JP2001332405A - Chip type resistance element and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip type resistance element which can easily realize an aimed resistance value range and can improve the fraction non-defective. SOLUTION: This chip type resistance element is constituted in such a way that pluralities of first and second internal electrodes 3a-3f and 4a-4f are formed in an elemental thermistor body 2 formed as an elemental resistor so that the electrodes 3a-3f and 4a-4f may be led out to the first and second end faces 2a and 2b of the elemental body 2. On at least one of the end faces 2a and 2b, an insulating layer 7 is formed to cover the exposed portion of at least one internal electrode 3a. The insulating layer 7 intercepts the electrical connection between the electrode 3a and an external electrode 5. Consequently, the resistance value of the chip type resistance element is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a chip-type resistance element such as a chip-type thermistor element, and more particularly, to a chip-type resistance element having an internal electrode formed in a resistor element.

[0002]

2. Description of the Related Art Conventionally, chip type thermistor elements have been widely used for temperature detection and temperature compensation. With respect to the chip-type resistance element, a multilayer thermistor element has been proposed in order to reduce the fluctuation of the resistance value due to the influence of the external environment.

FIG. 7 is a sectional view showing a conventional laminated chip thermistor element. Chip type thermistor element 5
1, a plurality of first internal electrodes 53a, 53b and a plurality of second internal electrodes 54a, 54b are provided in the thermistor body 52.
b is formed. The internal electrodes 53a and 53b are end faces 5
2a, and the internal electrodes 54a, 54b are extended to the end face 52b. First and second outer portions 55 and 56 are formed so as to cover the end surfaces 52a and 52b.

In the chip type thermistor element 51, the overall resistance is controlled by the resistance between the internal electrodes 53a and 53b and the internal electrodes 54a and 54b. Therefore, the influence of the external environment can be suppressed.

In the chip type thermistor element 51, the resistance value is controlled by the internal electrodes 53a, 53b, 54a, 54
b, the number of stacked layers, the size, and the first and second internal electrodes 53a, 5
This is performed by controlling a gap distance between the first internal electrode 3b and the second internal electrodes 54a and 54b.

[0006]

When the chip type thermistor element 51 is manufactured, a ceramic sintered body 52 is obtained by laminating the internal electrodes 53a to 54b and ceramics and firing them integrally. However, the ceramic sintered body 52 is actually obtained by firing, and
Is formed, even if the resistance value is controlled in consideration of various factors as described above, the resistance value varies and the resistance value tends to deviate from the target resistance value. Therefore, it has been difficult to increase the yield of the chip type thermistor element 51.

[0007] The above problem has been a problem not only in the chip type thermistor element 51 using a thermistor element but also in a multilayer resistance element in general. SUMMARY OF THE INVENTION An object of the present invention is to provide a chip-type resistor element capable of solving the above-mentioned drawbacks of the prior art, further improving the accuracy of the resistance value, and further increasing the non-defective rate, and a method of manufacturing the same.

[0008]

According to a first aspect of the present invention, there is provided a chip-type resistor element comprising: a resistor element having first and second outer surface portions; a resistor element formed in the resistor element; A plurality of first internal electrodes extended to an outer surface portion; a plurality of second internal electrodes formed in the resistor body and extended to the second outer surface portion; Of the first and second outer surface portions respectively formed
At least one of a second external electrode and at least one of first and second outer surface portions of the resistor element;
And an insulating layer that cuts off electrical connection between the two internal electrodes and the first or second external electrode.

In a specific aspect of the chip-type resistance element according to the present invention, the first and second outer surface portions are opposed to the first and second outer surface portions.
It is a second end face. In the chip-type resistance element according to the present invention, a thermistor element is preferably used as the resistance element, thereby forming a chip-type thermistor element.

A method of manufacturing a chip-type resistance element according to the present invention is directed to a method of manufacturing a chip-type resistance element. Providing a resistor element having a plurality of second internal electrodes drawn out to the outer surface of the resistor element; and at least one of the first and second outer surface portions of the resistor element. Forming an insulating layer so as to cover an exposed portion of the electrode; and forming first and second external electrodes on the first and second outer surface portions after forming the insulating layer. It is characterized by the following.

[0011] In a specific aspect of the production method according to the present invention,
The first and second outer surface portions are opposing first and second end surfaces. In still another specific aspect of the method for manufacturing a chip-type resistor according to the present invention, the step of preparing a plurality of the resistor elements includes the step of covering the first and second outer surfaces of at least one resistor element. Forming a first and second electrode, and measuring a resistance value between the first and second electrodes, wherein the remaining resistance elements are changed in accordance with a difference between the measured value and a target resistance value. Forming the insulating layer on the body,
Characterized in that the external electrodes are formed.

In the method of manufacturing a chip-type resistor according to the present invention, a thermistor element is preferably used as the resistor, whereby a chip-type thermistor element is obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be clarified by describing specific embodiments with reference to the drawings.

FIGS. 1A and 1B are a cross-sectional view and a perspective view showing the appearance of a chip type thermistor element according to a first embodiment of the present invention. The chip type thermistor element 1 is a chip type NTC thermistor element having a negative resistance temperature characteristic. The chip type thermistor element 1 has a thermistor element body 2 in the shape of a rectangular parallelepiped.

The thermistor body 2 is made of a ceramic having a negative resistance temperature characteristic. In the thermistor body 2, a plurality of first internal electrodes 3a to 3f are arranged so as to overlap in the thickness direction via a ceramic layer. Further, a plurality of second internal electrodes 4a to 4f are arranged so as to overlap in the thickness direction with a ceramic layer interposed therebetween with a predetermined facing gap from the tips of the internal electrodes 3a to 3f.

In this embodiment, the internal electrodes 3a to 3f are positioned at the same height as the corresponding internal electrodes 4a to 4f.
That is, although they are formed on the same plane, they may be formed at different height positions.

The internal electrodes 3a to 3f and the internal electrodes 4a
Although the size of the opposing gap between the first and second internal electrodes is the same, the opposing gaps between all corresponding first and second internal electrodes do not necessarily have to be the same.

The first internal electrodes 3 a to 3 f are extended to the first end face 2 a of the thermistor body 2. The internal electrodes 4 a to 4 f are drawn out to a second end face 2 b facing the first end face 2 a of the thermistor body 2.

On the first end face 2a, the first
The insulating layer 7 covers the exposed portion of the internal electrode 3a.
Are formed. Also, the first and second end faces 2a, 2b
The first and second external electrodes 5 and 6 are formed so as to cover. The first and second external electrodes 5 and 6 are end faces 2a and 2b
Not only to cover the upper surface 2c, the lower surface 2d, and both side surfaces 2e of the thermistor body 2.

In this embodiment, the external electrodes 5 and 6 are formed by applying and baking a conductive paste.
Is formed by applying and baking an insulating paste mainly composed of an insulating material such as glass or alumina.
Therefore, in manufacturing, the baking of the external electrodes 5 and 6 and the baking of the insulating layer 7 can be performed simultaneously.

This embodiment is characterized in that the thermistor body 2
The insulating layer 7 is formed on the first end face 2a of the first embodiment, whereby the internal electrode 3a is electrically disconnected from the external electrode 5. Therefore, in the chip-type thermistor element 1 of the present embodiment, the resistance value can be adjusted so as to increase the resistance value by forming the insulating layer 7 as compared with the case where the insulating layer 7 is not formed.

That is, in mass-producing the chip-type thermistor element 1, the resistance value can be corrected by forming the insulating layer 7, whereby the chip-type thermistor element 1 having a target resistance value can be easily obtained. . This will be described with reference to FIGS.

In manufacturing the chip type thermistor element 1, a plurality of ceramic green sheets are prepared, and the internal electrodes 3a to 3f, 4a are provided on the ceramic green sheets.
Print an electrode pattern corresponding to .about.4f. Then, the ceramic green sheets on which such electrode patterns are printed are laminated, and further, plain ceramic green sheets are laminated on the upper and lower sides to obtain a laminate. The laminate is pressed in the thickness direction and then fired to obtain the thermistor body 2. In this case, the resistance value is changed to the internal electrodes 3a to 3f, 4
a to 4f, the number of layers, the interval between the layers, the first and second internal electrodes 3
Even if it is controlled by the facing gap between a to 3f and 4a to 4f, the resistance value varies after the actual firing.

Therefore, according to the present invention, after a large number of thermistor element bodies 2 are formed, first and second electrodes 8 and 9 are formed on at least one thermistor element body 2 as shown in FIG. The electrodes 8, 9 may be formed in the same manner as the external electrodes 5, 6, or may be formed by another method.

Next, the resistance between the electrodes 8 and 9 is measured.
When the obtained measured value is different from the target resistance value, particularly when the measured value is lower than the target resistance value, the remaining thermistor element is increased so as to increase the resistance value according to the deviation from the target resistance value. 2, an insulating layer 7 is formed.

That is, the insulating layer 7 is formed on the remaining thermistor body 2, and then the first and second external electrodes 5 and 6 are formed. Therefore, by forming the insulating layer 7,
Using a large number of thermistor bodies 2 obtained in the firing lot, the chip type thermistor element 1 can be mass-produced so as to have a target resistance value and a resistance value in the vicinity thereof. Therefore, the yield of the chip type thermistor element 1 can be reliably increased.

When forming the insulating layer, FIG.
As shown in the figure, the opening 1 is formed on the end face 2a side of the thermistor body 2.
The mask 10 having Oa is brought into contact with the mask 10 and immersed in the insulating paste. The opening 10a has a shape corresponding to a region where the insulating layer 7 is formed. Therefore, by pulling up the thermistor body 2 from the insulating paste and drying it, the insulating paste layer 7a is formed on the end face 2a (see FIG. 4). Then, after the insulating paste layer 7a has dried,
The chip type thermistor element 1 can be obtained by applying and baking a conductive paste for forming the first and second external electrodes 5 and 6.

The first and second external electrodes 5 and 6 may be formed by baking the insulating paste 7a first and then applying and baking a conductive paste. In the above embodiment, the first and second external electrodes 5 and 6 are formed by applying and baking a conductive paste. However, in order to enhance the solderability on the electrode film formed by such baking, May be plated.

The external electrodes 5 and 6 may be formed by plating, vapor deposition, sputtering, or the like, instead of applying and baking a conductive paste. When heating is not required for forming the external electrodes 5 and 6, as the material forming the insulating layer 7, other insulating materials such as a synthetic resin can be used in addition to the insulating paste.

In the first embodiment, the insulating layer 7 is formed so as to electrically disconnect one internal electrode 3a from the first external electrode 5, but depending on the deviation from the target resistance value. ,
The insulating layer 7 can be formed in various modes.

That is, when the measured value is lower than the target resistance value, as shown in FIG.
The insulating layer 7b may be formed so as to cover exposed portions of the first internal electrodes 3a and 3b on the first end face 2a.

As shown in FIG. 5B, the first and second end faces 2a and 2b are insulated so as to cover the exposed portions of the single first and second internal electrodes 3a and 4a. The layers 7, 7c may be formed.

Further, as shown in FIG. 6, when the measured value is lower than the target resistance value, insulating layers 7, 7d are formed on the first end face 2a, and the second end face 2b The insulating layers 7c and 7e may be formed thereon. In this case, the first internal electrodes 3a, 3f and the first
Are electrically disconnected from the external electrodes 5 and the insulating layers 7c and 7e
As a result, the second internal electrodes 4a and 4f are electrically disconnected from the second external electrode 6.

That is, on at least one of the first and second end faces 2a and 2b, at least one of the plurality of internal electrodes is electrically cut off from the external electrodes by the insulating layer, thereby reducing the resistance value. The resistance value is adjusted in the increasing direction.

Accordingly, in the case where the thermistor body 2 is obtained by designing the resistance value slightly lower than the target resistance value in advance in designing the resistance value, and obtaining the thermistor body 2, the resistance value correction method of the above-described embodiment is used. The chip thermistor element can be reliably obtained, and the yield of the chip thermistor element can be increased.

In the above embodiment, the thermistor body 2
Although a semiconductor ceramic having a negative resistance-temperature characteristic has been used, a chip-type PTC thermistor element may be formed by using a thermistor element having a positive temperature-temperature characteristic.

The present invention can be applied not only to chip-type thermistor elements but also to ordinary chip-type fixed resistors and chip-type varistors. Further, in the above embodiment, the first and second external electrodes are formed so as to cover the opposing first and second end faces of the rectangular parallelepiped thermistor element body 2. The external electrodes need not necessarily be formed on the first and second end surfaces. That is, when the first and second outer surface portions from which the first and second internal electrodes are drawn are not the first and second end faces, the first and second internal electrodes are drawn out. First and second external electrodes are formed on the first and second outer surface portions.

[0038]

In the chip-type resistor according to the present invention, an insulating layer is formed on at least one of the first and second outer surface portions, whereby at least one of the first and second internal electrodes is formed. The electrical connection between the internal electrode and the first or second external electrode is interrupted. Therefore, by forming the insulating layer, the resistance can be corrected in a direction to increase the resistance value.
By controlling the formation position of the insulating layer, it is possible to stably obtain a chip-type resistance element having a target resistance value range,
It is possible to increase the yield rate of chip-type resistance elements.

When the first and second outer surface portions are opposed first and second end surfaces, the extended portions of the first and second internal electrodes are largely separated. So
The insulating layer and the first and second external electrodes can be easily formed, and can be handled in the same manner as a conventionally known chip-type resistance element.

When a thermistor element is used as the resistor element, a chip-type thermistor element having a target resistance value range can be stably provided according to the present invention. It is possible to improve the accuracy of the resistance value in a chip-type thermistor element that is easy to operate.

According to the method of manufacturing a chip-type resistor according to the present invention, since the first and second external electrodes are formed after the formation of the insulating layer, at least one internal electrode is formed by forming the insulating layer. By interrupting the electrical connection between the electrode and the first or second external electrode, the chip-type resistor according to the present invention can be easily obtained, and the resistance accuracy of the chip-type resistor can be effectively improved. Can be enhanced.

In the manufacturing method according to the present invention, when the first and second outer surface portions are the first and second end surfaces facing each other, a chip type having external electrodes on both end surfaces which has been conventionally known. It can be handled in the same manner as an electronic component, and the insulating layer and the first and second external electrodes can be easily formed.

In the manufacturing method according to the present invention, a plurality of resistor elements are prepared, and first and second electrodes are formed on the first and second outer surface portions of at least one resistor element, and the resistance value is determined. When the insulating layer is formed according to the difference between the target resistance value and the measured value, the resistance value is corrected based on the resistance value of the resistor element obtained in the same firing lot. Therefore, the accuracy of the resistance value can be effectively increased, and the yield of the chip-type resistance element can be increased.

In the manufacturing method according to the present invention, when a thermistor element is used as the resistor element, the accuracy of the resistance value can be effectively improved in a chip-type thermistor element in which the resistance value tends to shift during firing. Can be.

[Brief description of the drawings]

FIGS. 1A and 1B are a longitudinal sectional view and a perspective view showing an appearance of a chip-type thermistor element according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining a step of measuring a resistance value of a thermistor element in obtaining the chip-type thermistor element of the first embodiment.

FIG. 3 is a cross-sectional view for explaining a step of forming an insulating layer on an end face of the thermistor body.

FIG. 4 is a sectional view showing a thermistor body on which an insulating paste layer is formed.

FIGS. 5A and 5B are cross-sectional views showing respective chip-type thermistor elements according to a modification of the first embodiment of the present invention.

FIG. 6 is a sectional view showing another modification of the chip-type thermistor element according to the first embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing a conventional chip type thermistor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Chip-type thermistor element 2 ... Thermistor element body 2a, 2b ... 1st, 2nd end surface 3a-3f ... 1st internal electrode 4a, 4f ... 2nd internal electrode 5, 6 ... 1st, 2nd External electrode 7: insulating layer 7a: insulating paste layer 7b to 7e: insulating layer

Claims (7)

[Claims] 1. A resistor element having first and second outer surface portions, and a plurality of first internal electrodes formed in the resistor element and drawn out to the first outer surface portion. A plurality of second internal electrodes formed in the resistor body and drawn out to the second outer surface portion; and formed on the first and second outer surface portions of the resistor body, respectively. First and second external electrodes formed on at least one of the first and second outer surface portions of the resistor element, and at least one internal electrode and the first
A chip-type resistance element, comprising: an insulating layer that interrupts electrical connection with a second external electrode. 2. The chip-type resistance element according to claim 1, wherein said first and second outer surface portions are opposed first and second end faces. 3. The resistor element is a thermistor element.
The chip-type resistance element according to claim 1. 4. A plurality of first internal electrodes having first and second outer surface portions and extending to a first outer surface portion, and a plurality of first internal electrodes extending to a second outer surface portion. Preparing a resistor element having two internal electrodes; and forming an insulating layer on at least one of the first and second outer surface portions of the resistor element so as to cover an exposed portion of at least one internal electrode. Forming the first and second external electrodes on the first and second outer surface portions after forming the insulating layer. Production method. 5. The method according to claim 4, wherein the first and second outer surface portions are opposed first and second end surfaces. 6. A step of preparing a plurality of said resistor elements; forming first and second electrodes so as to cover first and second outer surfaces of at least one resistor element; Measuring the resistance value between the second electrode, forming the insulating layer with respect to the remaining resistive element according to the difference between the measured value and the target resistance value, and 6. The method according to claim 4, wherein two external electrodes are formed.
3. The method for manufacturing a chip-type resistor element according to 1. 7. The method for manufacturing a chip-type resistance element according to claim 4, wherein a thermistor element is used as said resistance element.