1. Before soldering BGA, both the PCB and BGA should be baked in a constant temperature oven at 80°C to 90°C for 10 to 20 hours.

2. The purpose is to remove moisture and adjust the baking temperature and time appropriately based on the moisture level.

3. PCBs and BGAs can be soldered directly without unpacking.

4. In particular, when performing all the following operations, wear an electrostatic wrist strap or anti-static gloves to avoid potential damage to the chip caused by static electricity.

5. Before soldering the BGA, it is essential to accurately align the BGA with the pads on the PCB.

6. Two methods are used for alignment: optical alignment and manual alignment.

7. Currently, manual alignment is primarily utilized, which involves aligning the circumference of the BGA with the silkscreen markings around the PCB pad.

8. Here’s a tip: during the alignment process, even if the BGA is not perfectly aligned, and the solder ball and the pad deviate by about 30%, soldering can still proceed.

9. This is because the solder ball will automatically align with the pad due to the tension between them during the melting process.

10. After completing the alignment, place the PCB on the bracket of the BGA rework station and secure it to ensure it is level with the station.

11. Select an appropriate hot air nozzle (slightly larger than the BGA) and choose the corresponding temperature profile to begin soldering.

12. Once the temperature profile is complete, allow the assembly to cool down, thereby completing the BGA soldering process.

13. The following is an introduction to four special plating methods used in PCB circuit board soldering.