Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Other

Toshiba Tungaloy Co., Ltd.

Motomasa Imai

Osamu Furukawa

Mitsuo Harata

Takashi Takahashi

Fumio Ueno

Koji Yamakawa

Kazuhide Abe

Hiroshi Toyoda

Hideyuki Kanai

Naoki Shutoh

Koji Sakui

Hiroshi Endo

Masaki Kobayashi

Iwao Mitsuishi

Takaaki Yasumoto

Akihiro Horiguchi

Mitsuo Kasori

Hisakazu Iizuka

Masaru Hayashi

Yoshiko Goto

Katsuyoshi Oh-Ishi

Hideyasu Andoh

Shoji Kozuka

Hideo Ohkuma

Naoki Shuto

Yoshiko Kohanawa

Yuji Katsumura

Toshiyuki Takahashi

Osamu Hirao

Kazuo Nishijima

Seiichi Yoshida

Disclosed is a power resistor which has a large heat capacity per unit volume and an appropriate and stable electrical resistance, and in which the resistance changes little with time due to surge absorption. This power resistor includes a sintered body containing aluminum oxide and carbon, and a pair of electrodes formed on the two opposing surfaces of the sintered body. This sintered body consists of first regions containing a small amount of carbon or not containing carbon and second regions containing a larger amount of carbon than in the first regions and so arranged as to be connected to the electrodes.

Power resistor, method of manufacturing the same, and power circuit

A non-volatile semiconductor memory device, includes a memory cell having a capacitor formed by stacking a semiconductor layer and a ferroelectric layer between a pair of electrodes, the semiconductor layer and the ferroelectric layer forming a semiconductor-ferroelectric junction, a writing circuit in which a voltage higher than a coercive electric field of the ferroelectric material is applied to the capacitor of the memory cell to align a polarization direction of the ferroelectric layer in a predetermined direction so as to set a capacitance of the capacitor at a predetermined value, thereby writing data corresponding to the predetermined value of the capacitance, and a reading circuit in which a voltage less than the coercive electric field of the ferroelectric layer is applied to the capacitor of the memory cell in which the data is written, thereby reading the data.

Non-volatile semiconductor memory device capable of electrically

A metal oxide resistor for suppressing variations in resistivity in use in an atmosphere at a high temperature or humidity. Such a metal oxide resistor includes a sintered body in which carbon particles having an average grain size of 1 .mu.m or less exist in the grain boundaries of metal oxide particles in an amount of 0.05 to 3 wt %, and electrodes formed on at least two opposing surfaces of the sintered body.

Metal oxide resistor, power resistor, and power circuit breaker

A semiconductor memory device comprises a plurality of memory cells arranged in the form of a matrix to constitute rows-and columns, a plurality of first driving lines, connected to the memory cells, for transmitting a first driving signal to the memory cells, one of the plurality of first driving lines being selected by a row address, a plurality of second driving lines, connected to the memory cells, for transmitting a second driving signal to the memory cells, one of the plurality of second driving lines being selected by a column address, a plurality of read/write lines, connected to the memory cells, for performing read/write operations with respect to the memory cells, and a plurality of sense amplifiers connected to the read/ write lines, wherein one of the plurality of sense amplifiers is selected by the column address, and the memory cells in the same column are connected to the same sense amplifier through the read/write lines.

Semiconductor memory device using ferroelectric capacitor and having

A compact power circuit breaker having a large breaking capacity and stable breaking performance by using a compact closing resistor unit having high performance. The power circuit breaker includes a main switch arranged in a current path, an auxiliary switch connected to the current path parallel with respect to the main switch and turned on prior to an ON state of the main switch, and a closing resistor unit connected in series with the auxiliary switch and incorporated with a resistor having a sintered body consisting of a Zn--Ti--Co--O--based oxide and having metal components consisting of titanium calculated as titanium oxide (TiO.sub.2) in an amount of 0.5 to 25 mol %, cobalt calculated as cobalt oxide (CoO) in an amount of 0.5 to 30 mol %, and Zn as substantially the balance.

Power circuit breaker and power resistor

A semiconductor memory device comprises a ferroelectric capacitor, a voltage output circuit for outputting a first voltage for reversely polarizing the ferroelectric capacitor and a second voltage by which the polarization of the ferroelectric capacitor is not reversed, regardless of data stored in the ferroelectric capacitor, a first reference capacitor having a such a capacitance as to accumulate less charge than charge which the ferroelectric capacitor accumulates, when the second voltage is applied to the ferroelectric capacitor, a second reference capacitor having such a capacitance that as to accumulate greater charge than the charge which the ferroelectric capacitor accumulates while the ferroelectric capacitor is forwardly polarized, when the first voltage is applied to the ferroelectric capacitor, thus reversely polarizing the ferroelectric capacitor, a sense amplifier connected to the ferroelectric capacitor and the first or second reference capacitor, a reference-capacitor selecting circuit for connecting the first reference capacitor to the sense amplifier when the voltage output circuit outputs the second voltage, and connecting the second reference capacitor to the sense amplifier while the voltage output circuit outputs the first voltage, and a circuit for determining data from the presence or absence of an electric charge in the ferroelectric capacitors while the memory is set in volatile mode, and for determining data from the direction in which the ferroelectric capacitor is polarized, while the memory is set in nonvolatile mode.

Memory having ferroelectric capacitors polarized in nonvolatile mode

According to this invention, there is disclosed a compact power circuit breaker having a large breaking capacity and stable breaking performance due to a compact closing resistor unit having high performance. The power circuit breaker includes a main switching mechanism having an arc extinguishing function, an auxiliary switching mechanism parallelly connected to the main switching mechanism and having an arc extinguishing function, and a closing resistor unit connected in series with the auxiliary switching mechanism and incorporated with a resistor containing zinc oxide (ZnO) as a main component and titanium figured out as titanium oxide (TiO.sub.2) in an amount of 0.5 to 25 mol% and nickel figured out as nickel oxide (NiO) in an amount of 0.5 to 30 mol. % as sub-components.

A resistor element includes a hollow cylindrical sintered body and a pair of electrodes formed on the upper and lower surfaces of the sintered body. The sintered body contains ferrite as a main constituent and contains 0.05 to 10% by volume of an insulator phase formed at the crystal grain boundary of the ferrite crystals. An insulating layer is formed to cover the side surface of the sintered body. The sintered body contains an oxide material selected from the group consisting of 0.005 to 2.0% by weight of bismuth oxide calculated in terms of Bi.sub.2 O.sub.3, 0.01 to 3.0% by weight and 0.005 to 2.0% by weight of silicon oxide and aluminum oxide calculated in terms of SiO.sub.2 and Al.sub.2 O.sub.3 respectively, and 0.01 to 3.5% by weight and 0.001 to 1.6% by weight of silicon oxide and calcium oxide calculated in terms of SiO.sub.2 and CaO, respectively.

Electrical resistor element and method of manufacturing the same

A ferroelectric capacitor includes a ferroelectric layer consisting of lead zirconate titanate formed on a silicon substrate, a plurality of rectangular trenches formed in the direction of thickness of the ferroelectric layer with a ferroelectric material therebetween, and first and second electrodes consisting of metal tungsten buried in the trenches to oppose each other with the ferroelectric material therebetween.

Ferroelectric capacitor and a semiconductor device having the same

When a portion of the Pb of a Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 -based ceramic composition within the region bounded by lines connecting a, b, c, d, e and f points in the ternary composition diagram of the accompanying FIG. 1 is substituted by a small amount of Ca, a high dielectric constant type ceramic composition is obtained which has a small temperature coefficient of dielectric constant and which is effective as a material for multilayer ceramic capacitors.

High dielectric constant type ceramic composition

To obtain a ceramic material having a high dielectric constant (K=2300 to 7000), a high insulation resistance (CR=4000 to 18000 ohmF), a low temperature dependence (.+-.10%) to (.+-.22, -33%) upon dielectric constant over a wide temperature range (-55 and +125.degree. C.) and a relatively low sintering temperature (1000.degree. C. to 1250.degree. C.), BaTiO.sub.3 powder at least 50 wt % of which is 0.7 to 3 .mu.m in particle size) is mixed with another compound with perovskite structure mainly composed of oxides of Pb, Ba, Sr, Zn, Nb, Mg and Ti before sintering. Further, part of Ti of BaTiO.sub.3 is substitutable with Zr or Sn, and part of Ba of BaTiO.sub.3 is substitutable with Sr, Ca or Ce.

High dielectric constant ceramic material and method of manufacturing

A method is disclosed which manufactures a recording head adapted to be moved relative to a recording medium, which is comprised of a conductive substrate and dielectric layer formed on the conductive substrate, to permit data to be recorded on the recording medium with the use of a conductive/magnetic toner on the recording medium. A conductive/magnetic sheet is attached to an insulating substrate of a first size with an adhesive layer therebetween, the first size of the insulating substrate is greater than a second size thereof defined by an insulating substrate of a finally completed recording head. The conductive/magnetic sheet is selectively etched to form an array of slits at a predetermined interval with both ends of the slits located beyond the side edges of an insulating substrate of a finally completed recording head. At one side edge portion of the conductive/magnetic sheet the conductive/magnetic sheet is electroplated to form a plated layer for a bonding pad. Those areas of the conductive/magnetic sheet, plated layer and insulating substrate, which are located beyond the side edge of the insulating substrate of the finally completed recording head, are cut to form a parallel array of electrodes and a bonding pad on one side edge portion of the conductive/magnetic electrodes.

Magnetic recording head and method for manufacturing

A metal oxide varistor is disclosed which a component of grain bodies comprised of zinc oxide and a component of grain boundary layers comprised of another metallic oxide, containing metal other than zinc wherein at least a portion of these starting materials comprised a fine particle powder prepared by a co-precipitatin method. The metal oxide varistor of the present invention is excellent in varistor characteristics such as non-linearity to voltage, life performances and capability of energy dissipation, is small in a scatter of the above characteristics between manufacture lots or within each lot at the time of manufacture, and has a good quality stability. Unexpected results are obtained when the co-precipitated fine particles are subjected to a refrigeration-dehydration type process.

Metal oxide varistor made by a co-precipation process and freeze-dried

A varistor having good voltage-current nonlinear characteristics and a long life performance. The varistor is formed of a sintered body consisting essentially of zinc oxide as a major component, 0.1 to 5 mol % of bismuth in terms of Bi.sub.2 O.sub.3, 0.1 to 5 mol % of cobalt in terms of Co.sub.2 O.sub.3, 0.1 to 5 mol % of manganese in terms of MnO, 0.1 to 5 mol % of antimony in terms of Sb.sub.2 O.sub.3, 0.1 to 5 mol % of nickel in terms of NiO, and 0.001 to 0.05 mol % of aluminum in terms of Al.sup.3+.

Varistor includes oxides of bismuth, cobalt, manganese, antimony, nickel

A varistor comprising a basic component consisting essentially of ZnO as a principal constituent and, as auxiliary components, bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb) and nickel (Ni) in an amount, when calculated in terms of Bi.sub.2 O.sub.3, Co.sub.2 O.sub.3, MnO, Sb.sub.2 O.sub.3 and NiO, respectively, of Bi.sub.2 O.sub.3 : 0.1 to 5 mol %, Co.sub.2 O.sub.3 : 0.1 to 5 mol %, MnO: 0.1 to 5 mol %, Sb.sup.2 O.sub.3 : 0.1 to 5 mol % and NiO: 0.1 to 5 mol %; and an additional constituent comprising boron (B) in an amount, when calculated in terms of B.sub.2 O.sub.3, of 0.001 to 1 wt % based on said basic component, the Bi.sub.2 O.sub.3 of the sintered body comprising not less than 30% of .alpha.-phase . In another embodiment, the above basic component may further comprise at least one of Al, In and Ga in a prescribed amount and the above additional component may be (i) B with or without at least one of Ag and Si in a prescribed amount or (ii) a glass containing B in a prescribed amount.

Growing community of inventors

Tokyo, Japan

Motomasa Imai