Integrated circuit in all kinds of circuits are used, integrated circuit pin density, not easy to disassemble welding, as a general maintenance master or electronic technology practitioners, how to welding integrated circuit, and we talk about the following.
1. Dual in-line integrated circuit, two soldering irons can be used, and tin can be added to heat and disassemble the two pins at the same time.
2. Solder must be left on the circuit board of the plug-in integrated circuit after butt welding, which leads to the plug of the welding hole. We usually use suction gun to clean up the residue of the welding hole.
3. If the integrated circuit is damaged and needs to be replaced, the pin of the integrated circuit can be cut off with a sharp cutter, and then the remaining pin on the circuit board can be cleaned with a soldering iron.
4. In addition, in the disassembly of integrated circuits, tweezers and magnifying glasses are commonly used. Otherwise, they cannot be implemented by eyes alone.
5. The hot air gun is very convenient for welding and disassembly of SMD integrated circuit. It can heat the whole module of integrated circuit in the whole area, so that each welding point can be heated evenly and disassembled successfully
6. There are some other disassembly and welding methods, such as integrated circuit such as BGA. Welding and disassembly are not easy and require special tools.
SMC disassembly and welding skills
The disassembly process of SMT integrated circuit is as follows:
1. Before disassembly, carefully observe the position and position of the integrated circuit in the circuit board to be removed, and make a mark, so that when welding according to the corresponding mark to install the integrated circuit, to avoid installation errors.
(2) with a small brush will patch integrated circuit around the impurities clean, and then to patch integrated circuit pin coated with a little rosin powder or rosin water.
(3) adjust the hot air gun temperature and wind speed. Generally, the temperature switch is set to 3 ~ 5, and the wind speed switch is set to 2 ~ 3.
(4) when disassembling with a single nozzle, should pay attention to make the nozzle and the disassembled integrated circuit keep vertical, and along the integrated circuit around the pin movement, uniform heating of each pin, the nozzle can not touch the integrated circuit and surrounding peripheral components, blow welding position to be accurate, and can not blow to the integrated circuit around the components.
(5) after the solder of each lead of the integrated circuit is completely melted, lift or clamp the integrated circuit with tweezers, and cannot be forced, otherwise it is very easy to damage the copper foil connected with the integrated circuit.
With no hot air desoldering station or heat gun maintenance personnel, can adopt the following method to remove the 1 piece of integrated circuit: the IC column pin first coated with rosin, and soldering connects all the column pin, and then use soldering iron to soldering heat, after waiting for the solder melts on the column pin, with thin blade (such as a shaving razor blades) in advance to between circuit board and pins, remove the soldering iron to wait for a few seconds after take out the blade, so the column pin of integrated circuits and circuit board out, then use the same method to separate other pins integrated circuits and circuit boards, finally can remove the integrated circuit.
The welding process of SMC is as follows:
(1) the solder spot on the circuit board with a soldering iron finishing flat, if necessary, can be less solder solder should be filled tin, and then clean the impurities around the solder spot with alcohol.
(2) to be welded integrated circuit and circuit board on the welding position of good, and then use a soldering iron welding integrated circuit diagonal of the four pins, the integrated circuit fixed, and on the pin coated with rosin water or some rosin powder.
(3) if the hot air gun welding, can be used hot air gun blowing welding integrated circuit around the lead, after the solder melting circuit board solder spot, remove the hot air gun, lead and circuit board solder spot glued together. If soldering is done with an electric soldering iron, apply a small amount of solder to the tip of the soldering iron and drag it along a line of pins. The solder will stick each pin to the solder spot of the circuit board. If some of the pins of the integrated circuit are solder connected short circuit, can be the first multiple strands of copper wire to absorb the excess solder, and then coated with rosin water, with a soldering iron in the heat at this place, the remaining solder between the pins will automatically disconnect, back to the lead.
(4) after the completion of welding, check the integrated circuit between the pins have no short circuit or leakage welding, inspection can use magnifying glass or multimeter detection, if there is a leakage welding, the use of tip soldering iron for welding, and finally use anhydrous alcohol to clean up the rosin around the integrated circuit.