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:
Oct. 02, 2001
Filed:
Jan. 03, 2001
John Gillette Davis, Charlotte, NC (US);
Joseph Michael Kielbasa, Charlotte, NC (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and device for attaching a module having a ball grid array or column grid array of solder material thereon arranged in a given pattern or footprint to a substrate having an array of connector pads arranged in the same pattern is provided. A preformed alignment device has an array of through holes therein aligned in the same pattern or footprint as the ball grid array or column pattern on the module and the pattern of contact pads on the substrate. The through holes in the preform are filled with a solder material which can be either a solder paste or a solid solder or with a curable conductive adhesive. The solder preferably is a lead-tin eutectic, but in any event has a melting point of less than about 240° C. and in the case of the conduction adhesive, will cure below about 240° C. The preform with the filled through holes is interposed between the module and the substrate with the material in the holes in contact with the solder balls or columns and the contact pads. Heat is applied to reflow the solder or cure the adhesive in the holes to join the module to the substrate. Depending upon the composition of the solder of the balls or columns, they might or might not melt. In the case of solid solder, thin films of flux material can be applied to opposite faces of the preform to prevent the solder from dislodging therefrom and to act as a flux when the solder is reflowed.