JPH0515405U - Stacked Chip Thermistor - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a highly accurate and uniform multilayer chip thermistor that can control the initial resistance value of the chip thermistor without changing the material composition and shape of the chip thermistor element. The purpose is to [Structure] Ceramic laminated body 5 of chip thermistor element
External electrodes 7a and 7b are formed on both ends of a and 5b, and an internal electrode 6a formed to be connected to one external electrode 7a and an external electrode 7b on the other side are connected to one laminated surface of the ceramic laminated body. The internal electrodes 6b formed on one stacked surface are opposed to each other without overlapping. In the above structure, the initial resistance value of the chip thermistor can be controlled by changing the distance L between the internal electrodes 6a and 6b or the number of stacked layers. Further, since the electrodes are composed of the internal electrodes 6a and 6b, the external electrode 7a , 7b can be maintained without causing electrode melting or dropping of the element body, and the initial resistance value of the chip thermistor can be made highly accurate and uniform.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a laminated chip thermistor used as a temperature sensor in various consumer devices and the like.

[0002]

[Prior Art]

 In the conventional chip thermistor, as shown in FIG. 6, end electrodes 2a and 2b are formed so as to cover the outer peripheries at both ends of a rectangular parallelepiped ceramic element body 1 with Ag-Pd alloy or the like. ..

The initial resistance value of the chip thermistor is determined by the composition, shape dimension (volume), or inter-electrode distance of the ceramic body 1. However, as shown in FIG. 6, when an Ag-Pd alloy is used for the end electrodes, when the electrodes are uniformly applied and formed on the entire surface of the ceramic body, the shape effect affects the accuracy of the inter-electrode distance L1. As a result, the accuracy of the initial resistance value of the chip thermistor also decreases.

Further, FIG. 7 shows a case where the end electrodes 4a and 4b are formed by plating electrodes of Cu, Ni, Sn-Pb or the like on the outer peripheries of both ends of the ceramic body 3, but as shown in FIG. The base material may melt during the reaction to cause a dropout phenomenon of the base body, and the substantial inter-electrode distance L2 changes, leading to non-uniform initial resistance.

[0005]

[Problems to be solved by the device]

 As described above, in the conventional chip thermistor, it is difficult to keep the distance between the electrodes constant at the stage of forming the electrodes, and therefore, there is a problem that the accuracy of the initial resistance value of the chip thermistor element deteriorates and becomes nonuniform. is there.

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a multilayer chip thermistor having high accuracy and a uniform initial resistance value.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an external electrode formed at both ends of a ceramic laminate, and an internal electrode formed to be connected to one external electrode on one laminated surface of the ceramic laminate. The respective tip portions of the internal electrodes formed on one laminated surface connected to the other external electrode are opposed to each other with a gap maintained therebetween without overlapping.

[0008]

[Action]

 According to the chip thermistor having the above-mentioned configuration, the ceramic element bodies are formed in a laminated shape, and the electrodes are connected to the laminated surfaces 1 and 2 respectively to the end electrodes provided at both ends of the ceramic element body. By doing so, it is possible to maintain a stable distance between the electrodes without the influence of the shape effect during electrode formation and the phenomenon of the element falling off, and to improve the accuracy and uniformity of the initial resistance of the chip thermistor. Can be promoted.

[0009]

【Example】

 Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a cross section of a chip thermistor according to a first embodiment of the present invention, in which two thin plate-shaped ceramic bodies 5a and 5b are superposed and formed in a laminated shape. As shown in FIG. 2, the two ceramic elements 5a and 5b have two ceramic layers on which the internal electrodes 6a and 6b are respectively formed on the back surface of the upper layer and the surface of the lower layer by vapor deposition, sputtering, thick film printing or the like. The internal electrodes are thermocompression-bonded on the same plane so as to be opposed to each other with a space therebetween, and external electrodes 7a and 7b are formed on the outer circumferences of both ends of the ceramic body 5. Here, the distance L between the internal electrodes and the shortest distance L0 of the external electrodes are formed so that L <L0, and the shortest distance L0 of the external electrodes and the longitudinal dimension W of the ceramic element body are substantially equal to each other. ..

4 and 5 show a cross section of a chip thermistor and a manufacturing method thereof in the second embodiment of the present invention. Of the three thin plate-shaped ceramic bodies 8a, 8b, 8c, internal electrodes 9a, 9b are formed on the upper surfaces of the ceramic bodies 8a, 8b so as to face each other with a space therebetween. Then, after the ceramic bodies 8a, 8b, 8c are thermocompression bonded, external electrodes 10a, 10b are formed on the outer circumferences of both ends thereof.

In the case of the multilayer chip thermistor configured as in the first embodiment, as shown in FIG. 3, its initial resistance value increases or decreases in proportion to the interelectrode distance L. Therefore, when the internal electrodes are formed, the interelectrode distance L can be variably set by controlling the internal electrode dimensions L3 and L4 in the longitudinal direction of the multilayer chip thermistor. Therefore, the initial resistance value as the chip thermistor element can be set. It is possible to control without changing the material composition and shape.

Further, in the case of the configuration of the second embodiment, since the internal electrodes are formed with steps, the inter-electrode distance L becomes slightly longer than that of the chip thermistor of the first embodiment, and accordingly, The initial resistance value also increases slightly. That is, the initial resistance value can be delicately controlled by changing the number of stacked chip thermistors so that the steps are formed between the electrodes.

Furthermore, since the electrodes are composed of internal electrodes due to the laminated structure, the initial resistance value of the chip thermistor element is unaffected even if the substrate is melted or the element body is dropped when the external electrodes are formed. I will not receive it.

As described above, the chip thermistor has a laminated structure, and the initial resistance value of the chip thermistor element can be controlled by changing the size or the number of laminated internal electrodes.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

[0017]

[Effect of the device]

 According to the present invention described in detail above, it is possible to control the initial resistance value as a chip thermistor element by changing the size or the number of stacked internal electrodes of the chip thermistor having a laminated structure, and further forming the external electrode. The initial resistance value of the chip thermistor element is not affected by the dissolution or dropping of the base material at any given time.Therefore, a multilayer chip thermistor with high accuracy and uniform initial resistance value is provided. be able to.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a multilayer chip thermistor of the present invention.

FIG. 2 is a view for explaining the manufacturing method of the first embodiment of the multilayer chip thermistor of the present invention.

FIG. 3 is a graph showing the relationship between the interelectrode distance and the initial resistance value of the first embodiment of the multilayer chip thermistor of the present invention.

FIG. 4 is a sectional view showing a second embodiment of the multilayer chip thermistor of the present invention.

FIG. 5 is a view for explaining the manufacturing method of the second embodiment of the multilayer chip thermistor of the present invention.

FIG. 6 is a sectional view for explaining a first conventional example.

FIG. 7 is a sectional view for explaining a second conventional example.

[Explanation of symbols]

 5a, 5b Ceramic body 6a, 6b Internal electrode 7a, 7b External electrode

Claims (1)

[Scope of utility model registration request] 1. External electrodes are formed on both ends of a ceramic laminate, and an internal electrode formed so as to be connected to one external electrode and one external electrode are formed on one laminated surface of the ceramic laminate. A multilayer chip thermistor, characterized in that the respective tip portions of the internal electrodes formed on one laminated surface are opposed to each other with a space therebetween, without overlapping.