BGA Package

What is BGA?
 Meaning Ball grid array ,A ball grid array (BGA) is a type of surface-mount packaging used for integrated circuits.
The BGA is descended from the pin grid array (PGA), which is a package with one face covered (or partly covered) with pins in a grid pattern. These pins are used to conduct electrical signals from the integrated circuit to the printed circuit board (PCB) where it is placed on. In a BGA, the pins are replaced by balls of solder stuck to the bottom of the package. The device is placed on a PCB that carries copper pads in a pattern that matches the solder balls. The assembly is then heated, either in a reflow oven or by an infrared heater, causing the solder balls to melt. Surface tension causes the molten solder to hold the package in alignment with the circuit board, at the correct separation distance, while the solder cools and solidifies.
 BGA package picture