JPH08240500A - Capacitance type pressure sensor and its manufacture - Google Patents

Abstract

PURPOSE: To provide a capacitance type pressure sensor on which characteristic dispersion is reduced by enhancing dimensional accuracy of a gap between a fixing base board and a diaphragm. CONSTITUTION: The capacitance type pressure sensor is provided with a fixing base board 1 in which a first electrode 3 is formed on a surface and which is composed of an electric insulating material, a diaphragm 2 in which a second electrode 4 is formed on the surface and which is composed of an electric insulating elastic material, a spacer layer 5 and a spacer 6 which are formed in at least one peripheral edge part of the first electrode 3 and the second electrode 4, and the first electrode 3 and the second electrode 4 are opposed to each other, and the fixing base board 1 and the diaphragm 2 are joined together through the specer layer 5 and the specer 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small and high-performance capacitance type pressure sensor for converting a pressure change into a capacitance change of an electrode provided on a diaphragm and further converting it into an electric output, and a method for manufacturing the same. Regarding

[0002]

2. Description of the Related Art Capacitance type pressure sensors utilize the fact that the diaphragm is deformed by pressure and the distance between the electrodes is changed to change the electrostatic capacitance generated between the electrodes. A conventional electrostatic capacitance type pressure sensor is one in which a gap between a substrate on which an electrode is formed and a diaphragm is fixed by sealing the diaphragm to the substrate with a sealing glass containing beads (JP-A-57-97422). there were.

[0003]

Although it is effective to reduce the inter-electrode distance gap in order to reduce the size and performance of the electrostatic capacitance type pressure sensor, the electrodes 13, 14 as shown in FIG.
The gap between the substrate 11 and the diaphragm 12 in which the diaphragm is formed is fixed by sealing the diaphragm 12 to the substrate 11 with the sealing glass 15 containing the minute beads 16 (Japanese Patent Laid-Open No. 57-57).
No. 97422), the sealing glass 15 is softened at a high temperature to seal and fix the substrate 11 and the diaphragm 12, and the minute beads 16 in the sealing glass 15 cause a gap of several tens of μm or less between the substrate 11 and the diaphragm 12. Is controlling the gap. However, at the temperature for sealing the glass, the glass does not spread sufficiently because the viscosity of the glass is large, and microscopically, like the substrate 11, the sealing glass, the minute beads 16, the sealing glass 15, and the diaphragm 12, A small amount of sealing glass 15 exists between the substrate 11 and the minute beads 16 and between the minute beads 16 and the diaphragm 12. Therefore, since it is not possible to form a minute gap only with the minute beads 16, there is a problem in that the dimensional accuracy of the minute gap is poor and the capacitance varies.

The capacity is C = εAX ^-1 (where C is capacity and A is
Is the electrode area, ε is the dielectric constant, and X is the electrode spacing). The smaller the electrode spacing, the larger the capacity. Also dC /
Since dX = −εAX ⁻² , it can be seen that the smaller the electrode spacing, the higher the sensitivity. The height of the gap formed by the spacer layer 5 and the spacer 6 is usually about 0.1 μm to several 1
0 μm is preferable, and about 0.02 μm for high capacity and high sensitivity.
1 μm to several tens of μm is more preferable. However, the gap height is about 0.1 μm for higher capacity and higher sensitivity.
When the gap height is set to several tens of μm, a slight variation in the gap height causes variation and variation in the capacitance, and therefore the gap height needs to be controlled very strictly.

The present invention solves the above-mentioned conventional problems, and its first object is to reduce the capacitance variation of the capacitance type pressure sensor by separating the spacer and the spacer layer. is there.

A second object is to reduce the capacitance variation by keeping the deflection diameter of the diaphragm of the capacitance type pressure sensor constant.

In addition, it is a third object to make the deflection diameter of the diaphragm of the capacitance type pressure sensor constant and to stabilize the size of the minute gap to reduce the capacitance variation.
The purpose is.

A fourth object is to reduce the capacitance variation of the capacitance type pressure sensor to reduce the variation when converting the electric signal.

A fifth object of the present invention is to make the deflection diameter of the diaphragm of the electrostatic capacitance type pressure sensor constant so as to reduce the capacitance variation and reduce the variation at the time of electric signal conversion.

In addition, the deflection diameter of the diaphragm of the electrostatic capacitance type pressure sensor is made constant, and the dimension of the minute gap is stabilized to reduce the capacitance variation and the variation at the time of electric signal conversion. The purpose is.

A seventh object is to manufacture the electrostatic capacitance type pressure sensor with a small capacitance variation by separately forming the spacer and the spacer layer.

An eighth object of the present invention is to manufacture the electrostatic capacitance type pressure sensor with a small capacitance variation by separately forming the spacer and the spacer layer with high dimensional accuracy.

A ninth object is to easily manufacture the capacitance type pressure sensor with small capacitance variation by forming the spacer and the spacer layer separately with high dimensional accuracy and easily.

The tenth feature of the present invention is to easily manufacture the capacitance type pressure sensor with a small capacitance variation by forming the spacer and the spacer layer separately with high dimensional accuracy and easily without clogging the spacer in the spacer forming device. The purpose is.

[0015]

In order to achieve the above first object, the present invention provides a fixed substrate made of an electrically insulating material having a first electrode formed on the surface thereof, and a second electrode formed on the surface thereof. A diaphragm made of a formed electrically insulating elastic material,
A spacer layer and a spacer formed on a peripheral portion of at least one of the first electrode and the second electrode, wherein the first electrode and the second electrode are arranged to face each other, and the spacer layer and the spacer The fixed substrate and the diaphragm are bonded to each other via.

Further, in order to achieve the second object, the present invention provides a spacer on the outer periphery of the spacer layer.

Further, in order to achieve the third object, the present invention provides a plurality of spacer layers formed at the peripheral edge of the electrode and a spacer provided in the gap between the spacer layers.

In order to achieve the fourth object, the present invention provides a fixed substrate made of an electrically insulating material having a first electrode formed on the surface thereof, and an electric substrate having a second electrode formed on the surface thereof. A diaphragm made of an insulative elastic material, a spacer layer and a spacer formed on the peripheral portion of at least one of the first electrode and the second electrode, and the first electrode and the second electrode face each other. The fixed substrate is bonded to the diaphragm via the spacer layer and the spacer, and a spacer is provided on the outer periphery of the spacer layer to convert a capacitance change corresponding to a pressure change into an electric signal.

Further, in order to achieve the fifth object of the present invention, a spacer is provided on the outer periphery of the spacer layer, and a capacitance change corresponding to a pressure change is converted into an electric signal.

In order to achieve the sixth object of the present invention, a plurality of spacer layers formed at the peripheral edge of the electrode and spacers are provided in the gaps between the spacer layers, and a capacitance change corresponding to a pressure change is caused by an electric signal. Is converted to.

In order to achieve the seventh object, the present invention comprises the step of forming a predetermined electrode pattern on the fixed substrate and the diaphragm, and a spacer layer on the periphery of at least one of the fixed substrate and the diaphragm. And a spacer, and a step of connecting the fixed substrate and the diaphragm in a state where the electrode patterns on the fixed substrate and the diaphragm are separated by the spacer layer and the spacer and are arranged to face each other, thereby manufacturing the electrostatic capacitance pressure sensor. It is a thing.

In order to achieve the eighth object, the present invention is to manufacture a capacitance type pressure sensor by forming a spacer by drawing with a resin paste containing a spacer.

In order to achieve the ninth object, the present invention is to manufacture a capacitance type pressure sensor by screen-printing with a resin paste containing a spacer to form a spacer.

Further, in order to achieve the tenth object, the present invention is to manufacture a capacitance type pressure sensor by forming a pattern with a resin paste and then spraying spacers to form spacers.

[0025]

The present invention has the following functions due to the above structure.

That is, by separating the spacer layer and the spacer around the periphery of at least one of the fixed substrate and the diaphragm, the spacer layer is held while maintaining the distance between the fixed substrate and the diaphragm by the spacer that does not deform during manufacturing. Since it can be formed, the thickness of the spacer layer can be made substantially constant. That is, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy.

Further, by forming a spacer on the outer periphery of the spacer layer at the periphery of at least one of the fixed substrate and the diaphragm, the deflection diameter of the diaphragm is made constant, and the gap between the fixed substrate and the diaphragm is controlled only by the spacer. Therefore, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy.

Further, by forming spacers in the gap of a plurality of spacer layers at the periphery of at least one of the fixed substrate and the diaphragm, the deflection diameter of the diaphragm is made constant, and the gap between the fixed substrate and the diaphragm is only the spacer. Since it is controlled by, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy.

By forming the spacer layer and the spacer separately on the periphery of at least one of the fixed substrate and the diaphragm, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy, and the change in capacitance between the electrodes can be controlled. It can be converted into an electrical output with high accuracy.

By forming spacers on the outer periphery of the spacer layer at the periphery of at least one of the fixed substrate and the diaphragm, the deflection diameter of the diaphragm is kept constant and the gap between the fixed substrate and the diaphragm is controlled by the spacer alone. Therefore, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy, and the change in capacitance between the electrodes can be converted with high accuracy into an electrical output.

Further, by forming spacers in the gaps of a plurality of spacer layers on the periphery of at least one of the fixed substrate and the diaphragm, the deflection diameter of the diaphragm is made constant, and the gap between the fixed substrate and the diaphragm is only the spacer. Since it is controlled by, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy,
The change in capacitance between the electrodes can be converted into an electrical output with high accuracy.

Further, since the gap between the fixed substrate and the diaphragm can be accurately and easily formed, it is possible to reduce the variation between elements, reduce the size, increase the capacity, and increase the accuracy, simplify the manufacturing process, and mass-produce. Becomes possible.

By forming the spacer by drawing, the gap between the fixed substrate and the diaphragm can be formed accurately and easily, so that it is possible to reduce the variation between elements, reduce the size, increase the capacity, and increase the accuracy. The manufacturing process can be simplified and mass-produced.

By forming the spacer by screen printing, the gap between the fixed substrate and the diaphragm can be formed accurately and easily, so that it is possible to reduce the variation between elements, reduce the size, increase the capacity, and increase the accuracy. The manufacturing process can be simplified and mass production can be achieved.

Further, by printing the resin paste and then spraying the spacers to form the spacers, it is possible to accurately and easily form the gap between the fixed substrate and the diaphragm. It is possible to realize high precision and high accuracy, simplify the manufacturing process, and mass produce.

[0036]

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

First, an accurate gap management method using spacers, which is a feature of the present invention, will be described. For example, (1) a resin paste containing a high melting point spacer is formed by screen printing on the peripheral edge of the electrode. (2) When the spacer layer made of the glass frit is degreased and fired, the resin paste, which is an organic substance, is not burned and decomposed first, and only the spacer remains behind. (3) The spacer layer is degreased and fired to leave a low melting point glass layer. (4) The low melting point glass layer is deformed by load molding, but the high melting point spacer is not deformed, so the gap is controlled by the spacer.

In FIG. 1, a fixed substrate 1 made of an electrically insulating material having a first electrode 3 formed on the surface thereof, and a diaphragm 2 made of an electrically insulating elastic material having a second electrode 4 formed on the surface thereof, The first electrode 3 and the second electrode 4 are provided with a spacer layer 5 and a spacer 6 formed on the peripheral portion of at least one of the first electrode 3 and the second electrode 4.
Are opposed to each other, and the fixed substrate 1 and the diaphragm 2 are joined via the spacer layer 5 and the spacer 6. As the electrode shape, as shown in FIG. 4, a fixed substrate 1 of an electrically insulating insulating material having a first electrode 3 formed on the surface, and an electrically insulating substrate having a measurement electrode 4a and a reference electrode 4b formed on the surface A diaphragm 2 made of a flexible elastic material, a first electrode 3, a measurement electrode 4a, and a reference electrode 4b.
Are opposed to each other, and the spacer layer 5 and the spacer 6 are disposed.
The fixed substrate 1 and the diaphragm 2 are joined via the. The reason why the measurement electrode 4a and the reference electrode 4b are used instead of the second electrode 4 is to prevent a change in the sensor characteristics due to a change in the inter-electrode distance due to a disturbance such as a temperature change. By calculating and compensating the measuring capacitance and the reference capacitance, the temperature characteristic and the non-linearity can be made extremely small. Examples will be shown below.

(Example 1) Fixed substrate 1 (thickness 1.1 mm)
As the diaphragm 2 (thickness 0.25 mm), silica (SiO ₂ ), barium oxide (BaO), boric acid (B ₂ O)
₃ ) Prepare a barium borosilicate glass plate (glass transition point 630 ° C.) consisting of ₃ ), and use gold as a first electrode 3 and a second electrode 4 on a fixed substrate 1 and a diaphragm 2 to a thickness of 0.1 μm by a sputtering method. Formed by. As shown in FIG. 1, a glass frit with a low melting point (softening point 470 ° C.) having a thermal expansion coefficient almost the same as that of the glass fixed substrate was screen-printed to a thickness of about 12 μm on the fixed substrate 1 to form the spacer layer 5. After that, glass beads (glass transition point 630 ° C., particle size 10 ± 0.05) were formed in the blank portion of the spacer layer 5.
The spacer 6 composed of 0.1 μm) was screen-printed with a resin paste containing 0.1% by weight to form the spacer 6.
With the first electrode 3 and the second electrode 4 arranged so as to face each other, load molding is performed under conditions of a heating temperature of 480 ° C., a load of 0.2 kg weight, and a heating time of 10 minutes, and a spacer 6 is used. The fixed substrate 1 and the diaphragm 2 are integrally joined by the spacer layer 5. When the gap between the fixed substrate 1 and the diaphragm 2 was measured by a step gauge, it was 10 ± 0.05 μm, and the dimensional accuracy of the gap was extremely good. 100 samples are made in this process, and the measurement pressure is 500mmH.
Measure the capacitance value of the sensor alone at ₂ O and take 1
The average value of 00 pieces and its variation 3σ were determined, and the results are shown in (Table 1).

As is clear from (Table 1), the capacitance type pressure sensor manufactured by the process of the present invention had a small variation in characteristics.

(Example 2) A fixed substrate 1 (thickness: 1.1 mm) and a diaphragm 2 (thickness: 0.
15 mm), gold resinate having a thickness of 25 μm is formed on the fixed substrate 1 and the diaphragm 2 as the first electrode 3 and the second electrode 4 by a screen printing method, respectively, and then degreased and fired to a thickness of 0.1 μm. And After forming a spacer layer 5 on the fixed substrate 1 with a thickness of about 12 μm by screen printing, a glass frit with a low melting point (softening point of 550 ° C.) having almost the same thermal expansion coefficient as the fixed substrate of 96% alumina as shown in FIG. A spacer 6 made of glass beads (glass transition point: 710 ° C., particle diameter: 10 ± 0.05 μm) was screen-printed with a resin paste containing 0.1% by weight on the blank portion of the spacer layer 5 to form the spacer 6. With the first electrode 3 and the second electrode 4 arranged so as to face each other,
Load molding was performed under the conditions of a heating temperature of 580 ° C., a load of 0.2 kg, and a heating time of 10 minutes, and the fixed substrate 1 and the diaphragm 2 were integrally bonded with the spacer layer 5 via the spacer 6.
When the gap between the fixed substrate 1 and the diaphragm 2 was measured by a step gauge, it was 10 ± 0.05 μm, and the dimensional accuracy of the gap was extremely good. 100 samples were prepared in such a process, the respective capacitance values of the sensor alone at a measurement pressure of 500 mmH ₂ O were measured, the average value of 100 and its variation 3σ were obtained, and the result was calculated as ( (Table 1)
It was shown to.

As is clear from (Table 1), the capacitance type pressure sensor manufactured by the process of the present invention had a small variation in characteristics.

(Example 3) Fixed substrate 1 (thickness 1.1 mm)
And silica (SiO ₂ ), barium oxide (BaO), boric acid (B ₂ O) as the diaphragm 2 (thickness 0.25 mm).
₃ ) A barium borosilicate glass plate (glass transition point 630 ° C.) consisting of ₃ ) is prepared, and gold resinate is applied to the fixed substrate 1 and the diaphragm 2 as the first electrode 3 and the second electrode 4 respectively by a screen printing method of about 20 μm. It was formed to a thickness, degreased and fired to a thickness of 0.1 μm. As shown in FIG. 3, a glass frit with a low melting point (softening point 550 ° C.) having almost the same thermal expansion coefficient as that of the glass fixed substrate was screen-printed on the fixed substrate 1 to a thickness of about 10 μm to form the spacer layer 5. Then, a glass fiber (glass transition point 710 ° C., fiber diameter 7 ± 0.05) is provided in the blank portion of the spacer layer 5.
.mu.m and a fiber length of 25 .mu.m).
Spacers 6 were formed by drawing with a resin paste containing 5% by weight. With the first electrode 3 and the second electrode 4 arranged so as to face each other, the heating temperature is 550 ° C. and the load is 0.2 kg.
Load molding was performed under conditions of heavy weight and heating time of 10 minutes, and the fixed substrate 1 and the diaphragm 2 were integrally joined by the spacer layer 5 via the spacer 6. When the gap between the fixed substrate 1 and the diaphragm 2 was measured with a step gauge, it was 7 ± 0.05 μm, and the dimensional accuracy of the gap was extremely good. In this process, 100 samples were prepared and the measurement pressure was 5
The respective capacitance values of the sensor alone at the time of 00 mmH ₂ O were measured to obtain the average value of 100 pieces and its variation 3σ,
The results are shown in (Table 1).

As is clear from (Table 1), the capacitance type pressure sensor manufactured by the process of the present invention had a small variation in characteristics.

Example 4 A fixed substrate 1 (thickness: 1.1 mm) and a diaphragm 2 (thickness: 0.
15 mm) is prepared, and gold resinate is formed on the fixed substrate 1 and the diaphragm 2 as the first electrode 3 and the second electrode 4 by a screen printing method to a thickness of about 15 μm, respectively, and degreased.
It was calcined to a thickness of 0.1 μm. 96% as shown in Figure 4
A low-melting-point glass frit (softening point 550 ° C.) having almost the same coefficient of thermal expansion as the alumina fixed substrate is printed on the fixed substrate 1 by screen printing to a thickness of about 7 μm to form the spacer layer 5, and then the spacer layer 5 is formed. In the margin of the glass fiber (glass transition point 780 ℃, fiber diameter 5 ± 0.0
The spacer 6 composed of 5 μm and a fiber length of 25 μm) was drawn with a resin paste containing 0.5% by weight to form the spacer 6. With the first electrode 3 and the second electrode 4 arranged so as to face each other, a heating temperature of 650 ° C. and a load of 0.
Load molding was performed under the conditions of a weight of 2 kg and a heating time of 10 minutes to integrally bond the fixed substrate 1 and the diaphragm 2 with the spacer layer 5 via the spacer 6. Fixed substrate 1 and diaphragm 2
The gap between and was 5 ± 0.05 μm as measured with a step gauge, and the dimensional accuracy of the gap was extremely good. 100 samples were prepared in such a process, the respective capacitance values of the sensor alone at a measurement pressure of 500 mmH ₂ O were measured, the average value of 100 and its variation 3σ were obtained, and the result was calculated as ( The results are shown in Table 1).

As is clear from (Table 1), the capacitance type pressure sensor manufactured by the process of the present invention had a small variation in characteristics. A charging / discharging circuit is formed on the measuring electrode 4a and the reference electrode 4b of the sensor manufactured by such a method, and is connected to a charging / discharging time detection type detection circuit that generates a pulse output corresponding to the charging time difference between the respective capacities. Then, non-linearity correction and gain / offset adjustment were performed to convert to a predetermined voltage output. As a result, sensor characteristics with a total accuracy of less than 1% were obtained.

(Embodiment 5) Fixed substrate 1 made of silicon
(Thickness 1.1 mm) and diaphragm 2 (thickness 0.30 m
m) is prepared, and gold is plated on the fixed substrate 1 and the diaphragm 2 as the first electrode 3 and the second electrode 4 by plating.
2 μm was formed. As shown in FIG. 1, a glass frit with a low melting point (softening point 390 ° C.) having a thermal expansion coefficient almost the same as that of the silicon fixed substrate was printed on the fixed substrate 1 by screen printing to a thickness of about 8 μm to form the spacer layer 5. after,
A resin paste was drawn on a blank portion of the spacer layer 5, and a small amount of glass fiber (glass transition point 530 ° C., fiber diameter 7 ± 0.05 μm, fiber length 25 μm) was scattered on the portion to form the spacer 6. With the first electrode 3 and the second electrode 4 arranged so as to face each other, the heating temperature 400
Load molding was performed under conditions of a temperature of 0.2 ° C., a load of 0.2 kg, and a heating time of 10 minutes, and the fixed substrate 1 and the diaphragm 2 were integrally bonded with the spacer layer 5 via the spacer 6. When the gap between the fixed substrate 1 and the diaphragm 2 is measured with a step gauge, it is 7 ±
It was 0.05 μm, and the dimensional accuracy of the gap was extremely good. 100 samples were prepared in such a process, the respective capacitance values of the sensor alone at a measurement pressure of 500 mmH ₂ O were measured, the average value of 100 and its variation 3σ were obtained, and the result was calculated as ( The results are shown in Table 1).

As is clear from (Table 1), the capacitance type pressure sensor manufactured by the process of the present invention had a small variation in characteristics.

Example 6 Fixed substrate 1 (thickness: 1.1 mm) made of 96% alumina and borosilicate glass (glass transition point 54) having a thermal expansion coefficient almost the same as that of 96% alumina.
A diaphragm 2 (thickness: 0.25 mm) composed of 0 ° C.) is prepared, and a gold resinate is formed on the fixed substrate 1 and the diaphragm 2 as a first electrode 3 and a second electrode 4 by a screen printing method with a thickness of about 15 μm Then, degreasing and baking to 0.
The thickness was 1 μm. As shown in FIG. 2, a glass frit with a low melting point (softening point 460 ° C.) having almost the same coefficient of thermal expansion as the fixed substrate of 96% alumina (softening point 460 ° C.) is printed on the fixed substrate 1 with a thickness of about 7 μm to form the spacer layer 5. After forming, 0.5% by weight of the spacer 6 made of glass fiber (glass transition point 540 ° C., fiber diameter 5 ± 0.05 μm, fiber length 25 μm) in the blank portion of the spacer layer 5.
The spacer 6 was formed by drawing with the contained resin paste. With the first electrode 3 and the second electrode 4 arranged so as to face each other, load molding is performed under the conditions of a heating temperature of 450 ° C., a load of 0.2 kg weight, and a heating time of 10 minutes, and a spacer 6 is used. The fixed substrate 1 and the diaphragm 2 are integrally joined by the spacer layer 5. When the gap between the fixed substrate 1 and the diaphragm 2 was measured with a step gauge, it was 5 ± 0.05 μm, and the dimensional accuracy of the gap was extremely good. 100 samples are made in this process, and the measurement pressure is 500mm.
The respective capacitance values of the sensor alone at the time of H ₂ O were measured, the average value of 100 pieces and the variation 3σ thereof were obtained, and the results are shown in (Table 1).

As is clear from (Table 1), the capacitance type pressure sensor manufactured by the process of the present invention had a small variation in characteristics.

(Embodiment 7) Fixed substrate 1 (thickness 1.1 mm)
And silica (SiO ₂ ), barium oxide (BaO), boric acid (B ₂ O) as the diaphragm 2 (thickness 0.25 mm).
₃ ) A barium borosilicate glass plate (glass transition point 630 ° C.) consisting of ₃ ) is prepared, and gold is used as the first electrode 3 on the fixed substrate 1 and the measurement electrode 4a and the reference electrode 4b on the diaphragm 2 by the sputtering method. 0.01 μm was formed. As shown in FIG. 4, as the spacer layer 5, a low melting point glass (softening point 485 ° C.) having almost the same thermal expansion coefficient as the glass fixed substrate was formed on the fixed substrate 1 and the diaphragm 2 by the sputtering method to a thickness of 1.5 μm. Then, 0.1% by weight of a spacer 6 made of glass beads (glass transition point 580 ° C., particle diameter 1 ± 0.02 μm) is provided in a blank portion of the spacer layer 5.
Spacer 6 by screen printing with the contained resin paste
Was formed. With the first electrode 3 and the second electrode 4 arranged so as to face each other, a heating temperature of 480 ° C. and a load of 0.2
The load molding was performed under the conditions of the weight of kg and the heating time of 10 minutes, and the fixed substrate 1 and the diaphragm 2 were integrally bonded with the spacer layer 5 via the spacer 6. When the gap between the fixed substrate 1 and the diaphragm 2 was measured by a step gauge, it was 1 ± 0.02 μm, and the dimensional accuracy of the gap was extremely good. An oscillation circuit was connected to each of the measurement electrode 4a and the reference electrode 4b of the sensor manufactured by the above method, and the reference signal was canceled by connecting to the comparison circuit that compares the outputs of the respective oscillation circuits. Further, the frequency signal of the comparison circuit was connected to a frequency / voltage conversion circuit for converting it into a voltage signal and converted into a predetermined voltage output. As a result, sensor characteristics with a total accuracy of less than 1% were obtained.

(Comparative Example 1) Fixed substrate 11 (thickness: 1.1 m)
m) and diaphragm 12 (thickness 0.25 mm)
The same silica as in Example 1 (SiO₂), Barium oxide (Ba
O), boric acid (B₂O ₃) Barium borosilicate
Lath (glass transition point 630 ° C.) is prepared and fixed substrate 11
And the first electrode 13 and the second electrode 14 on the diaphragm 12.
As a result, gold is formed by sputtering to a thickness of 0.1μ
did. Glass bee in low melting point glass (softening point 480 ° C)
Spacers 16 (glass transition point 630 ° C., particles
Glass paste containing an appropriate amount of diameter 10 ± 0.05 μm)
Was screen-printed on the fixed substrate 11. First electrode 13
And the second electrode 14 are arranged so as to face each other,
Heating temperature 480 ° C, load 0.2 kg weight, heating time 10 minutes
Perform load molding under the conditions, and fix the base through the spacer 16.
The plate 11 and the diaphragm 12 are integrally connected by the spacer layer 15.
It matched. The gap between the fixed substrate 1 and the diaphragm 2 is stepped.
When measured with a difference meter, it is 10 ± 0.8 μm, and the gap
The dimensional accuracy of was poor. Repeat these steps to 1
Making 00 samples, measuring pressure 500mmH₂O
Measure the capacitance value of each sensor at 100
The central value and the variation 3σ of each of the
It is shown in 1). The capacitance type pressure sensor of the comparative example is (Table
As is clear from 1), the characteristic variation was large.

In the capacitance type pressure sensor of the present invention and the method for manufacturing the same, various materials (diaphragm, fixed substrate, electrode, spacer, spacer layer, etc.), bonding conditions (temperature, time, pressure, atmosphere, etc.), sensor The shapes (circles, squares, diameters, electrode patterns, thicknesses, dimensions such as gaps), circuit configurations, etc. are not limited to those in this embodiment.

[0054]

[Table 1]

[0055]

As described above, according to the capacitance type pressure sensor of the present invention and the manufacturing method thereof, the following effects can be obtained.

(1) By forming the spacer layer and the spacer separately on the periphery of at least one of the fixed substrate and the diaphragm, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy, so that the pressure with less variation can be obtained. A sensor is obtained.

(2) By forming spacers on the outer periphery of the spacer layer at the periphery of at least one of the fixed substrate and the diaphragm, the deflection diameter of the diaphragm is kept constant, and the gap between the fixed substrate and the diaphragm is only the spacer. Since it can be controlled by, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy, and a pressure sensor with less variation can be obtained.

(3) By forming spacers separately in the gaps of a plurality of spacer layers on the periphery of at least one of the fixed substrate and the diaphragm, the deflection diameter of the diaphragm is made constant, and the gap between the fixed substrate and the diaphragm is reduced. Since it can be controlled only by the spacer, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy, and a pressure sensor with less variation can be obtained.

(4) By forming the spacer layer and the spacer separately on the periphery of at least one of the fixed substrate and the diaphragm, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy, and the capacitance between the electrodes can be controlled. The change can be converted into an electric output with high accuracy.

(5) By forming a spacer on the outer periphery of the spacer layer at the periphery of at least one of the fixed substrate and the diaphragm, the deflection diameter of the diaphragm is made constant, and the gap between the fixed substrate and the diaphragm is only the spacer. It is possible to control the gap between the fixed substrate and the diaphragm with high accuracy, and it is possible to convert the capacitance change between the electrodes into an electrical output with high accuracy.

(6) By forming spacers separately in the gaps of a plurality of spacer layers on the periphery of at least one of the fixed substrate and the diaphragm, the deflection diameter of the diaphragm is kept constant and the gap between the fixed substrate and the diaphragm is reduced. Since it can be controlled only by the spacer, the gap between the fixed substrate and the diaphragm can be controlled with high accuracy, and the capacitance change between the electrodes can be converted with high accuracy into an electrical output.

(7) Since the gap between the fixed substrate and the diaphragm can be accurately and easily formed, it is possible to reduce the variation between elements, reduce the size, increase the capacity, and improve the accuracy, and simplify the manufacturing process. Mass production is possible.

(8) Since the gap between the fixed substrate and the diaphragm can be formed accurately and easily by forming the spacer by drawing, variation between elements can be reduced, downsizing, large capacity, and high accuracy can be realized. Therefore, the manufacturing process can be simplified and mass production can be realized.

(9) Since the gap between the fixed substrate and the diaphragm can be accurately and easily formed by forming the spacer by screen printing, the variation between elements can be reduced.
It is possible to realize miniaturization, large capacity, high precision, simplification of manufacturing process, and mass production.

(10) The gap between the fixed substrate and the diaphragm can be accurately and easily formed by printing the resin paste and then spraying the spacers to form the spacers. Larger capacity and higher accuracy can be realized, and the manufacturing process can be simplified and mass-produced.

[Brief description of drawings]

FIG. 1A is a plan view of an electrostatic capacity type pressure sensor according to an embodiment of the present invention. FIG. 1B is a sectional view of the same electrostatic capacity type pressure sensor.

FIG. 2A is a plan view of a capacitance type pressure sensor according to another embodiment of the present invention. FIG. 2B is a sectional view of the capacitance type pressure sensor.

FIG. 3A is a plan view of an electrostatic capacity type pressure sensor according to another embodiment of the present invention. FIG. 3B is a sectional view of the electrostatic capacity type pressure sensor.

FIG. 4A is a plan view of a capacitance type pressure sensor of another embodiment of the present invention. FIG. 4B is a sectional view of the capacitance type pressure sensor.

FIG. 5 is a sectional view of a conventional capacitance type pressure sensor.

[Explanation of symbols]

 1 Fixed Substrate 2 Diaphragm 3 First Electrode 4 Second Electrode 4a Measurement Electrode 4b Reference Electrode 5 Spacer Layer 6 Spacer

Claims (11)

[Claims] 1. A fixed substrate made of an electrically insulating material having a first electrode formed on the surface, a diaphragm made of an electrically insulating elastic material having a second electrode formed on the surface, and the first electrode. And a spacer layer and a spacer formed on at least one peripheral portion of the second electrode, the first electrode and the second electrode are arranged to face each other and via the spacer layer and the spacer A capacitance type pressure sensor in which the fixed substrate and the diaphragm are joined. 2. A fixed substrate made of an electrically insulating material having a first electrode formed on the surface, a diaphragm made of an electrically insulating elastic material having a second electrode formed on the surface, and the first electrode. And a spacer layer formed on at least one peripheral portion of the second electrode, and a spacer provided on the outer periphery of the spacer layer, wherein the first electrode and the second electrode are arranged facing each other and An electrostatic capacitance type pressure sensor in which the fixed substrate and the diaphragm are joined via the spacer layer and the spacer. 3. A fixed substrate made of an electrically insulating material having a first electrode formed on the surface, a diaphragm made of an electrically insulating elastic material having a second electrode formed on the surface, and the first electrode. A plurality of spacer layers formed on at least one peripheral portion of the second electrode and a spacer provided in a gap between the spacer layers, and the first electrode and the second electrode are arranged to face each other. An electrostatic capacitance type pressure sensor in which the fixed substrate and the diaphragm are joined via the spacer layer and the spacer. 4. A fixed substrate made of an electrically insulating material having a first electrode formed on the surface, a diaphragm made of an electrically insulating elastic material having a second electrode formed on the surface, and the first electrode. And a spacer layer and a spacer formed on at least one peripheral portion of the second electrode, the first electrode and the second electrode are arranged to face each other and via the spacer layer and the spacer An electrostatic capacitance type pressure sensor comprising: an element in which the fixed substrate and the diaphragm are joined together; and a conversion means for converting a capacitance change between the diaphragm and the fixed substrate caused by a pressure change into an electric signal. 5. A fixed substrate made of an electrically insulating material having a first electrode formed on the surface, a diaphragm made of an electrically insulating elastic material having a second electrode formed on the surface, and the first electrode. And a spacer layer formed on at least one peripheral portion of the second electrode, and a spacer provided on the outer periphery of the spacer layer, wherein the first electrode and the second electrode are arranged facing each other and An element in which the fixed substrate and the diaphragm are bonded to each other through the spacer layer and the spacer, and a conversion unit that converts a capacitance change between the diaphragm and the fixed substrate caused by a pressure change into an electric signal. Capacitive pressure sensor. 6. A fixed substrate made of an electrically insulating material having a first electrode formed on the surface, a diaphragm made of an electrically insulating elastic material having a second electrode formed on the surface, and the first electrode. A plurality of spacer layers formed on at least one peripheral portion of the second electrode and a spacer provided in a gap between the spacer layers, and the first electrode and the second electrode are arranged to face each other. Further, an element in which the fixed substrate and the diaphragm are joined via the spacer layer and the spacer, and a conversion means for converting a capacitance change between the diaphragm and the fixed substrate caused by a pressure change into an electric signal. Capacitive pressure sensor equipped. 7. The capacitance type pressure sensor according to claim 1, wherein the electrically insulating elastic material is alumina, silicon, or glass. 8. A step of forming a predetermined electrode pattern on the fixed substrate and the diaphragm, a step of forming a spacer layer and a spacer on the periphery of at least one of the fixed substrate and the diaphragm, and the step of forming the fixed substrate and the diaphragm on the fixed substrate and the diaphragm. And a step of coupling the fixed substrate and the diaphragm in a state where the electrode pattern is separated by the spacer layer and arranged so as to face each other, and a method for manufacturing a capacitance type pressure sensor. 9. A step of forming a predetermined electrode pattern on a fixed substrate and a diaphragm, and a step of forming a spacer by drawing a resin paste containing a spacer on at least one peripheral edge of the fixed substrate and the diaphragm. A step of forming a spacer layer on the peripheral edge of at least one of the fixed substrate and the diaphragm, and degreasing and firing in a state where the electrode patterns on the fixed substrate and the diaphragm are separated from each other by the spacer layer and the spacer and face each other. A method of manufacturing a capacitance type pressure sensor, the method including a step of coupling with a diaphragm. 10. A step of forming a predetermined electrode pattern on a fixed substrate and a diaphragm, and a step of forming a spacer by screen-printing with a resin paste containing a spacer on the periphery of at least one of the fixed substrate and the diaphragm. And a step of forming a spacer layer on the periphery of at least one of the fixed substrate and the diaphragm, and the fixed substrate by degreasing and firing in a state where the electrode patterns on the fixed substrate and the diaphragm are separated by the spacer layer and the spacer and face each other. A method of manufacturing an electrostatic capacitance type pressure sensor, the method including the step of coupling a diaphragm with a diaphragm. 11. A step of forming a predetermined electrode pattern on a fixed substrate and a diaphragm, and a step of forming a predetermined pattern with a resin paste on at least one peripheral edge of the fixed substrate and the diaphragm and then spraying spacers to form the spacers. The step of forming, the step of forming a spacer layer on the periphery of at least one of the fixed substrate and the diaphragm, and the degreasing and firing in a state where the electrode patterns on the fixed substrate and the diaphragm are separated by the spacer layer and the spacer and are arranged to face each other. And a step of connecting a fixed substrate and a diaphragm to each other.