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. 10, 2004
Filed:
Mar. 28, 2003
Jing Qi, Lake Zurich, IL (US);
Janice M. Danvir, Arlington Heights, IL (US);
Tomasz L. Klosowiak, Glenview, IL (US);
Prasanna Kulkarni, Schaumburg, IL (US);
Nadia Yala, Schaumburg, IL (US);
Freescale Semiconductor, Inc., Austin, TX (US);
Abstract
The invention provides a method for attaching a flip chip to an electrical substrate such as a printed wiring board. A bumped flip chip is provided, the flip chip including an active surface and a plurality of connective bumps extending from the active surface, each connective bump including a side region. A thin layer of an underfill material is applied to the active surface of the flip chip and to a portion of the side regions of the connective bumps. The flip chip is positioned on the electrical substrate, the electrical substrate including a thick layer of a solder mask disposed on the electrical substrate. The flip chip is heated to electrically connect the flip chip to the electrical substrate, wherein the underfill material and the solder mask combine to form a stress-relief layer when the flip chip is electrically connected to the electrical substrate.