Pressure sensor module and electronic component

A pressure sensor module includes a pressure sensor, a bump, and a laminated substrate. The pressure sensor includes a semiconductor substrate; a cavity; a pressure-sensitive element; and a conductive section. The cavity is disposed inside the semiconductor substrate such that a thin-plate region of the semiconductor substrate is provided and the thin-plate region being defined as a diaphragm. The pressure-sensitive element is arranged at the diaphragm. The conductive section is electrically connected to the pressure-sensitive element and disposed on the face of the semiconductor substrate at a region excluding the diaphragm. The bump is electrically connected to the conductive section. The laminated substrate includes a wiring base material electrically connected to the pressure sensor via the bump. The wiring base material is disposed inside the laminated substrate. A face of the wiring base material is electrically connected to the bump and has an exposed area from the laminated substrate.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a pressure sensor module, and more particularly relates to a module structure that detects pressure in a diaphragm and has low fluctuation of pressure sensor characteristics, and a structure that can package the pressure sensor and application specific integrated circuit (ASIC) or another semiconductor device at high density and in a small size.

The present invention claims priority on Japanese Patent Application No. 2008-114262, filed on Apr. 24, 2008, and the contents of which are incorporated herein by reference.

2. Description of the Related Art

Pressure sensors are used in various fields such as household electric appliances, medical equipment, and vehicle parts. Semiconductor pressure sensors are increasingly being used, since they are small and highly reliable. Recently, with the aim of mounting pressure sensors in portable devices, there is a particular demand for a smaller package structure.

To realize a very small package, as disclosed in Japanese Unexamined Patent Application, First Publication No. 2007-248212, the applicant considered a surface mountable chip size package (CSP), and proposed a small pressure sensor module that can be realized by mounting a pressure sensor on a laminated substrate which an ASIC internally containing amplification and compensation circuits is buried in.FIG. 10is a representative example of that structure. A pressure sensor112including a diaphragm111is mounted on a laminated substrate115in which an ASIC114is buried in via a bump113. While this structure is suitable for realizing a small module in which a combination of devices such as the ASIC114and the pressure sensor112are mounted, some problems were discovered during subsequent systematic consideration.

In the conventional module structure shown inFIG. 10, since the pressure sensor112is mounted on a topmost face115A of the laminated substrate115, stress generated in the laminated substrate115is liable to be applied to the pressure sensor112. Therefore, due to the stress applied from the laminated substrate115to the pressure sensor112, there is some fluctuation in the output characteristics of the pressure sensor112before and after mounting it on the laminated substrate115. This makes it difficult to obtain a pressure sensor module130having desired output characteristics.

SUMMARY OF THE INVENTION

The present invention has been realized in view of the above problems, and aims to provide a pressure sensor module in which fluctuation in the output characteristics of a pressure sensor due to stress generated in the laminated substrate is unlikely to occur, enabling the pressure sensor to achieve desired output characteristics.

A pressure sensor module according to a first aspect of the present invention includes a pressure sensor including: a semiconductor substrate; a cavity (space); a pressure-sensitive element; and a conductive section, wherein the cavity is disposed inside the semiconductor substrate and arranged substantially along a face of the semiconductor substrate at a substantially central area of the face such that a thin-plate region of the semiconductor substrate is provided at one side of the cavity, the thin-plate region being defined as a diaphragm, wherein the pressure-sensitive element is arranged at the diaphragm, wherein the conductive section is electrically connected to the pressure-sensitive element and is disposed on the face of the semiconductor substrate at a region excluding the diaphragm; a bump electrically connected to the conductive section; and a laminated substrate including a wiring base material electrically connected to the pressure sensor via the bump, wherein the wiring base material is disposed inside the laminated substrate, and a face of the wiring base material is electrically connected to the bump and has an exposed area from the laminated substrate.

A pressure sensor module according to a second aspect of the present invention is characterized in that, in the first aspect, the pressure sensor is surrounded by the laminated substrate such that at least a face of the semiconductor substrate is exposed.

A pressure sensor module according to a third aspect of the present invention is characterized in that, in the first aspect, the wiring base material is a semiconductor device.

An electronic component according to a fourth aspect of the present invention is characterized in that it includes the pressure sensor module of the first aspect.

According to the present invention, the wiring base material that is electrically connected to the pressure sensor is arranged within the laminated substrate, and the pressure sensor is mounted thereon. While stress generated in the laminated substrate is greatest at a topmost face of the laminated substrate, in this invention the wiring base material is arranged within the laminated substrate. Therefore, the stress applied to the pressure sensor can be reduced more than when it is mounted on a conventional pressure sensor module. Since this makes it possible to suppress the fluctuation in output characteristics of the pressure sensor before and after mounting due to the stress, and to provide a pressure sensor module with desired output characteristics.

The above and other aspects of the present invention will become apparent upon consideration of the following detailed descriptions of exemplary embodiments thereof, particularly when taken in conjunction with the accompanying drawings wherein like reference numerals in the various figures are utilized to designate like components.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention will be explained in detail with reference to the drawings, these are not to be considered limitative of the invention, which can be modified in various ways without departing from its main features.

First Embodiment

FIG. 1is a schematic cross-sectional view showing one example of a pressure sensor module according to a first embodiment of the present invention. In the embodiment, a pressure sensor module30A mainly includes a pressure sensor10, bumps18, and a laminated substrate20. In a face11aof a semiconductor substrate11, the pressure sensor10includes a cavity (gap portion)13that extends substantially parallel to the face11ainside a central area “α” of the semiconductor substrate11. A thin-plate region at a side13aof the cavity13is defined as a diaphragm14. Pressure-sensitive elements15are arranged in the diaphragm14. The pressure sensor11includes conductive sections16that are electrically connected to the pressure-sensitive elements15, wherein the conductive sections16are arranged in a region excluding the diaphragm14on the face11a. The bump18is arranged in each conductive section16respectively, and is electrically connected to the conductive section16separately. The laminated substrate20includes a wiring base material21that is electrically connected to the pressure sensor10via the bumps18. Further, the wiring base material21is arranged inside the laminated substrate20. At least one part of a face21aof the wiring base material21that is electrically connected to the bumps18is exposed from the laminated substrate20. Each of these constituent parts will be explained in detail below.

The semiconductor substrate11can be made from, for example, a silicon wafer or such like. In this embodiment, the face11aof the semiconductor substrate11where the diaphragm14is formed is arranged opposite the face21aof the wiring base material21.

The cavity13is a space formed inside the semiconductor substrate11and adjacent to the face11aof the semiconductor substrate11. In this embodiment, the cavity13is an airtight space in the semiconductor substrate11to which a face of the diaphragm14faces. The size of the cavity13can be set appropriately such that the diaphragm14has a desired thickness.

There are no limitations on the shape of the diaphragm14, which need only obtain a direct proportional relationship between pressure and static capacitance within the load pressure range of the measured target, and can be any shape such as rectangular, square, circular; in this example it is rectangular.

The pressure-sensitive elements15are gauge resistances (R1to R4) arranged in a peripheral portion of the diaphragm14, their output signals varying in accordance with the amount of bending of the diaphragm14, and pressure thereby being detected.FIG. 2is an electrical wiring view showing the pressure-sensitive elements15.

As shown inFIG. 2, these gauge resistances (R1to R4) are electrically connected by lead wires (not shown) to form a Wheatstone bridge. Since forces of compression and elongation in the peripheral portion of the diaphragm14are easily applied to the pressure-sensitive elements15, a highly sensitive pressure sensor10can be obtained.

In this embodiment, the pressure-sensitive elements15is arranged near the diaphragm14and buried in the semiconductor substrate11at the face11a. Alternatively, they can be arranged at any location that enables them to detect bending of the diaphragm14, e.g. they can protrude from the face11aof the semiconductor substrate11.

The conductive sections16are made by fabricating a thin film of any type of metal that is generally used as material for electrode, such as Al, Cr, Au, Ag, Cu, and Ti, on the face11aof the semiconductor substrate11using a method such as vaporization, sputtering, non-electrolytic plating, etc.

The pattern of the conducive sections16can be patterned by using a mask to cover portions of the face11aof the semiconductor substrate11where the conductive sections will not be fabricated and forming a metal film only in portions where the conductive sections will be fabricated, or by forming a uniform metal film on the face11aof the semiconductor substrate11and then performing photolithography to etch this metal film to a desired pattern.

There are no particular limitations on the bumps18, which need only be capable of electrically connecting the pressure sensor10to the wiring base material21arranged in the laminated substrate20. When the pressure sensor10and the laminated substrate20are electrically connected via the bumps18, a gap (interval)1is formed between the face21aof the wiring base material21and the face11aof the semiconductor substrate11. Due to the formation of the gap1, the pressure sensor10is not directly subjected to stress from the laminated substrate20, enabling that stress to be alleviated.

The laminated substrate20is configured by superimposing, for example, three substrates20a,20b, and20c, as shown inFIG. 1. In this embodiment, the laminated substrate20need only have two or more substrates composed of the same or different materials, there being no particular limitation on the number of substrates that are superimposed. In this embodiment, three substrates are superimposed. Alternatively, two substrates are acceptable, as is a laminated substrate formed by superimposing a plurality of substrates.

There are no particular limitations on the substrates that constitute the laminated substrate20, and conventional substrates can be used, such as a flexible printed circuit board with a polyimide base, etc.

A wiring base material21is arranged on the laminated substrate20, and is electrically connected to the pressure sensor10. A wiring portion23is also arranged on the laminated substrate20, and is electrically connected to the wiring base material21.

The wiring portion23connects a pressure signal from the pressure sensor10outputted from the conductive sections16or the wiring base material21to, for example, an amplification circuit or a temperature compensation circuit fabricated on the laminated substrate20. There are no particular limitations on the wiring portion23, which can be made from a metal that is generally used as material for electrode, such as Al, Cl, Au, Ag, Cu, and Ti.

The wiring base material21is arranged on the laminated substrate20and the pressure sensor10is mounted on it.

By arranging the wiring base material21within the laminated substrate20, and mounting the pressure sensor10so that the diaphragm14is opposite the wiring base material21, mechanical stress from the outside can be prevented from acting on and damaging sections that are vulnerable to damage, such as the joined portions between the diaphragm14and the bumps18.

Conductors22are arranged on the wiring base material21, and electrically connect to the conductive sections16of the pressure sensor10. There are no particular limitations on the conductors22, which can be made from any metal that is generally used as material for electrode, such as Al, Cr, Au, Ag, Cu, and Ti, this metal being selected with due consideration for its compatibility with the wiring base material21and the bumps18.

According to this embodiment, the wiring base material21that is electrically connected to the pressure sensor10is arranged within the laminated substrate20, and the pressure sensor10is mounted thereon. Since stress generated in the laminated substrate20is greatest at the topmost face20A of the laminated substrate20, the stress applied to the pressure sensor10can be reduced more than when it is mounted on a conventional pressure sensor module.

Also, rather than mounting the pressure sensor10directly on the laminated substrate20, it is arranged at an gap from side faces of the laminated substrate20and the face21aof the laminated substrate20. Stress generated in the laminated substrate20and applied to the pressure sensor10is thus alleviated, and fluctuation in output characteristics of the pressure sensor10before and after mounting caused by this stress can be suppressed, whereby a pressure sensor module30A with desired output characteristics can be provided.

In particular, this invention can be configured simply by arranging the wiring base material21within a conventional laminated substrate, and mounting the pressure sensor10on the wiring base material21. This makes it easy to provide a pressure sensor module30A which is unlikely to have fluctuating output characteristics.

Since the wiring base material21is arranged within the laminated substrate20, the pressure sensor module30A which the pressure sensor10is mounted in can be made thinner, and mechanical stress from the outside can be prevented from acting on and damaging sections that are vulnerable to damage, such as the joined portions between the diaphragm14and the bumps18.

Second Embodiment

FIG. 3is a schematic cross-sectional view showing one example of a pressure sensor module30B according to a second embodiment of the present invention. Like parts to those in the first embodiment are designated with like reference codes, and are not repetitiously explained.

In this embodiment, in the face that the pressure sensor10is mounted on, the topmost face20A of the laminated substrate20is at the same position as the top face of the pressure sensor10(other face11bof the semiconductor substrate11) or higher than that. Consequently, side faces11cof the semiconductor substrate11are enclosed by the laminated substrate20a, and, in the completed pressure sensor module30B, direct outside force against the pressure sensor10is considerably suppressed.

Therefore, in addition to the effects of the first embodiment described above, direct outside force against the pressure sensor10can be considerably suppressed both during delivery and after mounting it on a product, and dramatic reductions can be achieved in stress applied during delivery affects the diaphragm14, change in the output characteristics of the pressure sensor10, detachment of the pressure sensor10from the laminated substrate20after being mounting on the product, or problems arising from breakage in electrical connection and damage to the diaphragm14.

Third Embodiment

FIG. 4is a schematic cross-sectional view showing one example of a pressure sensor module30C according to a third embodiment of the present invention. In this embodiment, the pressure sensor module30C differs from the pressure sensor module30A of the first embodiment in that a semiconductor device31is arranged within the laminated substrate20, and electrically connected to the pressure sensor10. Like parts to those in the first embodiment are designated with like reference codes, and are not repetitiously explained.

There are no particular limitations on the semiconductor device31, which can include, for example, an application specific integrated circuit (ASIC) that performs sensitive amplification, temperature compensation, etc. for the pressure sensor10.

According to the pressure sensor module30C of the third embodiment, the semiconductor device (e.g. ASIC)31that controls the pressure sensor10is provided within the laminated substrate20, thereby eliminating the need for an external control circuit or such like to control the pressure sensor10. Therefore, in addition to the effects obtained by the first embodiment, this embodiment can provide the pressure sensor10and a semiconductor device31such as a control circuit for the pressure sensor10together in one package. Thereby the pressure sensor module30C that is small and thin can be obtained. Moreover, by burying a variety of semiconductor devices31in the laminated substrate20, a highly functional, high-density pressure sensor package can be provided.

In this embodiment, as in the second embodiment, the topmost face20A of the laminated substrate20can be exposed so that it is at the same position as the other face11bof the semiconductor substrate11, or higher than that, the pressure sensor10being covered with (surrounded by) the laminated substrate20. This obtains the same effects as those of the second embodiment.

Fourth Embodiment

FIG. 5is a schematic cross-sectional view showing one example of a pressure sensor module30D according to a fourth embodiment of the present invention. In this invention, the pressure sensor module30D differs from the pressure sensor module30A of the first embodiment in that a semiconductor device31is used as a wiring base material21arranged within the laminated substrate20.

In the semiconductor device31, an electrical circuit32is formed on a face31awhere the pressure sensor10is mounted, a portion of this circuit32is electrically connected to the bumps18, and the semiconductor device31is electrically connected to the pressure sensor10. This enables signals to be exchanged between the pressure sensor10and the semiconductor device31.

In this embodiment, by using the semiconductor device31as the wiring base material21, in addition to the effects of the first and the third embodiments mentioned above, a pressure sensor module30D that is smaller and thinner than the pressure sensor module30C of the third embodiment can be obtained.

In this embodiment, as in the second embodiment, the topmost face20A of the laminated substrate20can be exposed so that it is at the same position as the other face11bof the semiconductor substrate11, or higher than that, the pressure sensor10being covered with the laminated substrate20. The same effects as those of the second embodiment can be obtained.

Fifth Embodiment

FIG. 6is a schematic cross-sectional view showing one example of a pressure sensor module30E according to a fifth embodiment of the present invention.

In this embodiment, the pressure sensor module30E mainly includes a pressure sensor60, bumps18, and a laminated substrate20. In a face61aof a semiconductor substrate61, the pressure sensor60includes a cavity63that extends substantially parallel to the face61ainside a central area “α” of the semiconductor substrate61. A thin-plate region at a side of the cavity63is defined as a diaphragm64. Pressure-sensitive elements65are arranged in the diaphragm64. The pressure sensor60also includes conductive sections66that are electrically connected to the pressure-sensitive elements65and are arranged in a region excluding the diaphragm64on the face61a. The bump18is arranged in each conductive section66respectively, and is electrically connected to the conductive sections66separately. The laminated substrate20includes a wiring base material21that is electrically connected to the pressure sensor60via the bumps18.

Further, the wiring base material21is arranged inside the laminated substrate20, and at least one part of a face21aof the wiring base material21that is electrically connected to the bumps18is exposed from the laminated substrate20.

In this embodiment, the pressure sensor module30E differs from the pressure sensor module30A of the first embodiment in regard to three points, firstly, that through-hole electrodes62are provided in the pressure sensor60, so that one end62aof the through-hole electrode62is electrically connected to the conductive section66and another end62bof the through-hole electrode62is exposed on other face61bof the semiconductor substrate61, secondly, that the through-hole electrodes62are electrically connected to the wiring base material21via the bumps18, and thirdly, that the diaphragm64is arranged on the face61aon the reverse of the semiconductor substrate61with respect to the face61bopposite the laminated substrate20.

The semiconductor substrate61, the cavity63, the diaphragm64, the pressure-sensitive elements65, and the conductive sections66are respectively similar to the semiconductor substrate11, the cavity13, the diaphragm14, the pressure-sensitive elements15, and the conductive sections16of the first embodiment.

There are no particular limitations on the through-hole electrodes62, conventional electrodes can be used; and which can be formed by, for example, a through-hole in the semiconductor substrate61can be filled with gold, another metal material, or a solder alloy, etc.

According to this embodiment, the wiring base material21that is electrically connected to the pressure sensor60is arranged in the laminated substrate20and the pressure sensor60is mounted on it. Since stress generated in the laminated substrate20is greatest at the topmost face20A of the laminated substrate20, the stress applied to the pressure sensor60can be reduced more than when it is mounted on a conventional pressure sensor module. Also, rather than mounting the pressure sensor60directly on the laminated substrate20, it is arranged at an gap from side faces of the laminated substrate20and the face21aof the laminated substrate20.

The fluctuation in output characteristics of the pressure sensor60before and after mounting caused by the stress can be suppressed, whereby a pressure sensor module30E with desired output characteristics can be provided.

In particular, this invention can be configured simply by arranging the wiring base material21within a conventional laminated substrate, and mounting the pressure sensor60on the wiring base material21. This makes it easy to provide a pressure sensor module30E whose output characteristics are unlikely to fluctuate.

Since the wiring base material21is arranged within the laminated substrate20, the pressure sensor module30E which the pressure sensor60is mounted on can be made thinner, and mechanical stress from the outside can be prevented from acting on and damaging sections that are vulnerable to damage, such as the joined portions between the diaphragm14and the bumps18.

Sixth Embodiment

FIG. 7is a schematic cross-sectional view showing one example of a pressure sensor module30F according to a sixth embodiment of the present invention. Like parts to those in the first and fifth embodiments are designated with like reference codes, and are not repetitiously explained.

In this embodiment, at the face that the pressure sensor60is mounted on, the topmost face20A of the laminated substrate20is at the same position as the top face of the pressure sensor60(a face61aof the semiconductor substrate61) or higher than that. Side faces61cof the semiconductor substrate61are thus enclosed by the laminated substrate20a, and, in the completed pressure sensor module30F, direct outside force applied to the pressure sensor60is considerably suppressed.

Therefore, in addition to the effects of the fifth embodiment described above, direct outside force against the pressure sensor60can be considerably suppressed both during delivery and after mounting it on a product, and dramatic reductions can be achieved in the effects of stress applied during delivery on the diaphragm64and leading to change in the output characteristics of the pressure sensor60, detachment of the pressure sensor60from the laminated substrate20after being mounting on the product, or problems arising from breakage in electrical connection and damage to the diaphragm64.

Seventh Embodiment

FIG. 8is a schematic cross-sectional view showing one example of a pressure sensor module30G according to a seventh embodiment of the present invention. In this embodiment, the pressure sensor module30G differs from the pressure sensor module30E of the fifth embodiment in that a semiconductor device31is additionally arranged within the laminated substrate20.

There are no particular limitations on the semiconductor device31, which can include, for example, an application specific integrated circuit (ASIC) for performing sensitive amplification, temperature compensation, etc., for pressure, sensor60.

According to the pressure sensor module30G of this embodiment, as in the pressure sensor module30B of the second embodiment, the semiconductor device (e.g. ASIC)31for controlling the pressure sensor60is provided within the laminated substrate20, thereby eliminating the need for an external control circuit or such like to control the pressure sensor60.

Therefore, in addition to the effects obtained in the fifth embodiment, this embodiment can provide the pressure sensor60and the semiconductor device31such as a control circuit for the pressure sensor60together in one package, and thereby the pressure sensor module30G that is small and thin can be obtained. Moreover, by burying various semiconductor devices31in the laminated substrate20, a highly functional, high-density pressure sensor package can be provided.

Incidentally, in this embodiment, as in the sixth embodiment, the topmost face20A of the laminated substrate20can be exposed so that it is at the same position as the face61aof the semiconductor substrate61, or higher than that, the pressure sensor60being covered with the laminated substrate20. The same effects as those of the sixth embodiment can be obtained.

Eighth Embodiment

FIG. 9is a schematic cross-sectional view showing one example of a pressure sensor module30H according to an eighth embodiment of the present invention. In this embodiment, the pressure sensor module30H differs from the pressure sensor module30E of the fifth embodiment in that a semiconductor device31is used as a wiring base material21arranged within the laminated substrate20.

In the semiconductor device31, an electrical circuit32is formed on a face31awhere the pressure sensor60is mounted, a portion of this circuit32is electrically connected to the bumps18, and the semiconductor device31is electrically connected to the pressure sensor60. Signals can thus be exchanged between the pressure sensor60and the semiconductor device31.

In this embodiment, by using the semiconductor device31as the wiring base material21, in addition to the effects of the fifth and seventh embodiments mentioned above, it is possible to obtain a pressure sensor module30H that is smaller and thinner than the pressure sensor module30G of the seventh embodiment.

In this embodiment, as in the sixth embodiment, the topmost face20A of the laminated substrate20can be exposed30that it is at the same position as the face61aof the semiconductor substrate61, or higher than that, the pressure sensor60being covered with the laminated substrate20. The same effects as the sixth embodiment cm be obtained.

In the pressure sensor module30according to the first to the eighth embodiments described above, the coefficients of thermal expansion (CTE) of the wiring base material21is preferably approximately the same as that of the semiconductor substrates11and61of the pressure sensors10and60.

When a pressure sensor is attached by direct reflow on a laminated substrate in the conventional manner at a certain temperature (usually around 260° C.), due to the difference of the CTE between the sensor and the substrate, at the usage temperature of the pressure sensor (e.g. room temperature), there is residual stress near the soldered bump. Consequently, stress on the diaphragm changes before and after mounting the pressure sensor, whose output characteristics change as a result.

Due to the difference of CTE between the pressure sensor and the laminated substrate, residual stress changes (creep) over time, whereby the characteristics of the sensor also fluctuate over time. When thermal fluctuation is added to this, the sensor and the substrate expand and contract in accordance with their CTE, resulting in poor thermal reliability.

If the CTE of the wiring base material21is approximately the same as that of the semiconductor substrates11and61of the pressure sensors10and60, stress caused by difference in their CTE can be suppressed. It is also possible to minimize residual stress after the pressure sensors10and60are attached by direct reflow to the laminated substrate20, and fluctuation (creep) in this stress over time.

This makes it possible to reduce fluctuation in the output characteristics of the pressure sensors10and60before and after mounting, to maintain desired output characteristics, and to dramatically increase reliability of the temperature cycle and the like.

The wiring base material21can be modified as appropriate in accordance with the semiconductor substrates11and61used in the pressure sensors10and60. For example, it can be made from silicon, ceramic, glass, etc.

Incidentally, when using the semiconductor device31as the wiring base material21, the CTE of the wiring base material21is preferably approximately the same as that of the semiconductor substrates11and61of the pressure sensors10and60. As with the wiring base material21described earlier, this makes it possible to suppress stress caused by difference in the CTE, and to minimize residual stress after the pressure sensors10and60are attached by direct reflow on the laminated substrate20and fluctuation (creep) in this stress over time.

This makes it possible to obtain a pressure sensor module which can reduce fluctuation in the output characteristics of the pressure sensors10and60before and after mounting, can maintain desired output characteristics, and can dramatically increase the reliability of the temperature cycle and the like.

The semiconductor device31can be modified as appropriate in accordance with the semiconductor substrates11and61used in the pressure sensors10and60. For example, it can be made from silicon, ceramic, glass, etc.

An electronic component of the present invention includes the pressure sensor module30described in any one of the first to the eighth embodiments described above. Therefore, since the electronic component is hardly affected by stress from the outside or inside, it becomes possible to provide an electronic component that can detect pressure with high precision and superior reproducibility.

Since the invention can provide a pressure sensor module that alleviates stress applied to a pressure sensor and maintains desired output characteristics, it is ideally applicable to various electronic components which are used, for example, in measuring pressure such as air pressure, water pressure, and oil pressure, and which can measure with high precision and superior reproducibility.

While the invention has been particularly shown and described with reference to exemplary embodiments thereof, the invention is not limited to the exemplary embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the following claims.