Abstract: To provide a process capable of efficiently producing a spherical aluminum nitride powder having a size most suited for use as a filler, and having a high sphericalness and a large particle strength. A spherical aluminum nitride powder is produced by using a spherical granulated product of an alumina powder or an alumina hydrate powder as a starting material, and feeding the spherical granulated product to the step of reductive nitrogenation so as to be reductively nitrogenated.

Abstract: [Problems] To provide a process capable of efficiently producing a spherical aluminum nitride powder having a size most suited for use as a filler, and having a high sphericalness and a large particle strength. [Means for Solution] A spherical aluminum nitride powder is produced by using a spherical granulated product of an alumina powder or an alumina hydrate powder as a starting material, and feeding the spherical granulated product to the step of reductive nitrogenation so as to be reductively nitrogenated.

Abstract: A sintered ceramics for mounting a light-emitting element, which is capable of realizing high optical reflectance over the entire region from ultraviolet radiation to visible light. The sintered ceramics has a light-reflective face of which reflectance to light in each wavelength in the range of 250 nm˜750 nm is 70% or more. The light-reflective face satisfies following reaction: |RA?RB|?20 when reflectance to light of 750 nm is defined as RA%, and reflectance to light of 300 nm is defined as RB. The sintered ceramics has not layer to be peeled from the light-reflective face when a Tape Peeling Test is carried out to the light-reflective face in accordance with the method described in JIS H8504 (1990).

Abstract: A non-oxide ceramics having improved performances and functions by forming a high-quality oxide film on the surface of a non-oxide ceramics such as aluminum nitride. The method for the formation of the non-oxide ceramics comprises the steps of: (1) providing a non-oxide ceramics; (2) introducing the non-oxide ceramics into a furnace and then regulating the atmosphere within the furnace so as to have an oxidizing gas content of not more than 0.5 mmol in terms of total number of moles of the oxidizing gas per m3 of the inside of the furnace; (3) heating the non-oxide ceramics to a temperature at or above a temperature, which is 300° C.

Abstract: [PROBLEMS] To provide a metallized non-oxide ceramic shaped article having high adhesive strength between a metal layer and a substrate and the adhesion durability and to provide a process for producing the same. [MEANS FOR SOLVING PROBLEMS] The process for producing a metallized shaped article includes: a heating step of heating a non-oxide ceramic shaped article to a temperature at or above a temperature, which is 300° C.

Abstract: A module substrate consists of a substrate mounting electronic parts on one surface thereof, a conductor for electrically conducting the electronic parts mounted on the substrate to the other surface of the substrate, a conductive solder for attaching the conductor to a base substrate movably contacting the other surface of the substrate to electrically connect the electronic parts with the base substrate, and a deformable bushing for holding the conductor to maintain the attachment of the conductor to the base substrate regardless of whether the base substrate is moved.

Abstract: A filter device for a transmitter-receiver antenna includes a transmission side filter having resonators and a reception side filter having resonators. Each of the transmission side resonators has a first characteristic impedance ratio other than one. On the other hand, each of the reception side resonators has a second characteristic impedance ratio being set to a value which prevents spurious resonance of the reception side filter at an integral multiple of a fundamental resonance frequency of the transmission side filter, so as to avoid the situation where spurious components increase at the above-noted integral multiple in a frequency characteristic of the transmission side filter being affected by a frequency characteristic of the reception side filter.

Abstract: A high-frequency filter of the type having a plurality of resonators open at least at one end thereof, a dielectric board forming an input/output coupling and an interstage coupling, and a case for holding therein the resonators and the dielectric board, wherein the dielectric board is made of a ceramic having a critical stress intensity factor K.sub.1c of not less than 5 MPa.multidot.m.sup.1/2 and a dielectric dissipation factor tan. .delta. of not exceeding 1% in a working frequency band of said high-frequency filter, and wherein electrodes are provided on the dielectric board to form an input/output coupling capacity and an interstage coupling capacity. The high-frequency filter of the foregoing construction has the advantage of an excellent mechanical strength which is capable of withstanding severe mechanical loads such as falling impacts or various stresses.

Abstract: A dielectric ceramic composition represented by the compositional formula: .sub.x BaO-.sub.y TiO.sub.2 -.sub.z Nd.sub.2 O.sub.3 -.sub.t Sm.sub.2 O.sub.3 -.sub.w Bi.sub.2 O.sub.3 so composed as to be in the molar fractions of 0.06.ltoreq.x.ltoreq.0.25, 0.60.ltoreq.y.ltoreq.0.80, 0.05.ltoreq.z.ltoreq.0.18, 0<t.ltoreq.0.07 and 0<w.ltoreq.0.05, provided that x+y+z+t+w=1, and a compositional range of Y<0.68 and Z>0.15 is excluded. As an additive, at least one of Al.sub.2 O.sub.3, ZrO.sub.2, etc. may be added. Part of Ba may be replaced with at least one of Sr, Ca and Mg. The Sm.sub.2 O.sub.3 and Nd.sub.2 O.sub.3 each may have a purity of at least 70 wt. %.

Abstract: A flat type dielectric filter comprises a substantially U-shaped strip line formed such that each center frequency of spurious output deviates from each odd number frequency times the center frequency of the dielectric filter. That is, it comprises a first portion so curved to form an open loop and two second portions formed to have a larger width than the first portion, each of the second portions being provided to an end of the first portion such that each extends in the opposite direction to the other. In this filter, input/output electrodes confronting ends of U-shaped strip line can be formed on a different layer from the layer where the resonator is formed in order to reduce its size. Reduction of size can be obtained by vertically folding the U-shaped strip line extending horizontally. Terminals of this filter formed on the side surface have a first layer formed on the side surface and a second layer formed on the first layer.

Abstract: A dielectric resonator comprising a cylindrical substrate comprised of a dielectric ceramic, a first conductive film comprised of copper, formed on the inner surface, outer surface and one end of said cylindrical substrate, and a second conductive film comprised of at least one solder and tin, formed on said first conductive film. Thus the dielectric resonator of the present invention can be free from oxidation of the copper film when heating is carried out not in an inert gas environment but in the atmosphere. Hence it becomes unnecessary to use various devices for carrying out the heating in an inert gas environment as so required in the conventional cases. This also enables reduction of the number of processing steps, resulting in an improvement in productivity. Moreover, its weatherability can be improved, so that it can promise a long lifetime.

Abstract: A coaxial dielectric resonator for use at high frequency. The outer or inner peripheral surface of a tubular dielectric member is stepped so as to provide a greater suppression of spurious resonance. The dielectric member has a prism-shaped outer configuration so as to provide a high Q value, as well as improved space factor.