JP2013181950A - Method for encapsulating encapsulation liquid of differential pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a zero point adjustment mechanism of a differential pressure sensor, to eliminate necessity to adjust a zero point as an independent process after completion of assembly of the differential pressure sensor, and to guarantee long term stability of zero point adjustment.SOLUTION: Encapsulation chambers 6-1 and 6-2 are made into vacuum, a medium 5-1 for transmitting pressure is encapsulated in the encapsulation chamber 6-1, and a medium 5-2 for transmitting pressure is encapsulated in the encapsulation chamber 6-2. Then, the medium 5-2 for transmitting the pressure is sealed in the encapsulation chamber 6-2, a signal ΔP to be output from a sensor diaphragm 3-1 is monitored while performing pressure encapsulation of the medium 5-1 for transmitting the pressure, when it is confirmed that the signal ΔP reaches a setting value which is preset as a zero point output value, the pressure encapsulation of the medium 5-1 for transmitting the pressure is terminated, and the medium 5-1 for transmitting the pressure is sealed in the encapsulation chamber 6-1.

Description

  The present invention relates to a sealing liquid sealing method for a sealing liquid sealing type differential pressure sensor that seals a pressure transmission medium as a sealing liquid.

  Conventionally, there are various types of differential pressure sensors. Among them, there is a sealed liquid sealing type differential pressure sensor in which a pressure transmission medium is sealed as a sealed liquid (for example, see Patent Document 1). . In this sealed liquid-sealed differential pressure sensor, an incompressible fluid such as silicone oil is used as a pressure transmission medium. FIG. 8 shows a cross-sectional view of a main part of an example of a conventional sealed liquid-sealed differential pressure sensor.

  In FIG. 8, 1 is a metal body, and has a first space 1-2 and a second space 1-3 partitioned by a partition wall 1-1 as an internal space. The partition wall 1-1 is provided with a through passage 1-4 that communicates the first space 1-2 and the second space 1-3. A first metal diaphragm (first pressure receiving diaphragm) 2-1 is provided in the opening 1-2a of the first space 1-2, and the opening 1-3a of the second space 1-3 is provided in the opening 1-3a. Is provided with a second metal diaphragm (second pressure receiving diaphragm) 2-2.

  Reference numeral 3 denotes a sensor chip, which is composed of a sensor diaphragm 3-1 and a pedestal 3-2. The sensor diaphragm 3-1 is made of silicon or the like, and the pedestal 3-2 is made of silicon or glass. The center portion of the sensor diaphragm 3-1 is thin, and a recess 3-1c is formed on the other surface 3-1b with respect to the one surface 3-1a, and the other of which the recess 3-1c is formed. One end surface 3-2a of the pedestal 3-2 is joined to the surface 3-1c side. The pedestal 3-2 has a cylindrical shape, and the communication passage 3- connected to the other surface 3-1b of the sensor diaphragm 3-1 by the hollow portion 3-2c and the concave portion 3-1c of the sensor diaphragm 3-1. 3 is formed.

  The sensor chip 3 has a communication passage 3-3 that communicates with the other surface 3-1b of the sensor diaphragm 3-1, such that one surface 3-1a of the sensor diaphragm 3-1 faces the first pressure receiving diaphragm 2-1. It is joined to the wall surface 1-1a of the partition wall 1-1 located on the first space 1-2 side so as to communicate with the through passage 1-4 of the partition wall 1-1. That is, the other end surface 3-2b of the pedestal 3-2 is connected to the wall surface 1- 1 of the partition wall 1-1 so that the hollow portion 3-2c of the pedestal 3-2 communicates with the through passage 1-4 of the partition wall 1-1. It is made to join to 1a. Hereinafter, a joint portion between the pedestal 3-2 and the partition wall 1-1 is referred to as a first joint portion 4-1, and a joint portion between the pedestal 3-2 and the sensor diaphragm 3-1 is referred to as a second joint portion 4-2. To do.

  The body 1 is sealed with a first pressure transmission medium 5-1 using the first space 1-2 as the first enclosure chamber 6-1. In addition, the communication path 3-3 that communicates with the second space 1-3, the through passage 1-4 of the partition wall 1-1, and the other surface 3-1b of the sensor diaphragm 3-1 is defined as a second enclosure chamber 6-2. The second pressure transmission medium 5-2 is sealed. The sealing of the first pressure transmission medium 5-1 into the first enclosure chamber 6-1 and the sealing of the second pressure transmission medium 5-2 into the second enclosure chamber 6-2 are as follows. Both are performed under the same conditions (under atmospheric pressure), and the sealing pressures of the first pressure transmission medium 5-1 and the second pressure transmission medium 5-2 are equal.

  In this sealed liquid sealing type differential pressure sensor 100, the pressure P1 received by the first pressure receiving diaphragm 2-1 is one surface 3 of the sensor diaphragm 3-1 via the first pressure transmission medium 5-1. The pressure P2 received by the second pressure receiving diaphragm 2-2 is transmitted to the other surface 3-1b of the sensor diaphragm 3-1 via the second pressure transmitting medium 5-2. As a result, the sensor diaphragm 3-1 bends according to the pressure difference between the pressures P1 and P2, and a signal according to the pressure difference is output from the sensor diaphragm 3-1. The sensor diaphragm 3-1 is formed with a strain resistance gauge whose resistance value changes according to a pressure change as a configuration for outputting a signal according to the pressure difference.

  Usually, the first pressure receiving diaphragm 2-1 receiving the pressure P1 is used as the high pressure side, and the second pressure receiving diaphragm 2-2 receiving the pressure P2 is set as the low pressure side.

  In the differential pressure sensor 100, since the internal sensor chip 3 has individual characteristic variations, the output when the pressure difference between the pressures P1, P2 to the pressure receiving diaphragms 2-1 and 2-2 is zero (zero point). (Zero output adjustment) is performed after assembly of the differential pressure sensor 100 is completed.

  Note that Patent Document 2 discloses a method and mechanism for adjusting the zero point of the differential pressure sensor. Patent Document 2 discloses various examples of a zero point adjustment mechanism provided in a differential pressure sensor. For example, in FIG. 1 of Patent Document 2, the pressure receiving diaphragm displacement means provided on the high pressure side causes the high pressure side pressure receiving diaphragm to be recessed so that the rigidity when expanded is smaller than that of the low pressure side pressure receiving diaphragm. A configuration is shown in which the shift of the output to the positive side due to the large amount of medium used is reduced. Further, in FIG. 4 of Patent Document 2, a communication path that communicates the high pressure side pressure transmission medium and the low pressure side pressure transmission medium is provided, and the high pressure side pressure transmission medium and the low pressure side pressure are provided in the middle of the communication path. A configuration is shown in which a valve mechanism for changing the ratio of the amount of the transmission medium enclosed is provided.

JP-A-1-241193 (Patent No. 2595749) JP 2000-205985 A

  However, the numerous zero point adjustment mechanisms disclosed in Patent Document 2 may deteriorate as the differential pressure sensor is used for a long time, or the adjustment may be shifted when an excessive pressure is applied to the pressure receiving diaphragm. There was a problem that the long-term stability of zero adjustment was not guaranteed. In addition, a mechanism for adjusting the zero point must be provided, and a step for adjusting the zero point after the assembly of the differential pressure sensor is also required.

  The present invention has been made to solve such a problem. The object of the present invention is to provide a zero point adjusting mechanism in the differential pressure sensor or to perform a zero point as an independent process after the assembly of the differential pressure sensor is completed. It is an object of the present invention to provide a method for enclosing a sealing liquid in a differential pressure sensor that can guarantee the long-term stability of zero-point adjustment without having to perform the above adjustment.

  In order to achieve such an object, the present invention provides a sensor chip including a sensor diaphragm that outputs a signal corresponding to a pressure difference received on one surface and the other surface, and a body that accommodates the sensor chip in its internal space. A first pressure receiving diaphragm provided in a first opening communicating with the internal space of the body, a second pressure receiving diaphragm provided in a second opening communicating with the internal space of the body, A first sealing chamber formed between the pressure receiving diaphragm and the one surface of the sensor diaphragm is sealed as a sealing liquid, and the pressure received by the first pressure receiving diaphragm is transmitted to one surface of the sensor diaphragm. The second pressure receiving diaphragm is sealed as a sealed liquid in a second sealing chamber formed between the pressure transmission medium, the second pressure receiving diaphragm and the other surface of the sensor diaphragm. A sealing method for sealing liquid in a differential pressure sensor comprising a second pressure transmission medium for transmitting the received pressure to the other surface of the sensor diaphragm, wherein the first sealing chamber and the second sealing chamber are evacuated. A second step of enclosing the first pressure transmission medium in the first enclosure chamber and enclosing the second pressure transmission medium in the second enclosure chamber after the first step; A third step of sealing the second pressure transmitting medium sealed in the second sealing chamber after the second pressure transmitting medium is sealed in the second sealing chamber; and the first sealing chamber After the first pressure transmission medium is sealed into the first pressure chamber, the fourth step of pressurizing and sealing the first pressure transmission medium into the first sealing chamber, and the output from the sensor diaphragm during the execution of the fourth step The fifth step of monitoring the signal and the value of the signal output from the sensor diaphragm monitored in the fifth step are the first When it is confirmed that a preset value has been reached as a value to be output when the pressure difference between the pressure received by the pressure receiving diaphragm and the pressure received by the second pressure receiving diaphragm is zero, the first enclosure chamber A sixth step of ending the pressure sealing of the first pressure transmission medium to the first sealing chamber, and after the completion of the pressure sealing of the first pressure transmission medium to the first sealing chamber, And a seventh step of sealing the pressure-filled first pressure transmission medium.

  According to this invention, the first sealing chamber and the second sealing chamber are evacuated in the first step, the first pressure transmission medium is sealed in the first sealing chamber in the second step, and the first The second pressure transmission medium is sealed in the two sealing chambers. Then, after the second pressure transmission medium is sealed in the second enclosure chamber, the second pressure transmission medium is sealed in the second enclosure chamber. In addition, after the first pressure transmission medium is sealed in the first sealing chamber, pressurization and sealing of the first pressure transmission medium in the first sealing chamber is started, and the first sealing chamber is transferred to the first sealing chamber. During pressurization of the first pressure transmission medium, the signal output from the sensor diaphragm is monitored. The value of the signal output from the sensor diaphragm is determined in advance as a value to be output when the differential pressure between the pressure received by the first pressure receiving diaphragm and the pressure received by the second pressure receiving diaphragm is zero. When the predetermined set value is reached, pressurization and sealing of the first pressure transmission medium into the first sealing chamber is finished. Then, after the pressure sealing of the first pressure transmission medium into the first sealing chamber is completed, the first pressure transmission medium is sealed in the first sealing chamber.

  Thus, according to the present invention, the zero point adjustment of the differential pressure sensor is substantially performed when the sealing of the first pressure transmission medium and the second pressure transmission medium to the differential pressure sensor is completed. It will be. For this reason, it is not necessary to perform the zero point adjustment as an independent process after the assembly of the differential pressure sensor, and it is not necessary to provide a zero point adjusting mechanism in the differential pressure sensor. Further, since there is no zero point adjustment mechanism in the differential pressure sensor, there is no possibility of deterioration even when used for a long period of time, and it is possible to ensure the long-term stability of zero point adjustment.

  In the present invention, the sensor chip is accommodated in the internal space of the differential pressure sensor. For example, a body having a first space and a second space defined by a partition wall having a through passage as internal spaces is provided, and a first pressure receiving diaphragm is provided in an opening of the first space of the body. A second pressure receiving diaphragm is provided in the opening of the second space. Then, one side of the sensor diaphragm faces the first pressure receiving diaphragm, and the communication path communicating with the other surface of the sensor diaphragm is communicated with the through-passage of the partition wall, so that the partition wall located on the first space side The sensor chip is bonded to the wall surface. Then, the first pressure transmission medium is sealed in the first space, and the second pressure transmission medium is sealed in the communication path that communicates with the second space, the through-hole of the partition wall, and the other surface of the sensor diaphragm. To do.

  In the present invention, the sensor chip only needs to include a sensor diaphragm, and may not necessarily have a configuration including a sensor diaphragm and a pedestal. When the sensor chip is configured to include a sensor diaphragm and a pedestal, the joint portion of the sensor chip includes a joint portion between one end surface of the pedestal and the other surface side of the sensor diaphragm, the other end surface of the pedestal, and a partition wall. There are two places at the joint with the wall. When the sensor chip is configured only by the sensor diaphragm, the joint portion of the sensor chip is one place of the joint portion between the wall surface of the partition wall and the other surface side of the sensor diaphragm.

  According to the present invention, after the second pressure transmitting medium is completely sealed in the second sealing chamber, the first pressure transmitting medium is pressurized and sealed in the first sealing chamber. During pressurization and sealing of the first pressure transmission medium in the sealing chamber, the signal output from the sensor diaphragm is monitored, and the value of the signal output from the sensor diaphragm is equal to the pressure received by the first pressure receiving diaphragm and the second pressure. When it is confirmed that a preset value is reached as an output value when the pressure difference between the pressure received by the pressure receiving diaphragm is zero, the first pressure transmission medium is applied to the first enclosure chamber. Since the pressure sealing is finished and the first pressure transmitting medium pressurized and sealed in the first sealing chamber is sealed, the first pressure transmitting medium to the differential pressure sensor and the second pressure transmitting medium are sealed. When the sealing of the pressure transmission medium is completed, the zero point adjustment of the differential pressure sensor is The thing that takes place. For this reason, it is not necessary to perform the zero point adjustment as an independent process after the assembly of the differential pressure sensor, and it is not necessary to provide a zero point adjusting mechanism in the differential pressure sensor. Further, since there is no zero point adjustment mechanism in the differential pressure sensor, there is no possibility of deterioration even when used for a long period of time, and it is possible to ensure the long-term stability of zero point adjustment.

It is sectional drawing which shows the principal part of one Embodiment (Embodiment 1) of the differential pressure sensor with which the sealing liquid was sealed using the sealing liquid sealing method of the differential pressure sensor which concerns on this invention. It is sectional drawing which shows the principal part of other Embodiment (Embodiment 2) of the differential pressure sensor with which the sealing liquid was sealed using the sealing liquid sealing method of the differential pressure sensor which concerns on this invention. It is a figure explaining the sealing process (1st process) of the sealing liquid of the differential pressure sensor of Embodiment 1. FIG. It is a figure explaining the sealing process (2nd process) of the sealing liquid of the differential pressure sensor of Embodiment 1. FIG. It is a figure explaining the sealing process (3rd process) of the sealing liquid of the differential pressure sensor of Embodiment 1. FIG. It is a figure explaining the sealing process (4th process, 5th process, 6th process) of the sealing liquid of the differential pressure sensor of Embodiment 1. FIG. It is a figure explaining the sealing process (7th process) of the sealing liquid of the differential pressure sensor of Embodiment 1. FIG. It is sectional drawing which shows the principal part of an example of the conventional sealing liquid sealing type differential pressure sensor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a main part of one embodiment (embodiment 1) of a differential pressure sensor sealed with a sealed liquid using the sealed liquid sealing method of the differential pressure sensor according to the present invention. In FIG. 8, the same reference numerals as those in FIG. 8 denote the same or equivalent components as those described with reference to FIG.

  In the differential pressure sensor of the first embodiment, the sealing pressure of the first pressure transmission medium 5-1 sealed in the first sealing chamber 6-1 is sealed in the second sealing chamber 6-2. The sealing pressure of the stopped second pressure transmission medium 5-2 is set higher. A differential pressure sensor in which the sealing pressure of the first pressure transmission medium 5-1 is higher than the sealing pressure of the second pressure transmission medium 5-2 is distinguished from the differential pressure sensor 100 shown in FIG. For this reason, reference numeral 200 indicates.

  Further, in this differential pressure sensor 200, the sensor chip 3 is composed of the sensor diaphragm 3-1 and the pedestal 3-2, but the pedestal 3-2 is omitted and the sensor diaphragm 3 is omitted as shown in FIG. -1 may be the sensor chip 3 and may be configured to be bonded to the wall surface 1-1a of the partition wall 1-1 (second embodiment). In the differential pressure sensor 300, the concave portion 3-1c of the sensor diaphragm 3-1 serves as a communication path 3-3 that communicates with the other surface 3-1b of the sensor diaphragm 3-1. Further, the sensor chip 3 has only one joint portion of the joint portion 4-1 between the other surface 3-1b side of the diaphragm 3-1 and the wall surface 1-1a of the partition wall 1-1.

[Encapsulation of sealing liquid]
Next, referring to FIG. 3 to FIG. 7, a sealing liquid filling step when the differential pressure sensor 200 is assembled will be described as an embodiment of the sealing liquid sealing method according to the present invention.

  In FIG. 3, 7 is an oil pot, 8 is a filled liquid (pressure transmission medium) stored in the oil pot, 9 is a vacuum pump, 10 is a pressurizing device, 11 is a controller, and 12 to 16 are valves. Thus, a sealing device 400 for sealing liquid with respect to the differential pressure sensor 200 is configured.

  In this sealing device 400, the valve 15 is provided in the communication path L1 to the first sealing chamber 6-1 of the differential pressure sensor 200, and the valve 14 is the second sealing chamber 6- 6 of the differential pressure sensor 200. 2 is provided in the communication path L2. The communication passages L1 and L2 communicate with the main pipeline L3 via valves 15 and 14, and a valve 13 is provided between the main pipeline L3 and the oil pot 7, and between the main pipeline L3 and the vacuum pump 9. A valve 12 is provided, and a valve 16 is provided between the main line L3 and the pressurizing device 10.

  The controller 11 is realized by hardware including a processor and a storage device, and a program that realizes various functions in cooperation with the hardware. The controller 11 responds to a signal ΔP output from the sensor diaphragm 3-1 in the differential pressure sensor 200, that is, a pressure difference received by one surface 3-1a and the other surface 3-2a of the sensor diaphragm 3-1. The signal ΔP is sent.

  The controller 11 is set with a set value ΔP0 that is compared with the value of the signal ΔP from the sensor diaphragm 3-1. This set value ΔP0 should be output from the sensor diaphragm 3-1 when the pressure difference between the pressure P1 received by the first pressure receiving diaphragm 2-1 and the pressure P2 received by the second pressure receiving diaphragm 2-2 is zero. It is predetermined as the value of the signal ΔP (zero point output value).

  Using the sealing device 400 configured and connected in this manner, the first pressure transmission medium 5-1 is supplied to the first sealing chamber 6-1 of the differential pressure sensor 200 through the following steps. The second pressure transmission medium 5-2 is sealed in the second sealing chamber 6-2. The pressure transmission mediums 5-1 and 5-2 are sealed under a constant temperature and an atmospheric pressure.

[First step]
First, as shown in FIG. 3, the valves 13 and 16 are closed, the valves 12, 14 and 15 are opened, the vacuum pump 9 is activated, and the first enclosure chamber 6-1 and the second chamber 2 of the differential pressure sensor 200 are activated. The inside of the enclosure chamber 6-2 is evacuated.

[Second step]
Next, as shown in FIG. 4, the valve 12 is closed, the valve 13 is opened, and the oil is stored in the oil pot 7 in the first enclosure chamber 6-1 and the second enclosure chamber 6-2 of the differential pressure sensor 200. The filled liquid 8 is poured. That is, the first pressure transmission medium 5-1 is enclosed in the first enclosure chamber 6-1, and the second pressure transmission medium 5-2 is enclosed in the second enclosure chamber 6-2.

[Third step]
Then, after the end of the sealing, as shown in FIG. 5, the valve 13 and the valve 14 are closed, the communication path L2 is closed and disconnected, and the second pressure transmission medium 5-2 is placed in the second sealing chamber 6-2. Is sealed. As a result, the second pressure transmission medium 5-2 is sealed in the second enclosure chamber 6-2 at atmospheric pressure.

[Fourth step]
Next, as shown in FIG. 6, the valve 16 is opened, the pressurizing device 10 is started, and pressurization of the first pressure transmission medium 5-1 into the first enclosing chamber 6-1 is started. To do.

[Fifth step]
During pressurization and sealing of the first pressure transmission medium 5-1 into the first sealing chamber 6-1 by the pressurizing device 10, the controller 11 monitors the signal ΔP output from the sensor diaphragm 3-1. .

[Sixth step]
When the controller 11 confirms that the value of the signal ΔP output from the signal ΔP output from the sensor diaphragm 3-1 has reached the preset value ΔP0 that is predetermined as the zero point output value, the controller 11 Send a stop signal. Thereby, pressurization enclosure of the 1st pressure transmission medium 5-1 to the 1st enclosure chamber 6-1 is completed.

[Seventh step]
After the pressurization and sealing of the first pressure transmission medium 5-1 into the first sealing chamber 6-1 is completed, as shown in FIG. 7, the valve 15 and the valve 16 are closed, and the communication path L1 is opened. The first pressure transmission medium 5-1 is sealed in the first enclosure chamber 6-1 by closing and separating. Thus, the first pressure transmission medium 5-1 is sealed in a state of being pressurized in the first enclosure chamber 6-1.

  By passing through such a sealing process, the second pressure transmission medium 5-2 is sealed in the second sealing chamber 6-2 at atmospheric pressure, and the second pressure transmission medium 5-2 In a state where the pressure is higher than the sealing pressure, the first pressure transmission medium 5-1 is sealed in the first sealing chamber 6-1.

  Further, the zero point adjustment of the differential pressure sensor 200 is completed when the sealing of the first pressure transmission medium 5-1 and the second pressure transmission medium 5-2 is completed through such an encapsulation process. Is substantially performed. This eliminates the need for zero point adjustment as an independent process after assembly of the differential pressure sensor 200, and eliminates the need to provide a zero point adjustment mechanism in the differential pressure sensor 200. In addition, since the zero point adjustment mechanism does not exist in the differential pressure sensor 200, there is no possibility of deterioration even when used for a long period of time, and it is possible to ensure the long-term stability of the zero point adjustment. In addition, since there are no restrictions on the design related to zero point adjustment, the degree of freedom in design is increased, and the design burden can be reduced and the product performance can be improved.

  In the sealing step of the sealing liquid described above, the first pressure transmitting medium 5-1 and the second pressure transmitting medium 5- to the first sealing chamber 6-1 and the second sealing chamber 6-2 are used. 2 was sealed, the second pressure transmission medium 5-2 was sealed, and then the pressure sealing of the first pressure transmission medium 5-1 was started. Encapsulation of the first pressure transmission medium 5-1 into one enclosure chamber 6-1 and enclosure of the second pressure transmission medium 5-2 into the second enclosure chamber 6-2 are performed independently. In this manner, the first pressure transmission medium 5-1 is continuously sealed and pressurized and sealed in the first sealing chamber 6-1 while the second pressure transmission medium 5-2 is sealed. It may be.

  Further, in the sealing step of the sealing liquid described above, the vacuum pump 9 is started, the pressurizing device 10 is started, the valves 12 to 16 are opened and closed, and the first pressure transmission medium 5-1 and the second pressure transmission medium 5 are used. -2 sealing may be performed automatically or manually.

  Further, the sealing step of the sealing liquid can be applied to a sealing liquid sealing type gauge pressure sensor and an absolute pressure sensor, and the same effect can be expected by making the zero point constant by adjusting the sealing pressure.

  In the above-described embodiment, the sensor diaphragm 3-1 is a type in which a strain resistance gauge whose resistance value changes according to a pressure change is formed, but may be a capacitive sensor chip. A capacitance type sensor chip includes a substrate having a predetermined space (capacitance chamber), a diaphragm disposed in the space of the substrate, a fixed electrode formed on the substrate, and a movable electrode formed on the diaphragm. And. When the diaphragm is deformed by receiving pressure, the distance between the movable electrode and the fixed electrode changes, and the capacitance between them changes.

[Extension of the embodiment]
The present invention has been described above with reference to the embodiment. However, the present invention is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the technical idea of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Body, 1-1 ... Partition, 1-1a ... Wall surface, 1-2 ... 1st space, 1-3 ... 2nd space, 1-4 ... Through-passage, 2-1 ... 1st pressure receiving diaphragm 2-2 ... second pressure receiving diaphragm, 3 ... sensor chip, 3-1 ... sensor diaphragm, 3-1a ... one surface, 3-1b ... other surface, 3-1c ... concave, 2-2 ... pedestal 3-3 ... Communication path, 4-1 ... first joint, 4-2 ... second joint, 5-1 ... first pressure transmission medium, 5-2 ... second pressure transmission Medium, 6-1 ... first enclosure chamber, 6-2 ... second enclosure chamber, 7 ... oil pot, 8 ... enclosed liquid (pressure transmission medium), 9 ... vacuum pump, 10 ... pressurizer, 11 ... Controller, 12-16 ... Valve, 200, 300 ... Differential pressure sensor, 400 ... Encapsulation device.

Claims (2)

A sensor chip including a sensor diaphragm that outputs a signal corresponding to a pressure difference received on one surface and the other surface;
A body containing the sensor chip in its internal space;
A first pressure-receiving diaphragm provided in a first opening communicating with the internal space of the body;
A second pressure receiving diaphragm provided in a second opening communicating with the internal space of the body;
A first sealing chamber formed between the first pressure receiving diaphragm and one surface of the sensor diaphragm is sealed as a sealing liquid, and the pressure received by the first pressure receiving diaphragm is applied to one of the sensor diaphragms. A first pressure transmission medium that transmits to the surface;
A second sealing chamber formed between the second pressure receiving diaphragm and the other surface of the sensor diaphragm is sealed as a sealing liquid, and the pressure received by the second pressure receiving diaphragm is the other pressure of the sensor diaphragm. A method for enclosing a sealing liquid of a differential pressure sensor comprising a second pressure transmission medium that transmits to a surface,
A first step of evacuating the first enclosure chamber and the second enclosure chamber;
After the first step, a second step of enclosing the first pressure transmission medium in the first enclosure chamber and enclosing the second pressure transmission medium in the second enclosure chamber;
A third step of sealing the second pressure transmission medium sealed in the second sealing chamber after completion of sealing of the second pressure transmission medium in the second sealing chamber;
A fourth step of pressurizing and sealing the first pressure transmission medium into the first sealing chamber after completion of sealing of the first pressure transmission medium into the first sealing chamber;
A fifth step of monitoring a signal output from the sensor diaphragm during execution of the fourth step;
The value of the signal output from the sensor diaphragm monitored in the fifth step is output when the differential pressure between the pressure received by the first pressure receiving diaphragm and the pressure received by the second pressure receiving diaphragm is zero. A sixth step of ending the pressure sealing of the first pressure transmission medium in the first sealing chamber when it is confirmed that a set value predetermined as a power value has been reached;
A seventh step of sealing the first pressure transmission medium pressurized and sealed in the first sealing chamber after completion of pressurizing and sealing the first pressure transmission medium in the first sealing chamber. A method for enclosing a sealing liquid in a differential pressure sensor, comprising: In the method for enclosing the liquid in the differential pressure sensor according to claim 1,
The body is
Having a first space and a second space defined by a partition wall having a through passage as the internal space;
The first pressure receiving diaphragm is:
Provided in the opening of the first space;
The second pressure receiving diaphragm is:
Provided in the opening of the second space;
The sensor chip is
Positioned on the first space side so that one surface of the sensor diaphragm faces the first pressure-receiving diaphragm and a communication path communicating with the other surface of the sensor diaphragm is communicated with the through-passage of the partition wall. Bonded to the wall of the partition wall,
The first pressure transmission medium is
Sealed in the first space;
The second pressure transmission medium is
The sealing method of the sealing liquid of the differential pressure sensor, wherein the second space, the through-passage of the partition wall, and a communication path communicating with the other surface of the sensor diaphragm are sealed.

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