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:
Mar. 07, 1995
Filed:
Oct. 26, 1993
Mark E Ferguson, all or Charlotte, NC (US);
Kenneth J Guskie, all or Charlotte, NC (US);
Leon S Nguyen, all or Charlotte, NC (US);
Joseph D Poole, Troutman, NC (US);
Stuart L Young, Charlotte, NC (US);
Simon Yu, Concord, NC (US);
International Business Machines, Corporation, Armonk, NY (US);
Abstract
Disclosed is a method of populating printed circuit boards with surface mount technology devices in a multi-board work board holder. The method includes the steps placing the printed circuit boards into a multi-board work board holder having a plurality of apertures corresponding to the individual printed circuit boards. The multi-board work board holder is placed onto a surface mount technology production line, and solder paste is selectively applied onto contact pads on surfaces of the printed circuit boards. Integrated circuit chips are next placed onto the solder paste bearing surface of the printed circuit boards, with the contact leads of the integrated circuit chips bearing on deposited solder paste. The printed circuit boards and the work board holder are heated to the reflow temperature of the solder. The x-y plane and z axis coefficients of thermal expansion of the multi-board work board holder are matched to the x-y plane and z-axis coefficients of thermal expansion of the printed circuit boards to avoid warpage and misalignment of the printed circuit boards.