Mobile, tablet, and ultrabook technologies require components with increasingly reduced dimensions. The form factor and footprint of components may be decreased by reducing the real estate required to mount components to a printed circuit board (PCB). The Ball Grid Array (BGA) technique uses solder balls or bumps to electrically and mechanically attach components, such as a packaged die, to a PCB. Current designs employ non-critical to function (NCTF) balls in regions of high stress, such as in the corner and die shadow regions of the mounting surface of a package. NCTF balls serve primarily a structural role, and are not used to carry input/output signals due to the low solder joint reliability (SJR) of balls in high stress regions.
USPTO Backgrounds
USPTO Backgrounds