JP2005083972A - Capacitance type sensor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitance type sensor and its manufacturing method which enhance detection sensitivity of a physical quantity without enlarging the size of the whole sensor. <P>SOLUTION: A beam part 4 is formed in a thin belt shape having the narrow width, and the other end part thereof is connected to an inside corner part of a frame part 2 on a position reached by making approximately three-quarter round of a box part 3 through a clearance between an electrode support part 7 of fixed electrodes 6X, 6Y and the frame part 2. Since a portion excepting both end parts of the beam part 4 is arranged between the fixed electrodes 6X, 6Y disposed around the box part 3 and the frame part 2, the length dimension of the beam part 4 is elongated and the displacement of the box part 3 is enlarged without enlarging the dimension of the whole acceleration sensor 1, to thereby enhance the detection sensitivity of the physical quantity (acceleration). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a capacitance type sensor that detects acceleration and angular velocity from capacitance between a fixed electrode and a movable electrode, and a method for manufacturing the same.

  Conventionally, a fixed electrode, a movable electrode opposed to the fixed electrode, a mass portion that supports the movable electrode and is displaced by a physical quantity, and one or more beams that are flexibly formed and are connected to the mass portion at one end. Sensor that is formed by processing a semiconductor substrate, and a frame portion that is formed in a frame shape surrounding the fixed electrode, the movable electrode, the mass portion, and the beam portion and to which the other end portion of the beam portion is connected Have been proposed (see, for example, Patent Document 1).

  FIG. 12 is a plan view of a conventional capacitive acceleration sensor. A mass portion 31, a beam portion 32, a fixed electrode 33, and a movable electrode 34 are arranged inside a frame portion 30 formed in a rectangular frame shape. The mass portion 31 has a substantially quadrangular shape, and movable electrodes 34 are formed in a comb shape on each of the four sides. The beam portion 32 is narrow and formed in a bent shape, and one end portion is connected to the inner corner portion of the frame portion 30 and the other end portion is connected to the four corners of the mass portion 31 so that the mass portion 31 can be bent freely. I support it. Further, the fixed electrode 33 is also formed in a comb-like shape, and is disposed between each side of the mass portion 31 and the frame portion 30 and alternately faces each movable electrode 34.

Thus, when acceleration is applied, the mass portion 31 is displaced and the gap between the movable electrode 34 and the fixed electrode 33 changes, so that the capacitance between the fixed electrode 33 and the movable electrode 34 also changes. By measuring the change in capacitance with an external circuit (not shown), the direction and magnitude of acceleration can be detected. The acceleration sensor having such a structure is generally formed by processing a semiconductor substrate such as silicon by a semiconductor fine processing technique such as etching.
Japanese Patent No. 3327595

  By the way, in order to increase the detection sensitivity of a physical quantity (acceleration in the case of the above-described conventional example) with an electrostatic capacitance sensor, the displacement amount of the mass portion relative to the physical quantity may be increased. However, in the above conventional example, the four beam portions 32 are arranged between the four corners of the mass portion 31 and the inner corner portion of the frame portion 30 facing the four corners. It is difficult to ensure a sufficient length, and there is a limit to increasing the displacement of the mass portion 31 without increasing the overall dimensions of the sensor.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a capacitance type sensor capable of increasing the detection sensitivity of a physical quantity without increasing the overall size of the sensor and a method for manufacturing the same. There is to do.

  In order to achieve the above object, the invention of claim 1 is a capacitance type sensor that detects a physical quantity such as acceleration or angular velocity by a capacitance between the movable electrode and the fixed electrode, the fixed electrode; A movable electrode that faces the fixed electrode, a mass portion that supports the movable electrode and is displaced by a physical quantity, and one or a plurality of beams that are formed so as to be flexible and are connected to the mass portion at one end and fixed at the other end. In a capacitive sensor formed by processing a semiconductor substrate, at least a part of a portion excluding both ends of the beam portion is disposed on the opposite side to the mass portion with respect to the fixed electrode. And

  According to this invention, it is possible to increase the displacement of the mass part by increasing the length of the beam part without increasing the overall dimension of the sensor, and it is possible to increase the detection sensitivity of the physical quantity. A sensor can be provided.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the beam portion is formed in a shape that circulates around the mass portion and the fixed electrode.

  According to the present invention, it is possible to further increase the physical dimension detection sensitivity by further extending the length of the beam portion.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the mass portion is provided with a groove from the peripheral edge toward the center, and the beam portion is connected to the mass portion at an end portion on the center side of the groove. Is arranged in the groove.

  According to the present invention, it is possible to further increase the physical dimension detection sensitivity by further extending the length of the beam portion.

  The invention of claim 4 is characterized in that in the invention of claim 1, 2 or 3, two beam portions are provided.

  According to the present invention, the displacement amount of the mass portion is increased and the detection sensitivity of the physical quantity is increased as compared with the case where four beam portions are provided.

  The invention of claim 5 is characterized in that, in the invention of claim 1, 2 or 3, four beam portions are provided.

  According to the present invention, the stability of the mass portion with respect to vibration is increased and the detection accuracy is improved as compared with the case where two beam portions are provided.

  According to a sixth aspect of the present invention, in the first to fifth aspects of the present invention, there is provided a regulating means for regulating the amount of deflection of the beam portion.

  According to this invention, when an excessive physical quantity is applied, the amount of deflection of the beam portion is restricted by the restricting means, and damage to the beam portion can be prevented.

  A seventh aspect of the present invention is the structure according to any one of the first to sixth aspects, wherein the thick portion formed by processing the semiconductor substrate together with the mass portion and the beam portion is provided around the beam portion and the beam portion. It is characterized by being arranged at a part having a relatively large distance from the object.

  According to the present invention, there is a possibility that the beam portion may be etched more than necessary when the semiconductor substrate is processed (etched) at a portion where the distance between the beam portion and the structure provided around the beam portion is large. By arranging the thick part in such a part, it is possible to prevent the beam part from being etched more than necessary, and to prevent the detection sensitivity from varying.

  According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the fixed electrode and the movable electrode face each other substantially in parallel with the arrangement direction of the mass portion and the beam portion, and the mass in a direction orthogonal to the arrangement direction. A second fixed electrode facing the movable electrode is disposed on at least one side of the portion.

  According to the present invention, acceleration in each direction of the x-axis and y-axis of the three-dimensional orthogonal coordinate system is detected by a change in capacitance between the fixed electrode and the movable electrode, and the second fixed electrode and the movable electrode are detected. An acceleration sensor that can also detect acceleration in the z-axis direction due to a change in capacitance between the two can be realized.

  A ninth aspect of the invention is characterized in that, in the eighth aspect of the invention, the beam portion is formed such that a thickness in a direction orthogonal to the arrangement direction is smaller than a thickness of the mass portion.

  According to the present invention, it is possible to increase the amount of displacement of the mass portion in the z-axis direction and increase the detection sensitivity of acceleration in that direction.

  The invention of claim 10 is the frame part according to any one of claims 1 to 9, wherein the frame part is formed in a frame shape surrounding the fixed electrode, the movable electrode, the mass part and the beam part, and the other end part of the beam part is connected. The frame portion is fixed to a pair of substrates made of an insulator from both sides in a direction orthogonal to the arrangement direction of the mass portion and the beam portion, and one substrate has one or more corner portions cut out. An electrode pad electrically connected to the fixed electrode is provided at a position exposed to the outside through the opening.

  According to the present invention, when a large number of capacitive sensors are manufactured from a single wafer, the openings are arranged so as to straddle a plurality of adjacent sensors. The openings can be formed at the same time, which facilitates manufacturing.

  The invention of claim 11 is characterized in that, in the invention of claim 10, the substrate has two openings.

  According to this invention, it is possible to suppress a decrease in the strength of the substrate due to the opening.

  The invention of claim 12 is characterized in that, in the invention of claim 10 or 11, the outline of the opening is formed only by a straight line.

  According to the present invention, the area of the portion excluding the opening can be increased as compared with the case where the outline of the opening is formed in a curved line, and foreign matters such as dust pass through the opening at the time of manufacture. It becomes difficult to adhere to parts.

  The invention of claim 13 is the invention according to any one of claims 1 to 12, wherein the fixed electrode and the movable electrode are formed in a comb-like shape, and the beam portion, the fixed electrode and the movable electrode etch the semiconductor substrate by reactive ion etching. It is characterized by being formed.

  According to the present invention, it is possible to increase the facing area between the fixed electrode and the movable electrode, and the physical quantity detection sensitivity can be further increased.

  A fourteenth aspect of the invention is a manufacturing method for manufacturing the capacitive sensor according to the tenth, eleventh or twelfth aspect of the invention, wherein a plurality of sensor blocks are formed on a wafer, and individual sensor blocks are cut out from the wafer to statically. In a manufacturing method for manufacturing a capacitive sensor, a plurality of holes are formed in an insulator constituting a substrate, and the insulator is bonded to the wafer so that the holes straddle the boundary of adjacent sensor blocks in the wafer. The sensor block is cut out from the wafer together with the insulator.

  According to the present invention, it is possible to provide an opening only at a necessary portion of the insulator, and in addition, in the sensor block cut out from the wafer, the opening is opened at a boundary portion with another adjacent sensor block. Therefore, the operation of bonding the wire to the electrode pad through the opening can be easily performed.

  According to the present invention, it is possible to increase the displacement amount of the mass portion by extending the length of the beam portion without increasing the overall size of the sensor, and to increase the detection sensitivity of the physical quantity. There is an effect that a sensor can be provided.

  Embodiments in which the present invention is applied to a capacitive semiconductor acceleration sensor will be described in detail below with reference to the drawings. However, the capacitive sensor of the present invention is not limited to an acceleration sensor, and the technical idea of the present invention can be applied to a capacitive sensor that detects physical quantities such as angular velocity and pressure in addition to acceleration. Needless to say.

  FIG. 1 shows a capacitance type semiconductor acceleration sensor (hereinafter simply referred to as “acceleration sensor”) 1 of the present embodiment, where FIG. 1 (a) is a plan view and FIG. 1 (b) is A in FIG. 1 (a). FIG. As shown in FIG. 1 (a), the frame portion 2 is formed in a substantially square flat frame shape having substantially the same vertical and horizontal dimensions. The mass portion 3 is formed in a substantially rhombic flat shape, and comb-like movable electrodes 5X and 5Y are formed on the four sides, respectively. The fixed electrodes 6X and 6Y are also formed in a comb-like shape like the movable electrodes 5X and 5Y, and are arranged between the sides of the mass portion 3 and the frame portion 2 so as to be alternately opposed to the movable electrodes 5X and 5Y. doing. The fixed electrodes 6X and 6Y are supported by an electrode support portion 7 having a width wider than that of the fixed electrodes 6X and 6Y.

  The mass portion 3 is provided with narrow grooves 8 from the four apexes toward the center portion, and one end portion of each of the four beam portions 4 is connected to the mass portion 3 at the center end portion of each groove 8. It is connected. Each beam portion 4 is formed in a thin band shape that is narrower than the groove 8, is curved in an arc shape outside the apex side end portion of the groove 8, and is opposite to the mass portion 3 with respect to the fixed electrodes 6X and 6Y ( That is, the other end portion is formed at the inner corner portion of the frame portion 2 at a position where the periphery of the mass portion 3 passes through the gap between the electrode support portion 7 and the frame portion 2 of the fixed electrodes 6X and 6Y. Are connected. The beam portion 4 formed in a thin belt shape is at least flexible in the width direction, and the mass portion 3 supported by the four beam portions 4 inside the frame portion 2 is arranged in the x-axis direction in FIG. It can be displaced in the y-axis direction. In the present embodiment, the frame portion 2 having a rectangular frame shape is provided as a structure for fixing the end portion of the beam portion 4. However, the frame portion 2 is not necessarily provided, and the end portion of the beam portion 4 can be fixed. Any structure is acceptable.

  Here, a notch 3a parallel to the movable electrodes 5X and 5Y is provided in the vicinity of the pair of apexes of the mass portion 3 facing each other with the groove 8 therebetween, and the mass portion 3 is displaced when the mass portion 3 is largely displaced. Is provided in the notch 3a. That is, when an impact is applied from the outside, it is possible to prevent the stopper portion 20 from interfering with the mass portion 3 in the notch 3a and the mass portion 3 from being excessively displaced.

  Then, when the acceleration is applied, the mass portion 3 is displaced in the xy plane, and the gap between the fixed electrode 6X and the movable electrode 5X changes according to the amount of displacement in the x-axis direction, and the capacitance between the two is changed. Similarly, the gap between the fixed electrode 6Y and the movable electrode 5Y changes according to the amount of displacement in the y-axis direction, and the capacitance between the two also changes. By measuring the length, the direction and magnitude of the applied acceleration can be detected. However, the principle of acceleration detection is the same as that of a conventional capacitive sensor, and thus detailed description thereof is omitted.

  Thus, in the present embodiment, since the portions excluding both ends of the beam portion 4 are arranged on the opposite side of the mass portion 3 with respect to the fixed electrodes 6X and 6Y, the size of the entire acceleration sensor 1 is not increased. It is possible to increase the amount of displacement of the mass portion 3 by extending the length of the beam portion 4 and to increase the detection sensitivity of the physical quantity (acceleration). The length of the beam portion 4 is increased by forming the beam portion 4 in a spiral shape that circulates around the mass portion 3 and the fixed electrodes 6X and 6Y. This also increases the amount of displacement of the mass portion 3. Acceleration detection sensitivity can be increased. Further, a groove 8 extending from the peripheral edge of the mass portion 3 toward the center is provided, and one end of the groove 8 is connected to the mass portion 3 at the central end portion, and a part of the beam portion 4 is disposed in the groove 8. Therefore, it is possible to extend the length of the beam portion 4 by the amount disposed in the groove 8, and this also increases the displacement amount of the mass portion 3 and increases the detection sensitivity of acceleration. it can.

  By the way, in the present embodiment, the mass portion 3 is swingably supported by the four beam portions 4. However, as shown in FIG. 2, for example, the mass portion 3 is composed of only two beam portions 4 at diagonal positions. If the structure is used, the amount of displacement of the mass portion 3 is increased as compared with the case where it is supported by the four beam portions 4, and the acceleration detection sensitivity can be further increased. However, the structure in which the mass unit 3 is supported by the four beam units 4 is more stable than the structure in which the mass unit 4 is supported by the two beam units 4 with respect to vibrations other than acceleration that is not a detection target. There is an advantage that the detection accuracy of the acceleration that should be detected is improved.

  Note that, when an excessive acceleration is applied, the amount of bending of the beam portion 4 becomes too large, and there is a possibility that problems such as breakage may occur. Therefore, it is desirable to provide a restricting means for restricting the amount of bending of the beam portion 4. For example, as shown in FIG. 3, it is only necessary to form a plurality of protruding beam stoppers 9 facing each other with a predetermined gap between them, and when the excessive acceleration is applied, The amount of deflection is restricted by hitting the beam stopper 9, and damage to the beam portion 4 can be prevented.

  Here, the beam part 4, the movable electrodes 5X and 5Y and the fixed electrodes 6X and 6Y in the present embodiment are dry-etched on a semiconductor substrate (for example, a silicon substrate), for example, inductively coupled plasma type reactive ion etching (ICP-RIE). In the case where a structure having a high dimensional ratio (aspect ratio) between the length and the width is formed as in the beam portion 4, if the surrounding etching region is large, the gas is etched after etching the etching region. May easily enter, and the beam portion 4 may be thinned due to excessive etching up to a region that should not be etched. Therefore, in this embodiment, as shown in FIGS. 1 and 4, the distance between the beam portion 4 and a structure (for example, the frame portion 2 and the stopper portion 20) provided around the beam portion 4 is relatively large. The etching region is reduced by disposing the thick portion 10 that is not etched in the vicinity of the portion, that is, the portion of the beam portion 4 that is curved in an arc shape. By arranging the thick portion 10 in this way, the etching area in the vicinity of the beam portion 4 is reduced, so that the beam portion 4 can be prevented from being etched more than necessary, and the detection is made by the narrowness of the beam portion 4. This prevents variations in sensitivity. The beam portion 4 and the structure provided around the beam portion 4 are not limited to the present embodiment, and the structure provided around the beam portion 4 and the beam portion 4 in any configuration. By providing a thick portion at a portion where the distance from the object is relatively large, thinning of the beam portion 4 can be suppressed.

  Incidentally, as shown in FIG. 5, a pair of insulators (for example, glass) from both sides in a direction (vertical direction in FIG. 5) orthogonal to the arrangement direction of the mass part 3 and the beam part 4 (horizontal direction in FIG. 5). In general, the substrates 11 and 12 are joined to the frame portion 2 and the frame portions 2 are reinforced by the substrates 11 and 12. In such a structure, if the second fixed electrode 15 is formed on the surface of each of the substrates 11 and 12 facing the movable electrodes 5X and 5Y, the static electricity between the second fixed electrode 15 and the movable electrodes 5X and 5Y is formed. The acceleration in the vertical direction in FIG. 5, that is, the acceleration in the z-axis direction can be detected by the change in the capacitance, and an acceleration sensor capable of detecting the acceleration in the 3-axis direction can be realized. However, in order to increase the acceleration detection sensitivity in the z-axis direction, the beam portion 4 is formed so that the thickness of the beam portion 4 along the z-axis is smaller than the thickness of the mass portion 3 as shown in FIG. It is desirable to increase the amount of displacement of the mass portion 3 in the z-axis direction so as to be easily bent in the z-axis direction.

  When the frame portion 2 is reinforced by the pair of substrates 11 and 12 as described above, as shown in FIG. 7, the electrode pads 13 for fixed electrodes formed on the surface of each electrode support portion 7 and the frame portion. In order to perform wire bonding to the electrode pad 14 for the movable electrode formed on the surface 2, it is necessary to provide openings 12 a on the substrates 12 to be bonded to the surface side of the frame portion 2. On the other hand, in the case where the semiconductor substrate is processed and formed like the acceleration sensor 1 of the present embodiment, one substrate 11 is bonded to the back surface of the semiconductor substrate (wafer), and processing such as etching is performed on the surface of the wafer. Thus, a manufacturing method is adopted in which a large number of acceleration sensors 1 are formed side by side, and the other substrate 12 is bonded to the surface of the wafer, and then the individual acceleration sensors 1 are cut out from the wafer. Accordingly, the acceleration sensor 1 before being cut out from the wafer (hereinafter, the one before being cut out for the sake of simplicity is referred to as a “sensor block”) is adjacent to a total of eight sensor blocks 1 diagonally in the vertical and horizontal directions. Since the openings 12a formed at the four corners of the acceleration sensor 1 are arranged across the four adjacent sensor blocks 1, the portions corresponding to the corners of the four adjacent sensor blocks 1 If the substrate 12 is cut out, it is possible to simultaneously form the openings 12a in the four substrates 12 of the sensor block 1 at one place, compared with the case where the openings 12a are individually formed for each sensor block 1. Thus, there is an advantage that the opening 12a can be easily manufactured.

  Here, since it is considered that the strength of the substrate 12 decreases when the openings 12a are formed at the four corners of the substrate 12, respectively, the openings 12a are formed only at the two corners on the diagonal line as shown in FIG. In addition, it is desirable that four fixed electrode electrode pads 13 and movable electrode electrode pads 14 are arranged in a range exposed by each opening 12a to suppress a decrease in strength of the substrate 12 due to the opening 12a. Further, as shown in FIGS. 7 and 8, by forming the outline of the opening 12a only by a straight line, the area of the portion excluding the opening 12a of the substrate 12 is made larger than when the outline is formed by a curve. This makes it difficult for foreign matters such as dust to adhere to the mass portion 3 and the beam portion 4 through the opening 12a during manufacturing.

  Finally, a method for manufacturing the acceleration sensor 1 of the present embodiment will be described. First, an insulator to be the substrate 11 is bonded to the back surface of the wafer, and etching is performed from the front surface of the wafer by ICP-RIE to form the mass portion 3, the beam portion 4, the movable electrodes 5X and 5Y, the fixed electrodes 6X and 6Y, and the like. To do. Here, by etching by reactive ion etching such as ICP-RIE, it is possible to etch uniformly to a deep position in the thickness direction of the wafer. Therefore, the depth of the movable electrodes 5X and 5Y and the fixed electrodes 6X and 6Y. The size of the direction, that is, the opposing area of both can be increased, and as a result, the acceleration detection sensitivity can be improved.

  On the other hand, a plurality of octagonal holes in plan view are formed through the insulator serving as the substrate 12, and the center of each hole is aligned with the point where the corners of the four adjacent sensor blocks 1 are gathered to align the surface of the wafer. An insulator is joined to (see FIG. 10). And if each sensor block 1 is cut out from a wafer with an insulator (board | substrates 11 and 12) in the position shown with the broken line in FIG. 10, the acceleration sensor with which board | substrates 11 and 12 were joined to both front and back as shown in FIG. 1 is obtained. In FIG. 11, details of the frame portion 2, the mass portion 3, the beam portion 4 and the like are not shown.

  Thus, if a hole for forming the opening 12a is previously provided in the insulator constituting the substrate 12 as described above, the opening 12a can be provided only in a necessary portion of the insulator (substrate 12). In addition, in the sensor block (acceleration sensor) 1 cut out from the wafer, the opening 12a is opened at the boundary with the other adjacent sensor block (acceleration sensor) 1, so that a bonding tool such as a capillary is used. However, there is an advantage that the work of bonding wires to the electrode pads 13 and 14 through the opening 12a can be easily performed without being surrounded by the substrate 12 on all sides.

The embodiment of this invention is shown, (a) is a top view, (b) is the AA sectional view taken on the line in FIG. It is a top view which shows the other structure same as the above. It is a top view of the principal part same as the above. It is a top view of the principal part same as the above. It is sectional drawing which shows the other structure same as the above. It is sectional drawing which shows other structure same as the above. It is a top view of the state which joined the board | substrate same as the above. It is a top view of the state which joined the board | substrate same as the above. FIG. 9 is a sectional view taken along line B-B in FIG. 8. It is explanatory drawing for demonstrating the manufacturing method same as the above. It is a perspective view in which a part was omitted. It is a top view of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Acceleration sensor 2 Frame part 3 Mass part 4 Beam part 5X, 5Y Movable electrode 6X, 6Y Fixed electrode 7 Electrode support part 8 Groove

Claims (14)

  A capacitance type sensor that detects a physical quantity such as acceleration or angular velocity by a capacitance between a movable electrode and a fixed electrode, and supports the fixed electrode, the movable electrode facing the fixed electrode, the movable electrode, and Capacitance formed by processing a semiconductor substrate with a mass portion that is displaced by a physical quantity, and one or more beam portions that are flexibly formed and connected to the mass portion at one end and fixed at the other end In the capacitive sensor, at least a part of a portion excluding both ends of the beam portion is disposed on the opposite side of the mass portion with respect to the fixed electrode.   2. The capacitive sensor according to claim 1, wherein the beam portion is formed in a shape that circulates around the mass portion and the fixed electrode.   The mass portion is provided with a groove from the periphery toward the center, and the beam portion is connected to the mass portion at an end portion on the center side of the groove, and a part thereof is disposed in the groove. 2. The capacitive sensor according to 2.   The electrostatic capacity type sensor according to claim 1, comprising two beam portions.   4. The capacitive sensor according to claim 1, comprising four beam portions.   The electrostatic capacity sensor according to claim 1, further comprising a restricting unit that restricts a deflection amount of the beam portion.   A thick portion formed by processing a semiconductor substrate together with a mass portion and a beam portion is disposed at a portion where a distance between the beam portion and a structure provided around the beam portion is relatively large. The capacitive sensor according to claim 1.   The fixed electrode and the movable electrode are opposed substantially parallel to the arrangement direction of the mass portion and the beam portion, and a second fixed electrode is arranged on at least one side of the mass portion in a direction orthogonal to the arrangement direction. The capacitance type sensor according to any one of claims 1 to 7, wherein   9. The capacitive sensor according to claim 8, wherein the beam portion is formed so that a thickness in a direction orthogonal to the arrangement direction is smaller than a thickness of the mass portion.   The frame part is formed in a frame shape surrounding the fixed electrode, the movable electrode, the mass part, and the beam part, and the other end part of the beam part is connected, and the frame part is orthogonal to the arrangement direction of the mass part and the beam part. Fixed to a pair of substrates made of an insulator from both sides in one direction, and one substrate has an opening formed by notching one or more corners, and is fixed to a position exposed to the outside through the opening. The capacitive sensor according to claim 1, further comprising an electrode pad electrically connected to the electrode.   The capacitive sensor according to claim 10, wherein the substrate has two openings.   12. The capacitance type sensor according to claim 10, wherein the outline of the opening is formed by only a straight line.   The fixed electrode and the movable electrode are formed in a comb shape, and the beam portion, the fixed electrode, and the movable electrode are formed by etching a semiconductor substrate by reactive ion etching. The capacitance type sensor described.   13. A manufacturing method for manufacturing a capacitive sensor according to claim 10, 11 or 12, wherein a plurality of sensor blocks are formed on a wafer, and each sensor block is cut out from the wafer to manufacture a capacitive sensor. In a manufacturing method, a plurality of holes are formed in an insulator constituting a substrate, and after bonding the insulator to the wafer so that the holes straddle the boundary of adjacent sensor blocks in the wafer, the individual sensor blocks are combined with the insulator. A method of manufacturing a capacitive sensor, characterized by cutting out from a wafer.

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