, the disassembled part can be separated from the printed circuit board. The tin absorbing electric soldering iron is a special tin absorbing tool, which is assembled with the ordinary tin absorbing device and the electric soldering iron. It should be noted that: in the local heating process to prevent static electricity, the power of the electric iron and the size of the iron head should be appropriate.