KOA Corporation | Date: 2015-03-11
Provided are: a chip resistor whose resistance value can be adjusted with high accuracy while maintaining high sulfurization resistance of electrodes of the chip resistor even in the case where the resistance value of the chip resistor is low; and a method for manufacturing this chip resistor. This chip resistor (1) includes: an insulating film that covers a resistor substance (4) formed so as to make contact with both of a pair of electrodes (3, 3) formed on an upper surface (2A) of an insulating substrate (2). Each of the pair of electrodes (3, 3) includes: (1) a main electrode layer (3B) that contains silver as a main metal component and 10 weight % or more of palladium as another metal component, and an auxiliary electrode layer (3A) that is lower in specific resistance than the main electrode layer (3B); (2) a laminate part where the auxiliary electrode layer (3A) and the main electrode layer (3B) are sequentially laminated in this order on a single surface of the insulating substrate (2); and (3) an exposed part (3A1) of the auxiliary electrode layer (3A) where a part of the auxiliary electrode layer (3A) is not covered with the main electrode layer (3B) on a far side from the resistor substance (4), and parts (3B1) that extend from a near side to the far side with respect to the resistor substance (4).
Koa Corporation | Date: 2015-04-06
In a metal plate resistor, the bonded surface between the resistance body and the electrode can be prevented from peeling off. The metal plate resistor comprises a resistance body; an electrode consisting of metal material having a higher conductivity than the resistance body, and the electrode bonded with the resistance body; a recessed portion formed in an end face of the electrode on a side bonded with the resistance body; and a fixation hole formed in the electrode for inserting a bolt; wherein an end portion of the resistance body is fitted into the recessed portion in the electrode. The recessed portion is provided with wall portions on both sides in a width direction of the resistance body, and in a direction substantially perpendicular to a penetration direction of the fixation hole. The recessed portion is opened to an end face and a first surface of the electrode.
Koa Corporation | Date: 2015-06-08
Provided is a current detection resistor, which has a jumper function and a low resistance resistor function at the same time. The resistor is a metal plate resistor, which comprises a resistor body consisting of a metal material and a pair of electrodes consisting of a metal material having higher conductivity than the resistor body, wherein the resistor body is bonded between the electrodes. The pair of electrodes comprises a first electrode and a second electrode longer than the first electrode, wherein a slit is formed in the second electrode so that a portion of the second electrode becomes a terminal for voltage detection. The end of the slit does not reach the resistor body. The first electrode and the second electrode are respectively provided with mounting portions connecting to wiring patterns, and the resistor body is formed in the vicinity of the mounting portion of the first electrode.
Koa Corporation | Date: 2015-05-01
Provided is a metal plate resistor, which is able to be manufactured easily, and which has heat dissipation characteristics with a small variation, while maintaining small and compact structure. The resistor includes a resistance body (11) consisting of a metal material, a terminal portion (12) electrically conducting to the resistance body, a mold body (20) for covering the resistance body, a guide member (16A) formed on a portion on a surface of the resistance body except a central portion thereof, and a heat equalizing plate (14) disposed on the guide member and adhered at least to a central portion of the resistance body by an adhesive for absorbing heat generated in the resistance body. The guide member (16A) is preferably formed by pre-molding and disposed on a mount surface side of the resistance body. The heat equalizing plate (14) preferably overwraps on the terminal portions (12).
Koa Corporation | Date: 2015-06-15
Provided is a chip type fuse excellent in resistance to climatic condition, where the fuse is able to operate stably under high temperature and high humidity environments. The fuse includes an insulative substrate; an under-glass layer formed on the insulative substrate; a fuse element formed on the under-glass layer; a pair of electrodes formed at both end sides of the fuse element; and an over-glass layer covering at least a fusing section of the fuse element; wherein the fuse element includes a layer where a first metal layer and a second metal layer are piled up, and a barrier layer consisting of a third metal layer, which covers the first metal layer and the second metal layer with width that is wider than the width of the first metal layer and the second metal layer. The third metal layer overwraps the second metal layer intervening and the first metal layer.
Koa Corporation | Date: 2016-04-20
Provided is a current detection device, which is capable of measuring a large current with a high degree of accuracy and reliability. The current detection device comprises a first wiring member consisting of a highly conductive material, a second wiring member consisting of a highly conductive material, and a resistance body consisting of a metal material having a smaller temperature coefficient of resistance than the highly conductive materials used in the wiring members. The first wiring member and the second wiring member are welded to the resistance body, and the second wiring member is longer than the first wiring member. The second wiring member has a plurality of bent portions. The plurality of bent portions includes portions bent to horizontal direction and portions bent to vertical direction. Voltage detection terminals are formed in the vicinity of the resistance body on the first and second wiring members.
Koa Corporation | Date: 2015-01-30
To provide a shunt resistor and a current detection device including the shunt resistor, to which a busbar, a board, and the like can be easily fixed with sufficient strength wherein only minimum processing of electrodes is required. Screwing members (bolt (14) and nut (15)) that are separate members from electrodes (12) of the resistor (10), are fixed on the electrodes (12). The current detection device includes the shunt resistor (10), which has at least a pair of electrodes (12). One screwing member (14) fixed beforehand on at least one electrode (12) is screw fastened with the other screwing member (15) while disposing a prescribed intervening member (20) between the one screwing member and the other screwing member. Here, the prescribed intervening member (20) includes a board mounting a current detection circuit thereon and/or busbars.
Koa Corporation | Date: 2014-11-19
A method for manufacturing a chip resistive element including a substrate, a resistor formed on the substrate, and electrodes connected to opposite ends of the resistor, the method including an electrode forming step of forming the electrodes on the substrate. The electrode forming step includes a step of forming a first electrode layer on the substrate using a first electrode material containing silver, and a step of forming a second electrode layer on the first electrode layer using a second electrode material containing silver and palladium. The first electrode material has a higher silver content than the second electrode material.
KOA Corporation | Date: 2015-10-23
There is provided a resistor in which a first resistive part of a resistive element that electrically conducts between a pair of electrodes formed on either end of an insulating substrate has a meandering pattern meandering on the substrate surface and a swelling pattern that has a form in which a part of the meandering pattern swells out from the stroke width of the meandering pattern, a second resistive part that is electrically connected in series to the first resistive part is shorter than the entire length of the first resistive part, and has a wider width than the stroke width of the meandering pattern, and a trimming groove is formed in at least either the swelling pattern or the second resistive part. This can improve resistance accuracy and provide a high voltage resistor with high withstand voltage property.
Koa Corporation | Date: 2016-07-01
Provided is a thin-film resistor that has a higher resistance value than the conventional thin-film resistors while retaining excellent TCR characteristics. The thin-film resistor includes a substrate, a pair of electrodes formed on the substrate, and a resistive film connected to the pair of electrodes. The resistive film includes a first resistive film and a second resistive film, the second resistive film having a different TCR from that of the first resistive film, and each of the first resistive film and the second resistive film contains Si, Cr, and N as the main components.