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:
Nov. 24, 1998
Filed:
Jan. 24, 1997
Kenneth Walter Economy, Escondido, CA (US);
Ronald Allen Norell, Oceanside, CA (US);
Richard Leigh Bumann, Olivenhain, CA (US);
Unisys Corporation, Blue Bell, PA (US);
Abstract
Solder balls are placed onto multiple I/O pads of an integrated circuit package by the steps of a) providing a template with a channel which has multiple openings on a surface of the template that match the pattern of the I/O pads; b) pouring a plurality of the solder balls onto the surface of the template; c) vibrating the template and thereby seating a respective solder ball in each of the template openings; d) turning the template over, after the vibrating step and while a vacuum is applied to the channel, to remove excess solder balls from the template; and e) removing the vacuum from the channel when the solder balls on the turned over template are aligned to the I/O pads of the integrated circuit package. Due to the vibrating step, the solder balls settle in the template openings in a position where vacuum leaks past the solder balls become minimized; and that stops the solder balls from dropping out of the template openings when the template is turned over. Also, since the steps a-d place the solder balls on all of the I/O pads in parallel, the time in which those steps are performed is many times smaller than the time in which a pick and place machine can put the solder balls on all of the I/O pads sequentially.