Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Hirayoshi Tanei

Shoichi Iwanaga

Akira Ikegami

Tsuyoshi Fujita

Shousaku Ishihara

Kousaku Morita

Fumiyuki Kobayashi

Yutaka Akiba

Yasunori Narizuka

Masahide Okamoto

Tokio Isogai

Hideo Arima

Masato Nakamura

Nobuo Nakagawa

Norio Sengoku

Naoya Kitamura

Fumikazu Tagami

Hitoshi Yokono

Kaoru Uchiyama

Masao Yano

Hiroatsu Tokuda

Katsuo Abe

Seiichi Onoda

Nobuyuki Sugishita

Hiromi Tosaki

Takanobu Noro

Noriyuki Taguchi

Yasuo Akutsu

Yasumasa Koakutsu

Tamio Takeuchi

Hiroshi Ohtsu

Kiyoshi Kawabata

Hiromi Isonae

Hiroshi Otsu

Masato Kirigaya

Hiroshi Soma

The present invention has an object to enhance the reliability of the electrical connection of a silver-based conductor film on the surface of a glass ceramic board. In order to achieve the object, according to the present invention, by the use of a conductor paste containing a silver particle having a specific surface area of 0.3 m /g to 3.0 m /g and no glass, printing is carried out on a glass ceramic board and the conductor paste is fired at a firing temperature having a difference of &plusmn;50&deg; C. from a softening temperature of amorphous borosilicate glass contained in the glass ceramic. Consequently, a silver-based conductor film having high reliability of the electrical connection is formed on the ceramic board.

Electronic component and method of manufacturing the same

A low-EMI circuit which realizes a high mounting density by converting the potential fluctuation of a power supply layer with respect to a ground layer which occurs on switching an IC device etc., into Joule's heat in the substrate without using any parts as a countermeasure against the EMI. Its structure, a circuit board using it, and a method of manufacturing the circuit board are also disclosed. Parallel plate lines in which the Q-value of the stray capacitance between solid layers viewed from the power supply layer and ground layer is equivalently reduced and which are matchedly terminated by forming a structure in which a resistor (resistor layer) and another ground layer are provided in addition to the power supply layer and the ground layer on a multilayered circuit board. A closed shield structure is also disclosed.

Low-EMI electronic apparatus, low-EMI circuit board, and method of manufacturing the low-EMI circuit board

A low-EMI circuit which realizes a high mounting density by converting the potential fluctuation off a power supply layer with respect to a ground layer which occurs on switching an IC device etc., into Joule's heat in the substrate without using any parts as a countermeasure against the EMI. Its structure, a circuit board using it, and a method of manufacturing the circuit board are also disclosed. Parallel plate lines in which the Q-value of the stray capacitance between solid layers viewed from the power supply layer and ground layer is equivalently reduced and which are matchedly terminated by forming a structure in which a resistor (resistor layer) and another ground layer are provided in addition to the power supply layer and the ground layer on a multilayered circuit board. A closed shield structure is also disclosed. This invention can remarkably suppress unwanted radiation by absorbing the potential fluctuation (resonance) which occurs in a power supply loop by equivalently reducing the Q-value of the stray capacitance, absorbing the standing wave by the parallel plate lines matchedly terminated and, closing and shielding the parallel plate lines.

Low-EMI electronic apparatus, low-EMI circuit board, and method of manufacturing the low-EMI circuit board.

Ceramic circuit substrate which is sintered at 900 to 1,050.degree. C. and have low relative dielectric constant, thermal expansion coefficient comparable to that of silicon, and high bending strength, and a method of manufacturing are provided by using a glass with a softening point of 850 to 1,100.degree. C., that is, a glass having a composition included in an area in FIG. 1 (triangular composition diagram of SiO.sub.2 --B.sub.2 O.sub.3 --R.sub.2 O, a composition is represented by the position of a small circle, the number in a small circle represents the composition number) defined with lines connecting points representing the first, third, tenth, eleventh, and fourth compositions respectively as raw material.

Circuit substrate and manufacture thereof, ceramic composition for

Ceramic circuit substrate which is sintered at 900.degree. to 1,050.degree. C. and have low relative dielectric constant, thermal expansion coefficient comparable to that of silicon, and high bending strength, and a method of manufacturing are provided by using a glass with a softening point of 850.degree. to 1,100.degree. C., that is, a glass having a composition included in an area in FIG. 1 (triangular composition diagram of SiO.sub.2 --B.sub.2 O.sub.3 --R.sub.2 O, a composition is represented by the position of a small circle, the number in a small circle represents the composition number) defined with lines connecting points representing the first, third, tenth, eleventh, and fourth compositions respectively as raw material.

Circuit substrate and electronics computer, using sintered glass ceramics

According to this method for manufacturing a multilayer glass-ceramic circuit board, a green sheet laminate is fired in a non-oxidizing atmosphere in a first firing step so that a void content of at least 10% is maintained and strength of the ceramic laminate is increased. Then the laminate is fired in an oxidizing atmosphere in a second firing step so that the organic binder contained in the laminate is removed and the residual carbon content is at most 200 ppm. Thereafter the laminate is fired in a reducing atmosphere in a third firing step to reduce the oxidized conductor circuit. Finally, the laminate is fired in a non-oxidizing atmosphere in a fourth firing step to densify the ceramic laminate. The firing temperature in the first, second and third steps is 100.degree.-200.degree. C. lower than the softening point of the glass and the firing temperature in the fourth step is higher than the softening point of the glass and lower than the melting point of the conductor.

Method for manufacturing multilayer ceramic substrate

A substrate for a magnetic disc, which comprises a crystallized glass consisting essentially of an amorphous glass continuous phase and crystal particles dispersed in the continuous phase, the substrate having fine projections of the crystal particles on the surface thereof, a method of producing the substrate, the magnetic disc using the substrate, and a method of producing the magnetic disc are provided. The crystallized glass is made from a glass material of a Li.sub.2 O--SiO.sub.2, Li.sub.2 O--Al.sub.2 O.sub.3 --SiO.sub.2, Li.sub.2 O--MgO--Al.sub.2 O.sub.3 --SiO.sub.2, MgO--Al.sub.2 O.sub.3 --SiO.sub.2, Na.sub.2 O--Al.sub.2 O.sub.3 --SiO .sub.2 or BaO--Al.sub.2 O.sub.3 --SiO.sub.2 system, and the crystal particles have one or more compositions selected from Li.sub.2 O--SiO.sub.2, Li.sub.2 O.2SiO.sub.2, Li.sub.2 O.Al.sub.2 O.sub.3.2Si.sub.2, Li.sub.2 O.Al.sub.2 O.sub.3 4SiO.sub.2, SiO.sub.2 and 2MgO--2Al.sub.2 O.sub.3.5SiO.sub.2, and an average particle size of 0.01 to 3.0 .mu.m, and are projected at a density of 10.sup.2 to 10.sup.6 / mm.sup.2 and at an average height of 0.005 to 0.2 .mu.m on the surface of the substrate, the total surface area of the projections of crystal particles occupying at most 30% of the unit surface area of the substrate. The projections are made by chemical etching with an aqueous solution of hydrofluoric acid, physical etching with sputtering under vacuum or ion-milling, or mechanical etching with sand blasting. The magnetic disc comprises the crystallized glass substrate, a chromium or chromium alloy undercoat film, thin magnetic film, protective carbon film and lubricant film.

Magnetic disc substrate

A ceramic thin film hybrid circuit board is provided by flattening the surface of a ceramic multi-layer interconnection substrate, forming capture pads on the flattened surface, filling spaces between the capture pads with an insulating layer composed of a glass material or an organic resin material, grinding the resultant surface until the capture pads are exposed to flatness, and laminating a plurality of thin film interconnection layers on the flattened surface. The ceramic thin film hybrid circuit board has an increased package density of mounted electronic parts such as LSIs and the like because failures of thin film interconnection layer generated owing to the roughness of the surface of the ceramic substrate, defects such as voids and the hollows produced with the capture pads are greatly reduced, and is very suitable for large scale electronic computers, in which the wiring length is reduced so as to reduce the signal delay.

Thin film ceramic multilayer wiring hybrid board

A ceramic composition comprising 55-70 vol % of a borosilicate glass consisting of 65-88 wt % of SiO.sub.2, 5-25 wt % of B.sub.2 O.sub.3, 1-5 wt % of one or more of Li.sub.2 O, K.sub.2 O and Na.sub.2 O, and 0-5 wt % of Al.sub.2 O.sub.3, 5-30 vol % of alumina as filler, 5-35 vol % of cordierite and 0-20 vol % of quartz glass is provided for a ceramic circuit board for an electronic device such as an electronic computer.

Ceramic composition and ceramic circuit board

A substrate for a magnetic disc, which comprises a crystallized glass consisting essentially of an amorphous glass continuous phase and crystal particles dispersed in the continuous phase, the substrate having fine projections of the crystal particles on the surface thereof, a method of producing the substrate, the magnetic disc using the substrate, and a method of producing the magnetic disc are provided. The crystallized glass is made from a glass material of a Li.sub.2 O-SiO.sub.2, Li.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2, Li.sub.2 O-MgO-Al.sub.2 O.sub.3 -SiO.sub.2, MgO-Al.sub.2 O.sub.3 -SiO.sub.2, Na.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 or BaO-Al.sub.2 O.sub.3 -SiO.sub.2 system, and the crystal particles have one or more compositions selected from Li.sub.2 O.multidot.SiO.sub.2, Li.sub.2 O.multidot.2SiO.sub.2, Li.sub.2 O.multidot.Al.sub.2 O.sub.3 .multidot.2SiO.sub.2, Li.sub.2 O.multidot.Al.sub.2 O.sub.3 .multidot.4SiO.sub.2, SiO.sub.2 and 2MgO.multidot.2Al.sub.2 O.sub.3 .multidot.5SiO.sub.2, and an average particle size of 0.01 to 3.0 .mu.m, and are projected at a density of 10.sup.2 to 10.sup.6 /mm.sup.2 and at an average height of 0.005 to 0.2 .mu.m on the surface of the substrate, the total surface area of the projections of crystal particles occupying at most 30% of the unit surface area of the substrate. The projections are made by chemical etching with an aqueous solution of hydrofluoric acid, physical etching with sputtering under vacuum or ion-milling, or mechanical etching with sand blasting. The magnetic disc comprises the crystallized glass substrate, a chromium or chromium alloy undercoat film, thin magnetic film, protective carbon film and lubricant film.

Magnetic disc comprising a substrate of an amorphous glass continuous

An optical switch having a small number of optical connections includes a substrate in which are provided a first light path for conducting optical signals and a second light path consisting of a photosensitive element and light emitting element in pairs. An optical fiber cable is interrupted by the substrate, and optical signals in the fiber cable are transmitted through the first light path or intervened by an electrical system through the second light path in response to the switching movement of the substrate.

Optical switch

A method for manufacturing the insulating layers of a glass multilayer wiring board from a mixture of (1) 30-90 wt. % of a borosilicate glass consisting of 55-75 wt. % of SiO.sub.2, 13-25 wt. % of B.sub.2 O.sub.3, 5-13 wt. % of Al.sub.2 O.sub.3, each 1-5 wt. % of PbO, MgO, and BaO, and each 1-2 wt. % of Na.sub.2 O and K.sub.2 O and (2) 70-10 wt. % of a silica glass, is provided.

Glass multilayer wiring board and method for its manufacture

A dew sensor of direct current type and resistance-lowering type with increasing humidity for quick and sharp detection of dewing is provided, which comprises a pair of counterposed electrodes, humidity-sensitive layer of insulating porous metal oxide with a porosity of 20 to 60% provided on and between the counterposed electrodes, and an organic polymer coating layer having a thickness of 0.05 to 2 .mu.m provided on the humidity-sensitive layer.

Dew sensor

A porcelain composition comprising Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3, PbTiO.sub.3 and Pb(Yb.sub.1/2 Nb.sub.1/2)O.sub.3 preferably within the range as defined by closed area of A-B-C-D-A in the accompanying triangular diagram can give a sintered product by sintering at a temperature as low as 1000.degree. C. or lower. The resulting sintered product has a high relative dielectric constant and a small dielectric loss tangent.

Low temperature sintering porcelain composition

A low temperature-sinterable dielectric composition is provided, whose sintered composition when prepared by firing a uniform mixture consisting of lead ferrotungstate, lead titanate and manganese dioxide at a temperature of not higher than 1,000.degree. C. has the general formula A.Pb(Fe.sub.2/3 W.sub.1/3).sub.1-x Ti.sub.x O.sub.3 +B.MnO.sub.2, wherein 0.005.ltoreq..times..ltoreq.0.65, A=0.95-0.9995, and B=0.0005-0.05, a relative dielectric constant of at least 2,000 at 25.degree. C., a dissipation factor (tan .delta.) of not more than 5% at 25.degree. C., and a specific resistance of at least 10.sup.9 .OMEGA..cm at 25.degree. C. Also provided is a thick film capacitor having a dielectric layer prepared from said composition.

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Yokohama, Japan

Hirayoshi Tanei