Ngk Spark Plug Company, Limited

Other

Ngk Spark Co., Ltd.

Hiroshi Katagiri

Hirofumi Ozeki

Masahiko Okuyama

Hidetoshi Mizutani

Toshiya Asano

Tadashi Shingaki

Tatsuya Takemura

Tetsuya Ishii

Makoto Suzuki

Kanji Hayashi

Noritaka Yoshida

A coreless wiring board has no core board but a laminated structure in which a conductor layer and resin insulating layers are alternately laminated into a multilayer. Each of the resin insulating layers is formed to contain a glass cloth in an epoxy resin. A plurality of via holes is formed to penetrate each of the resin insulating layers, and a filled via conductor for electrically connecting the conductor layers is formed in the via holes respectively. A tip of the glass cloth contained in each of the resin insulating layers is protruded from an internal wall surface of the via hole and cuts into a sidewall of the filled via conductor.

Multilayer wiring board and method of manufacturing the same

A coreless wiring board has no core board but a laminated structure in which a conductor layer and resin insulating layers are alternately laminated into a multilayer. Each of the resin insulating layers is formed to contain a glass cloth in an epoxy resin. A plurality of via holes taking a shape of an inverse truncated cone and having steps on internal wall surfaces is formed to penetrate each of the resin insulating layers, and a filled via conductor for electrically connecting the conductors is formed in each of the via holes.

Multilayer wiring board

Composition for producing low sintering temperature ceramic dielectrics and method of manufacturing such dielectrics

A grinding body for on-line roll grinding has a grindstone of a cup shape. The grindstone is on a surface portion, and near a peripheral edge, of a circular support base plate, so that a peripheral edge portion of the circular support base plate has on a surface side thereof a two-layer structure. This two-layered structure includes a flat ring-shaped portion jutting toward an inner periphery so as to define a groove opening inward. The grindstone is mounted on the flat ring-shaped portion; and a damping material is filled and mounted into the groove. This grinding body can effectively prevent the formation of a spiral mark and a pitching surface mark, improve the grinding power and grinding accuracy, and prolong the life of the grindstone.

Grinding body for on-line roll grinding

The multilayer microelectronic circuit comprises a main capacitor dielectric layer, a main capacitor first electrode disposed on one of opposite sides of the main capacitor dielectric layer, a main capacitor second electrode disposed on the other of the opposite sides of the main capacitor dielectric layer in a way as to oppose the main capacitor first electrode through the main capacitor dielectric layer, a first trimming capacitor dielectric layer disposed on a side of the main capacitor first electrode opposite to the main capacitor dielectric layer, a first trimming capacitor electrode disposed on a side of the first trimming capacitor dielectric layer opposite to the main capacitor first electrode in a way as to oppose the main capacitor first electrode through the first trimming capacitor dielectric layer, a second trimming capacitor dielectric layer disposed on a side of the first trimming capacitor electrode opposite to the first trimming capacitor dielectric layer, and a second trimming capacitor electrode disposed on a side of the second trimming capacitor dielectric layer opposite to the first trimming capacitor electrode in a way as to oppose the first trimming capacitor electrode through the second trimming capacitor dielectric layer. The first trimming capacitor electrode is first trimmed for rough adjustment of a capacitance of the circuit. The second trimming capacitor electrode is then trimmed for fine adjustment of the capacitance.

Multilayer microelectronic circuit with trimmable capacitors

A multilayer microelectronic circuit to be directly mounted on a substrate and to be used, for example, as a resonator. The multilayer microelectronic circuit comprises a plurality of dielectric layers and patterned electrodes which are laminated one upon another to form a laminated structure, the dielectric layers and the patterned electrodes forming an electrical circuit. The laminated structure has side surfaces extending along a direction in which the dielectric layers and the patterned electrodes are laminated. An input line is formed at one of the side surfaces and connected with an input section of the electrical circuit. An output line is formed at one of the side surfaces and connected with an output section of the electrical circuit. A grounding line is formed at one of the side surfaces and connected with a grounding section of the electrical circuit. Additionally, a signal line formed at one of the side surfaces, for connecting sections of the electrical circuit. The signal line has an end positioned adjacent a mounting surface at which the multilayer microelectronic circuit is directly mounted on the substrate, in which the end of the signal line is separate from the mounting surface so as to be insulated from electrical contact with the substrate.

Multilayer microelectronic circuit

Powders of BaCO.sub.3, TiO.sub.2, ZnO, etc. are mixed to each other at a predetermined ratio of quantity, calcined in an atmospheric air at 90.degree.-120.degree. C., and pulverized to obtain a calcined powder having an average grain size from 1 to 3 .mu. m. 0.1 to 20 parts-by weight of a powder having an average grain size from 0.1 to 1.5 .mu.m comprising a glass having a transition point of not higher than 450.degree. C. obtained by mixing powders of Pb.sub.3 O.sub.4, SiO.sub.2, Na.sub.2 O, etc. to each other, melting and then pouring into water and pulverizing the thus obtained glass is admixed to the calcined powder. The mixture is dried, pelleted by adding a resin and the pellet powder is molded into a cylindrical shape, applied with CIP (Cold isotactic press), and the molding product after the treatment is sintered in an atmospheric air at 850.degree. to 1000.degree. C. to obtain a dielectric ceramic sintered at low temperature. The resultant dielectric ceramic has high denseness and high unloaded Q value while maintaining .tau.f within a practical range.

Composition for producing low sintering temperature ceramic dielectrics

The present invention provides a microwave dielectric ceramic composition in which .epsilon.r, Qu and .tau.f are generally controlled within a practical characteristic range and each of the characteristics is maintained in a well balanced state. A ceramic composition of the present invention comprises a composition represented by xBi.sub.2 O.sub.3 -(1-x) (yNb.sub.2 O.sub.5 -(1-y)Ta.sub.2 O.sub.5) in which 0.45.ltoreq.x.ltoreq.0.55 and 0.1.ltoreq.y&lt;1.0 as a main ingredient, to which not more than 0.8 parts by weight of V.sub.2 O.sub.5 is added and incorporated. An another ceramic composition comprises a composition represented by Bi(NbxTa1-x)O.sub.4 in which 0&lt;x.ltoreq.0.96 as a main ingredient, to which not more than 5 wt % of V.sub.2 O.sub.5 and not more than 2 wt % of PbO are added and incorporated. An another ceramic composition comprises the main ingredient as described above to which not more than 5 wt % of V.sub.2 O.sub.5 and not more than 2 wt % of MnO.sub.2 are added and incorporated. An another ceramic composition comprises the main ingredient as described above to which not more than 2 wt % of V.sub.2 O.sub.5 and not more than 1 wt % of TiO.sub.2 are added and incorporated. An another ceramic composition comprises the main ingredient as described above, to which not more than 2 wt % of V.sub.2 O.sub.5, not more than 2 wt % of MnO.sub.2 and not more than 0.7 wt % of TiO.sub.2 are added and incorporated. Instead of TiO.sub.2 described above, not more than 0.5 wt % (particularly not more than 0.4 wt %) of PbO can be added and incorporated.

Microwave dielectric ceramic composition

A ceramic composition having a high value .epsilon.r while maintaining Qu and .tau.f each in a range of practical characteristic. The present invention is applicable to dielectric resonators and impedance matching of various kinds of microwave circuits. The ceramic composition comprises Ba.sub.1-x Sr.sub.x (Zn.sub.1/3 Nb.sub.2/3)O.sub.3 (in which 0.6.ltoreq..times..ltoreq.1.0) as the main ingredient, to which TiO.sub.2 is incorporated by 0.01 to 1 parts by weight based on 100 parts by weight of the main ingredient. The ceramic composition may have a Qu value of 2000 to 2900 (at 4.5 GHz), relative dielectric constant of 39 to 42, and a temperature constant of resonance frequency (.tau.f) in the range of -8 to +10 ppm/.degree.C. The ceramic composition may not contain Sr.sub.5 Nb.sub.4 O.sub.15 or Ba.sub.4 Nb.sub.2 O.sub.9. It may index for the regularity of the B site ingredient of 7-9.times.10.sup.-2. The ceramic composition may be prepared by calcination, sintering, and an annealing treatment after sintering. A calcination atmosphere and a sintering atmosphere may be ZnO atmosphere.

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Aichi, Japan

Hiroshi Katagiri