JPH05135914A - Chip type thermistor and thermistor electrode and manufacture of chip type thermistor - Google Patents

Abstract

PURPOSE:To provide a thermistor having a low resistance value and capable of also inhibiting the dispersion of the resistance value minimally. CONSTITUTION:A chip type thermistor is manufactured by forming a thermistor body 23 onto an alumina substrate 10 in specified size, and the alumina substrate 10, electrode terminals alternately extended in specified length in the directions of opposite electrode base sections from both electrode base sections 11, 21 separated and formed at a fixed distance on the alumina substrate 10 and the thermistor body layer 23 on the electrode terminals are formed. In the chip type thermistor of this constitution, distance among the electrodes can be kept constant arbitrarily, the effect of mass production is improved, interelectrode resistance values can also be lowered, and the dispersion of the resistance values can also be inhibited minimally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type thermistor, a thermistor electrode and a method for manufacturing a chip type thermistor.

[0002]

2. Description of the Related Art Due to recent demands for smaller size and lighter weight, electric parts used are also becoming smaller. For this reason, the thermistor is also required to be a small chip type. However, the conventional chip type thermistor of this type has the configuration shown in FIG. That is, as shown in FIG. 6, for example, the electrodes 2 are provided on both side surfaces of the alumina substrate 1, and the thermistor body 3 is formed between the electrodes 2.

Alternatively, as shown in FIG. 7, a lower electrode 4 is provided on the upper surface of an alumina substrate 1, a thermistor body 3 is formed on the lower electrode 4, and the thermistor body 3 is further sandwiched. The upper electrode 5 was sandwiched between them.

[0004]

However, in the thermistor shown in FIG. 6, since the distance between the electrodes is large, the resistance value inevitably becomes large, and it is almost difficult to reduce the resistance. For example, in a conventional product of this type, the resistance value is about 1
It could only be in the range of MΩ to 100 MΩ. Further, it is difficult to suppress the variation in the resistance value, and the variation is about ± 30%.

Further, in the structure shown in FIG. 7, particularly large variations in resistance value occur due to variations in thickness when forming each portion and variations in the bonding area between the electrodes 4 and 5 and the thermistor body 3. Further, since the trimming cannot be performed, a variation of about 50% or more cannot be avoided, and it is difficult to manufacture a thermistor having a small resistance value error. Further, since the upper electrode 5 is formed, unevenness is inevitably generated on the upper surface, which causes troubles in the manufacturing equipment, and there is a drawback that mass productivity is deteriorated.

[0006]

The present invention has been made for the purpose of solving the above-mentioned problems, and has the following structure as one means for solving the above-mentioned problems. That is, a chip-type thermistor formed by forming a thermistor body on an alumina substrate of a predetermined size, wherein the alumina substrate and both electrode bases provided on the alumina substrate at a predetermined distance apart from each other are provided on the opposite electrode base surface. A chip type thermistor is formed by alternately forming electrode terminals extending a predetermined length and forming a thermistor body layer on the electrode terminals.

Alternatively, a thermistor electrode in a chip type thermistor which is provided on an alumina substrate of a predetermined size and has a thermistor body formed on the upper part thereof, the thermistor electrode being provided on the alumina substrate at a predetermined interval. Both of the electrode bases thus formed and electrode terminal portions alternately extending from the both electrode bases toward the mating electrode base by a predetermined length. Furthermore,
The above electrode is a silver-palladium-based thick film grace, and the thermistor body is a grace mainly composed of Mn, Co, Fe, and Cu-based composite oxides.

[0008]

In the above construction, both electrode bases arranged at a predetermined interval on an alumina substrate of a predetermined size and electrode terminals alternately extending from the two electrode bases toward the mating electrode base by a predetermined length. An electrode forming step of forming an electrode material forming a portion to a predetermined thickness, a thermistor forming step of forming a thermistor body on the electrode formed in the electrode forming step following the electrode forming step, and a thermistor forming step By forming the thermistor by a sintering process of heating and sintering the formed thermistor body, it is possible to provide a chip-type thermistor and a thermistor electrode which have a high mass-production effect and can have a low interelectrode resistance value.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described in detail below with reference to the drawings. 1 to 5 are views for explaining one embodiment according to the present invention, FIG. 1 is a partially cutaway perspective view showing a configuration of one embodiment according to the present invention, and FIG. FIG. 3 is a top view showing a state in which electrodes are arranged before forming the thermistor body 3, FIG. 3 is a sectional view taken along the line XX ′ in FIG. 1, and FIG.
FIG. 5 is a cross-sectional view of the Y'plane, and FIG. 5 is a manufacturing process diagram of this embodiment.

First, the configuration of an embodiment according to the present invention will be described with reference to FIGS. In the figure, 10 is an alumina substrate similar to the alumina substrate 1 shown in FIG. 5 or 6,
In this embodiment, the sintered body is 96% alumina. 1
Reference numerals 1 and 21 denote both electrode base portions arranged on the alumina substrate 10, and the present embodiment is constituted by the electrode terminals 12 and 22 alternately extending from the respective electrode base portions 11 and 21 toward the mating electrode base portion by a predetermined length. Forming the thermistor electrode. In this electrode formation state, as is apparent from FIG. 2, the electrode arrangement intervals of the electrode base portions 11 and 21 and the electrode terminals 12 and 22 are substantially constant.

A thermistor body 23 is formed on the upper portion of such an electrode portion. In this embodiment, a silver-palladium-based thick film grace is used as this electrode,
As the thermistor body, a grace mainly composed of Mn, Co, Fe, and Cu-based complex oxide is used, and this grace is heated and baked as described later. The method of manufacturing the chip type thermistor of the present embodiment shown above will be described below with reference to the process chart of FIG.

The following description is not limited to the case where only one thermistor is manufactured, and it goes without saying that a plurality of thermistors can be simultaneously manufactured. And
In the final step, each thermistor may be separated. First, the alumina substrate manufacturing process of forming the alumina substrate 10 in step 1 in a predetermined size is performed to manufacture an alumina substrate in a size of a predetermined manufacturing unit. This unit has an arbitrary size, and it may be prepared for each thermistor, for example, several tens of them may be prepared at the same time, and it may be produced depending on each case.

Then, in step 2, on the upper surface of the alumina substrate 10, as shown in FIG.
Then, the electrode printing step of forming the electrode terminals 12 and 22 extending alternately by a predetermined length on the opposite electrode base surface is performed. In this embodiment, the electrode patterns 11, 12, 2 as shown in FIG.
1, 22 are formed on the alumina substrate 10 by a method such as printing / etching. Then, in step 3, for example, 850 ° C.
Then, an electrode firing step of forming a thermistor electrode by heating and firing for about 10 minutes is performed.

Then, in step 4, the thermistor body 23 is formed on the electrode patterns 11, 12, 21, 22 of the alumina substrate 10.
Is formed, and this is heated and baked in step 5 at, for example, 850 ° C. for about ten minutes. In the example described above, the electrodes are fired in the step 3 and the thermistor body 23 is fired in the step 5, respectively, but the present embodiment is not limited to this example. You may perform the following process 4, and then perform the process of baking an electrode pattern and a thermistor body at once. Further, in this case, it is possible to trim the electrodes and the like on the alumina substrate 10, and by trimming the pattern portion before the final product, it is possible to further suppress variations in resistance and the like. .. Therefore, it is essential to perform trimming when it is necessary to suppress variations in resistance value.

Finally, in step 6, if necessary, the thermistor is separately molded for each chip. For example, when a large number of thermistors are manufactured at the same time, separate molding is performed for each chip, and when the chips are manufactured for each chip, the peripheral portion is shaped. The chip thermistor of this embodiment manufactured in this manner has, for example, a width of about 1.23 mm plus or minus 0.1 mm and a length of about 2.0.
mm plus or minus 0.1 mm, the thickness of the alumina substrate 10 is approximately 0.5 mm plus or minus 0.1 mm, the thickness of the electrode portion is approximately 10 μm plus or minus 2 μm, and the thermistor body 23
Of about 25 μm plus or minus 5 μm.
Alternatively, as another example, for example, a width of approximately 1.6 mm plus or minus 0.1 mm, a length of approximately 3.2 mm plus or minus 0.1 mm, a thickness of the alumina substrate 10 of approximately 0.6 mm plus or minus 0.1 mm, an electrode portion Thickness of the thermistor body 23 is about 25 μmm
It is formed within plus or minus 5 μm.

In the present embodiment, the resistance value is 100Ω to 100Ω.
Even if trimming or the like with KΩ is not performed at all, the variation in the resistance value can be set to plus or minus 30%. In addition, in order to suppress the variation in the resistance value to a low level, it is possible to further reduce the variation in the resistance value when trimming is performed, and it is possible to suppress the variation to approximately plus or minus 5%.

As described above, according to the present embodiment, both electrode base portions arranged at a predetermined interval on the alumina substrate of a predetermined size and the electrode base portions of the two electrode base portions alternate with each other. An electrode forming step of forming an electrode material having a predetermined thickness to form an electrode terminal portion extending a predetermined length, and a thermistor forming of forming a thermistor body on the electrode formed in the electrode forming step following the electrode forming step By forming the thermistor by a process and a sintering process in which the thermistor body formed in the thermistor forming process is heated and sintered, the mass production effect is high, and the interelectrode resistance value can be lowered, resulting in a variation in the resistance value. A thermistor that can be kept low can be provided.

[0018]

As described above, according to the present invention, the distance between the electrodes can be arbitrarily and constant, a thermistor having a low resistance value can be provided, and the variation in the resistance value can be suppressed to the minimum. You can

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a configuration of an embodiment according to the present invention.

FIG. 2 is a top view showing an electrode arrangement state before forming the thermistor body of the present embodiment.

FIG. 3 is a sectional view taken along the line XX ′ in FIG.

FIG. 4 is a sectional view taken along the line XX ′ of FIG.

FIG. 5 is a manufacturing process diagram of the present embodiment.

FIG.

FIG. 7 is a diagram showing an example of a conventional thermistor.

[Explanation of symbols]

 1,10 Alumina substrate 2,4 Electrode 5 Upper electrode 11,21 Electrode base 12,22 Electrode terminal 3,23 Thermistor body

Claims (5)

[Claims] 1. A chip-type thermistor comprising a thermistor body formed on an alumina substrate of a predetermined size, comprising an alumina substrate and a counter electrode composed of both electrode bases provided on the alumina substrate at a predetermined distance from each other. A chip-type thermistor comprising: electrode terminals extending alternately by a predetermined length toward the base and a thermistor body layer formed on the electrode terminals. 2. The chip type according to claim 1, wherein the electrode is a silver-palladium-based thick film grace and the thermistor body is a grace mainly composed of Mn, Co, Fe, and Cu-based composite oxides. Thermistor. 3. A thermistor electrode in a chip type thermistor which is provided on an alumina substrate of a predetermined size and has a thermistor body formed on the upper part thereof, the thermistor electrode being provided on the alumina substrate at a predetermined interval. An electrode for a thermistor, comprising: both electrode bases formed and electrode terminal portions alternately extending from the both electrode bases toward a mating electrode base by a predetermined length. 4. The chip type according to claim 3, wherein the electrode is a silver-palladium-based thick film grace, and the thermistor body is a grace mainly composed of Mn, Co, Fe, and Cu-based composite oxides. Electrode of the thermistor. 5. A method for manufacturing a chip type thermistor, which comprises forming a thermistor body on an alumina substrate of a predetermined size, wherein both electrodes are arranged on the alumina substrate of a predetermined size with a predetermined interval. An electrode forming step of forming an electrode material having a predetermined thickness to form an electrode terminal portion that alternately extends a predetermined length from the base portion and the opposite electrode base portion toward the opposite electrode base surface; and the electrode forming step and the electrode forming step. 7. A method for manufacturing a chip type thermistor, comprising: a thermistor forming step of forming a thermistor body on the electrode formed in 1 .; and a sintering step of heating and sintering at least the thermistor body formed in the thermistor forming step.