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. 14, 2004
Filed:
Mar. 11, 2003
Yukihiro Kitamura, Nagano, JP;
Takayuki Takahashi, Nagano, JP;
Mitsuru Ohta, Nagano, JP;
Yuji Ogawa, Nagano, JP;
Dowa Mining Co., Ltd., Tokyo, JP;
Abstract
In a ceramic circuit board having a ceramic substrate and a metal circuit plate bonded to one surface of the ceramic substrate, assuming that the warpage of the ceramic circuit board is a difference in height between the center and edge of the metal circuit plate and is positive (+) when the circuit board warps so as to be concave on the side of the metal circuit plate, the warpage of the ceramic circuit board is in the range of from −0.1 mm to +0.3 mm when the ceramic circuit board is heated to 350° C., and in the range of from +0.05 mm to +0.6 mm when the temperature of the ceramic circuit board is returned to a room temperature after the ceramic circuit board is heated to 350° C. The initial warpage of the ceramic circuit board is in the range of from +0.05 mm to +0.6 mm.