JPH07167657A - Gas rate sensor manufacturing method and gas rate sensor - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a method of manufacturing a gas rate sensor and a gas rate sensor, and in particular, an object thereof is to form an electrode and a sensing wire by using an etching process to obtain a microminiature and highly accurate structure. And [Method] A method of manufacturing a gas rate sensor and a gas rate sensor according to the present invention include electrodes (6a to 6d), sensing wires (7a, 7b), and through holes formed on a substrate (30) made of an insulating material, a semiconductor, or a conductor by etching. (35, 36) is formed and a gas rate sensor is formed by etching.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas rate sensor, and more particularly to a novel improvement for obtaining an ultra-compact and highly accurate gas rate sensor by forming electrodes, sensing wires and the like by using an etching process.

[0002]

2. Description of the Related Art As a gas rate sensor of this type that has been conventionally used, for example, the configuration disclosed in Japanese Patent Laid-Open No. 1-166771 shown in FIGS. That is, reference numeral 1 in FIGS.
What is indicated by is a casing which has a substantially cylindrical shape as a whole and is open at both ends. Each end of this casing 1 is closed by a pump holder 2 and a relay terminal plate 3, respectively. The inside is blocked from the outside. The pump holder 2 is provided with a vibrating plate 4a made of an electrostrictive ceramic disc, and the peripheral portion of the vibrating plate 4a is integrally fixed to the pump holder 2, whereby the electrostrictive vibrating pump 4 (gas pump) is Has been formed.

Further, inside the casing 1, the electrode holder 5 is provided at a position separated from the vibrating plate 4a by a predetermined distance.
Are arranged, and the electrode holder 5 is configured as shown in FIG. That is, the electrode holder 5 is formed with four gas guide holes 5a to 5d, and further four electrodes 6a to 6d are arranged symmetrically with respect to the central axis. Of these electrodes 6a-6d, electrodes 6a and 6b
Between the space and between 6c and 6d, hot wires 7a and 7b
Are connected by welding.

Further, in the vicinity of the relay terminal plate 3 in the casing 1, a nozzle hole 8 and an auxiliary hole 9 are provided.
A nozzle plate 10 having a nozzle plate 10 is provided, and a dust plate 11 is provided between the relay terminal plate 3 and the nozzle plate 10 at a substantially intermediate position therebetween. A pump chamber 12 is formed between the diaphragm 4 a of the electrostrictive vibration pump 4 (gas pump) and the pump holder 2, and the gas delivered by the electrostrictive vibration pump 4 is a gas guide hole. 5
It is sent to the gas flow path 13 via a to 5d.

A signal processing circuit section 14 composed of an IC is provided outside the relay terminal plate 3 of the casing 1.
The signal processing circuit unit 14 receives power from the outside and
It is connected to the relay terminal 15 of the relay terminal plate 3 for taking out the output signals of the hot wires 7a and 7b to the outside.

The relay terminal plate 3 has lead pins 1
6 is provided, and this lead pin 16 has an outer casing 1
7 is connected to an external terminal 18 provided on the terminal 7. The external terminal 18 supplies the electric power required for operating the electrostrictive vibration pump 4 and the electric power required for heating the hot wires 7a and 7b to the signal processing circuit section 14 and the lead pin 16.
And has a function of appropriately supplying it through a plurality of lead wires 19 arranged in the axial direction in the casing 1. Further, the external terminal 18 has a function of outputting the output signals of the hot wires 7a and 7b after passing through the signal processing circuit section 14 to the outside.

The conventional gas rate sensor is constructed as described above, and its operation will be described below. First, when the electrostrictive vibration pump 4 (gas pump) is energized, the vibrating plate 4a vibrates and the gas in the pump chamber 12 is compressed. The compressed gas is discharged from the vibrating plate 4a and the electrode holder 5 is discharged. Through the discharge port 5e of
Each of the electrodes 6a to 6d is introduced into the space formed between the nozzle plate 10 and the dust plate 11, passes through the nozzle hole 8 and the auxiliary port 9, and inside the space 1b inside the hollow cylindrical portion 1a inside the casing 1. It is ejected toward 6d.

The above-mentioned compressed gas is uniformly discharged to the hot wires 7a and 7b welded to the electrodes 6a to 6d, and then discharged toward the diaphragm 4a through the gas guide holes 5a to 5d. The gas again passes through the flow path 13 and the nozzle plate 10 by the action of the electrostrictive vibration pump 4 (gas pump).
, And circulates in the casing 1 in the direction of the arrow. In the above-described state, when the angular velocity is not applied to the casing 1, the hot wires 7a and 7b are uniformly cooled, but when the angular velocity is applied from the outside, the gas flow is deviated in the casing 1. However, a non-uniform state occurs between the hot wires 7a and 7b, which causes a minute voltage difference between the hot wires 7a and 7b. By measuring this voltage difference, the voltage is applied to the casing 1. The angular velocity can be detected.

[0009]

Since the conventional gas rate sensor is constructed as described above, it has the following various problems. That is, the sensing wire must be welded between the electrodes by soldering, etc.
The welding work was extremely difficult because the sensing wire was thin (tens of microns). In addition, in the overall configuration of the gas rate sensor, only the sensing wire is provided on the electrode holder, and all the other circuits and the like are provided on the casing side, which limits the miniaturization. Further, the characteristics differ depending on the temperature difference between the sensing unit and the other lead wires and the resistance unit, and there is a problem in the accuracy of the gas rate sensor as a whole.

The present invention has been made to solve the above problems, and in particular, an electrode, a sensing wire and the like are formed by using an etching process to obtain an ultra-compact and highly accurate gas rate sensor. With the goal.

[0011]

A gas rate sensor according to the present invention comprises a first step of forming a metal film on a substrate made of an insulating material and capable of being etched, and a plurality of electrodes and sensing wires by etching the metal film. And a third step of forming a through hole in the substrate below each of the sensing wires by etching after the completion of the second step.

The method of manufacturing the gas rate sensor according to the present invention is as follows.
A first step of forming an insulating film on a substrate made of a semiconductor or a conductor and capable of being etched, a second step of forming a metal film on the insulating film, and forming a plurality of electrodes and sensing wires on the metal film by etching. The method comprises a third step of forming and a fourth step of forming a through hole in the substrate and the insulating film below each sensing wire by etching after the completion of the third step.

The gas rate sensor according to the present invention comprises a substrate made of an insulating material and capable of being etched, an electrode provided on the substrate and having a plurality of sensing wires, a plurality of resistors provided on the substrate, A through hole formed on a substrate and corresponding to the sensing wire is provided, and gas can be supplied to the sensing wire through the through hole.

The gas rate sensor according to the present invention comprises a substrate made of a semiconductor or a conductor and capable of being etched, an electrode having a plurality of sensing wires provided on the substrate via an insulating film, and provided on the substrate. A configuration is provided in which a plurality of resistors and first and second through holes formed in the substrate and the insulating film and corresponding to the sensing wires are provided, and gas can be supplied to the sensing wires through the through holes. .

More specifically, the amplifier is connected to the electrode on the substrate.

More specifically, the amplifier is provided on the insulating film so as to be connected to the electrodes.

[0017]

In the method of manufacturing a gas rate sensor and the gas rate sensor according to the present invention, a plurality of electrodes and sensing wires are formed on a metal film on a substrate by etching, and through holes are formed on the substrate corresponding to the sensing wires by sensing. And the resistance and the amplifier are directly or indirectly provided on the substrate, the overall configuration is ultra-miniature, and the angular velocity input by each sensing wire can be detected with high accuracy. .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a gas rate sensor manufacturing method and a gas rate sensor according to the present invention will be described in detail below with reference to the drawings. In addition, the same or equivalent portions as those of the conventional example will be described using the same reference numerals. 1 to 5 show a method of manufacturing a gas rate sensor according to the present invention. Reference numeral 30 in FIGS. 1 to 5 denotes, for example, a substrate made of a semiconductor or a conductor and capable of being etched, and the substrate 30 is capable of being etched through an insulating film 31 made of an etchable material. A metal film 32 made of a material is formed.

In the above structure, when the etching process is performed by the well-known photo etching technique, the plurality of electrodes 6a are formed according to the pattern (not shown) of the photo mask.
A pair of sensing wires 7a and 7b spaced apart from each other are integrally formed so as to be integrally connected to 6d to 6d.
In addition, the metal film 32 is provided in the vicinity of each of the electrodes 6a to 6d.
A frame portion 34 made of is formed.

Next, the substrate 30 and the insulating film 31 described above are subjected to an etching process, as shown in FIG. 5, so as to correspond to the sensing wires 7a and 7b. 35 and 36 are formed. The first through hole 35 is formed in the substrate 30, and the second through hole 36 is formed in the insulating film 31.

By the above-mentioned etching processes, the sensing wires 7a and 7b are formed in an electrically independent state, and the gas rate sensor 40 having the structure shown in FIG. 4 and FIG. By supplying gas from above the sensing wires 7a and 7b and allowing the gas to pass through the through holes 35 and 36, a gas drift caused by a known external angular velocity input is applied to the sensing wires 7a and 7b. It can be detected as a resistance difference of 7b.

Also, in the above-described embodiment, the substrate 30
Although the case where the metal film 32 is formed on the insulating film 31 is described above, for example, the substrate 30 is made of an etchable insulating material such as crystal, sapphire, or glass,
The metal film 32 is directly formed on the substrate 30, and the sensing wires 7a and 7b and the first wire are formed by etching.
The gas rate sensor 40 may be obtained by forming the through hole 35.

As is well known, the gas rate sensor 40 is constructed as shown in FIG. 9 as an electrical connection, and has a pair of resistors R ₁ and R ₂ and sensing wires 7a and 7b. The bridge circuit 41 is constituted by the above, and the output signal 14A can be obtained by the amplifier 14 which is connected to the bridge circuit 41 and is composed of the differential amplifier.

In the case of another embodiment shown in FIG. 6, the resistors R ₁ and R ₂ are provided on the insulating film 31 between the electrodes 6a to 6d, and the other electrodes 6b and 6c are connected to the connecting portion 6A. It is also possible to form a structure in which the thickening device 14 is provided on the insulating film 31 so as to obtain the electrical connection of FIG.
In addition, the number of sensing wires 7a and 7b may be two or more for multi-axis detection.

[0025]

Since the gas rate sensor manufacturing method and the gas rate sensor according to the present invention are configured as described above, the following effects can be obtained. That is, since the electrodes and the sensing wires are formed on the substrate by etching, and the through holes for gas supply to the substrate are formed by etching, the configuration of the gas rate sensor is extremely easy and the miniaturization is achieved. And high precision can be achieved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a method of manufacturing a gas rate sensor according to the present invention.

FIG. 2 is a configuration diagram in which the sensing wire of FIG. 1 is etched.

FIG. 3 is a perspective view of FIG. 2.

FIG. 4 is a perspective view showing a gas rate sensor after the final etching process.

5 is a cross-sectional view of FIG.

FIG. 6 is a perspective view showing another embodiment.

FIG. 7 is a cross-sectional view showing a conventional gas rate sensor.

8 is a cross-sectional view of the main part of FIG.

FIG. 9 is an electrical connection diagram of a conventional gas rate sensor.

[Explanation of symbols]

6a to 6d Electrodes 7a and 7b Sensing wires R ₁ and R ₂ Resistance 14 Magnifier 30 Substrate 31 Insulating film 32 Metal film 35, 36 Through hole

Claims (6)

[Claims] 1. A first step of forming a metal film (32) on a substrate (30) made of an insulating material and capable of being etched, and a plurality of electrodes (6a to 6d) and a plurality of electrodes (6a to 6d) formed by etching the metal film (32). A second step of forming the sensing wires (7a, 7b), and after the second step is completed, a through hole (35) is formed in the substrate (30) below each of the sensing wires (7a, 7b) by etching. A method of manufacturing a gas rate sensor, which comprises the third step. 2. A first step of forming an insulating film (31) on a substrate (30) made of a semiconductor or a conductor and capable of being etched, and a first step of forming a metal film (32) on the insulating film (31). In two steps, the metal film (32) is etched into a plurality of electrodes (6a
~ 6d) and a third step of forming the sensing wires (7a, 7b), and after the completion of the third step, each of the sensing wires (7a, 7a, 7b)
A method of manufacturing a gas rate sensor, comprising a fourth step of forming through holes (35, 36) by etching in the substrate (30) and the insulating film (31) below 7b). 3. A substrate (30) made of an insulating material and capable of being etched, electrodes (6a to 6d) provided on the substrate (30) and having a plurality of sensing wires (7a, 7b), and the substrate (30). 3
0) a plurality of resistors (R ₁ , R ₂ ) provided on the substrate (30)
It is provided with a through hole (35) corresponding to the sensing wire (7a, 7b) formed in, the gas can be supplied to the sensing wire (7a, 7b) through the through hole (35). Characteristic gas rate sensor. 4. A substrate (30) made of a semiconductor or a conductor and capable of being etched, and an electrode () having a plurality of sensing wires (7a, 7b) provided on the substrate (30) via an insulating film (31). and 6 a to 6 d), a plurality of resistors provided in the upper substrate (30) and (R _1, R _2), said formed substrate (30) and the insulating film (31) the sensing wire (7a, 7b) The first and second through holes (35, 36) corresponding to the above are provided, and the gas can be supplied to the sensing wires (7a, 7b) through the through holes (35, 36). Gas rate sensor that does. 5. The electrodes (6a-6d) are provided on the substrate (30).
A gas rate sensor characterized in that an amplifier (14) connected to is provided. 6. The electrodes (6a-6) on the insulating film (31).
Gas rate sensor according to claim 4, characterized in that it is provided with an amplifier (14) connected to d).