The I / O terminals of BGA package are distributed under the package in the form of round or columnar solder joints. The advantage of BGA technology is that although the number of I / O pins increases, the pin spacing increases instead of decreasing, thus improving the assembly yield; Although its power consumption increases, BGA can be soldered by controlled collapse chip method, which can improve its electrothermal performance; The thickness and weight are reduced compared with the previous packaging technology.