When disassembling the BGA on the board, it is necessary to protect the components so as not to damage the circuit or components of the board. In the case of desoldering, a water-impregnated cotton lump can be placed on the adjacent IC. Many plastic power amplifiers and soft-packaged fonts have poor high temperature resistance, and the temperature during blowing is not too high, otherwise it is easy to blow them.
Place an appropriate amount of flux on the IC to be removed and blow it into the bottom of the IC as much as possible to help the solder joints under the chip melt evenly.
Adjust the temperature and wind of the heat gun. Generally, the temperature is 3-4 files, the wind is 2-3 steps, and the air nozzle is moved and heated about 3cm above the chip until the tin beads under the chip are completely melted, and the whole chip is clamped with tweezers. Note: When heating the IC, blow the IC around, do not blow the IC in between, otherwise it is easy to blow the IC up, the heating time should not be too long, otherwise the board will be blown.
After the BGA chip is removed, there is residual tin on the pad and on the board. At this time, add a sufficient amount of solder paste on the PCBA board, remove the excess solder on the board with an electric soldering iron, and apply tin on the board. Make each soldering leg of the board smooth and round, then use the water to wash the solder on the chip and the board. Be careful when removing the solder. Otherwise, the green paint on the pad will be scraped off or The pad is peeled off.
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