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. 15, 1995
Filed:
Jan. 13, 1994
Jerry I Tustaniwskyj, Mission Viejo, CA (US);
Maria D Alvarez, El Cajon, CA (US);
Steve J Bezuk, Poway, CA (US);
Robert E Rackerby, San Diego, CA (US);
Patrick A Weber, Escondido, CA (US);
Unisys Corporation, Blue Bell, PA (US);
Abstract
A method of stretching solder joints between the input/output pads of an electrical component and corresponding input/output pads on a substrate includes the steps of: melting the solder joints; confining the component while the solder joints are melted such that the component can only move substantially perpendicular to the substrate; pulling the component, while the component is confined, by an external force in a direction away from the substrate to thereby stretch the melted solder joints; compelling the movement of the component to stop when the component has moved a predetermined distance; and, solidifying the solder joints while the component is compelled to stop. By stretching the solder joints with the above method, the solder joint shape can be changed from convex to concave; and thermally induced stress/strain in the joint is substantially reduced.