US Patent 7642660 Method and apparatus for reducing electrical interconnection fatigue

A method and apparatus is provided that pertains to resisting crack initiation and propagation in electrical interconnections between components and substrates in ball grid array microelectronic packages. A hybrid of dielectric defined and non-dielectric defined electrical interconnects reduces the potential for electrical interconnection failure without having to control the dielectric defined interconnect ratio of substrates. In addition selective orientation of the dielectric defined edge portion of the electrical interconnect away from the point where cracks initiate resists crack propagation and component failure.