Method for manufacture of high-frequency dielectric ceramics
AssigneeSumitomo Metal Mining Co., Ltd.
InventorsKazutoshi Matsumoto, Koh Takada, Takehiro Hyuga
Life of this patent
Estimating the term…
Abstract
A dielectric ceramics possessing a high level of unloaded Q and low loss at high frequency beneficial for communications at high frequency is produced by a method which comprises heating a green compact of a composition represented by the general formula: xBaO.yMgO.zTa.sub.2 O.sub.5 (wherein x, y, and z satisfy 0.5.ltoreq.x.ltoreq.0.7, 0.15.ltoreq.y.ltoreq.0.25, 0.15.ltoreq.z.ltoreq.0.25, and x+y+z=1) to a temperature in the range of 1,500.degree. to 1,700.degree. C. at a temperature increasing rate of 100.degree. to 1,600.degree. C./minute and subsequently retaining the green compact at the temperature for not less than 30 minutes.
Claims12
A method for the production of BaO-MgO-Ta.sub.2 O.sub.5 type dielectric ceramic which contains no Mn, said method comprising the steps of
- (a) providing a green compact composed of a material consisting essentially of xBao.yMgO.zTa.sub.2 O.sub.5, wherein x, y and z satisfy the following relationships:
- 0.56.ltoreq.x.ltoreq.0.64, 0.18.ltoreq.y.ltoreq.0.22, 0.18.ltoreq.z.ltoreq.0.22, and x+y+z=1, said material containing no Mn, by combining suitable amounts of BaCO.sub.3, MgO and Ta.sub.2 O.sub.5 to form a mixture, calcinating the mixture and subsequently compression molding the calcined mixture,
- (b) heating said green compact at a rate of 100.degree. C. to 1,600.degree. C. per minute to a temperature of 1,500.degree. C. to 1,700.degree. C., and
- (c) maintaining said heated green compact at between 1,500.degree. C. and 1,700.degree. C. for at least 30 minutes.
Dependencies are inferred from the claim text.