Murata Manufacturing Co., Ltd.

Murata Mfg. Co., Ltd.

Norimitsu Kitoh

Masahiko Kawase

Yukiko Ueda

Akira Kumada

Michihiro Murata

Hidenobu Kimoto

Ikuya Taniguchi

Ryoichi Urahara

Nobuhiro Itoh

A chip thermistor has a pair of outer electrodes opposite each other with a specified distance in between on one of the surfaces of a thermistor element and an inner electrode extending inside the thermistor element so as to overlap these outer electrodes in the direction perpendicular to the surface on which the outer electrodes are formed. An electrically insulating layer is preferably formed on the same surface as and between the pair of outer electrodes. Each of the outer electrodes may be formed with two or more layers, the outermost of the layers being of gold. The resistance value of such a chip thermistor can be adjusted by abrading at least a portion of the edges of the thermistor element together with portions of the outer electrodes.

Method of producing chip thermistors

A resistor element has a ceramic body with a first outer electrode and a second outer electrode formed on its mutually opposite externally facing end surfaces and a plurality of mutually oppositely facing pairs of inner electrodes inside the ceramic body. Each of these pairs has a first inner electrode extending horizontally from the first outer electrode and a second inner electrode extending horizontally from the second outer electrode towards the first outer electrode and having a front end opposite and separated from the first inner electrode by a gap of a specified width, these plurality of pairs forming layers in a vertical direction. The gap of at least one of these plurality of pairs of inner electrodes is horizontally displaced from but overlapping with the gaps between the other pairs of inner electrodes. For producing such a resistor element, the distance of displacement is set according to a given target resistance value intended to be had by the resistor element. Alternatively, the thickness of those portions of the ceramic body between at least one of mutually adjacent pairs of the inner electrodes is different from the thickness of the portions of the ceramic body between the other mutually adjacent pairs of the inner electrodes.

Thermister chips

The present invention is to provide a chip type electronic part without the risk of generating a tombstone at the time of soldering on a circuit substrate. External electrodes are formed at both end parts of an electronic part element, with the external electrodes comprising electrodes at the base layer formed as a thin film and solders at the outermost layer, with the solders at the outermost layer containing Sn and Pb as the main component and 0.1 to 0.4% by weight of Ag.

Chip type electronic part

Methods of producing resistor elements

A chip thermistor has a pair of outer electrodes opposite each other with a specified distance in between on one of the surfaces of a thermistor element and an inner electrode extending inside the thermistor element so as to overlap these outer electrodes in the direction perpendicular to the surface on which the outer electrodes are formed. An electrically insulating layer is preferably formed on the same surface as and between the pair of outer electrodes. Each of the outer electrodes may be formed with two or more layers, the outermost of the layers being of gold.

Chip thermistors

Resistor elements and methods of producing same

After a plurality of electronic devices such as thermistor elements are produced, each having electrodes formed on the surface of a ceramic body, they are separated into groups according to their measured resistance values. Those with resistance values smaller than a specified allowable range are repaired, having their electrodes abraded such that their resistance values are increased and brought into the specified allowable range.

Method of producing electronic devices with uniform resistance values

In order to increase the thermoelectromotive force delivery by a thermoelectric element as a whole or regulate the temperature coefficient of such thermoelectromotive force, n-type semiconductive ceramic members and p-type semiconductive ceramic members are assembled to form such element and are electrically connected with each other. The n-type and p-type semiconductive ceramic members are provided in the form of plate members, which are stacked so as to be interconnected by insulating layers and conductor layers. The insulating and conductor layers are provided on opposite surfaces of adjacent plate members by thick film printing and baking performed thereafter.

Thermoelectric element using semiconductive ceramic material

A charge completion detector comprises a thermoelectric detecting element outputting a thermally generated electromotive force in correspondence with the rise of temperature incidental to the completion of charging a secondary cell, and detecting means electrically connected to the thermoelectric detecting element for detecting the thermally generated electromotive force generated in the thermoelectric detecting element. The thermoelectric detecting element comprises a base material of semiconductive ceramics and a plurality of pairs of electrodes formed spaced apart from each other by a prescribed distance on the base material for forming hot junctions and cold junctions. A heat radiating member is thermally coupled to the cold junctions of the base material. The temperature of the hot junction side thermally coupled to the secondary cell will be approximately the same as that of the secondary cell while the temperature of the cold junction side is kept at an environmental temperature. The rise of temperature is detected based on the change of the thermally generated electromotive force based on the difference between the temperatures of the hot junctions and cold junctions.

Growing community of inventors

Shiga, Japan

Norimitsu Kitoh