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:
Aug. 10, 1999
Filed:
Feb. 21, 1997
Thomas A Gordon, San Diego, CA (US);
Other;
Abstract
A method and apparatus allow securing of balls to ball grid array electronic components. A component having a surface with rows and columns of electrical contact solder pads is removed from a printed circuit board for rework. Excess solder is removed from the solder pads and the surface is pressed against a stencil having a pattern of holes corresponding to the component contact pad pattern. Each of the holes is filled with a solder ball. The assembly is heated to melt the at least the solder pads. Where lower melting solder balls are used, the pads and balls both melt. Where high melting temperature solder balls are used, only the solder pads melt. The assembly is cooled to solidify melted solder, the stencil is removed, the component is cleaned and is ready for reuse. Preferably, the stencil is formed from a material that bows in one direction when heated, so that when the stencil is held against the pad array surface and heated, bowing forces will very tightly press the stencil against the surface, preventing molten solder from migrating between surface and stencil.