摘要:
In a method of manufacturing piezoelectric ceramics by molding pre-fired or calcined powders of ingredients of a piezoelectric ceramic material and sintering the powder mold at a high pressure, the powder mold is pre-sintered at an atmospheric pressure before sintering at high pressure (HIP). Preferably, after the sintering HIP step, a thermal treatment is performed at a temperature of from 500 to 1000.degree. C. under an oxidizing atmosphere. For a Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 --PbTiO.sub.3 based piezoelectric ceramic, the composition is preferably set to (Pb.sub.1-x Ba.sub.x)[(Zn.sub.1/3 Nb.sub.2/3).sub.1-y Ti.sub.y ]O.sub.3, where 0.001
摘要:
A piezoelectric device including an insulating substrate and a displacement layer formed on the insulating substrate including a first common electrode, a piezoelectric layer and a plurality of second electrodes laid on the insulating substrate in the stated order, where a part of a surface of the piezoelectric device in a region where the first and the second electrodes overlap each other is projected out of the rest part of the surface. The thus-formed piezoelectric device can increase the amount of displacement of the displacement layer.
摘要:
A process of producing a multiple-layer circuit board of aluminum nitride, including the steps of: preparing green sheets of aluminum nitride, forming on the green sheets conductor patterns of a conductor paste containing tungsten as a main conductor component, laminating the green sheets with the conductor patterns formed thereon to form a lamination, and firing the lamination in a container made of boron nitride and in a pressurized nitrogen gas atmosphere.
摘要:
An epoxy resin composition contains an epoxy resin as a substratal resin and incorporates therein a polyallylphenol curing agent. The composition may also contain a polyphenol compound. The epoxy resin may have a naphthalene skeleton. The epoxy resin composition may also include a blend of two or more epoxy resins.
摘要:
Disclosed is an alumina substrate having a high density, a high degree of surface smoothness and excellent dielectric properties and a process for its manufacture. The process comprises prefiring a green sheet prepared from alumina powder at an elevated temperature, for example between 1200.degree. and 1350.degree. C., to remove combustible substances from the sheet, treating the resultant prefired substrate with an acid aqueous solution to eliminate acid-soluble and decomposable substances from the substrate, and firing the acid-treated substrate at an elevated temperature, for example between 1500.degree. and 1650.degree. C.