The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 28, 1995
Filed:
Dec. 29, 1993
Dell USA, L.P., Austin, TX (US);
Abstract
A rework process for ball grid array (BGA) packages which allows for reuse of devices that have been removed for lack of integrity of solder interconnections. The process uses a rework tool which comprises a plate including one or more depressions corresponding to the contours of inverted BGA packages. A BGA package to be reworked is placed in a respective depression with what remains of the original solder ball grid facing upward. The residual solder balls are wicked away, thus leaving the BGA package with the pads that the solder balls were attached to being exposed. A stencil with BGA patterns punched into it is then placed over the rework tool and solder paste is screened onto the rework tool so that the solder is deposited on the BGA pads via the openings in the stencil. The entire fixture is then subjected to a reflow process to cause the solder to ball up during this process. After the reflow process has completed, the stencil is removed, leaving behind a ball grid array similar to that found in the original package.