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:
Jul. 30, 2002
Filed:
Feb. 10, 2000
Charles W. Eichelberger, Wakefield, MA (US);
James E. Kohl, Reading, MA (US);
EPIC Technologies, Inc., Woburn, MA (US);
Abstract
Structures and methods are provided for absorbing stress between a first electrical structure and a second electrical structure connected together, wherein the first and second structures have different coefficients of thermal expansion. A dielectric material is disposed on at least one of the first and second electrical structures. This dielectric material is a low modulus material which has a high ultimate elongation property (LMHE dielectric). Preferably, the LMHE dielectric has a Young's modulus of less than 50,000 psi and an ultimate elongation property of at least 20 percent. The LMHE dielectric can be photo patternable to facilitate formation of via openings therein and a metal layer is formed above the LMHE dielectric which has conductors capable of expanding or contracting with the dielectric. Conductors of the metal layer disposed above the dielectric and connected to vias in the dielectric have a length significantly greater than the maximum displacement due to thermal expansion between the first and second electrical structures, e.g., a length which is at least five times the displacement.