Ngk Insulators, Inc.

Tatsuya Terazawa

Yoshimasa Kondo

Takao Saito

Naoya Takase

Shoji Yokoi

Takayuki Sakurai

Yuji Watanabe

Wataru Shionoya

Yasuharu Kuno

Sozaburo Hotta

Naoyuki Shimada

An ozone generator includes one or more electrode pairs each containing two electrodes arranged at a distance of a predetermined gap length and a power source for applying an alternating-current voltage between the two electrodes. In the ozone generator, ozone is produced when a source gas flows at least between the two electrodes and a discharge is generated between the two electrodes. The ozone generator has a discharge space formed between the two electrodes, and the ozone generator satisfies the condition of 0.5&#x3c;V/f/L wherein V (m/s) represents a flow velocity of the source gas flowing through the discharge space, f (Hz) represents a frequency of the alternating-current voltage, and L (m) represents a length of the discharge space in the main flow direction of the source gas.

Method for generating ozone

An ozone generator includes a housing having an internal cavity and a plurality of electrode pairs located in the internal cavity. The electrode pairs each contain two electrodes arranged at a distance of a predetermined gap length, and a discharge space is formed between the two electrodes, whereby ozone is produced when a source gas flows at least between the two electrodes and a discharge is generated between the two electrodes. The ozone generator has a non-discharge portion in an arbitrary cross-section having a normal direction parallel to a main flow direction of the source gas in the internal cavity.

Ozone generator

A distance from a negative output terminal of a secondary winding of the transformer to a feeding terminal of the cathode plate is longer than a distance from a positive output terminal of the secondary winding to a feeding terminal of the anode. The anode side feeding path electrically connects the feeding terminal of the anode bar to the positive output terminal of the secondary winding. The cathode side feeding path electrically connects the feeding terminal of the cathode plate to the negative output terminal of the secondary winding. A path length of the cathode side feeding path is longer than a path length of the anode side feeding path. The housing is formed by an electric conductor and is electrically connected to the cathode side feeding path.

Reactor structure and plasma treatment apparatus

A DC source generates a DC voltage between a positive electrode and a negative electrode. An inductive element and a parallel-connected switch-circuits unit are provided in a conductive path extending from the positive electrode to the negative electrode. The parallel-connected switch-circuits unit includes a plurality of switch circuits connected in parallel with one another. The switch circuit opens and closes the conductive path in accordance with a drive signal inputted from a drive circuit. The drive signal causes the plurality of switch circuits to successively perform an ON operation in which the conductive path is closed and then opened. A pulse voltage generation period in which a pulse voltage occurs in the inductive element continuously follows an ON period which is a duration from when the conductive path is closed to when the conductive path is opened.

Pulse generation circuit

A semiconductor switching device having a switch circuit is disposed in an environment having a relatively low temperature, with a transformer disposed in an environment having a relatively high temperature. A conduction path extends from a first DC input terminal to a second DC input terminal. An inductor is inserted in a section from a first branch to a second branch in the conduction path, and the switch circuit is inserted in a portion other than the section of the conduction path. A first transmission wire of a transmission line electrically connects the first branch and a first input terminal of a primary winding to each other. A second transmission wire of the transmission line electrically connects the second branch and a second input terminal of the primary winding to each other, and where the excitation inductance of the primary winding is higher than the excitation inductance of the inductor.

Pulse generator and method of disposing pulse generator

An amorphous carbon film forming apparatus includes a supporting electrode that is connected to ground and supports a substrate, a counter electrode that is disposed so as to face the supporting electrode and has a mixed-gas injection orifice, a chamber containing the supporting electrode and the counter electrode, and a DC pulse generator having a pulse source that applies a DC pulse voltage between the supporting electrode and the counter electrode. An amorphous carbon film is formed by supplying a mixed gas between the supporting electrode and the counter electrode such that the percentage of the acetylene gas relative to the carrier gas is 0.05% by volume or more and 10% by volume or less, and by generating plasma while a DC pulse voltage having a pulse width of 0.1 &#x3bc;sec or more and 5.0 &#x3bc;sec or less is applied to the counter electrode.

Method for forming amorphous carbon film

A direct current pulse voltage is applied on a treatment gas to generate a discharge plasma. The duty ratio of the direct current pulse voltage is controlled within the range of 0.0001% or more and 8.0% or less. The rise time of the direct current pulse voltage is controlled in the range of not lower than 0.1 V/nsec and not higher than 10000 V/nsec. Alternatively, a positive pulse and a negative pulse are applied from a single power source for performing the discharge plasma and the impurity implantation.

Methods of generating plasma, of etching an organic material film, of generating minus ions, of oxidation and nitriding

A pulse voltage is applied on a process gas to generate discharge plasma. The pulse voltage has a duty ratio controlled in a range of 0.001 percent or more and 8.0 percent or less. Preferably, the discharge plasma has an electron density of 1&#xd7;10cmor larger and an electron temperature of 1.5 eV or lower at a supplied power of 1.0 W/cmor more per a unit area of a discharge electrode.

Method of generating discharge plasma

A pulse power source comprises a first circuit, a second circuit, a transformer for coupling the first circuit and the second circuit, and a switching controller. The second circuit comprises a third semiconductor switch connected in series with a secondary winding of the transformer. The third semiconductor switch is connected in such a direction that a voltage generated in the second circuit is reverse-biased during a period in which the second semiconductor switch is turned on. A gate amplifier for forming a control signal from the switching controller into a pulse and outputting the pulse as a pulse signal is connected between a gate terminal and a cathode terminal of the third semiconductor switch.

High voltage pulse power circuit

A method for drying a honeycomb formed body using microwaves is provided. The method can reduce the difference in the drying speed inside the honeycomb formed bodies during the drying process and can dry the honeycomb formed bodies without cell deformation. The method comprises placing the honeycomb formed body in a drying furnace with the cell axis in the vertical direction and irradiating the honeycomb with microwaves at a frequency of 300&#x2013;30,000 MHz. The difference of the water content in the vertical direction of the honeycomb formed bodyis maintained at 0.3% per mm or less during microwave irradiation.

Growing community of inventors

Kasugai, Japan

Tatsuya Terazawa