AREA ARRAY PACKAGE WITH NON-ELECTRICALLY CONNECTED SOLDER BALLS

摘要

An area array package includes a plurality of solder balls not used as electrical connectors. These non-connected solder balls, or "dummy balls," provide protection to solder balls connected to live pins and therefore increase reliability of the area array package. The dummy balls may be placed in the corners, along the diagonals or in other high stress locations on the area array package. To further increase reliability, a continuous copper ball land pad may be used to connect each group of corner dummy balls. Continuous copper pads help to reduce stress on the dummy balls. For center-depopulated BGA packages, an array of dummy balls may be used in the center of the package to prevent substrate bending and improve drop test reliability.