BGA
full spelling ： Ball Grid Array
Ball Grid Array is a type of memory chip connection methodology. It is a type of surface-mount packaging used for integrated circuits. Ball grid array chips typically use a group of solder balls, arranged in concentric rectangles to connect to a circuit board.
In a BGA, the pins are replaced by balls of solder stuck to the bottom of the package. The BGA is a solution to the problem of producing a miniature package for an integrated circuit with many hundreds of pins. BGA chips are often used in mobile applications where PGA (pin grid array) chips would take up too much space due to the pins used to connect the chips to the circuit board.