Abstract: In a metal base substrate with a low-temperature sintering ceramic layer located on a copper substrate, bonding reliability is increased between the copper substrate and the low-temperature sintering ceramic layer. A raw laminated body is prepared by stacking, on a surface of a copper substrate, a low-temperature sintering ceramic green layer including a low-temperature sintering ceramic material containing about 10 mol % to about 40 mol % of barium in terms of BaO and about 40 mol % to about 80 mol % of silicon in terms of SiO2, and this raw laminated body is subjected to firing at a temperature at which the low-temperature sintering ceramic green layer is sintered. In the thus obtained metal base substrate, a glass layer composed of Cu—Ba—Si based glass with a thickness of about 1 ?m to about 5 ?m is formed between the metal substrate and the low-temperature sintering ceramic layer.

Abstract: In a metal base substrate with a low-temperature sintering ceramic layer provided on a metal substrate, while making it possible to make the metal substrate from copper, the low-temperature sintering ceramic layer is less likely to crack or peel at the interface with the metal substrate, and the anti-peeling strength of a surface conductor is improved. In the metal base substrate, the thermal expansion coefficient of the metal substrate is greater than the thermal expansion coefficient of the low-temperature sintering ceramic layer, the average difference in thermal expansion coefficients of the metal substrate and the low-temperature sintering ceramic layer at approximately 25° C. to 400° C. is about 4 ppm/° C. to about 9 ppm/° C., and the low-temperature sintering ceramic layer has a Young's modulus less than about 120 GPa, and a flexural strength of about 200 MPa or more.

Abstract: A low-temperature sintering ceramic material showing little variation in composition after firing, realizing high bending strength in a sintered body, and capable of forming a reliable ceramic substrate showing high peel strength of a surface electrode includes a main constituent ceramic material containing about 48 weight % to about 75 weight % in terms of SiO2 of Si, about 20 weight % to about 40 weight % in terms of BaO of Ba, and about 5 weight % to about 20 weight % in terms of Al2O3 of Al, and an accessory constituent ceramic material containing, relative to 100 parts by weight of the main constituent ceramic material, about 2 parts to about 10 parts by weight in terms of MnO of Mn and about 0.1 parts to about 10 parts by weight respectively in terms of TiO2 and Fe2O3 of at least one selected from Ti and Fe, and substantially not includes both Cr oxide and B oxide.

Abstract: To provide a ceramic composition not only having little compositional variation after burning, but a high flexural strength of the sintered body, and a high Q value in a microwave band, a ceramic composition used for forming a ceramic layer of a multi-layer ceramic substrate contains 47.0 to 67.0 wt. % of SiO2, 21.0 to 41.0 wt. % of BaO, and 10.0 to 18.0 wt. % of Al2O3, and contains as a first additive, 1.0 to 5.0 parts by weight of CeO2, relative to a total of 100 parts of SiO2, BaO and Al2O3, and as a second additive, 2.5 to 5.5 parts by weight of MnO, relative to a total of 100 parts by weight of SiO2, BaO, Al2O3 and CeO2, and is substantially free of Cr. As a third additive, at least one of Zr, Ti, Zn, Nb, Mg and Fe, and as a fourth additive, a Co component and/or a V component, may be contained.

Abstract: Provided is a mono- or multilayer ceramic substrate which exhibits a high flexural strength. The substrate contains a sintered ceramic which includes respective crystal phases of quartz, alumina, fresnoite, sanbornite, and celsian, in which the relationship between the diffraction peak intensity A in the (201) plane of the fresnoite and the diffraction peak intensity B in the (110) plane of the quartz, measured by a powder X-ray diffractometry in the range of the diffraction peak angle 2?=10 to 40°, is A/B?2.5. The fresnoite crystal phase preferably has an average crystal grain size of 5 ?m or less. In firing to obtain this ceramic sintered body, the maximum temperature falls within the range of 980 to 1000° C.

Abstract: In a sintered body of low temperature cofired ceramic constituting ceramic layers of a multilayer ceramic substrate provided with external conductor films, which is obtained by sintering a non-glass low temperature cofired ceramic material, respective crystalline phases of quartz, alumina, and fresnoite are deposited. The ceramic layers are, because of being in the form of a sintered body of non-glass low temperature cofired ceramic, less likely to fluctuate in composition, and the multilayer ceramic substrate can be thus inexpensively and easily manufactured therefrom. In addition, the ceramic layers have the above-mentioned respective crystalline phases deposited therein, and thus have a high joint strength with the external conductor films, and moreover, the sintered body itself has a high fracture touhgness value.

Abstract: In a sintered body of low temperature cofired ceramic constituting ceramic layers of a multilayer ceramic substrate provided with external conductor films, which is obtained by sintering a non-glass low temperature cofired ceramic material, respective crystalline phases of quartz, alumina, and fresnoite are deposited. The ceramic layers are, because of being in the form of a sintered body of non-glass low temperature cofired ceramic, less likely to fluctuate in composition, and the multilayer ceramic substrate can be thus inexpensively and easily manufactured therefrom. In addition, the ceramic layers have the above-mentioned respective crystalline phases deposited therein, and thus have a high joint strength with the external conductor films, and moreover, the sintered body itself has a high fracture toughness value.

Abstract: A low-temperature sintering ceramic material showing little variation in composition after firing, realizing high bending strength in a sintered body, and capable of forming a reliable ceramic substrate showing high peel strength of a surface electrode includes a main constituent ceramic material containing about 48 weight % to about 75 weight % in terms of SiO2 of Si, about 20 weight % to about 40 weight % in terms of BaO of Ba, and about 5 weight % to about 20 weight % in terms of Al2O3 of Al, and an accessory constituent ceramic material containing, relative to 100 parts by weight of the main constituent ceramic material, about 2 parts to about 10 parts by weight in terms of MnO of Mn and about 0.1 parts to about 10 parts by weight respectively in terms of TiO2 and Fe2O3 of at least one selected from Ti and Fe, and substantially not includes both Cr oxide and B oxide.

Abstract: To provide a ceramic composition not only having little compositional variation after burning, but a high flexural strength of the sintered body, and a high Q value in a microwave band, a ceramic composition used for forming a ceramic layer of a multi-layer ceramic substrate contains 47.0 to 67.0 wt. % of SiO2, 21.0 to 41.0 wt. % of BaO, and 10.0 to 18.0 wt. % of Al2O3, and contains as a first additive, 1.0 to 5.0 parts by weight of CeO2, relative to a total of 100 parts of SiO2, BaO and Al2O3, and as a second additive, 2.5 to 5.5 parts by weight of MnO, relative to a total of 100 parts by weight of SiO2, BaO, Al2O3 and CeO2, and is substantially free of Cr. As a third additive, at least one of Zr, Ti, Zn, Nb, Mg and Fe, and as a fourth additive, a Co component and/or a V component, may be contained.