ABSTRACT

Ball grid array (BGA) is a package with one face covered with balls in a grid pattern. These balls, or solder spheres, conduct electrical signals from the integrated circuit (IC) to the printed circuit board (PCB) on which it is placed. These solder spheres can be placed manually or with automated equipment. These solder spheres are held in place with a tacky flux until soldering occurs. The device is placed on a PCB with 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. A BGA is a type of surface-mount packaging used for ICs.