Tiona Marie Marburger

US Patent:

6762495, Jul 13, 2004

Filed:

Mar 20, 2003

Appl. No.:

10/393666

Inventors:

Edward Reyes - San Diego CA
Ryan Lane - San Diego CA
Tiona Marburger - San Diego CA
Tom Gregorich - San Diego CA

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

H01L 2348

US Classification:

257737, 257738, 257697, 438109, 438613, 22818022

Abstract:

An area area package includes a plurality of solder balls not used as electrical connectors. These non-connected solder balls, or âdummy balls,â 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 location 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.