JP2003302300A - Pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent adverse influence of a potential generated between a device frame earth and a secondary power source in a liquid-sealed pressure sensor. <P>SOLUTION: In a pressure detection element 10, hermetic glass 13 is hermetically fixed to a central opening part 12 of an element housing 11 formed of metal. A lead pin 14 for leading an electric signal from a sensor chip 18 to the outside and a sensor chip mounting glass member 16 holding the sensor chip 18 are arranged in the hermetic glass 13. A metallic diaphragm 20 is fixed in the upper side opening edge part of the housing 11, and consequently, the liquid-sealed pressure sensor is constructed. A cylindrical space surrounding the sensor chip 18 is formed of a metallic lower plate 51 and a metallic member 52 and connected to a lead pin 14-1 connected to a zero potential of an electronic circuit mounted to the sensor chip 18. In this way, the electronic circuit on the sensor chip 18 is not unfavorably affected by a potential generated between the metallic diaphragm 20 and the sensor chip 18. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-sealed one-chip semiconductor pressure sensor.

[0002]

2. Description of the Related Art Pressure sensors include refrigerant pressure sensors for refrigeration, refrigeration, and air conditioning equipment, water pressure sensors for water supply, industrial pumps, steam pressure sensors for steam boilers, empty / hydraulic sensors for air / hydraulic industrial equipment, automobiles. It is used in various applications such as pressure sensors. In recent years, with the progress of semiconductor technology, a one-chip semiconductor pressure sensor in which a sensor detection element and a signal processing circuit are integrated on the same silicon chip has been developed.

Conventional liquid-sealed type (metal double diaphragm type)
The one-chip semiconductor pressure sensor will be described with reference to FIG. In FIG. 11, (a) is a cross-sectional view showing the configuration of a liquid-sealed one-chip semiconductor pressure sensor, and (b) is a cross-sectional view showing an enlarged part of the semiconductor sensor chip. As shown in this figure, the liquid ring pressure sensor is roughly divided into
It is composed of the pressure detection element 10, the joint portion 30, and the connector portion 40. Pressure detection element 10
Is a metal element housing 11, a hermetic glass 13 hermetically fixed to the central opening 12 of the element housing 11, a plurality of lead pins 14 hermetically mounted in the hermetic glass 13 in a penetrating state, and an oil filling pipe 15. Also, the sensor chip mounting member 16 and the sensor chip mounting member 1
The pressure detection sensor chip 18 is fixed to the upper end surface of the glass plate 6 via the glass 17. As shown in an enlarged view in FIG. 11 (b), the sensor chip 18 has a diaphragm (silicon diaphragm) formed by etching the central portion of the back surface of a silicon substrate, and a bridge circuit is formed above the silicon diaphragm portion. A plurality of pressure detecting elements (piezoresistive elements) 18-1 to be formed are formed, and an amplifier circuit which processes an output signal of the bridge circuit is formed around the pressure detecting element 18-1.
Electronic circuits 18-2 such as a straight line correction circuit, a temperature correction circuit, and a correction data holding circuit are integrated by a semiconductor circuit integration technique, and an oxide film 18-3 is formed on the surface side thereof. The pressure detecting sensor chip 18 and the lead pin 14 are connected by a wire or the like not shown, and an electric signal from the sensor chip 18 is led to the outside via the lead pin 14.

Further, the metal diaphragm 2 is provided at the upper opening edge of the central opening 12 of the element housing 11.
0 and a diaphragm protection cover 22 having a communication hole 21 that covers the same are hermetically fixed by welding their outer peripheral edge portions. The central opening 12 of the element housing 11, the hermetic glass 13, and the metal diaphragm 20 form a liquid sealing chamber 23 in which oil such as silicone oil is sealed. For example, the oil filling pipe 15 made of stainless steel is used as a filling port for filling the liquid sealing chamber 23 with oil, and after the oil filling is completed, the tip of the outer pipe is crushed and closely adhered, and the portion is welded. As a result, the oil is sealed in the liquid sealing chamber 23.

The pressure detecting element 10 includes an O-ring 24.
At the same time, the wire fitting member 35 is fitted into the element housing hole 31 of the joint portion 30, and the wire connecting member 35 is electrically connected to the lead pin 14,
The wire connection member 35 and the terminal 41 of the connector portion 40 are electrically connected. The connector section 40 together with the O-ring 25 is the joint section 3
By being fitted into the element storage hole 31 of 0 and caulking the opening edge portion 32 of the element storage hole 31,
It is fixedly connected to the joint portion 30 with the pressure detection element 10 sandwiched therebetween.

The joint portion 30 is a threaded portion 3 for mounting the sensor.
3, the pressure of the fluid is transmitted to the metal diaphragm 20 via the fluid pressure passage 34 to be measured. Since the metal diaphragm 20 is extremely thin, the pressure is transmitted to the oil without being lowered, and the silicon diaphragm of the sensor chip 18 is deformed by this pressure, and this is applied to the piezoresistive element 18
The electric signal detected at -1 is processed by the electronic circuit 18-2 and taken out through the lead pin 14 and the terminal 41.

[0007]

When such a one-chip semiconductor pressure sensor is used, the secondary voltage (for example, 5 V DC) of the device to which the pressure sensor is attached is an electronic circuit on the sensor chip 18. The element housing 11 is connected to the frame ground of the device. Here, the electronic circuit on the sensor chip 18 and the element housing 11 are in a highly insulated state. The secondary power source is insulated from the primary power source by a transformer or the like, but since the impedance of the sensor is higher, a potential is generated between the metal diaphragm 20 welded to the element housing 11 and the sensor chip 18. Then, this may adversely affect the electronic circuit and the non-volatile memory in the sensor chip 18.

Therefore, an object of the present invention is to provide a pressure sensor capable of preventing the adverse effect due to the potential even when a potential is generated between the device frame ground and the secondary power source. There is.

[0009]

In order to achieve the above object, a pressure sensor of the present invention is fixed to a metal housing and a central opening provided in the metal housing, and a pressure sensor chip is provided. A sensor chip mounting member to support, a pipe for oil filling, and a hermetic glass provided with a lead pin for guiding an electric signal from the pressure sensor chip to the outside, and a metal diaphragm joined to one end surface of the housing. A liquid-sealing type pressure sensor having a pressure detection element having, between the pressure sensor chip and the metal diaphragm,
A conductive member having a potential equal to the zero potential of the electronic circuit mounted on the pressure sensor chip is provided.

The conductive member is provided so as to surround the pressure sensor chip. Further, the conductive member is joined to a lead pin connected to the zero potential of the electronic circuit. Furthermore, the conductive member is a metal plate provided between the pressure sensor chip and the metal diaphragm and supported by the metal oil filling pipe. Furthermore, the conductive member is supported by a plurality of support pins provided on the hermetic glass. Furthermore, the conductive member is supported by a ring-shaped support member provided on the hermetic glass. Furthermore, the conductive member is supported by a guide member that is provided by being fitted into the metal housing. The conductive member is joined to the oil filling pipe, and the oil filling pipe is electrically connected to the lead pin connected to the zero potential of the electronic circuit. Furthermore, the conductive member is supported by a metal support member provided on the hermetic glass. The metallic support member is electrically connected to the lead pin connected to the zero potential of the electronic circuit.
Furthermore, the conductive member is joined to a metal member fitted to the inner peripheral surface of the hermetic glass. A lead pin connected to the zero potential of the electronic circuit is caulked and fixed to the metal member. Furthermore, the conductive member is a metal thin film provided on the surface of the sensor chip.

[0011]

1 is a diagram showing the configuration of a pressure detecting element 10 in a first embodiment of a pressure sensor of the present invention. In this figure and the following figures, the same components as those in FIG. 11 are designated by the same reference numerals and the description thereof will be omitted. As shown in FIG. 1, in this embodiment, a metal lower plate 51 is provided so as to surround the sensor chip 18.
And the metal member 52 are provided, and the lower plate 51 and the metal member 52 form a cylindrical space, for example, in which the sensor chip 18 is arranged. Then, using the pressing plate 54, the lead pin 14-1 connected to the zero potential of the electronic circuit integrated in the sensor chip 18 and the metal member 52 are connected by welding or the like. As a result, the potentials of the lower plate 51 and the metal member 52 become the same potential as the zero potential of the electronic circuits integrated on the sensor chip 18, and the sensor in the space surrounded by the lower plate 51 and the metal member 52. The potential around the chip 18 becomes the zero potential of the electronic circuit. Therefore, it is possible to prevent the potential difference between the metal diaphragm 20 and the metal diaphragm 20 from adversely affecting the electronic circuits integrated in the sensor chip 18. An opening 53 is provided in the metal member 52 so that pressure is transmitted to the silicon diaphragm of the sensor chip 18 via the oil in the liquid sealing chamber 23.

FIG. 2 is a diagram showing the structure of the pressure detecting element 10 in the second embodiment of the pressure sensor of the present invention. As shown in this figure, in this embodiment, the sensor chip 18 and the metal diaphragm 20 are
A metal plate 55 is provided between And this metal plate 55
End portion of the lead pin 14-1 connected to the oil filling pipe 15 near the opening of the metal oil filling pipe 15 and connected to the zero potential of the electronic circuit integrated on the oil filling pipe 15 and the sensor chip 18. And are electrically connected. The shape of the metal plate 55 may be circular or quadrangular as long as it covers the sensor chip 18. With this configuration, the metal plate 55 having the same potential as the zero potential of the electronic circuit integrated on the sensor chip 18 can be arranged between the sensor chip 18 and the metal diaphragm 20. Even if there is a potential difference between the metal diaphragm 20 and the zero potential of the electronic circuit on the sensor chip 18, there is a potential difference between the zero potential of the electronic circuit on the sensor chip 18 and the metal plate 55. Since this does not occur, it is possible to prevent the electronic circuit integrated in the sensor chip 18 from being adversely affected.

FIG. 3 is a view showing the structure of the pressure detecting element 10 in the third embodiment of the pressure sensor of the present invention. As shown in FIG. 3, in this embodiment, it is supported by the hermetic glass 13. Multiple (for example, 3
Main) support pin 58, and a metal cap 56 supported by the support pin 58 is provided between the sensor chip 18 and the metal diaphragm 20. Then, the cap 56 and the tip of the metal oil filling pipe 15 are joined by welding or the like, and are connected to the zero potential of the electronic circuit integrated on the oil filling pipe 15 and the sensor chip 18. Lead pin 14-1
And connect. The cap 56 has an opening 5
7 is provided. As a result, the potential of the cap 56 becomes the same potential as the zero potential of the electronic circuit integrated on the sensor chip 18, and even if a potential difference occurs between the metal circuit and the metal diaphragm 20, the electronic circuit on the sensor chip 18 is also generated. Can be prevented from being adversely affected.

FIG. 4 is a diagram showing the structure of the pressure detecting element 10 in the fourth embodiment of the pressure sensor of the present invention. As shown in this figure, in this embodiment, a ring-shaped metal support ring 59 is provided in place of the support pin 58 in the third embodiment, and by this support ring 59. The cap 56 is supported. Further, a second metal cap 60 is also provided on the lower portion of the support ring 5 (lead-out side of the lead pin). As a result, the cap 56, the support ring 59, and the second cap 60 can surround the sensor chip 18, the glass 17, the sensor chip mounting member 16, the lead pin 14, and the like as a whole. In the figure, there are lead pins 14 that do not project from the second cap 60, but these are lead pins used only during test adjustment. Therefore,
Even if a potential difference occurs between the metal diaphragm 20 and the electronic circuit on the sensor chip 18, it is possible to prevent the electronic circuit integrated on the sensor chip 18 from being adversely affected.

FIG. 5 is a diagram showing the structure of the pressure detecting element 10 in the fifth embodiment of the pressure sensor of the present invention. As shown, in this embodiment, as in the third and fourth embodiments described above, a metal cap 56 having an opening 17 is provided in the metal diaphragm 20.
The cap guide 61 made of a ring-shaped non-conductive material is fitted into the element housing 11 so as to cover the sensor chip 18. The cap 56 is supported by fitting. As in the case described above, the cap 56 is joined to the tip end portion of the oil filling pipe 15, and the oil filling pipe 15 is connected to the sensor chip 18.
It is electrically connected to the lead pin 14-1 connected to the zero potential of the electronic circuit integrated above. This allows
Even if there is a potential difference between the metal diaphragm 20 and the electronic circuit on the sensor chip 18, it is possible to prevent the electronic circuit on the sensor chip 18 from being adversely affected.

FIG. 6 is a diagram showing the structure of the pressure detecting element 10 in the sixth embodiment of the pressure sensor of the present invention. As shown in this figure, in this embodiment, similarly to the embodiment shown in FIG. 4, a metal support ring 64 is provided, and the metal plate 62 is provided at the upper end of this support ring 64.
The metal plate 62 is disposed between the metal diaphragm 20 and the sensor chip 18 by bonding the. Then, the metal support ring 64 and the lead pin 14-1 connected to the zero potential of the electronic circuit integrated on the sensor chip 18 are electrically connected to each other as shown in FIG. The metal plate 62 and the metal support ring 64, which have the same potential as the zero potential of the electronic circuit, surrounds the sensor chip 18. An opening 63 is provided in the metal plate 62. As a result, even when a potential difference is generated between the metal diaphragm 20 and the electronic circuit on the sensor chip 18, it is possible to prevent the electronic circuit on the sensor chip 18 from being adversely affected.

In each of the above-described embodiments, a conductive member provided between the sensor chip 18 and the metal diaphragm 20 (the metal plate 51 and the metal member 52 in FIG. 1, the metal plate 55 in FIG. 2, and FIGS. Cap 5 in FIG.
6 and the metal plate 62 in FIG. 6) to have a potential equal to the zero potential of the electronic circuit on the sensor chip 18, the lead pin 14 connected to the zero potential of the electronic circuit.
-1 and the metal member 52 are joined together (the embodiment of FIG. 1), or the metal plate 55 or the cap 56 and the metal oil filling pipe 15 are joined together to form the oil filling pipe 15 And the lead pin 14-1 are electrically connected to each other by soldering a lead wire or the like (the embodiment of FIGS. 2 to 5), or the metal plate 62 and the metal support ring 64 are connected. The metal support ring 64 and the lead pin 14-1 are joined and electrically connected by soldering a lead wire or the like (the embodiment of FIG. 6). However, it is also possible to electrically connect the zero potential of the electronic circuit and the metal plate or the cap by other means.

A seventh embodiment of the pressure sensor of the present invention will be described with reference to FIG. Here, FIG. 7A shows the pressure detection element 10 according to the present embodiment.
FIG. 8B is a diagram showing an example of the configuration of the pressure sensor chip 18 in which the hermetic glass 13 in FIG.
FIG. 3 is a diagram showing a part of a state viewed from the side opposite to the side on which is mounted (hereinafter referred to as the outer side). As shown, in this example, a metal support ring 64 is provided as in the embodiment shown in FIG. 6, and the metal plate 62 is joined to the support ring 64. The electrical connection between the support ring 64 and the lead pin 14-1 connected to the zero potential of the electronic circuit is not soldered but the hermetic glass between the lead pin 14-1 and the metal support ring 64. This is done by applying a conductive adhesive 65 to the surface of 13. Instead of applying the conductive adhesive 65, the lead pin 14-1 is used.
It is also possible to insert or fit conductive parts that engage with both the support ring 64 and the support ring 64.

Next, an eighth embodiment of the present invention will be described with reference to FIGS. 8 and 9. In this embodiment, the electrical connection between the lead pin 14-1 and the conductive member for setting the conductive member to the zero potential of the electronic circuit is performed by the above-mentioned soldering, conductive adhesive, or conductive material. A method other than parts is used to perform the pressure detection element on the metal diaphragm side (inner side). FIG. 8A is a sectional view showing the structure of the pressure detection element 10 according to the present embodiment. As shown in this figure, in this embodiment, the height of the outer peripheral portion of the hermetic glass 13 is formed higher than that of the central portion,
A ring-shaped metal member 66 is fitted inside the outer peripheral portion. Then, a hole for inserting the lead pin 14-1 connected to the zero potential of the electronic circuit is formed in the metal member 66, and the lead pin 14-1 is inserted into the hole,
By crushing and crimping the metal member 66, the metal member 66 and the lead pin 14-1 are mechanically and electrically connected. The metal plate 62 is joined to the upper surface of the metal member 66. In FIG. 8B,
A top view showing the metal member 66 and the lead pin 14-1 integrated in this way is a sectional view thereof. In this way, the metal member 66 and the lead pin 14-1 are integrated and inserted into the hermetic glass 13 for glass hermetic treatment.

FIG. 9 is a view for explaining a method of caulking and fixing the metal member 66 and the lead pin 14-1. 9A to 9C show a state in which the flat metal member 66 is caulked and connected,
(A) is the upper surface, (b) is the lower surface, and (c) is the case where both the upper and lower surfaces are crimped. In addition, (d) and (e) of FIG.
As shown in FIG. 5, a burring process may be performed around the hole into which the lead pin 14-1 is inserted and the caulking may be performed. In this way, the caulking can be fixed by various methods.

As described above, according to this embodiment, since the lead pin 14-1 and the metal member 66 are caulked and connected to each other, strong mechanical strength can be achieved, and a product resistant to vibration and impact can be obtained. . In addition, it is possible to expect the effect of improving productivity by eliminating the step of connection on the outer side. Furthermore, the number of parts can be reduced. Furthermore, since the metal member 66 is fixed by the inner surface of the outer peripheral portion of the hermetic glass 13, the amount of oil filled can be reduced, and the temperature output characteristic of the sensor can be improved.

10A and 10B are views showing the configuration of the ninth embodiment of the pressure sensor of the present invention, FIG. 10A is a sectional view showing the configuration of the sensor chip portion in the present embodiment, and FIG. It is the top view seen from above. In each of the above-mentioned respective embodiments, the sensor chip 18 and the metal diaphragm 2 are all provided.
A metal member such as a metal plate or a cap connected to the zero potential of the electronic circuit mounted on the sensor chip 18 is arranged in the space between the sensor chip 18 and the sensor chip 18. A metal thin film 70 is provided on the upper surface of the chip 18, and the thin film 70 is connected to the zero potential of the electronic circuit 18-2. As described above, the pressure detection element 18-1 is formed above the diaphragm portion (pressure detection portion) of the sensor chip 18, and the electronic circuit 18-2 including the nonvolatile memory and the like is arranged so as to surround the pressure detection element 18-1. .
Therefore, in this embodiment, a metal thin film 70 is provided on the surface of the oxide film 18-3 corresponding to the portion of the sensor chip 18 where the electronic circuit 18-2 is formed, as shown in FIG. The thin film 70 is used as the sensor chip 18
It is arranged to be connected to the zero potential of the upper electronic circuit 18-2. This thin film 70 can be formed by, for example, aluminum vapor deposition. Here, the metal thin film 70 is provided only on the surface of the portion corresponding to the electronic circuit 18-2, and is not provided on the surface of the diaphragm portion where the pressure detection element 18-1 is formed. Since the portion is repeatedly stressed by the pressure, metal fatigue occurs when the metal thin film 70 is formed on the surface of the diaphragm portion, and thermal strain is caused by the difference in thermal expansion coefficient between the metal thin film 70 and the sensor chip 18. This is to prevent the occurrence of the noise and the deterioration of the characteristics of the sensor. This allows
Even if there is a potential difference between the metal diaphragm 20 and the sensor chip 18, the sensor chip 1
It is possible to prevent the electronic circuit integrated on the semiconductor device 8 from being adversely affected.

In the above description, the sensor chip 18
All of the conductive members (51, 52, 55, 56, 62, 59, 64, etc.) for ensuring the zero potential of the electronic circuit mounted in are made of metal, but instead of this,
A conductive resin or the like can also be used.

[0024]

As described above, according to the pressure sensor of the present invention, the sensor chip can be placed in the non-electric field (zero potential), and the influence of the potential generated between the device frame ground and the secondary power source. Thus, it is possible to prevent the circuits in the chip and the non-volatile memory from being adversely affected.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a pressure detecting element in a first embodiment of a pressure sensor of the present invention.

FIG. 2 is a sectional view showing a configuration of a pressure detection element in a second embodiment of the pressure sensor of the present invention.

FIG. 3 is a sectional view showing a configuration of a pressure detecting element in a third embodiment of the pressure sensor of the present invention.

FIG. 4 is a cross-sectional view showing the structure of a pressure detecting element in a fourth embodiment of the pressure sensor of the present invention.

FIG. 5 is a cross-sectional view showing the configuration of a pressure detecting element in a fifth embodiment of the pressure sensor of the present invention.

FIG. 6 is a cross-sectional view showing the configuration of a pressure detecting element in a sixth embodiment of the pressure sensor of the present invention.

7A and 7B are views for explaining a pressure detecting element according to a seventh embodiment of a pressure sensor of the present invention, FIG. 7A is a sectional view, and FIG. 7B is an electrical connection portion between a support ring and a lead pin. FIG.

8A and 8B are views for explaining a pressure detecting element in an eighth embodiment of a pressure sensor of the present invention, FIG. 8A is a sectional view of the pressure detecting element, and FIG. 8B is a sectional view of a metal member and a lead pin. FIG. 3 is a front view showing a state of being integrated by crimping, and FIG.

FIG. 9 is a diagram showing various modes of caulking connection between a metal member and a lead pin in an eighth embodiment of a pressure sensor of the present invention.

10A and 10B are diagrams showing a configuration of a sensor chip portion in a ninth embodiment of a pressure sensor of the present invention, FIG. 10A being a sectional view and FIG. 10B being a plan view.

FIG. 11 is a cross-sectional view showing a configuration of a conventional pressure sensor.

[Explanation of symbols]

1 step 2 Tapered part 10 Pressure detection element 11 Element housing 12 Central opening 13 Hermetic glass 14 Lead pin 14-1 Lead pin connected to zero potential of electronic circuit 15 Oil filling pipe 16 Sensor chip mount member 17 glass 18 Pressure detection sensor chip 20 metal diaphragm 21 communication holes 23 Liquid Sealing Room 30 joint 40 Connector 51, 55, 62 Metal plate 52 Metal member 53, 57, 63 openings 56, 60 cap 58 Support pin 59, 64 Support ring 61 Cap guide 65 Conductive adhesive 66 Metal member 70 Metal thin film

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yuji Kanai             1311 Aobadai, Tokorozawa, Saitama Prefecture Made by Sagimiya Co., Ltd.             Sakusho Tokorozawa Office (72) Inventor Kazuhiro Izumiya             1311 Aobadai, Tokorozawa, Saitama Prefecture Made by Sagimiya Co., Ltd.             Sakusho Tokorozawa Office (72) Inventor Hajime Takeuchi             1311 Aobadai, Tokorozawa, Saitama Prefecture Made by Sagimiya Co., Ltd.             Sakusho Tokorozawa Office (72) Inventor Takashi Tojo             1311 Aobadai, Tokorozawa, Saitama Prefecture Made by Sagimiya Co., Ltd.             Sakusho Tokorozawa Office (72) Inventor Yuji Kimura             1311 Aobadai, Tokorozawa, Saitama Prefecture Made by Sagimiya Co., Ltd.             Sakusho Tokorozawa Office F term (reference) 2F055 AA40 BB20 CC02 DD04 EE13                       FF11 FF38 GG22 HH11                 4M112 AA01 BA01 CA01 CA16 DA18                       DA20 EA02 EA11 EA13 EA14                       FA06 GA01

Claims (13)

[Claims] 1. A metal housing, a sensor chip mounting member that is fixed to a central opening provided in the metal housing and supports the pressure sensor chip, an oil filling pipe, and electricity from the pressure sensor chip. A hermetic glass provided with a lead pin for guiding a signal to the outside, and a liquid ring type pressure sensor having a pressure detection element having a metal diaphragm joined to one end surface of the housing, wherein the pressure is A pressure sensor, wherein a conductive member having a potential equal to zero potential of an electronic circuit mounted on the pressure sensor chip is provided between the sensor chip and the metal diaphragm. 2. The pressure sensor according to claim 1, wherein the conductive member is provided so as to surround the pressure sensor chip. 3. The pressure sensor according to claim 2, wherein the conductive member is bonded to a lead pin connected to the zero potential of the electronic circuit. 4. The conductive member is a metal plate provided between the pressure sensor chip and the metal diaphragm and supported by the oil filling pipe made of metal. 1. The pressure sensor according to 1. 5. The pressure sensor according to claim 1, wherein the conductive member is supported by a plurality of support pins provided on the hermetic glass. 6. The pressure sensor according to claim 1, wherein the conductive member is supported by a ring-shaped support member provided on the hermetic glass. 7. The pressure sensor according to claim 1, wherein the conductive member is supported by a guide member fitted and provided in the metal housing. 8. The conductive member is joined to the oil filling pipe, and the oil filling pipe is electrically connected to a lead pin connected to a zero potential of the electronic circuit. The pressure sensor according to any one of claims 4 to 7. 9. The pressure sensor according to claim 1, wherein the conductive member is supported by a metal support member provided on the hermetic glass. 10. The pressure sensor according to claim 9, wherein the metal support member is electrically connected to a lead pin connected to the zero potential of the electronic circuit. 11. The pressure sensor according to claim 1, wherein the conductive member is joined to a metal member fitted to an inner peripheral surface of the hermetic glass. 12. The pressure sensor according to claim 11, wherein a lead pin connected to the zero potential of the electronic circuit is caulked and fixed to the metal member. 13. The pressure sensor according to claim 1, wherein the conductive member is a metal thin film provided on the surface of the sensor chip.