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:
Sep. 06, 2011
Filed:
Jan. 15, 2008
Kushal Bhattacharjee, Kernersville, NC (US);
Sergei Zhgoon, Moscow, RU;
Kushal Bhattacharjee, Kernersville, NC (US);
Sergei Zhgoon, Moscow, RU;
RF Micro Devices, Inc., Greensboro, NC (US);
Abstract
The present invention provides a composite structure having a supporting substrate between a piezoelectric substrate and a compensation layer. The materials used to form the piezoelectric substrate and the compensation layer in isolation, have higher thermal coefficients of expansion (TCE) relative to the TCE of the materials forming the supporting substrate. Once the composite structure is created, the piezoelectric substrate and compensation layer tend to expand and contract in a similar manner as temperature changes. The expansion and contraction forces applied to the supporting substrate by the piezoelectric substrate due to temperature changes are substantially countered by similar opposing forces applied by the compensation layer, resulting in the opposing forces substantially counteracting one another. Due to the counteraction, the composite structure resists bending or warping, reducing expansion and contraction and increasing stress of the piezoelectric substrate, and thus reducing the effective TCE and TCF of the piezoelectric substrate.