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. 06, 1996
Filed:
Sep. 15, 1994
George W Chiu, Palo Alto, CA (US);
Intel Corporation, Santa Clara, CA (US);
Abstract
A method for forming solder balls and an apparatus and method for forming solder columns on the electrical contact pads of an electronic package in order to establish a more reliable electrical and mechanical connection between an electronic package and a printed circuit board. In one embodiment, solder balls are formed on the electrical contact pads of a package by placing solder cylinders over the electrical contact pads and then passing the package through a reflow furnace where the solder cylinders take the form of spheres and are wetted onto the pads. In a second embodiment, a laminated solder column is formed that is resistant to collapse during the manufacturing process. The laminated solder column comprises a solder cylinder being clad on its top and bottom surfaces with a solder material having a lower melting temperature than that of the center solder cylinder. When attaching the solder column to a package or a printed circuit board reflow temperatures are maintained above the melting temperature of the cladding material but below the melting temperature of the center solder cylinder such that the cladding is wetted onto the electrical contact pads of the package or printed circuit board while the center solder cylinder maintains its solid form.