JPH05243008A - Thermistor device - Google Patents

Abstract

PURPOSE:To obtain a chip type thermistor device, in which a plurality of thermistor elements are constituted integrally in a single sintered body and by which an electronic equipment can be miniaturized and cost reduced. CONSTITUTION:In a chip type negative temperature coefficient thermistor device 1, internal electrodes 3, 4 and internal electrodes 5, 6 are formed into a sintered body 2 composed of semiconductor ceramics capable of being worked as a thermistor, and external electrodes 7, 8 are formed so as to be electrically connected to the internal electrodes 3, 4 and external electrodes 9, 10 so as to be electrically connected to the internal electrodes 5, 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermistor device constructed by using a sintered body made of semiconductor porcelain, and particularly,
The present invention relates to a thermistor device in which a plurality of thermistor characteristic portions are formed in one sintered body.

[0002]

2. Description of the Related Art For example, a crystal oscillator for temperature compensation (TCX)
In some cases, it is necessary to connect a plurality of thermistor elements in one circuit, such as O). Conventionally, when the above circuit is constructed, a required number of thermistor elements are mounted on a printed circuit board. As the thermistor element used, various types such as a chip type thermistor element and a thermistor element with a lead wire have been used. Each of these thermistor elements had a structure in which electrodes were formed on both main surfaces of a single plate type semiconductor ceramic.

[0003]

With the miniaturization of electronic / electrical devices, there is a strong demand for miniaturization of electronic components used in these devices. However, TCXO
In forming a circuit that requires a plurality of thermistor elements as described above, the method of preparing and mounting the required number of thermistor elements as in the related art has a limit in downsizing the device. Moreover, since a plurality of thermistor elements are prepared and mounted, the cost of the above-mentioned equipment tends to be high. On the other hand, there has been no chip type thermistor device in which a plurality of thermistor elements are integrated.

An object of the present invention is to provide a single chip type thermistor device having a plurality of thermistor characteristic portions, thereby achieving a circuit size reduction and a cost reduction required for a plurality of thermistor devices. To aim.

[0005]

According to the present invention, a sintered body made of a semiconductor porcelain capable of functioning as a thermistor, a plurality of internal electrodes arranged so as to form a thermistor characteristic portion in the sintered body, and In the thermistor device, which is formed on the outer surface of the sintered body and includes a pair of external electrodes electrically connected to a predetermined internal electrode among the plurality of internal electrodes, a plurality of internal electrodes and a pair of the internal electrodes are provided. The thermistor device is characterized in that a plurality of thermistor characteristic portions including the external electrodes are formed in the sintered body.

[0006]

Since the conventional chip type thermistor element has a structure in which electrodes are formed on both end surfaces of a single-plate semiconductor ceramic, it is not possible to form thermistor characteristic portions having different resistance values in one thermistor element. It was very difficult. On the other hand, the present invention is a so-called laminated type thermistor device in which internal electrodes are formed in a sintered body made of semiconductor porcelain to form a thermistor characteristic portion, and therefore the thermistor characteristic portion including internal electrodes and external electrodes is used. It is easy to configure a plurality of the above-mentioned ones using a single sintered body.

That is, the present invention is characterized in that a plurality of thermistor characteristic portions are formed in a single sintered body by forming a laminated thermistor by using the ceramic laminated electronic component technology. A plurality of thermistor characteristic portions having different characteristics can be easily configured in a single chip type thermistor device.

[0008]

Description of Embodiments First Embodiment FIGS. 1 and 2 show a chip type negative characteristic thermistor device according to a first embodiment. The chip type negative characteristic thermistor device 1 is configured by using a sintered body 2 made of a material capable of functioning as a thermistor such as a semiconductor ceramic made of manganese-nickel oxide. Inside the sintered body 2,
As shown in FIGS. 1B and 2, internal electrodes 3 to 6 are formed. That is, in the cross-sectional portion along the line AA in FIG. 1A, a pair of internal electrodes 3 and 4 are arranged at the same height position so that their tips are opposed to each other at the central portion of the sintered body 1. ing. In addition, in the cross-section portion along the line BB of FIG. 1A, at the position separated laterally from the position where the internal electrodes 3 and 4 are formed, the same height position as the internal electrodes 3 and 4 is provided. In addition, the internal electrodes 5 and 6 are arranged so that their tips are opposed to each other.

On the outer surface of the sintered body 1, there are external electrodes 7 and 8 electrically connected to the internal electrodes 3 and 4, respectively, and external electrodes 9 and 10 electrically connected to the internal electrodes 5 and 6. Has been formed. Therefore, in this embodiment, the external electrodes 7 and 8 are
In between, the first thermistor characteristic portion is connected to the external electrode 9.1.
A second thermistor characteristic portion is formed between 0. Further, since the distance between the tips of the internal electrodes 3 and 4 is made different from the distance between the tips of the internal electrodes 5 and 6, the resistance values of the first and second thermistor characteristic portions are made different.

As shown in the exploded perspective view of FIG. 3, the sintered body 2 is printed with a conductive paste for forming the internal electrodes 3 to 6 on the upper surface of the ceramic green sheet 11, and the conductive paste is formed above and below the conductive paste. An appropriate number of unprinted ceramic green sheets 12a to 12c, 12d to 12
It is obtained by stacking f, press-bonding in the thickness direction, and integrally firing. That is, it can be easily obtained by utilizing the multilayer ceramic electronic component technology.

Modification of the First Embodiment In the negative characteristic thermistor device 1 of the first embodiment, both the first thermistor characteristic portion and the second thermistor characteristic portion have the internal electrodes 3, 3 on the same plane. 4 or the internal electrodes 5 and 6 are arranged such that their tips are opposed to each other with a predetermined distance therebetween. Instead of this,
As shown in FIG. 4A, the first thermistor characteristic portion is configured in the same manner as in the first embodiment, and as shown in FIG.
Regarding the second thermistor characteristic portion, internal electrodes 5a arranged such that their tips are opposed to each other with a predetermined distance therebetween,
6a as well as the internal electrode 5 via the ceramic layer 2a.
The non-connection type internal electrode 13 may be arranged so as to overlap with a and 6a (FIG. 5).

Further, as shown in FIG. 6, a plurality of internal electrodes 14a to 14c are formed in the ceramic body 2 in the sintered body 2.
The thermistor characteristic portions arranged so as to overlap with each other via b and 2c may be used to configure at least one of the first and second thermistor characteristic portions.

Second Embodiment FIGS. 7A and 7B are cross-sectional views for explaining the internal electrode structure of the first and second thermistor characteristic portions in the negative characteristic thermistor device of the second embodiment. It is a figure and is a figure corresponding to Drawing 2 (a) and (b) shown about a 1st example, respectively. As is apparent from FIG. 7A, the sintered body 2
In a cross-section (see FIG. 1A) taken along the line AA, the pair of internal electrodes 15 and 16 are arranged so that their tips face each other with a predetermined distance therebetween. On the other hand, FIG.
In the cross-sectional portion of the sintered body 2 taken along the line BB shown in (a), the internal electrodes 17, 18 are arranged so that their tips are opposed to each other with a predetermined distance. This embodiment is characterized in that the internal electrodes 15 and 16 and the internal electrodes 17 and 18 are the sintered body 2.
Are formed at different height positions. That is, in the negative characteristic thermistor device of the second embodiment, the first thermistor characteristic portion and the second thermistor characteristic portion are formed at different height positions in the thickness direction of the sintered body 2.

FIG. 8 is an exploded perspective view showing a process for obtaining the negative characteristic thermistor device of the second embodiment. In order to obtain the negative characteristic thermistor device of the second embodiment, the internal electrodes 15, 1 are formed on the upper surface of the ceramic green sheet 19.
Print a conductive paste to form 6. Further, on the upper surface of the ceramic green sheet 20, the internal electrodes 17,
A conductive paste for forming 18 is printed. Then, between the ceramic green sheets 19 and 20, the ceramic green sheet 21 on which the conductive paste is not printed is printed.
A sintered body 2 can be obtained by interposing a and 21b, stacking an appropriate number of ceramic green sheets 21c to 21e and 21f to 21i on the upper and lower sides, press-bonding them in the thickness direction, and then firing. That is, since the chip type thermistor device of the present invention is obtained by using the monolithic ceramic electronic component technology, the height at which the internal electrodes are formed can be easily changed, and the height at which a plurality of thermistor characteristic portions are formed is high. The position can be easily changed.

Third Embodiment FIGS. 9 (a) and 9 (b) are sectional views for explaining a negative characteristic thermistor device of the third embodiment, and FIG. 2 showing the first embodiment. It is a figure equivalent to (a) and (b). In the third embodiment, in the cross-section of the sintered body 2 taken along the line AA, the internal electrodes 22 and 23 are arranged so that their tips are opposed to each other with a predetermined distance. On the other hand, in the cross-section portion of the sintered body 2 along the line BB, the internal electrodes 22, 2
A pair of internal electrodes 24, 25 are arranged in a portion lower than the position where 3 is formed so that their tips are opposed to each other with a predetermined distance therebetween. And the non-connection type internal electrode 26
Is formed at a position lower than the internal electrodes 24, 25 so as to overlap the internal electrodes 24, 25 with the ceramic layer 2d interposed therebetween.

In the negative characteristic thermistor device according to the third embodiment, the heights at which the first thermistor characteristic portion and the second thermistor characteristic portion are formed are different from each other, and the second thermistor characteristic portion is further provided. The structure uses the non-connection type internal electrode 26 as described above.

In the sintered body 2 used in the negative characteristic thermistor device of the third embodiment, as shown in FIG. 10, a conductive paste for forming the internal electrodes 22, 23 is printed on the upper surface of the ceramic green sheet 27. Then, a conductive paste is printed on the upper surface of the ceramic green sheet 28 to form the internal electrodes 2
4 and 25 are formed, and a conductive paste for forming the unconnected internal electrodes 26 is printed on the upper surface of the ceramic green sheet 29. After that, ceramic green sheet 2
Ceramic green sheets 30a and 30b on which no conductive paste is printed are interposed between 7 and 28, a ceramic green sheet 29 is laminated on the lower side of the ceramic green sheet 28, and ceramics on which no conductive paste is printed are arranged above and below. Green sheets 30c to 30e, 30
It is obtained by stacking an appropriate number of f to 30h, pressing them in the thickness direction, and then firing.

Other Modifications As described above, in the chip type thermistor device of the present invention, a plurality of thermistor characteristic portions can be easily formed in a single sintered body by using the laminated ceramic electronic component technology. .. Therefore, various internal electrode structures can be adopted in addition to the above-described embodiments and modifications. For example, in the cross-sectional portion along the line AA shown in FIG. 2A, as shown in FIGS. 11A to 11C, internal electrodes 31a to 31d, internal electrodes 32a to 32h, and internal electrodes 33a to By forming 33f appropriately, the thermistor characteristic portion having various resistance values can be formed in the cross-section portion along the line AA.

Similarly, in the cross section along the line BB, as shown in FIGS. 12A and 12B, the internal electrodes 34a to 34c and the internal electrodes 35a to 35d are formed as shown. As a result, the thermistor characteristic portion having various resistance values can be configured. Next, a specific experimental example of the negative characteristic thermistor device according to the embodiment of the present invention will be described.

Experimental Example 1 A ceramic green sheet was obtained by forming a ceramic slurry containing semiconductor ceramics as a main component into a sheet. Next, on the upper surface of the above-mentioned ceramic green sheet, the unit cell has dimensions l ₁ = 1.125 mm, l ₂ = 0.
The conductive paste was printed so as to have a width of 6 mm (each has a width of 0.75 mm) to form internal electrodes 3 to 6. Next, the same number of ceramic green sheets of the same size were laminated on the upper and lower sides of the ceramic green sheet on which the internal electrodes were printed to obtain a laminated body having a total thickness of 1.7 mm. Next, the laminated body was pressed under a pressure of 2 ton cm ² and cut into unit cells, and then fired at a temperature of 1200 ° C. to obtain a sintered body. The obtained sintered body is shown in FIG.
It had dimensions of L ₁ = 1.99 mm, W ₁ = 2.3 mm and thickness 1.0 mm in (b).

Next, a conductive paste is applied to the exposed outer surface portions of the internal electrodes 3 to 6 and baked at a temperature of 800 ° C. for 10 minutes to form the internal electrodes 7 to 10 shown in FIG. Then, a chip type negative characteristic thermistor device 1 was obtained. The specific resistance ρ of the above sintered body is ρ = 1000Ω
・ It is cm. 2 of the first and second thermistor characteristic portions of the chip type negative characteristic thermistor device 1 obtained as described above.
The variations in the resistance values R ₂₅ and R ₂₅ , the B constant, and the variations in the B constant at 5 ° C. are as shown in Table 1 below.
In addition, the results of Table 1 are 10 negative characteristic thermistor devices 1.
Is an average value of.

[0022]

[Table 1]

Experimental Example 2 A ceramic green sheet having the same size as that prepared in Experimental Example 1 was prepared, and the ceramic green sheet 4 on which the internal electrodes 44 to 48 shown in FIGS. 13 (a) to 13 (c) were printed.
1-43 were prepared. That is, on the upper surface of the ceramic green sheet 41, the internal electrodes 44, 45 of the unit cell are formed.
However, the internal electrodes 44 and 45 are formed by printing the conductive paste so that the length is 1.25 mm and the width is 0.75 mm. Internal electrodes 46 and 47 of the unit cell are printed on the upper surface of the ceramic green sheet 42 so as to have a length of 1.25 mm and a width of 0.75 mm. On the upper surface of the ceramic green sheet 43, in a region having a length of 1.9 mm and a width of 0.75 mm, 0.25 m from the edges 43a and 43b of the ceramic green sheet 43.
Conductive paste is printed at a distance of m to form the internal electrodes 48 of the unit cells.

The ceramic green sheets 41-4
The thickness of 3 is 60 μm. Next, the same three ceramic green sheets as those described above are inserted except that the internal electrodes are not printed between the ceramic green sheets 41 and 42, and the ceramic green sheets 42 are directly below the ceramic green sheets 42. The green sheets 43 were laminated, and the same number of ceramic green sheets were laminated on the upper and lower sides to obtain a laminated body. The obtained laminated body was treated in the same manner as in Experimental Example 1 to obtain a sintered body, and external electrodes were formed in the same manner as in Experimental Example 1 to obtain a negative characteristic thermistor device. First and second of the obtained negative characteristic thermistor device
Resistance values of the thermistor characteristic part of R ₂₅ , R ₂₅
The results shown in Table 2 below were obtained for the variation of B, the B constant, and the variation of the B constant. The results shown in Table 2 are also 10
This is the average value for each negative characteristic thermistor device.

[0025]

[Table 2]

In the embodiments described above, the structure in which the first and second thermistor characteristic portions are formed in one sintered body has been described, but in the present invention, three or more thermistor characteristic portions are single. It may be arranged in the sintered body. Further, the thermistor device of the present invention can also be applied to a PTC thermistor device made of a material such as barium titanate-based semiconductor porcelain.

[0027]

According to the present invention, a chip type thermistor device is constructed by using the laminated ceramic electronic component technology, and a plurality of thermistor characteristic portions are constructed in a single sintered body. Therefore, it becomes possible to supply the chip type thermistor element, which has been conventionally prepared as a plurality of electronic components, as a single component. Therefore, it is possible to promote miniaturization of electronic circuits and electronic devices such as TCXO.

Further, since the chip type thermistor device of the present invention is constructed by using the laminated ceramic electronic component technology, the resistance of a wide range of several tens Ω to several hundred kΩ can be obtained by changing the internal electrode structure. The thermistor characteristic part exhibiting characteristics can be constructed in one chip-type component. In addition, multiple thermistor characteristics
When they are formed at different heights in the sintered body, the internal electrode structures are separately formed on the ceramic green sheets, so the characteristics of multiple thermistor characteristics can be adjusted independently. Therefore, it is possible to easily obtain a chip-type thermistor device exhibiting desired resistance characteristics.

[Brief description of drawings]

FIG. 1A is a perspective view of a chip type negative characteristic thermistor device of a first embodiment, and FIG. 1B is a plan sectional view taken along line CC of FIG.

2A is a sectional view taken along the line AA of FIG.
(B) is sectional drawing which follows the BB line.

FIG. 3 is an exploded perspective view for explaining a ceramic green sheet used to obtain the first embodiment.

FIG. 4A is a sectional view of a portion along a line AA of a sintered body according to a modification of the first embodiment, and FIG. 4B is a sectional view of a portion along a line BB.

FIG. 5 is a plan sectional view of a sintered body in a negative characteristic thermistor device of a modified example of the first embodiment.

FIG. 6 is a cross-sectional view showing a positive temperature coefficient thermistor portion in which a plurality of internal electrodes are laminated in a sintered body, which is a modification of the first embodiment.

7A is a sectional view taken along line AA of the sintered body of the chip type negative characteristic thermistor device of the second embodiment, and FIG.
-A sectional view of a portion along line B.

FIG. 8 is an exploded perspective view for explaining a plurality of ceramic green sheets used to obtain the second embodiment.

FIG. 9A is a sectional view taken along line AA of a sintered body used in the chip type negative characteristic thermistor device of the third embodiment,
(B) is sectional drawing which follows the BB line.

FIG. 10 is an exploded perspective view for explaining a plurality of ceramic green sheets used in the third embodiment.

11A to 11C are cross-sectional views each illustrating an internal electrode structure formed in a portion along the line AA.

12 (a) and 12 (b) are cross-sectional views each for explaining a modified example of the internal electrode structure formed in a portion along the line BB.

13A to 13C are plan views for explaining the ceramic green sheets prepared in Experimental Example 2 and the shape of internal electrodes formed thereon.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Chip type negative characteristic thermistor device 2 ... Sintered body 3-6 ... Internal electrode 7-10 ... External electrode

Claims (1)

[Claims] 1. A sintered body made of a semiconductor porcelain capable of functioning as a thermistor, a plurality of internal electrodes arranged to form a thermistor characteristic portion in the sintered body, and an outer surface of the sintered body. A thermistor device which is formed and includes a pair of external electrodes electrically connected to a predetermined internal electrode among the plurality of internal electrodes, wherein the thermistor includes the plurality of internal electrodes and a pair of external electrodes. A thermistor device, wherein a plurality of characteristic portions are formed on the sintered body.