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:
Dec. 27, 2005
Filed:
May. 23, 2003
Paul Morganelli, Upton, MA (US);
David Peard, Windham, NH (US);
Jayesh Shah, Plaistow, NH (US);
Douglas Katze, Sterling, MA (US);
Paul Morganelli, Upton, MA (US);
David Peard, Windham, NH (US);
Jayesh Shah, Plaistow, NH (US);
Douglas Katze, Sterling, MA (US);
National Starch and Chemical Investment Holding Corporation, New Castle, DE (US);
Abstract
A method for utilizing one or more pre-formed underfill compositions in the application of surface mount components, most commonly chip scale packages (CSP's), to substrates for use in electronic devices. The pre-formed underfill of the invention is applied directly to the top and/or sides of the CSP before the reflow process and softens during reflow to flow across the circuit/board gap. One underfill composition utilized for this method comprises a thermoplastic film system that provides a coating on the component that is smooth and non-tacky. The film may be applied selectively to parts of the CSP such that it overhangs the top of the component and upon reflow flows over the edge of the CSP to form a connection with the substrate. A second pre-applied underfill composition or solder paste may be applied as an adhesive to provide sufficient tack in order to hold the electronic assembly together during the assembly process and to serve as a flux to facilitate solder wetting.