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:
May. 22, 2007
Filed:
Mar. 22, 2004
Junji Nakamura, Nagano, JP;
Junji Nakamura, Nagano, JP;
Dowa Mining Co., Ltd., Tokyo, JP;
Abstract
There is provided a method for producing a reliable metal/ceramic bonding substrate at low costs by forming a desired fillet on the peripheral portion of a metal circuit by a small number of steps. After an active metal containing brazing filler metalis applied on a ceramic substrateto bond a metal memberthereto, a resistis applied on a predetermined portion of a surface of the metal memberto etch unnecessary portions, and then the resist is removed. Thereafter, unnecessary part of a metal layer, which is formed of a metal other than an active metal of the active metal containing brazing filler metal, is etched with a chemical to be removed. Then, unnecessary part of an active metal layer, which is formed of the active metal and a compound thereof, is selectively etched with a chemical, which inhibits the metal memberand the metal layerfrom being etched and which selectively etch the active metal layer, to form a metal circuit on the ceramic substrate. This metal circuit is chemically polished to form a fillet on the peripheral portion of the metal circuit.