JPH09229794A - Pressure detector - Google Patents

Abstract

(57) Abstract: A pressure detector capable of satisfactorily detecting the pressure of a fluid even when a diaphragm is integrally formed with a stem by a glass material. SOLUTION: A diaphragm (pressure receiving surface) 8 is formed integrally with a stem 7 made of a glass material, and a reinforcing member 9 is formed on the periphery of the diaphragm 8 to form a diaphragm container.
Form 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure detector for detecting the pressure of a medium such as gas or liquid, and more particularly to a so-called COD (Chip On Diaphrase) for bonding a pressure detection chip to a pressure receiving portion.
agm) type pressure detector.

[0002]

2. Description of the Related Art A COD type pressure detector in which a pressure detecting chip such as a resistance bridge IC chip is bonded to one surface of a pressure receiving portion such as a diaphragm with an adhesive or low melting point glass is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-194716. Is known for.

As shown in FIG. 5, such a pressure detector has a full-bridge resistance IC bonded to one side of a thin-walled pressure-sensitive strain-producing diaphragm (pressure-receiving portion) 2 integrally formed with a cylindrical stem 1. A chip (pressure detection chip) 3, a printed board 5 for drawing out a lead wire 4 from the electrode portion of the chip 3 by wire bonding, and soldering for outputting an electric signal according to pressure from the board 5 to the outside. And a conducting wire 6 drawn out by the. And
Since the chip 3 is integrated with the diaphragm 2 by adhesion, when the diaphragm 2 is slightly strained by pressure, the strain is transmitted, the balance of the bridge resistance of the chip 3 is lost, and an electric signal proportional to the pressure is generated. Then, it is amplified by the amplifier circuit formed on the substrate 5 and output to the outside by the conductor 6.

[0004]

For example, when the stem 1 and the diaphragm 2 are made of a glass material, the material is softer than a metal material, and therefore the diaphragm 2 is displaced when the pressure of the medium is transmitted to the diaphragm 2. At the same time, the stem 1 is also deformed, and there is a problem that the pressure is not properly transmitted to the pressure detection chip 3. Also,
Since the stem 1 is made of a glass material, the strain generated when the stem 1 is mounted and fixed and the strain generated by the difference in thermal expansion from the mounting portion affect the diaphragm 2.
There was a problem that the accurate pressure could not be detected. The present invention focuses on the above-mentioned problems, and provides a pressure detector capable of detecting the pressure of a medium well even when the diaphragm is integrally formed with the stem by a glass material.

[0005]

In order to solve the above problems, the present invention provides a pressure detector in which a pressure detecting chip is bonded on one surface of a pressure receiving portion which is displaced by the pressure of a medium, and is integrated with a stem made of a glass material. The pressure receiving portion is formed on the inner surface of the pressure receiving portion, and a reinforcing member is formed on the peripheral edge of the pressure receiving portion.

Further, in a pressure detector in which a pressure detecting chip is bonded to one surface of a pressure receiving portion that is displaced by the pressure of a medium, the pressure receiving portion is integrally formed with a stem made of a glass material, and is formed on the periphery of the pressure receiving portion. The first reinforcing member forms a diaphragm container, and a connecting member that is connected to the diaphragm container and suppresses the strain of the stem is provided.

Further, the connecting member forms a second reinforcing member that comes into contact with the first reinforcing member of the diaphragm container, and an extension portion made of the same material as the stem and having a predetermined length from the stem. In addition, mounting pieces are formed at the lower ends of the second reinforcing member and the extension.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A thin-walled diaphragm (pressure receiving portion) is integrally molded on a cylindrical stem made of a glass material, and a pressure detector chip is arranged on one side of this diaphragm, and a peripheral edge of the diaphragm is formed. Disposing a first reinforcing member made of a metal material (for example, Kovar metal),
By configuring the diaphragm container, the deformation of the stem of the diaphragm container when receiving the pressure of the medium is suppressed by the first reinforcing member, and the diaphragm in the vicinity of the pressure detection chip can be favorably displaced. The pressure of the medium can be detected well.

Further, a second reinforcing member that is in contact with the first reinforcing member of the diaphragm container and is made of a material equivalent to that of the first reinforcing member, and the same material as the stem that covers the second reinforcing member. And an extension consisting of
By connecting a connecting member that forms a mounting piece at the lower ends of the second reinforcing member and the extension to the diaphragm container, the mounting strain when the diaphragm container is mounted is reduced by the first and second reinforcing members. Is suppressed by
Strain generated by the difference in thermal expansion between the mounting portion for mounting and fixing the diaphragm container and the mounting piece is also attenuated by the extension portion having a soft material and having a predetermined length, thus suppressing the strain of the stem. Therefore, the displacement of the diaphragm due to the pressure of the medium can be satisfactorily transmitted to the pressure detection chip,
Accurate pressure detection is possible.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the embodiments shown in the accompanying drawings.

FIGS. 1 to 3 are sectional views of the essential parts showing the first embodiment. In FIG. 1, 7 is a cylindrical shape, for example, a stem made of Kovar glass (glass material), and 8 is formed integrally with the stem 7. The thin-walled diaphragm (pressure receiving portion) 9 is a first diaphragm made of, for example, Kovar metal, iron-nickel alloy (42 alloy), or the like, for preventing the stem 7 from being deformed when the pressure of the medium is applied to the diaphragm 8. The reinforcing member 9 is provided with a step portion 9a for disposing a circuit board to be described later, and the circuit board is adhered and fixed to the step portion 9a with an adhesive or a low melting point glass. A diaphragm container 10 is constituted by the above-mentioned respective parts 7, 8 and 9.

Reference numeral 3 is a pressure detection chip disposed on one side of the diaphragm 8, and 11 is a circuit board for amplifying an electric signal output from the pressure detection chip 3 and for compensating the temperature of the pressure detection chip 3. The circuit board 11 and the pressure detection chip 3 are electrically fixed by means such as wire bonding, and the electric signal processed by the circuit board 11 is
It is pulled out to the outside from a connector 12 arranged at 11 via a wiring cord 13.

In FIG. 2 and FIG. 3, 14 is a connecting member connected to the diaphragm container 10 and having a cylindrical shape substantially similar to the diaphragm container 10. The connecting member 14 is the stem 7.
And an extension 15 made of the same material (Kovar glass)
The reinforcing member 9 and the second reinforcing member 16 made of the same material (Kovar metal or iron-nickel alloy) are formed to have a predetermined length. The extension part 15 and the second reinforcing member 16 are made of the same material as that of the diaphragm container 10 in order to make the strain due to thermal expansion have the same level. The second reinforcing member 16 is configured so that when the facing surfaces of the stem 7 and the extension 15 are brought into contact with each other, the facing surfaces of the first reinforcing member 9 and the second reinforcing member 16 are brought into contact with each other. The second reinforcing member 16 forms a protrusion 17 extending toward the diaphragm container 10. The protrusion 17 prevents distortion of the stem 7 and plays a role of positioning the diaphragm container 10 and the connecting member 14.

A wiring cord is provided approximately at the center of the connecting member 14.
An insertion hole 18 for pulling 13 out is provided,
A step portion 20 for sealing the insertion hole 18 with a filler 19 made of epoxy or the like is formed at the final end of the insertion hole 18. Further, on the side of the step portion 20, the extension portion 15 and the second reinforcing member 16 are drawn outward (the lower ends of the extension portion 15 and the second reinforcing member 16) to connect the diaphragm container 10 to the connecting member 14. A mounting piece 21 for mounting to a mounting portion (not shown) is formed, and the mounting piece 21 is configured such that an elastic member 22 such as an O-ring is attached to the upper surface of the mounting piece 21 to be mounted on the mounting portion. ing.

The above-mentioned diaphragm container 10 and connecting member 14
Means applying a fluorine-based or silicon-based adhesive to the contact surfaces of the protruding portion 17 and the first reinforcing member 9 which are extendedly formed on the second reinforcing member 16 and the stem 7 and the extended portion 15. And fix it with adhesive. The pressure detector A is configured as described above.

According to the first embodiment, the deformation of the stem 7 when receiving the pressure of the medium prevents the first reinforcing member 9 and the second reinforcing member 9 from deforming.
The protrusion portion 17 extended from the reinforcing member 16 suppresses the mounting distortion of the diaphragm container 10 by the second reinforcing member 16 even when the diaphragm container 10 is mounted and fixed to a mounting portion (not shown). And again,
The strain generated by the difference in thermal expansion between the mounting portion and the mounting piece 21 is also softened by the material and is attenuated by the extension portion 15 having a predetermined length, and the strain of the stem 7 can be suppressed, so that the medium Since the displacement of the diaphragm 8 due to the pressure can be satisfactorily transmitted to the pressure detection chip 3, it is possible to accurately detect the pressure.

Next, a second embodiment of the present invention will be described with reference to FIG. 4. The same or corresponding portions as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 4 is a cross-sectional view of the essential parts showing the second embodiment. In the second embodiment, the protrusions formed on the first reinforcing member 9 of the diaphragm container 10 and the second reinforcing member 16 of the connecting member 14 are shown. 17
A gap 24 for disposing an elastic member 22 such as an O-ring is formed on each of the facing surfaces of the stem 7 of the diaphragm container 10 and the extension portion 23 of the connecting member 14 when the facing surfaces thereof are brought into contact with each other. Then, an adhesive or the like is applied to the contact surface between the protruding portion 14 and the first reinforcing member 9 and the connection is fixed, whereby the pressure detector A ′ is configured.

In the second embodiment having such a structure, the stem 7 and the extension portion are considered in consideration of surely abutting the respective facing surfaces of the first reinforcing member 9 and the protruding portion 17 of the second reinforcing member 16. The extension portion 23 is formed so as to have a predetermined space 24 on each surface facing the space 23, and the space 24 is sealed by the elastic member 22. Further, by providing the elastic member 22 as described above, even if the medium to be measured is corrosive (for example, acid or the like), it is possible to prevent the invasion from the gap 24, and the first reinforcing member 9 and It is possible to prevent deterioration of the adhesive agent that adheres the second reinforcing member 16.

Although the pressure detectors A and A'having the connecting member 14 have been described in the first and second embodiments, the present invention does not necessarily require the connecting member 14.
When 14 is not used, by forming a reinforcing member so as to reach the lower end surface of the stem from the diaphragm surface of the diaphragm container, the deformation of the stem when receiving the pressure of the medium,
Since it is possible to suppress the influence on the diaphragm due to the deformation of the stem at the time of mounting, it is possible to detect the pressure satisfactorily as in the above-described embodiment.

Further, the mounting piece 21 in the first and second embodiments.
Is formed so as to be drawn outward together with the extension portions 15 and 23 and the second reinforcing member 16, but the second reinforcing member 16
It is also possible to pull out only the outside to form a mounting piece.

Further, in the first embodiment, the contact surfaces of the diaphragm container 10 and the connecting member 14 are adhered and fixed by using an adhesive, but in order to improve the adhesive strength and reliability,
The stem 7 and the extension 15 may be welded by laser welding.

[0023]

According to the present invention, in a pressure detector in which a pressure detecting chip is bonded on one surface of a pressure receiving portion that is displaced by the pressure of a medium, the pressure receiving portion is formed integrally with a stem made of a glass material, and the pressure receiving portion is formed. The reinforcement member is formed on the peripheral edge of the portion, and the deformation of the stem when pressure is applied is suppressed by the reinforcement member, and the diaphragm in the vicinity of the pressure detection chip can be favorably displaced. The pressure can be detected well.

Further, in a pressure detector in which a pressure detecting chip is bonded to one surface of the pressure receiving portion which is displaced by the pressure of the medium, the pressure receiving portion integrally formed with the stem made of a glass material and the peripheral portion of the pressure receiving portion are formed. And a connecting member that is connected to the diaphragm container and suppresses the strain of the stem, and in particular, the connecting member is the diaphragm. A second reinforcing member that comes into contact with the first reinforcing member of the container, and an extension portion that is made of a material similar to that of the stem and has a predetermined length from the stem are formed, and the second reinforcing member and the extension are provided. A mounting piece is formed at the lower end of the stem to prevent mounting strain when mounting the diaphragm container by the first and second reinforcing members. The shape is suppressed, and the strain caused by the difference in thermal expansion between the mounting portion for mounting and fixing the diaphragm container and the mounting piece is also attenuated by the extension portion which is soft in material and has a predetermined length. Since the strain of the stem can be suppressed, the displacement of the diaphragm due to the pressure of the medium can be satisfactorily transmitted to the pressure detection chip, so that the accurate pressure can be detected.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a diaphragm container according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing the connecting member of the first embodiment.

FIG. 3 is a sectional view of a main part showing the pressure detector of the first embodiment.

FIG. 4 is a cross-sectional view of essential parts showing a pressure detector according to a second embodiment of the invention.

FIG. 5 is a sectional view of a main part showing a conventional example.

[Explanation of symbols]

 3 Pressure detection chip 7 Stem 8 Diaphragm (pressure receiving part) 9 First reinforcing member 10 Diaphragm container 14 Connection member 15,23 Extension part 16 Second reinforcing member 17 Projection part A, A'Pressure detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Wakai 1-1190, Fujihashi, Nagaoka City, Niigata Prefecture Nippon Seiki Co., Ltd. R & D Center

Claims (3)

[Claims] 1. A pressure detector in which a pressure detection chip is bonded to one surface of a pressure receiving portion that is displaced by the pressure of a medium, wherein the pressure receiving portion is formed integrally with a stem made of a glass material, and the pressure receiving portion is formed on the periphery of the pressure receiving portion. A pressure detector comprising a reinforcing member. 2. A pressure detector in which a pressure detection chip is bonded to one surface of a pressure receiving portion that is displaced by the pressure of a medium, the pressure receiving portion being integrally molded with a stem made of a glass material, and formed on the periphery of the pressure receiving portion. A pressure detector, comprising: a diaphragm container formed by the first reinforcing member, and a connection member connected to the diaphragm container to suppress distortion of the stem. 3. The connecting member forms a second reinforcing member that comes into contact with the first reinforcing member of the diaphragm container, and an extension portion that is made of the same material as the stem and has a predetermined length from the stem. The pressure detector according to claim 2, wherein a mounting piece is formed at the lower ends of the second reinforcing member and the extension.