JP2003050173A - Pressure sensor and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of the development for a touch mode electrostatic capacity type pressure sensor, having high sensitivity and high pressure resistance capable of realizing an extension (prolonging of a lifetime) of a period capable of guaranteeing stable operating characteristics as a pressure sensor being demanded. SOLUTION: The pressure sensor 50 comprises a substrate 16, formed with a second electrode 17, a through-electrode 51 connected to the electrode 17 through the substrate 16 and formed as a wiring led from the electrode 17 to a rear surface 16a side of the substrate. Thus, a cavity 20, having a high hermetical sealability can be formed, by connecting the substrate formed with a diaphragm 19 as a first electrode to the substrate 16 in the sensor 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch-mode electrostatic capacitance type pressure sensor, and more particularly to a structure of a pressure sensor capable of stably maintaining pressure measurement accuracy for a long period of time and a manufacturing method thereof.

[0002]

2. Description of the Related Art An electrostatic capacitance type pressure sensor has a diaphragm and an electrode which are deformed in response to a pressure between a substrate on which a diaphragm is formed and a substrate on which an electrode is formed with a certain gap (cavity portion). Has a structure in which they are joined so as to face each other, and the pressure is detected from the change in the electrostatic capacitance between the diaphragm and the electrode. Since a silicon or glass wafer can be used as a substrate for forming a diaphragm or an electrode, a large number of sensors can be manufactured at one time on the wafer, which is suitable for mass production at low cost.

Among the electrostatic capacitance type pressure sensors, for example, the touch mode type electrostatic capacitance type pressure sensor disclosed in US Pat. No. 5,528,452 includes a metal thin film formed on a glass substrate as shown in FIG. Forming a conductive film 1 which is an electrode
A dielectric film 2 is formed on the dielectric film 2, and a diaphragm 3 having conductivity is arranged opposite to the dielectric film 2 via a cavity 4 which is a slight gap. As shown in FIG. 3, the diaphragm 3 is bent and is in contact with the dielectric film 2 (referred to as a touch mode). Since the substrate 5 (silicon substrate) on which the diaphragm 3 is formed and the substrate 6 (glass substrate) on which the conductive film 1 and the dielectric film 2 are formed are usually bonded in vacuum, the cavity portion 4 is formed. There is a vacuum inside.

The diaphragm 3 is a P ⁺ layer in which n-type silicon is highly doped with boron. If the diaphragm 3 is regarded as one electrode, the conductive film 1, the dielectric film 2, and the diaphragm are detected when pressure is detected. A capacitor consisting of 3 will be formed. The change in the contact area between the diaphragm 3 and the dielectric film 2 is measured between the two electrodes (diaphragm 3
It is possible to measure the pressure applied to the diaphragm 3 by detecting it as a change in the electrostatic capacitance between the conductive film 1 and the conductive film 1.
The touch-mode capacitive pressure sensor has many excellent characteristics such as high sensitivity and high pressure resistance as compared with other capacitive pressure sensors, and a linear relationship between pressure and electrostatic capacitance.

FIG. 9 shows the relationship between the electrostatic capacity and the applied pressure of the touch mode electrostatic capacity type pressure sensor. Due to the characteristics of the touch-mode capacitive pressure sensor, the sensitivity is almost zero in the low-voltage region (non-contact region) before the diaphragm contacts the dielectric film. When the diaphragm comes into contact with the dielectric film, the capacitance of the sensor increases almost linearly with the pressure within a certain range (linear region), and when the pressure further increases, the sensitivity gradually decreases and the capacitance decreases. Changes are saturated (saturation region). The pressure at which the diaphragm comes into contact with the dielectric film, that is, the measurement start pressure, largely depends on the thickness of the diaphragm, the height of the cavity, and the pressure (vacuum degree) of the cavity.

To form a diaphragm using a silicon single crystal, an inorganic solution such as KOH or NaOH or an organic solution such as ethylenediamine / pyrocatechol (EDP) or tetramethylammonium hydroxide (TMAH) is used. This is often done by anisotropic etching utilizing the difference in etching rate depending on the crystal orientation of the crystal. Among the above-mentioned etching solutions, KOH aqueous solution is
It is often used for anisotropic etching of silicon single crystals because it has a higher etching rate and is less expensive than other etching solutions. The etch stop effect in the P ⁺ layer, that is, the effect that the etching rate becomes several tenths to several hundredths of that of the silicon layer in the region where the boron concentration exceeds 10 ¹⁹ cm ^-3 is used. As a result, a diaphragm having a thickness of several μm is usually formed.
By controlling the thickness of the diaphragm and the dimension of the electrode interval, the above-mentioned linear region can be adapted to the desired operating range of the sensor. For example, in the case of a tire pressure detecting sensor, the pressure range of about 10 kgf / cm ² It is only necessary to obtain stable operation inside.

[0007]

As described above,
The conventional touch-mode capacitive pressure sensor has features of high sensitivity and high withstand voltage, and stable operation can be obtained within a desired pressure range by changing the diaphragm thickness and the electrode interval. However, in the conventional pressure sensor, as described later, there is a problem that it takes time to seal the stepped portion caused by the lead-out wiring portion (hatched portion 14 in FIG. 11).

A detailed description will be given below with reference to FIGS. 10 (a), 10 (b) and 11. The pressure sensor shown in FIGS. 10 (a) and 10 (b) is a touch-mode capacitance type pressure sensor having a structure in which a silicon substrate 7 and a glass substrate 8 are bonded (pressure sensor according to US Pat. No. 5,528,452). ). A Cr film 9 as a second electrode (hereinafter sometimes referred to as a lower electrode) is formed on the glass substrate 8 to have a film thickness of about 0.1 μm, and a glass film 10 as a dielectric film is further formed thereon. The thickness is about 0.4 μm. The Cr film 9 and the glass film 10 were formed by a series of steps including vapor deposition of a film by sputtering and patterning by photolithography. The diaphragm 11 facing the lower electrode (Cr film 9) is doped with boron at a high concentration so as to function as a first electrode (hereinafter, may be referred to as an upper electrode) and has a planar view shape of 0. The rectangle was 4 mm × 1.5 mm. Here, as described in the above-mentioned US Pat. No. 5,528,452, by making the shape of the diaphragm 11 a rectangle having a ratio of the long side to the short side of 3: 1 or more, the pressure and the capacitance within a certain range can be reduced. It is possible to obtain linearity of change. The height h of the cavity portion 12 (distance between the dielectric film and the diaphragm) was about 3 μm. Further, two Al electrodes 13 for external connection are formed on a part of the glass substrate 8, one is connected to the diaphragm 11 which is the upper electrode, and the other is connected to the second electrode 9 which is the lower electrode. did. A series of manufacturing steps were performed using a silicon wafer and a glass wafer, and individual sensor elements (pressure sensors) were obtained by cutting both wafers after bonding.

FIG. 11 shows details of the planar shape of the lower electrode. As is clear from FIG. 11, the glass film 10 described above is used.
Have a portion mounted on the glass substrate 8 and a portion mounted on the lower electrode (Cr film 9. This portion is a lead wiring portion). The portion of the glass film 10 on the lower electrode is higher than the surrounding glass film 10 by the thickness of the lower electrode (about 0.1 μm). for that reason,
When a silicon substrate for forming the diaphragm 11 is bonded onto the glass film 10, it is difficult to seal the portion where the lower electrode and the silicon substrate overlap (the hatched portion 14 in FIG. 11) and its surroundings, resulting in reduced manufacturing efficiency and cost. Was invited to rise. In addition, since there is a possibility that the sealing property of the oblique line portion 14 and its surroundings and the sealing property of the cavity portion may be deteriorated by long-term use, stable operation characteristics as a high-sensitivity, high-voltage resistant pressure sensor are guaranteed for a long time. Is difficult and
There were complaints that it was difficult to extend the product life.

In view of the above problems, the present invention has a high sensitivity and a high withstand voltage which can improve the hermeticity of the cavity portion and can extend the period (longer life) in which stable operation characteristics can be guaranteed as a pressure sensor. It is intended to provide a touch-mode capacitive pressure sensor.

[0011]

In order to solve the above-mentioned problems, the invention according to claim 1 has a substrate having a diaphragm having conductivity as a first electrode and a conductive film as a second electrode. The formed substrate is joined so that the diaphragm and the conductive film face each other via the dielectric film and the cavity portion formed on the conductive film, and the diaphragm and the dielectric film. In a pressure sensor for measuring pressure from a change in electrostatic capacitance between both electrodes due to a change in contact area with a second electrode, the pressure sensor is connected to the second electrode by penetrating the substrate on which the second electrode is formed. One or more through electrodes are formed, and the through electrodes form wirings that are drawn from the second electrode to the back surface side of the substrate. The invention according to claim 2 is the pressure sensor according to claim 1, wherein the diameter of the through electrode is 5 μm or more and 100 μm or less. The invention according to claim 3 is the invention according to claim 1 or 2.
In the pressure sensor described in the paragraph 1, the contact point between the through electrode and the conductive film that is the second electrode is outside the contact surface between the diaphragm and the dielectric film at the time of pressure detection. . According to a fourth aspect of the present invention, a substrate on which a conductive diaphragm is formed as a first electrode and a substrate on which a conductive film is formed as a second electrode are formed on the conductive film. The diaphragm and the conductive film are joined so as to face each other via the dielectric film and the cavity portion, and the capacitance change between the two electrodes due to the change in the contact area between the diaphragm and the dielectric film. In the method of manufacturing a pressure sensor for measuring pressure, at least one or more through holes are opened in the substrate on which the second electrode is formed, and a conductive substance is embedded in the through hole, thereby removing the second electrode from the second electrode. It is characterized in that a through electrode is formed as a wiring drawn to the back surface side of the substrate. According to a fifth aspect of the invention, in the method of manufacturing the pressure sensor according to the fourth aspect, the through hole is formed by at least one of DEEP-RIE, drilling using a microdrill, sandblasting, and molding. Is characterized by. The invention according to claim 6 is the method for manufacturing a pressure sensor according to claim 4 or 5, wherein as a method of embedding a conductive substance in the through hole, a sputtering method, a plating method, a screen printing method, or a molten metal suction method is used. It is characterized in that at least one of them is used.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front sectional view showing a pressure sensor 50 according to an embodiment of the present invention. In FIG. 1, a pressure sensor 50 includes a silicon substrate (which may be referred to as a “silicon substrate” hereinafter), which is a substrate 15 on which a diaphragm having conductivity is formed as a first electrode, and a second sensor. A glass substrate, which is a substrate 16 on which a conductive film is formed as an electrode (this substrate may be hereinafter referred to as “glass substrate”), is bonded to form a cavity portion between the diaphragm and the conductive film. It is a touch-mode capacitive pressure sensor with a different structure.

A second electrode 17 is provided on the glass substrate 16.
As a (lower electrode), a conductive film having a thickness of about 0.1 μm (here, a Cr film; the second electrode may be referred to as a “conductive film” hereinafter) is formed, and a dielectric film 18 is formed thereon. A glass film having a film thickness of about 0.4 μm is formed. The formation of the second electrode 17 and the dielectric film 18 was performed by a series of steps including vapor deposition of a film by sputtering and patterning by photolithography. The diaphragm (upper electrode. The first electrode is hereinafter referred to as “diaphragm”) as the first electrode 19 facing the second electrode 17 (lower electrode. Cr film).
In some cases), boron is doped at a high concentration so as to function as the first electrode, and the shape in plan view is a rectangle of 0.4 mm × 1.5 mm. Here, as described in the above-mentioned US Pat. No. 5,528,452, the shape of the diaphragm 19 is a rectangle in which the ratio of the long side to the short side is 3: 1 or more, and the pressure and the capacitance change within a certain range. I tried to get linearity. Cavity 20
The height h1 (distance between the dielectric film 18 and the diaphragm 19) is about 3 μm. In addition, the glass substrate 16
An Al electrode 21 for connecting the diaphragm 19 to an external circuit was formed on a part of the upper part by connecting to the diaphragm 19.

In this pressure sensor 50, the glass substrate 16
The lead-out wiring from the second electrode 17 to the back surface 16a side of the glass substrate 16 is formed by the through electrode 16 formed in the above. As shown in FIGS. 2A to 2D, the through electrode 51 is formed by using the glass substrate 16 (FIG.
In FIG. 2A, a through hole 16b having a diameter of about 30 μm is formed to penetrate the glass substrate 16 in the thickness direction (see FIG.
(See (b)), metal (here, S
n) was embedded to form the through electrode 51 (see FIG. 2C), and the second electrode 17 was formed on the glass substrate 16.
A series of manufacturing steps were performed using a silicon wafer and a glass wafer, and individual sensor elements (pressure sensors) were obtained by cutting both wafers after bonding.

The formation of the through-hole 16b in the glass substrate 16 is referred to herein as so-called ICP-RIE (Inductively Couple).
DEEP-R by d Plasma Reactive Ion Etching)
IE (deep trench etching by plasma. RIE: R
However, the present invention is not limited to this, and for example, perforation with a microdrill, sandblasting, etc. are also possible. It is also possible to form the glass substrate 16 having the through holes 16b by molding the glass substrate 16. The metal embedded in the through hole 16b is not limited to Sn described above, and various conductive metals such as Cu can be used. Also, the through hole 16b
Although a molten metal suction method is adopted here as a method of embedding a metal to be the through electrode 51 in the inside, the present invention is not limited to this, and for example, embedding of a metal paste such as Cu paste by a screen printing method is also possible. Can be adopted.
The above-mentioned molten metal suction method is, for example, Japanese Patent Application No. 2000-355.
725, a method in which a metal melted at a high temperature is embedded in fine holes in a vacuum chamber. Further, the number of through electrodes 51 may be plural, and can be adjusted as necessary.

The through electrode 51 has a diameter of 5 μm or more and 100 or more.
It was formed to have a circular cross section with a size of μm or less (see FIGS. 5A and 5B, etc.). If it is less than 5 μm, the resistance value when forming a circuit increases, and if it exceeds 100 μm, the contact point with the lower electrode, which is the second electrode 17, is at a contact point with the diaphragm 19 and the dielectric, as will be described later. This is to ensure that the contact surface 34 with the body membrane 18 (see FIGS. 5A and 5B, etc.) is not caught.

On the glass substrate back surface 16a side, conductive pads 22 (see FIG. 3 (a)), conductive bumps 23 (see FIG. 3 (b)), and conductive circuit 24 (see FIG. 3), if necessary.
(See (c)) and the like can be formed so as to be electrically connected to the through electrode 51.

The through electrode 51 forms a wiring from the second electrode 17 to the glass substrate back surface 16a side. The wiring electrically connects between the second electrode 17 and an electric circuit such as a circuit board connected to the rear surface 16a of the glass substrate. 1 to 3A to 3C, the lead wiring to the glass substrate back surface 16a side formed by the penetrating electrode 51 is formed only for the second electrode 17 (lower electrode). In the pressure sensor (touch mode electrostatic capacitance type pressure sensor) shown in FIGS. 4A and 4B, in addition to the penetrating electrode 51 that forms the lead wiring from the second electrode, on the glass substrate 16. Diaphragm 19
From the Al electrode 25 formed so as to be electrically conductive with the through electrode 26 penetrating the glass substrate 16,
A lead wire is formed from the Al electrode 25 to the glass substrate back surface 16a side. Pressure sensor 50 shown in FIG.
Reference character a denotes a pressure sensor that can be directly mounted on a printed circuit board or the like by electrically connecting to the through electrode 26 on the back surface 16a side of the glass substrate to form the conductive pad 27 and the conductive bump 28. is there. In the pressure sensor 50b shown in FIG. 4B, the rewiring 29 is formed on the back surface 16a of the glass substrate, and the conductive bump 28 is formed on the rewiring 29. This is a degree of freedom.

As a method of forming the penetrating electrode 26, the same method as the penetrating electrode 51 which is drawn out from the second electrode 17 so as to penetrate the glass substrate 16 can be adopted. However, not only the glass substrate 16 but also the dielectric film 18 is used as the penetrating electrode 26 that forms the wiring drawn from the Al electrode 25.
It is also necessary to penetrate it. In addition, FIG. 4 (a), (b)
In the pressure sensor shown in FIG.
7, the conductive bumps 28 and the rewiring 29 are the same as in FIG.
It is similar to the pressure sensor 50 illustrated in FIG.

The pressure sensor 50c (touch mode electrostatic capacitance type pressure sensor) shown in FIG.
5 is directly bonded to the glass substrate 16 without using a dielectric film, and the second electrode 30 is formed on the glass substrate 16.
A conductive film (a Cr film here) and a dielectric film 31 (a glass film here) that covers the second electrode 30 are housed in a cavity 20 between the silicon substrate 15 and the glass substrate 16. The penetrating electrode 5 is formed so as to penetrate the glass substrate 16 from the second electrode 30 and is wired to the glass substrate rear surface 16a side.
1 and a penetrating electrode 26 formed so as to penetrate the glass substrate 16 directly from the silicon substrate 15 and wired to the glass substrate back surface 16a side. In this pressure sensor 50c, the second electrode 30 and the dielectric film 31 are formed in a position to be housed in the cavity portion 20, and the silicon substrate 15 and the glass substrate 1 are formed without interposing the dielectric film.
Since 6 and 6 are directly contacted and joined, there is an advantage that the thickness dimension can be reduced. In addition, the silicon substrate 15
There is also an advantage that the length of the through electrode 26 extracted from the can be shortened and an increase in the resistance value can be suppressed.

5 (a), 5 (b), 6 (a), 6 (b)
As shown in, the connection position between the through electrode 51 and the conductive film 17 (second electrode) may be anywhere outside the contact surface 34 between the diaphragm 19 and the dielectric film 18 at the time of pressure detection. With such a formation position of the through electrode 51, when unevenness is generated on the upper surface of the second electrode 17 at the connection position with the through electrode 51, this causes a problem that the accuracy of pressure measurement deteriorates. It can be avoided.

As described above, in this touch-mode capacitive pressure sensor, the through electrode 51 penetrating the glass substrate 16 forms the wiring extending from the second electrode to the glass substrate back surface 16a side. Since the wiring from the second electrode does not project onto the glass substrate 16, the cavity portion 20 having a high hermeticity can be reliably and easily formed by joining the silicon substrate 15 and the glass substrate 16. Therefore, the silicon substrate 15 and the glass substrate 1
Simplifies the sealing process at the time of joining with 6, improves manufacturing efficiency,
It is possible to realize cost reduction and extension of the period (longer life) during which stable operation characteristics can be guaranteed as a pressure sensor.

The pressure sensor of the present invention and the method of manufacturing the pressure sensor are not limited to those in the above embodiment, and the design can be changed as appropriate. For example, a specific shape of the through electrode can be appropriately changed, and a shape having a different cross-sectional diameter between the second electrode side and the back surface side of the substrate on which the second electrode is formed can also be adopted. . Further, the through electrode may have a shape that substantially penetrates the substrate on which the second electrode is formed in the thickness direction thereof, and does not necessarily have a size in which the substrate projects to both sides in the thickness direction. The through electrode is electrically connected to the second electrode from one side in the thickness direction of the substrate so that the conductive pad, the conductive bump, the conductive circuit, etc. can be easily connected from the other side in the thickness direction. It should be.

[0024]

As described above, according to the pressure sensor and the method of manufacturing the same of the present invention, the through electrode penetrating the substrate having the conductive film as the second electrode penetrates the conductive film to the substrate. By forming the wiring extending to the back surface side, the wiring from the conductive film does not project onto the substrate. For this reason, the substrate on which the conductive film is formed and the substrate on which the diaphragm as the first electrode facing the conductive film via the cavity is formed are joined together with sufficient sealing property. It can be secured and performed reliably, and a highly hermetically sealed cavity can be formed reliably and easily, which simplifies the sealing process when joining substrates, improves manufacturing efficiency, and reduces costs. it can. Also,
Since the airtightness of the cavity can be stably maintained for a long period of time, the pressure sensor has an excellent effect of extending the period (longer life) in which stable operation characteristics can be guaranteed.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a pressure sensor according to an embodiment of the present invention.

2A to 2D are diagrams showing a procedure for forming a through electrode.

3A and 3B are diagrams showing another embodiment of the pressure sensor of FIG. 1, wherein FIG. 3A is a diagram showing a configuration in which a conductive pad is formed on the back surface side of the glass substrate, and FIG. 3B is a configuration in which a conductive bump is formed. FIG. 3C is a diagram showing a configuration in which a conductive circuit is formed.

4 (a) to (c) show glass in addition to the through electrode drawn out from the second electrode, the Al electrode formed by being electrically connected to the diaphragm on the dielectric film, and the glass. FIG. 6 is a front cross-sectional view showing a configuration example in which a wiring drawn from an Al electrode to the back surface side of a glass substrate is formed by a through electrode penetrating a substrate.

5 is a diagram showing a state in which the diaphragm is in contact with the dielectric film by pressure in the pressure sensor of FIG.
(A) is a plan view showing the shape of the second electrode, and (b) is a front sectional view.

6A and 6B are diagrams showing a configuration in which the formation position of the through electrode of the pressure sensor of FIG. 1 is changed, in which FIG. 6A is a plan view showing the connection position of the through electrode with the second electrode, and FIG. It is a front sectional view in the state of (a).

FIG. 7 is a front sectional view showing a structure of a conventional pressure sensor.

8 is a front view showing a state in which the diaphragm is in contact with the dielectric film due to pressure in the pressure sensor of FIG.

FIG. 9 is a graph showing the relationship between pressure and capacitance in a touch-mode capacitive pressure sensor.

10A and 10B are diagrams showing in detail wirings drawn from the first and second electrodes of the pressure sensor of FIG. 7, wherein FIG. 10A is a plan view and FIG.

11 is a plan view showing the shape of a second electrode in the pressure sensor of FIG.

[Explanation of symbols]

15 ... Substrate on which first electrode is formed (silicon substrate), 16 ... Substrate on which second electrode is formed (glass substrate), 16a ... Substrate back surface, 16b ... Through hole, 17 ... Second electrode , Conductive film (Cr film), 18 ... Dielectric film (glass film), 19 ... First electrode, diaphragm, 20 ... Cavity part, 30 ... Second electrode, conductive film (Cr film), 31
... Dielectric film (glass film), 34 ... Contact surface, 50, 50a
˜50c ... Pressure sensor, 51 ... Through electrode.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hitoshi Nishimura             1-5-1 Kiba Stock Exchange, Koto-ku, Tokyo             Inside Fujikura (72) Inventor Kazuhisa Itoi             1-5-1 Kiba Stock Exchange, Koto-ku, Tokyo             Inside Fujikura (72) Inventor Tatsuo Suemasu             1-5-1 Kiba Stock Exchange, Koto-ku, Tokyo             Inside Fujikura (72) Inventor Isao Takizawa             1-5-1 Kiba Stock Exchange, Koto-ku, Tokyo             Inside Fujikura F term (reference) 2F055 AA40 BB01 CC02 DD05 DD07                       EE25 FF43 GG01 GG11                 4M112 AA01 BA07 CA01 CA03 CA04                       CA11 CA13 DA09 EA03 EA10                       EA11 EA13 FA01 FA07 GA01

Claims (6)

[Claims] 1. A substrate (15) having a conductive diaphragm (19) formed as a first electrode and a substrate (16) having conductive films (17, 30) formed as a second electrode. And the diaphragm and the conductive film are bonded to each other via the dielectric film (18, 31) and the cavity portion (20) formed on the conductive film, and the diaphragm and the conductive film are bonded to each other. In a pressure sensor that measures pressure from a change in electrostatic capacitance between both electrodes due to a change in contact area with a dielectric film, the second sensor is formed by penetrating the substrate on which a second electrode is formed. One or more penetrating electrodes (51) connected to the electrodes are formed, and the penetrating electrodes form the second electrode to the back surface of the substrate (16).
A pressure sensor (50, 50a to 50c), which is characterized in that a wiring extending to the a) side is formed. 2. The diameter of the through electrode is 5 μm or more and 10
The pressure sensor according to claim 1, wherein the pressure sensor has a diameter of 0 μm or less. 3. The through electrode is connected to the conductive film, which is a second electrode, outside the contact surface (34) between the diaphragm and the dielectric film at the time of pressure detection. The pressure sensor according to claim 1 or 2, which is characterized. 4. A substrate (15) on which a diaphragm (19) having conductivity is formed as a first electrode, and a substrate (16) on which conductive films (17, 30) are formed as second electrodes. And the diaphragm and the conductive film are bonded to each other via the dielectric film (18, 31) and the cavity portion (20) formed on the conductive film, and the diaphragm and the conductive film are bonded to each other. In a method of manufacturing a pressure sensor for measuring a pressure from a change in capacitance between both electrodes due to a change in a contact area with a dielectric film, at least one through hole (16) is formed in a substrate on which a second electrode is formed.
b) Opening and embedding a conductive substance in the through hole to form a through electrode (51) as a wiring that is drawn from the second electrode to the substrate back surface (16a) side. Sensor manufacturing method. 5. The method for manufacturing a pressure sensor according to claim 4, wherein the through hole is formed by at least one of DEEP-RIE, drilling using a microdrill, sandblasting, and molding. 6. The method according to claim 4, wherein at least one of a sputtering method, a plating method, a screen printing method, and a molten metal suction method is used as a method of embedding a conductive substance in the through hole. A method for manufacturing the described pressure sensor.