Tdk Corporation

Naoyoshi Yoshida

Yusuke Imai

Masayuki Uchida

Takeshi Yanata

Takeshi Oyanagi

Hitoshi Tanaka

Dai Matsuoka

Satoshi Goto

Takahiro Itami

Masato Hayatsu

Daiki Suzuki

Shin Kagaya

Kaname Ueda

Shunsuke Takahashi

Sota Hiraba

Katsunari Moriai

Yoshihiro Shinkai

Kouki Yamada

Kazuto Takeya

Koki Yamada

Hisashi Aiba

Kazuaki Kajiwara

Hiroya Nakamura

A transient voltage protection device comprises a pair of discharge electrodes opposing each other with a gap therebetween and a discharge inducing portion in contact with the pair of discharge electrodes. The discharge inducing portion comprises a ceramic component, metal particles, and pores discontinuously scattered. The pores have an average size of 0.05 μm or more and 1.04 μm or less.

Transient voltage protection device

A transient voltage protection device includes an element body formed with a cavity inside, a pair of external electrodes on the element body, and a pair of internal electrodes in the element body. The pair of internal electrodes oppose each other. Each internal electrode is connected to a corresponding external electrode of the pair of external electrodes. The element body includes a first inner surface and a second inner surface. The first and second inner surfaces define the cavity and oppose each other. The pair of internal electrodes are exposed to the cavity and disposed on the first inner surface. In a cross section along a direction in which the first inner surface and the second inner surface oppose each other, the first inner surface includes a contour different from a contour included in the second inner surface.

A transient voltage protection device includes: an element body; a cavity portion provided in the element body; a pair of internal electrodes disposed in the element body; and a pair of external electrodes connected to the pair of internal electrodes. The pair of internal electrodes extend along a first direction and face each other in a second direction intersecting the first direction. The cavity portion includes a gap region located between the pair of internal electrodes in the second direction. A tip portion of at least one of the pair of internal electrodes is in contact with only the element body.

A chip varistor includes an element body exhibiting varistor characteristics, internal electrodes containing a first electrically conductive material, and an intermediate conductor containing a second electrically conductive material. The intermediate conductor is separated from the internal electrodes in a direction in which the internal electrodes oppose each other, and is disposed between the internal electrodes. At least a part of the intermediate conductor overlaps the internal electrodes in the direction in which the internal electrodes oppose each other. The element body includes a low resistance region in which the second electrically conductive material is diffused. The low resistance region is located between the first and second internal electrodes in the direction in which the first and second internal electrodes oppose each other.

Method for producing chip varistor and chip varistor

A multilayer chip varistor includes an element body, first and second external electrodes, and first and second electrical conductor groups. The first electrical conductor group includes a first internal electrode connected to the first external electrode, and a first intermediate electrical conductor opposed to the first internal electrode. The second electrical conductor group includes a second internal electrode including a first electrically conductive material and connected to the second external electrode, and a second intermediate electrical conductor opposed to the second internal electrode. At least one of the first and second intermediate electrical conductors includes the second electrically conductive material. The element body includes a low electrical resistance region between the first and second internal electrodes. The second electrically conductive material is diffused in the low electrical resistance region.

Multilayer chip varistor

An electronic component includes an element body, a thin film layer disposed to cover a pair of end surfaces and four side surfaces, a first external electrode and a second external electrode, and internal conductors, wherein each of the first external electrode and the second external electrode has first electrode layers disposed on the thin film layer and electrically connected to the internal conductors, and second electrode layers disposed to cover the first electrode layers, and a thermal conductivity of the second electrode layers is lower than a thermal conductivity of the first electrode layers.

Electronic component

A voltage nonlinear resistor ceramic comprises: a Zn oxide; a Co oxide; an R (specific rare earth) oxide; a Cr oxide; an M1 (Ca, Sr) oxide; an M2 (Al, Ga, In) oxide; and strontium titanate. When content of the Zn oxide is assumed to be 100 mole portion in terms of Zn, content of the Co oxide is 0.30 to 10 mole portion in terms of Co, content of the R oxide is 0.10 to 10 mole portion in terms of R, content of the Cr oxide is 0.01 to 2 mole portion in terms of Cr, content of the M1 oxide is 0.10 to 5 mole portion in terms of M1, content of the M2 oxide is 0.0005 to 5 mole portion in terms of M2, and content of the strontium titanate is 0.10 to 5 mole portion in terms of SrTiO.

Voltage nonlinear resistor ceramic and electronic component

An element body has first and second faces opposed to each other. A first conductor has one end exposed in a first face and the other end located in the element body. The second conductor has one end exposed in a second face and the other end located in the element body. The element body has a first element body section having the nonlinear voltage-current characteristics and a second element body section in which an electric current is more likely to flow than in the first element body section. The first element body section is located at least in part between the first conductor and the second conductor, in a direction in which the first conductor and the second conductor are separated from each other. The other end of the first conductor and the other end of the second conductor are located in the second element body section.

Chip varistor

A voltage nonlinear resistor ceramic composition comprises zinc oxide, with respect to 100 mol of said zinc oxide, 0.30 to 10 mol of Co oxide in terms of Co, 0.10 to 10 mol of R oxide (note that R is at least one selected from a group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) in terms of R, 0.10 to 5 mol of Cr oxide in terms of Cr, 0.10 to 5 mol of oxide of at least one selected from Ca and Sr respectively in terms of Ca or Sr, 0.0005 to 5 mol of oxide of at least one selected from Al, Ga and In respectively in terms of Al, Ga or In, and 0.10 to 5 mol of barium titanate in terms of BaTiO.

Voltage nonlinear resistor ceramic composition and electronic component

In a varistor element, Ca exists in the grain interior of grains consisting primarily of ZnO in a varistor element body and Ca also exists in a grain boundary. In this crystal structure Ca replaces oxygen defects in the grain interior of grains consisting primarily of ZnO, in the varistor element body to make the ceramic structure denser Such crystal structure also decreases a ratio of an element tending to degrade the stability of the temperature characteristic of the varistor element, e.g., Si as a firing aid, in the grain boundary between grains. As a result, the varistor element has a stable temperature characteristic, which can decrease change in capacitance and tan &#x3b4; (thermal conversion factor of resistance) against change in temperature.

Varistor element

As for the voltage non-linear resistance element layer, sintered body (ceramics) having ZnO as main component is used. Said sintered body comprises Pr, Co, Ca and Na are added. Therefore, the ranges are 0.05 to 5.0 atm % of Pr, 0.1 to 20 atm % of Co, 0.01 to 5.0 atm % of Ca and 0.0001 to 0.0008 atm % of Na. When it is within the range, the capacitance changing rate at 85&#xb0; C. with standard being 25&#xb0; C. can be made to equal or less than 10%.

Voltage non-linear resistance ceramic composition and voltage non-linear resistance element

As for the voltage non-linear resistance element layera sintered body having ZnO as a main component is used. In this sintered body, Pr, Co, Ca, and either Cu or Ni are added. The ranges are; 0.05 to 5.0 atm % of Pr, 0.1 to 20 atm % of Co, 0.01 to 5.0 atm % of Ca, and 0.0005 to 0.05 atm % of either Cu or Ni. Within these ranges, the capacitance changing rate can be made to equal or less than 10 % at 85&#xb0; C. when 25&#xb0; C. is taken as standard.

Growing community of inventors

Tokyo, Japan

Naoyoshi Yoshida