1, close pin IC (D12) welding, first, with tweezers to hold the chip, aligned with the pad.
2, and then use the thumb to hold the chip, before the next step, be sure to confirm that the chip has been aligned with the pad, otherwise the next step is done and then found that the chip is not aligned is more troublesome.
3. Next, take a small piece of rosin with tweezers and place it next to the pin of the D12 chip. Note that rosin is used here, not the kind of thick flux (this flux will not hold the chip).
4, the next step is to use the soldering iron to loosen the pine incense. Rosin has two functions here: one is used to fix the chip on the PCB board, and the other is to assist the welding, ha ha. When melting rosin, the rosin should be as open as possible, evenly distributed on a row of pads.
5, and then also use rosin to fix the pin on the other side of D12, after this step D12 is firmly fixed on the PCB, so before checking whether the chip is accurately aligned with the pad, otherwise it is not very good to take after the rosin on both sides are good.
6. Melt the solder with a soldering iron, and then drag the soldering iron to the right along the contact point between the pin and the pad until it reaches the rightmost pin.
7. In this way, the pins on one side of D12 are welded, and the other side can be welded in the same way.