Patent ID: 6906414

Claim:
A stiffener for stiffening a substrate in a ball grid array (BGA) package, comprising: a substantially planar first surface having a centrally located cavity; a substantially planar second surface opposed to said first surface, wherein said second surface has a centrally located protruding portion that opposes said centrally located cavity; and at least one recessed portion in at least one edge of said first and said second surfaces, wherein said at least one edge has a first corner at a first end and a second corner at a second end, wherein said at least one recessed portion is located between said first and second corners of said at least one edge wherein the second surface is capable of attachment to the substrate such that said protruding portion extends through a centrally located window opening that is open at first and second surfaces of the substrate, and wherein said first surface of said stiffener in said cavity is capable of mounting an integrated circuit die.