In fact, it is the type of packaging technology used by the memory chip, and the packaging is to wrap the memory chip to avoid contact with the outside world and prevent external damage to the chip.
Impurities and bad gases in the air, and even water vapor, will corrode the precision circuits on the chip, causing electrical performance to deteriorate. Different packaging technologies differ greatly in manufacturing processes and processes, and packaging also plays a crucial role in the performance of the memory chip itself