JP5357166B2 - MEMS sensor and detection apparatus - Google Patents

Abstract

Disclosed is a MEMS sensor that can sense acceleration and angular velocity in three directions, while having overall good balance in a thin form. Disclosed is a MEMS sensor (1) with an overall rectangular shape, wherein a first motion space (15) is formed at the center, a second motion space (16) is formed on the right, and a third motion space (17) is formed on the left. A first moving body (41) is disposed inside the first motion space (15), which first moving body (41) moves in the Z direction. A second moving body (21) is disposed inside the second motion space (16), which second moving body (21) moves in the Y direction. A third moving body (21A) is disposed inside the third motion space (17), which third moving body (21A) moves in the X direction. Each motion space (15, 16, 17) and each moving body (21, 21A, 41) has a shape with 180° rotational symmetry and bilateral symmetry about a first center line O1.

Description

  The present invention relates to a MEMS sensor having a fine structure formed by processing a silicon layer, and in particular, a MEMS in which movable bodies that operate in three directions orthogonal to each other are supported on a common support substrate. The present invention relates to a sensor and a detection device.

A MEMS (Micro-Electro-Mechanical Systems) element is formed by finely processing an SOI (Silicon on Insulator) layer in which _two silicon (Si) wafers are joined via an insulating layer such as SiO ₂ . In the MEMS element, one silicon wafer of the SOI layer is used as a support substrate, and the other silicon wafer is separated by etching, and a movable body, a support section that supports the movable body so that the movable body can be operated, A detection unit that detects the amount of movement is formed. In addition, a driving unit that applies a driving force to the movable body is formed as necessary.

  When processing the SOI layer, the insulating layer between the support portion of the movable body and the support substrate is left and the support portion is fixed to the support substrate, and between the operation portion of the movable body and the support substrate. The insulating layer is removed, and the movable body is configured to be movable on the support substrate. Further, the detection unit and the drive unit are generally composed of a movable electrode that operates integrally with the movable unit, and a fixed electrode that forms a capacitance between the movable electrode and the fixed electrode unit. The support portion is fixed to the support substrate through the insulating layer.

  The MEMS element is configured as a micro relay as described in Patent Document 1 below, or used as an acceleration sensor, a vibration gyro, a pressure sensor, or the like.

  As described in Patent Document 1, normally, a MEMS element is configured to have a single operation function, and one MEMS element is packaged and used.

  Therefore, for example, when the MEMS element is configured as an acceleration sensor or a vibration type gyro, and three components of acceleration or angular velocity in three orthogonal directions in space are detected, three acceleration sensors or vibration type gyro having the same structure are used. It is necessary to install and package three sensors in directions that can correspond to the X axis, the Y axis, and the Z axis, which are orthogonal axes. Or it is necessary to individually manufacture acceleration sensors and vibration type gyros with different structures for the X-axis, Y-axis, and Z-axis, and package and use the three types of sensors together. Become.

  As described above, a sensor capable of detecting all the components of acceleration or angular velocity in three orthogonal directions contains three individual sensors in one packaging, so that the structure is complicated and large. .

  Patent Document 2 below discloses a composite MEMS sensor including a pair of vibrators and configured in a bilaterally symmetric shape. However, in this MEMS sensor, a pair of vibrators move in the same direction, and acceleration is detected by the operation of one vibrator and angular acceleration is detected by the operation of the other vibrator.

  As described above, conventionally, there is no idea of configuring a sensor that can detect all accelerations or angular velocities in three orthogonal directions as a small sensor arranged in a plane.

JP 2000-307018 A JP 2006-105698 A

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a MEMS sensor and an inspection apparatus that can be planarly configured as a single element and can detect acceleration and angular velocity in three orthogonal directions. .

  In addition, the present invention can mount a movable body that exhibits three different functions on the same substrate, and is capable of a balanced operation as a whole with a symmetrical overall structure. An object of the present invention is to provide a MEMS sensor and an inspection apparatus in which stress due to the reaction force can act on the whole in a balanced manner.

In the MEMS sensor according to the present invention, a frame layer is provided between a support substrate and a closing member parallel to the support substrate, and the first operation space, the second operation space, and the third operation space are sealed from the outside and separated from each other. Operating space is formed,
A first movable body is housed in the first operation space, a second movable body is housed in the second operation space, and a third movable body is housed in the third operation space. And the second movable body and the third movable body are supported so that the main movement directions are in three different directions orthogonal to each other, and the movable bodies are moved in the respective movement spaces. A detection unit that detects the amount of movement in the main movement direction of the body is provided,
The second operation space is arranged on one side of the first operation space, the third operation space is arranged on the other side, and the three operation spaces are arranged in a row, and the plane of the second operation space The shape and the planar shape of the third motion space are equal, and the planar shape of the three motion spaces is 180 degrees with respect to a center line passing through the center of the first motion space and orthogonal to the surface of the support substrate. rotationally symmetrical shape der of is,
Each detection unit provided in each operation space has an output side electrode and an input side electrode, and a plurality of the output side electrode and the input side electrode are provided in each detection unit,
Each output side electrode is electrically connected to an external connection pad via a first lead layer embedded in an insulating layer formed on the surface of the closing member,
In at least one of the detection units, the pattern lengths of the plurality of first lead layers are different, and the first lead layer having a long pattern length is different from the first lead layer having a short pattern length. those characterized that you have been formed in narrow width.

  In the MEMS sensor of the present invention, movable bodies are respectively provided in three operation spaces arranged in a plane on the same support substrate, and accelerations in three directions orthogonal to each other in the space are detected by the three movable bodies. It is configured to be able to. Since the three movable bodies that detect acceleration in three directions are arranged in a planar shape, it can be configured to be thin and small. In addition, by providing a drive unit that vibrates the movable body in each operation space, a vibrating gyroscope can be configured, and the angular velocity around three orthogonal axes can be detected by the three movable bodies. .

  Since the MEMS sensor according to the present invention has a rotationally symmetric shape of 180 degrees as a whole, the bonding stress between the frame layer and the support substrate that divides the three operation spaces and the bonding stress between the frame layer and the closing member are measured. The bias is reduced, and the entire sensor is less likely to warp.

  In the present invention, it is preferable that the second movable body and the third movable body have the same mass, and the first movable body has a symmetrical mass with respect to the center line.

  By distributing the mass of the movable body symmetrically as described above, it is possible to realize a balanced operation as a whole, for example, concentration of stress acting on the support substrate and the frame layer due to the reaction when the movable body operates. This can be avoided and a long life can be realized.

  Further, according to the present invention, main operation directions of the second movable body and the third movable body are parallel to the substrate surface of the support substrate and orthogonal to each other. The main operation direction is a direction perpendicular to the substrate surface of the support substrate.

  As described above, the operation direction of the first movable body is the vertical direction, and the operation directions of the second movable body and the third movable body located on both sides of the first movable body are the planar directions. The operation balance between the left and right sides can be achieved with the center line interposed therebetween, and it becomes easier to prevent bias and concentration of stress acting on the support substrate and the frame layer.

  In the present invention, the frame body layer, the movable body, the support section that supports the movable body so as to be movable in the main operation direction, and the detection section are formed separately from a common layer. That is, an SOI layer in which two Si layers are bonded via an insulating layer is used, one Si layer is used as the support substrate, and the other Si layer is used as a functional layer. A frame body layer, the movable body, a support section that supports the movable body so as to be movable in a main operation direction, and the detection section are separately formed.

  In the present invention, it is preferable that a communication path for communicating the adjacent operation spaces is formed in the frame layer.

  The first operation space, the second operation space, and the third operation space are sealed from the outside in a vacuum state in which the internal air is discharged or in a state close to a vacuum. In this case, if the three operation spaces communicate with each other through the communication path, the pressures in the three operation spaces can be made the same, that is, the degree of vacuum can be made the same. In some cases, an inert gas such as argon is sealed in the first operation space, the second operation space, and the third operation space, and in this case, all the operation spaces are connected. If connected by a passage, it is possible to prevent variations in pressure within each operation space.

  In this way, if the vacuum degree of each operation space can be made the same or the internal pressure can be made the same, it is possible to prevent uneven concentration of stress acting on the support substrate and the frame body layer due to pressure variations, and support. Problems such as warpage of the substrate and the frame layer are less likely to occur.

In the present invention, each detection unit provided in each operation space has an output side electrode and an input side electrode, and a plurality of the output side electrodes are provided in each detection unit,
Each output side electrode is electrically connected to an external connection pad via a first lead layer embedded in an insulating layer formed on the surface of the closing member,
In at least one of the detection units, the pattern lengths of the plurality of first lead layers are different, and the first lead layer having a long pattern length is different from the first lead layer having a short pattern length. It is preferable to be formed narrow. Thereby, in each detection part, each parasitic capacitance produced between each 1st lead layer and a closure member can be adjusted so that it may approach fixed.

Alternatively, in the present invention, each detection unit provided in each operation space has an output side electrode and an input side electrode, and a plurality of the output side electrodes are provided in each detection unit,
Each output side electrode is electrically connected to an external connection pad via a first lead layer embedded in an insulating layer formed on the surface of the closing member,
The formation position of each external connection pad is set according to the position of the terminal portion of the integrated circuit (IC),
The length and width of each first lead layer are adjusted so that the parasitic capacitance between each first lead layer and the closing member approaches a fixed value in each detection unit.

The detection device according to the present invention includes the MEMS sensor described above and an integrated circuit (IC), and the formation position of each external connection pad is set according to the position of the terminal portion of the integrated circuit (IC). And
Each external connection pad of the MEMS sensor and each terminal portion provided in the integrated circuit are conductively connected to obtain a differential output.

  The MEMS sensor of the present invention has an integrated shape that is long in one direction in which the first operation space, the second operation space, and the third operation space are arranged in a line. For example, depending on the position of the terminal portion of the external element Thus, the position of each detection unit provided in each operation space cannot be changed. Therefore, for example, when external connection pads are collectively provided near the first operation space located in the middle according to the position of the terminal portion, the second operation space and the third operation space located on both sides are In addition to being away from the position of the external connection pad, the pattern length of each first lead layer is likely to be different due to routing. However, in the present invention, the width of the lead layer is adjusted according to the length of the lead layer so that the parasitic capacitance generated between each first lead layer and the closing member in each detection unit approaches a certain value. A highly accurate differential output can be obtained. In addition, according to the configuration of the MEMS sensor of the present invention, it is possible to appropriately cope with connection to any integrated circuit (IC), and detection can be performed without restricting the integrated circuit (IC) side. It is possible to manufacture a detection device with excellent accuracy.

  Although the present invention is a single thin and planar sensor using, for example, SOI, it is possible to detect accelerations in three orthogonal directions and angular velocities around three axes. In addition, although there are three operation spaces inside, the planar shape of each operation space is symmetric with respect to the center line, so that the bonding stress at the joint between the frame layer and the support substrate, etc. Bias is less likely to occur.

  In addition, since a balanced operation as a whole can be realized, it is difficult to concentrate stress on a part, and it is easy to extend the life.

The top view which shows the structure in each operation space of the MEMS sensor of embodiment of this invention seeing through a support substrate, FIG. 2 is a cross-sectional view of the MEMS sensor, which corresponds to a cross-sectional view of FIG. 1 cut along the line II-II. FIG. 2 is an enlarged plan view showing the second operation space shown in FIG. It is sectional drawing of 2nd operation | movement space, and is equivalent to sectional drawing which cut | disconnected FIG. 3 by the IV-IV line. FIG. 3 is an enlarged plan view of the detection unit indicated by V in FIG. FIG. 3 is an enlarged plan view of the detection unit indicated by VI in FIG. Sectional drawing which shows the structure in the 1st operation | movement space of the MEMS sensor shown in FIG. (A) is an enlarged plan view showing a detection unit indicated by VIII in FIG. 1, (B) is a sectional view of (A), (A) is an enlarged plan view showing a detection unit indicated by IX in FIG. 1, (B) is a sectional view of (A), (A) (B) is sectional drawing which shows another embodiment of the detection part shown by VIII, and the detection part shown by IX, The partial top view of the detection apparatus provided with the MEMS sensor in this embodiment, The top view of the inspection device which shows another embodiment, FIG. 13 is an enlarged plan view of the MEMS sensor shown in FIG. 12.

  FIG. 1 shows a MEMS sensor according to an embodiment of the present invention. FIG. 2 is a plan view showing a structure of a frame body layer, a movable body arranged in the frame body layer, and a detection unit. FIG. It is a longitudinal cross-sectional view which shows the whole structure, and is corresponded in sectional drawing which cut | disconnected FIG. 1 by the II-II line. FIG. 3 is a plan view showing a structure in the second operation space arranged on the right side of the MEMS sensor shown in FIG. 4 is a longitudinal sectional view of the second operation space arranged on the right side of the MEMS sensor shown in FIG. 2, and corresponds to a sectional view taken along line IV-IV in FIG. FIGS. 5 and 6 are enlarged plan views of the V part and the VI part of the detection part in the second operation space shown in FIG. 3, respectively. FIG. 7 is an enlarged cross-sectional view showing a structure in the first operation space arranged at the center of FIG. FIGS. 8A and 9A show the structure of the detection unit arranged in the first operation space, and are enlarged plan views of the VIII part and the IX part of FIG. 1, respectively. FIGS. 8B and 9B are cross-sectional views of FIGS. 8A and 9A, respectively.

As shown in FIG. 1, the MEMS sensor 1 has a rectangular shape with long sides in the X direction and short sides in the Y direction. As shown in FIG. 2, in the MEMS sensor 1, a functional layer 10 is laminated on a support substrate 2, and a part of the functional layer 10 and the support substrate 2 are bonded via a first insulating layer 3. The support substrate 2, the functional layer 10, and the first insulating layer 3 are formed by finely processing an SOI (Silicon on Insulator) layer. The SOI layer used here is obtained by integrally bonding two silicon wafers with an SiO ₂ layer as an insulating layer (Insulator) interposed therebetween. One silicon wafer of the SOI layer is used as the support substrate 2, and the other silicon wafer is used as the functional layer 10, and the functional layer 10 is finely processed to separate the respective functional portions. Further, a part of the SiO ₂ layer is left to form the first insulating layer 3.

  As shown in FIG. 2, the functional layer 10 is overlaid with the closing member 4, and the functional layer 10 is sandwiched between the support substrate 2 and the closing member 4. The closing member 4 is a single Si substrate. The closing member 4 has a second insulating layer 5 formed on the surface facing the functional layer 10, and a conductor pattern is embedded in the second insulating layer 5 to form a lead layer. . The lead layer is individually connected to the movable electrode and the fixed electrode of the detection unit formed in the functional layer 10 and is also connected to a current-carrying pad provided outside the MEMS sensor 1. The second insulating layer 5 of the closing member 4 is bonded to a part of the functional layer 10 via the bonding layer 6.

  The closing member 4 is not limited to a single Si substrate, and may be a glass substrate or the like. Alternatively, the surface of the IC package in which various circuits such as a detection circuit are accommodated may be used as the closing member 4, and a part of the functional layer 10 may be bonded to the upper surface of the IC package via the bonding layer 6. In this case, the lead layer disposed in the second insulating layer 5 is connected to an electrode bump or the like provided on the upper surface of the IC package.

  As shown in FIG. 1, the functional layer 10 formed of one silicon wafer of the SOI layer is partially separated to form a frame body layer 11. The outer shape of the frame body layer 11 is a rectangular shape having a pair of long sides 11a, 11a extending in the X direction and a pair of short sides 11b, 11b extending in the Y direction, and the long sides 11a, 11a and the short sides 11b, 11b. Are coincident with the long and short sides of the support substrate 2 which is also rectangular.

  As shown in FIG. 1, a first hole 12, a second hole 13, and a third hole 14 are formed in the frame body layer 11, and each of the holes 12, 13, 14 is formed in the frame body layer 11. Is penetrated in the thickness direction. The planar shape of the first hole 12 is a rectangle elongated in the X direction, and its long side is parallel to the long sides 11 a and 11 a of the frame layer 11, and the short side is the short sides 11 b and 11 b of the frame layer 11. And parallel. Both the second hole 13 and the third hole 14 have a square planar shape. The sides of the holes 13 and 14 are parallel to both the long sides 11a and 11a and the short sides 11b and 11b.

  As shown in FIGS. 1 and 2, a line that passes through the center (centroid, center of gravity) of the first hole 12 and is perpendicular to the substrate surface of the support substrate 2 is defined as a first center line O1. Lines perpendicular to the substrate surface of the support substrate 2 through the centers (centroid and centroid) of the 13th and third holes 14 are defined as a second centerline O2 and a third centerline O3, respectively. The first hole 12, the second hole 13, and the third hole 14 are arranged such that the respective center lines O1, O2, and O3 are linearly arranged in the X direction.

  As shown in FIG. 1, the first hole 12 has a rotationally symmetrical shape of 180 degrees with respect to the first center line O1, and left and right across a line extending in the Y direction through the first center line O1. The shape is line symmetrical in the direction (X1-X2 direction). In addition, the second hole 13 and the third hole 14 are also rotationally symmetric with respect to the first center line O1 by 180 degrees, and with respect to a line extending in the Y direction through the first center line O1. The shape is line symmetrical in the left-right direction.

  In the embodiment shown in FIGS. 1 and 2, the long sides 11a and 11a and the short sides 11b and 11b of the frame layer 11 are also 180 degrees rotationally symmetric with respect to the first center line O1 and the first side The shape is symmetrical with respect to the left-right direction across a line extending in the Y direction through the center line O1.

At the facing portion between the support substrate 2 and the frame body layer 11, a frame-like insulating layer 3a is formed by the first insulating layer 3 in which a part of the SiO ₂ layer of the SOI layer is left. The frame-like insulating layer 3a is formed in the entire area of the facing portion between the support substrate 2 and the frame body layer 11 (region indicated by hatching in FIG. 1). However, in practice, when the SiO ₂ layer other than the first insulating layer 3 is removed by selective etching, a part of the frame-like insulating layer 3a is formed at the outer peripheral portions of the holes 12, 13, and 14. However, in this specification, the support substrate 2 and the frame body layer 11 include the state in which a part of the frame-like insulating layer 3a is missing at the peripheral portions of the holes 12, 13, and 14. It is expressed that the frame-like insulating layer 3a is formed in the entire area of the facing portion.

  As shown in FIG. 1, the first hole 12, the second hole 13, and the third hole are symmetrical with respect to the first center line O1, and the long sides 11a and 11a of the frame body layer 11 are formed. And the short sides 11b and 11b are also symmetric with respect to the first center line O1, so the region where the frame-like insulating layer 3a is formed is also rotationally symmetric with respect to the first center line O1, 180 degrees, In addition, the formation region of the frame-shaped insulating layer 3a is symmetrical to the left and right with respect to a line extending in the Y direction through the first center line O1.

Since the formation region of the frame-shaped insulating layer 3a is symmetrical with respect to the first center line O1, the frame-shaped insulating layer 3a formed by a part of the SiO ₂ layer of the SOI layer and the support formed by the silicon wafer Bonding stress with the substrate 2 acts evenly on the left and right across the first center line O1, and prevents a phenomenon in which a large warp occurs locally on the support substrate 2 due to the stress bias. It's easy to do.

  As shown in FIG. 1, if the opening pattern of the first hole 12, the second hole 13, and the third hole 14 is symmetrical with respect to the first center line O1, the frame body layer 11 Even if the shape of the outer side is not strictly symmetrical with respect to the first center line O1, the shape of the frame-like insulating layer 3a can be made almost symmetrical with respect to the first center line O1, and the insulating layer and the support are supported. The effect that the distribution of stress between the substrate 2 can be made uniform can be achieved.

  The bonding layer 6 that partially bonds the second insulating layer 5 and the functional layer 10 formed on the opposing surface of the closing member 4 is a movable electrode or a fixed electrode of the detection unit that is a part of the functional layer 10. It is the metal joining layer comprised so that electricity could be supplied to. This metal bonding layer is obtained by eutectic bonding or diffusion bonding of a metal layer formed on one of the surface of the second insulating layer 5 and the surface of the functional layer 10 and a metal layer formed on the other. In this case, for example, one metal layer is aluminum and the other metal layer is germanium or the like. An adhesive layer can also be used as the bonding layer 6.

  As shown in FIG. 2, a part of the bonding layer 6 becomes a seal bonding layer 6a, and the frame body layer 11 and the second insulating layer 5 of the closing member 4 are bonded by the seal bonding layer 6a. The seal bonding layer 6 a is formed so as to surround the entire periphery of the first hole 12 and to surround the entire periphery of the second hole 13 and the periphery of each of the third holes 14. Between the support substrate 2 and the frame layer 11, the entire peripheries of the first hole 12, the second hole 13, and the third hole 14 are joined by the frame-shaped insulating layer 3a. As a result of sealing the peripheral edge of each hole by the frame-shaped insulating layer 3a and the seal bonding layer 6a, the inside of the first hole 12 becomes the first operation space 15 closed from the outside. Similarly, the inside of the second hole 13 becomes the second operation space 16 closed from the outside, and the inside of the third hole 14 becomes the third operation space 17 closed from the outside.

  Note that the pattern of the region where the seal bonding layer 6a is formed is also symmetrical with respect to the first center line O1 and has a symmetrical shape of 180 degrees, and extends along the Y direction through the first center line O1. A symmetrical shape is preferred. In this way, the first hole 12, the second hole 13, and the third hole 14 are symmetrical with respect to the first center line O1, and the frame-shaped insulating layer 3a and the seal bonding layer 6a are also the first. By making the shape symmetrical with respect to the center line O1, the bonding stress between the frame body layer 11 and the support substrate 2 and the bonding stress between the frame body layer 11 and the closing member 4 can be made equal to the left and right, and the stress can be biased. It is easy to prevent and suppress the occurrence of distortion.

  The MEMS sensor 1 can detect acceleration in the Z direction in a direction perpendicular to the substrate surface of the support substrate 2 by the operation of the first movable body 41 provided in the first operation space 15. Further, by the operation of the second movable body 21 provided in the second operation space 16, the acceleration in the Y direction parallel to the substrate surface of the support substrate 2 can be detected, and the second operation body 17 provided in the third operation space 17. The acceleration in the X direction orthogonal to the Z direction and the Y direction can be detected by the operation of the third movable body 21A.

First, the structure in the second operation space 16 will be described with reference to FIGS.
As shown in FIG. 3 and FIG. 4, in the second operation space 16, a second movable body 21 and a support that is a support portion that movably supports the second movable body 21 in the Y1-Y2 direction. Arm portions 22 and 24 and elastic support portions 26, 27, 28, and 29 are provided, and a functional unit such as a detection unit is further provided. Each of these functional portions is formed by being separated together with the frame body layer 11 from one silicon wafer to be the functional layer 10 by an etching process.

  As shown in FIGS. 3 and 4, in the second operation space 16, a second movable body 21 is provided inside a square second hole 13 opened in the frame body layer 11. A support arm portion 22 extending in the Y1-Y2 direction is provided on the X1 side of the second center line O2. The support arm portion 22 is integrally formed with a square support conduction portion 23 at a position close to the second center line O2. A support arm portion 24 extending in the Y1-Y2 direction is provided on the X2 side from the second center line O2. The support arm portion 24 is integrally formed with a square support conduction portion 25 at a position close to the second center line O2.

  The second movable body 21 is sandwiched between the support arm portion 22 on the X1 side and the support arm portion 24 on the X2 side. The end portion on the Y1 side of the support arm portion 22 provided on the X1 side and the second movable body 21 are integrally connected via the elastic support portion 26, and the end portion on the Y2 side of the support arm portion 22 and the second end. The movable body 21 is integrally connected through an elastic support portion 27. The end portion on the Y1 side of the support arm portion 24 provided on the X2 side and the second movable body 21 are integrally connected via the elastic support portion 28, and the end portion on the Y2 side of the support arm portion 24 and the second end portion. The movable body 21 is integrally connected via an elastic support portion 28.

  As shown in FIG. 4, one surface of the support conductive portion 23 integrated with the support arm portion 22 is joined to the substrate surface of the support substrate 2 by a support insulating layer 3 b which is a part of the first insulating layer 3. ing. The other surface of the support conductive portion 23 is bonded to the second insulating layer 5 on the surface of the closing member 4 by a support bonding layer 6 b that is one of the bonding layers 6. Similarly, the other support conduction portion 25 is also bonded to the support substrate 2 through the support insulating layer 3b, and is bonded to the second insulating layer 5 by the support bonding layer 6b.

  The support conduction portions 23 and 25 are sandwiched and fixed between the support insulating layer 3b and the support bonding layer 6b from above and below, but the second movable body 21 and the support arm portions 22 and 24, which are other portions, are provided. The elastic support portions 26, 27, 28, and 29 are not bonded to the support substrate 2 and are not bonded to the second insulating layer 5. As shown in FIG. 3, the elastic support portions 26, 27, 28, and 29 are integrally formed of a silicon wafer together with the second movable body 21 and the support arm portions 22 and 24, and are thin and have a longitudinal direction. It is formed to be a meander pattern extending in the X direction. The second movable body 21 can move mainly in the Y1-Y2 direction by the bending deformation of the elastic support portions 26, 27, 28, 29 in the Y1-Y2 direction. Further, the second movable body 21 is difficult to move in the X1-X2 direction by the restraining force of the elastic support portions 26, 27, 28, 29.

  As shown in FIG. 3, on the Y1 side of the second movable body 21, a plurality of movable electrodes 21b extending linearly from the left side portion in the X1 direction are integrally formed. As shown in FIG. 5, the plurality of movable electrodes 21b extend in the X1 direction in parallel to each other with a constant width dimension. A plurality of movable electrodes 21a that extend linearly from the right side portion in the X2 direction are integrally formed on the Y1 side of the second movable body 21. The movable electrodes 21a extend in the X2 direction in parallel with each other with a constant width dimension.

  A plurality of movable electrodes 21d are integrally formed on the Y2 side of the second movable body 21 from the left side portion in the X1 direction. As shown in FIG. 6, the plurality of movable electrodes 21d are parallel to each other with a constant width dimension and extend linearly in the X1 direction. A plurality of movable electrodes 21c are integrally formed on the Y2 side of the second movable body 21 from the right side portion in the X2 direction. The right movable electrodes 21c are parallel to each other with a certain width and extend linearly in the X2 direction.

  At least one of the support conduction part 23 formed integrally with the support arm part 22 and the support conduction part 25 formed integrally with the support arm part 24 is interposed through a support joining layer 6b which is a metal joining part. The lead layer provided in the second insulating layer 5 is electrically connected. Each of the movable electrodes 21a, 21b, 21c, and 21d is connected to a detection circuit through a lead layer.

  As shown in FIG. 3, in the second operation space 16, a first fixed portion 31 and a second fixed portion 32 separated from the silicon wafer are provided further inside the second movable body 21. ing. The first fixing portion 31 is provided on the Y1 side with respect to the second center line O2. The first fixing portion 31 has a rectangular support conducting portion 33 at a position approaching the second center line O2. Are integrally formed. The second fixing portion 32 is provided on the Y2 side with respect to the second center line O2. The second fixing portion 32 has a rectangular support conduction portion 34 at a position approaching the second center line O2. Are integrally formed.

As shown in FIG. 4, the support conductive portion 33 integrated with the first fixing portion 31 is supported by the support substrate 2 via the support insulating layer 3 c formed by leaving the SiO ₂ layer that is the first insulating layer 3. It is joined to. Further, the second insulating layer 5 formed on the closing member 4 and the support conducting portion 33 are joined by a support joining layer 6 c that is one of the joining layers 6. The first fixing portion 31 is fixed with the support conducting portion 33 sandwiched between the support insulating layer 3c and the support bonding layer 6c, but the other portions are separated from the support substrate 2, Also away from the insulating layer 5. Similarly, the support conducting portion 34 integrated with the second fixing portion 32 is joined to the support substrate 2 via the support insulating layer 3c, and is connected to the second insulating layer 5 of the closing member 4 via the support joining layer 6c. It is joined. However, the second fixing portion 32 is separated from both the support substrate 2 and the second insulating layer 5 except for the support conduction portion 34.

  As shown in FIG. 3, the first fixing portion 31 includes an electrode support portion 31 a that extends linearly from the support conducting portion 33 in the Y1 direction. A plurality of fixed electrodes 31b are integrally formed on the X1 side of the electrode support portion 31a, and a plurality of fixed electrodes 31c are integrally formed on the X2 side of the electrode support portion 31a. FIG. 5 shows one fixed electrode 31c. Each of the plurality of fixed electrodes 31c extends linearly in the X2 direction with a constant width dimension. Each fixed electrode 31c enters between a plurality of movable electrodes 21b formed integrally with the second movable body 21, and each fixed electrode 31c has a distance δ1 toward the Y1 side with respect to the movable electrode 21b. They are facing each other. Similarly, the fixed electrodes 31b extending in the X1 direction from the electrode support portion 31a also enter between the movable electrodes 21a, and each fixed electrode 31b faces the movable electrode 21a with a distance δ1 toward the Y1 side. doing.

  The second fixing portion 32 is integrally formed with an electrode support portion 32a extending from the support conducting portion 34 in the Y2 direction. The electrode support portion 32a is provided with a plurality of fixed electrodes 32b extending linearly in the X1 direction and a plurality of fixed electrodes 32c extending linearly in the X2 direction. FIG. 6 shows a fixed electrode 32c extending in the X2 direction. The plurality of fixed electrodes 32c are inserted between the plurality of movable electrodes 21d formed on the second movable body 21, and each fixed electrode 31c is spaced from the movable electrode 21d by a distance δ2 in the Y2 direction. Opposite. Similarly, the plurality of fixed electrodes 32b extending in the X1 direction from the electrode support portion 32a also enter between the movable electrodes 21c, and the fixed electrode 32b faces the movable electrode 21c with a distance δ2 in the Y2 direction. doing.

  Since the support conduction portion 33 of the first fixed portion 31 is connected to the support bonding layer 6c which is a metal bonding layer, the fixed electrodes 31b and 31c are connected to the second insulating layer via the support bonding layer 6c. It is connected to the lead layer inside the layer 5. Similarly, the support conducting portion 34 of the second fixed portion 32 is also connected to the support bonding layer 6c, and the fixed electrodes 32b and 32c are leads inside the second insulating layer 5 via the support bonding layer 6c. Bonded to the layer. Each lead layer is connected to a detection circuit.

  As shown in FIG. 3, the second hole 13 forming the second operation space 16 is a quadrangle, and the second movable body 21 has a rotationally symmetrical shape of 180 degrees with respect to the second center line O2. The support arm portions 22 and 24 also have a rotationally symmetric shape of 180 degrees with respect to the second center line O2. Further, the arrangement of the support conductive portions 23 and 25 and the support conductive portions 33 and 34 is also 180 degrees rotationally symmetric with respect to the second center line O2. The elastic support portions 26 and 28 on the Y1 side and the elastic support portions 27 and 29 on the Y2 side also have a rotationally symmetric shape of 180 degrees with respect to the second center line O2.

  The second operation space 16 of the MEMS sensor 1 responds to acceleration in the Y1 direction or the Y2 direction. For example, when acceleration in the Y1 direction acts on the MEMS sensor 1, the second movable body 21 moves in the Y2 direction due to the reaction. At this time, the facing distance δ1 between the movable electrode 21b and the fixed electrode 31c shown in FIG. 5 increases, and the capacitance between the movable electrode 21b and the fixed electrode 31c decreases. This is the same between the movable electrode 21a on the X1 side and the fixed electrode 31b.

  On the other hand, when the second movable body 21 moves in the Y2 direction, the facing distance δ2 between the movable electrode 21d and the fixed electrode 31c shown in FIG. 6 is reduced, and the capacitance between the movable electrode 21d and the fixed electrode 31c is reduced. Will increase. This is the same between the movable electrode 21c on the X1 side and the fixed electrode 32b.

  An electric circuit detects a decrease and an increase in capacitance between the movable electrode and the fixed electrode, and obtains a difference between an output change due to an increase in the facing distance δ1 and an output change due to a decrease in the facing distance δ2. Thus, it is possible to detect a change in acceleration acting in the Y1 direction and the magnitude of the acceleration with a large output.

  In the second operation space 16, a capacitance detection type detection unit is configured by the facing portions of the movable electrodes 21 a, 21 b, 21 c, and 21 d and the fixed electrodes 31 b, 31 c, 32 b, and 32 c. Yes.

  The internal structure of the third operation space 17 shown in FIGS. 1 and 2 is rotated by 90 degrees through the second center line O2 with respect to the internal structure of the second operation space 16 shown in FIGS. Is exactly the same.

  As shown in FIGS. 1 and 2, the third movable body 21A provided in the third operation space 17 is different from the second movable body 21 shown in FIG. 3 through the second center line O2. It is exactly the same as the one rotated at a degree. In the third operation space 17, the third movable body 21A has a line-symmetric shape in the left-right direction (X1-X2 direction) with a line extending in the Y direction passing through the third center line O3. In the third operation space 17, support arm portions 22A and 24A extending in the X1-X2 direction are provided. The support arm portions 22A and 24A are the same as those obtained by rotating the support arm portions 22 and 24 shown in FIG. 3 by 90 degrees.

  As shown in FIG. 1, the support conducting portion 23A integral with the support arm portion 22A and the support conducting portion 25A integral with the support arm portion 24A are arranged on the Y1 side and the Y2 side with the third center line O3 interposed therebetween. ing. The surfaces on the Z1 side of the support conductive portions 23A and 25A are joined to the support substrate 2 via a support insulating layer 3b which is a part of the first insulating layer 3. Further, the surfaces on the Z2 side of the support conductive portions 23A and 25A are bonded to the second insulating layer 5 of the closing member 4 via the support bonding layer 6b.

  An elastic support portion is provided between the support arm portions 22A and 24A and the third movable body 21A. The elastic support portions are the same as those obtained by rotating the directions of the elastic support portions 26, 27, 28, and 29 shown in FIG. 3 by 90 degrees. By this elastic support portion, the third movable body 21A is movable in the X1-X2 direction and supported in the Y1-Y2 direction.

  The third movable body 21A is integrally formed with the same movable electrodes 21a, 21b, 21c, and 21d as shown in FIG. 3, and the movable electrodes extend linearly in the Y1-Y2 direction.

  In the third operation space 17, a first fixing portion 31A and a second fixing portion 32A are provided. The first fixing portion 31A extends from the support conducting portion 33A in the X2 direction, and the second fixing portion 32A extends from the support conducting portion 34A in the X1 direction. As shown in FIG. 2, the support conducting portions 33A and 34A are bonded to the support substrate 2 by the support insulating layers 3c and 3c which are the first insulating layers 3, and are closed by the support bonding layers 6c and 6c which are the bonding layers 6. It is joined to the second insulating layer 5 of the member 4.

  A fixed electrode extending in the Y1-Y2 direction is integrally formed on the first fixed portion 31A and the second fixed portion 32A. The facing state between the movable electrode formed on the third movable body 21A and the fixed electrode is obtained by rotating the facing state between the electrodes in the second operation space 16 shown in FIGS. 5 and 6 by 90 degrees. Is equal to

  The third operation space 17 operates by reacting to the acceleration in the X1-X2 direction. When the acceleration in the X1 direction or the X2 direction acts on the MEMS sensor 1, the third movable body 21A moves in the direction opposite to the direction of the acceleration due to the inertial force, and the amount of movement at that time is determined between the movable electrode and the fixed electrode. Is detected as a change in capacitance at the opposing detection unit.

Next, the structure in the first operation space 15 will be described.
Each functional part in the first operation space 15 shown in FIGS. 1, 2 and 7 is formed separately from one silicon wafer of the SOI layer together with the frame body layer 11.

  In the first operation space 15, a first movable body 41 is provided inside the first hole 12 of the frame body layer 11. As shown in FIG. 1, the first movable body 41 is integrally formed with a right mass portion 41A on the X1 side and a left mass portion 41B on the X2 side with respect to the first center line O1, and the right mass portion 41A. 41C is integrally formed between the left mass portion 41B and the left mass portion 41B. The first center line O1 is located at the connecting portion 41C. The first movable body 41 has a rotationally symmetric shape of 180 degrees with respect to the first center line O1, and has a symmetrical shape to the left and right across a line that passes through the first center line O1 and extends in the Y direction. .

  Support conduction portions 42 and 42 are provided at positions adjacent to the Y1 side and the Y2 side of the connecting portion 41C of the first movable body 41. A U-shaped right link portion 43A is provided outside the right mass portion 41A of the first movable body 41, and a left link portion 43B is provided outside the left mass portion 41B. The support conductive portions 42, 42, the right link portion 43 </ b> A, and the left link portion 43 </ b> B are formed separately from the silicon wafer of the functional layer 10 together with the first movable body 41.

  As shown in FIG. 1, two end portions on the X2 side of the right link portion 43A are rotatably connected to the support conducting portions 42 and 42 via hinge portions 44A and 44A, respectively. Two end portions on the X1 side of the portion 43B are rotatably connected to the support conducting portions 42 and 42 via hinge portions 44B and 44B, respectively. Further, two end portions on the X2 side of the right link portion 43A and two end portions on the X1 side of the left link portion 43B are connected to each other by connecting hinge portions 45 and 45 so as to be rotatable. The end portion on the X1 side of the right mass portion 41A of the first movable body 41 and the right link portion 43A are rotatably connected via hinge portions 46A and 46A, and the X2 side of the left mass portion 41B is on the X2 side. The end portion and the left link portion 43B are rotatably connected via hinge portions 46B and 46B.

  The hinge portions 44A, 44B, 45, 46A, 46B are formed in a cylindrical or prismatic shape with a silicon wafer, can be elastically twisted and deformed, and are not twisted by elastic force when no external force is applied. Restore to.

  As shown in FIG. 7, the surfaces of the support conductive portions 42, 42 facing the Z <b> 1 side are bonded to the support substrate 2 by a support insulating layer 3 d that is a part of the first insulating layer 3. The surfaces of the support conductive portions 42, 42 facing the Z <b> 2 side are bonded to the second insulating layer 5 of the closing member 4 by a support bonding layer 6 d that is a part of the bonding layer 6.

  The support conductive portions 42 and 42 are sandwiched and fixed between the support insulating layer 3d and the support bonding layer 6d, but the first movable body 41, the right link portion 43A, and the left link portion 43B are supported by the support substrate 2. And away from the respective surfaces of the second insulating layer 5. Therefore, as shown in FIG. 7, the right link portion 43A rotates counterclockwise with the hinge portion 44A as a fulcrum, and the left link portion 43B rotates clockwise with the hinge portion 44B as a fulcrum. The movable body 41 can move in the Z1 direction. On the contrary, the first movable body 41 can move in the Z2 direction by rotating the hinge portion 44A and the hinge portion 44B in the opposite direction to FIG.

  Further, when an external force in the Z direction is not applied, each hinge portion is restored to a state in which it is not twisted and deformed, so that the first movable body 41 has the Z1 direction and the Z2 direction in the first operation space 15. Neutral position that does not move to

  In FIG. 7, for the sake of illustration, the interval in the Z direction between the support substrate 2 and the second insulating layer 5 in the first operation space 15 is wider than that in the second operation space 16 shown in FIG. However, in practice, the first operation space 15, the second operation space 16, and the third operation space 17 have the same internal space in the Z direction. Further, the thickness dimension in the Z direction of the first movable body 41 is exactly the same as the thickness dimension of the second movable body 21 and the third movable portion 21A.

  As shown in an enlarged view in FIG. 8A, the right mass portion 41A of the first movable body 41 is integrally formed with a plurality of movable electrodes 47a extending linearly from the side portion on the Y1 side in the Y2 direction. ing. Similarly, the right mass portion 41A is integrally formed with a plurality of movable electrodes 47a that linearly extend in the Y1 direction from the Y2 side. As shown in an enlarged view in FIG. 9A, the left mass portion 41B of the first movable body 41 is integrally formed with a plurality of movable electrodes 47b extending linearly from the side portion on the Y1 side in the Y2 direction. ing. Similarly, the left mass portion 41B is integrally formed with a plurality of movable electrodes 47b extending linearly from the side portion on the Y2 side in the Y1 direction.

  The surface on the Z2 side of the support conducting portions 42, 42 is connected to a lead layer in the second insulating layer 5 through a support bonding layer 6d which is one of the bonding layers 6. Accordingly, each of the movable electrodes 47a and 37b formed integrally with the first movable body 41 passes through the right link portion 43A, the left link portion 43B and the support conducting portions 42 and 42, and further passes the support bonding layer 6d. Through the lead layer.

  As shown in FIG. 1, a right fixed portion 51 and a left fixed portion 53 are formed separately from the first movable body 41 inside the first movable body 41. The right fixing part 51 is located on the right side of the first center line O1, and the left fixing part 53 is located on the left side of the first center line O1. The right fixing portion 51 is integrally formed with a rectangular support conducting portion 52 at a position approaching the first center line O1, and the left fixing portion 53 is at a position approaching the first center line O1. A rectangular support conducting portion 54 is integrally formed.

  As shown in FIG. 2, the Z1 side surfaces of the support conductive portion 52 and the support conductive portion 54 are joined to the support substrate 2 by support insulating layers 3e and 3e, which are the first insulating layers 3, respectively. The Z2 side surfaces of the support conductive portion 52 and the support conductive portion 54 are bonded to the second insulating layer 5 of the closing member 4 by support bonding layers 6e and 6e, which are one of the bonding layers 6, respectively. However, the right fixing part 51 and the left fixing part 53 are apart from the support substrate 2 and the second insulating layer 5 except for the support conduction parts 52 and 54.

  As shown in FIG. 8A, the right fixed portion 51 is integrally formed with a plurality of fixed electrodes 51a extending in both the Y1 direction and the Y2 direction. As shown in FIG. 9A, the left fixed portion 53 is integrally formed with a plurality of fixed electrodes 53a extending in both the Y1 direction and the Y2 direction. The right fixed electrode 51a is joined to the lead layer in the second insulating layer 5 via the support conduction portion 52 and the support joining layer 6e, and the left fixed electrode 53a is also joined to the support conduction portion 54 in a support joining manner. It is bonded to the lead layer in the second insulating layer 5 through the layer 6e.

  As shown in FIGS. 8A and 9A, the plurality of right fixed electrodes 51a and the plurality of left fixed electrodes 53a extend linearly in the Y1 direction and the Y2 direction with a constant width dimension, and They are formed in parallel. Further, as shown in FIGS. 8B and 9B, the right fixed electrode 51a and the left fixed electrode 53a have the same thickness dimension in the Z direction and the same height position in the Z direction. Is formed.

  As shown in FIG. 8B, the movable electrode 47a formed integrally with the right mass portion 41A of the first movable body 41 has a thickness dimension in the Z direction equal to the thickness dimension of the fixed electrode 51a. When the first movable body 41 is in the neutral position in the Z direction, the movable electrode 47a is in a position shifted in the Z1 direction by δ3 from the fixed electrode 51a. As shown in FIG. 9B, the movable electrode 47b formed integrally with the left mass portion 41B of the first movable body 41 has the same thickness dimension in the Z direction as the left fixed electrode 53a. However, when the first movable body 41 is in the neutral position in the Z direction, the movable electrode 47b is displaced in the Z2 direction by δ4 from the fixed electrode 53a. The deviation amount δ3 shown in FIG. 8B is equal to the deviation amount δ4 shown in FIG. 9B.

  The first motion space 15 can respond to acceleration in the Z direction. For example, when acceleration in the Z2 direction acts on the MENS sensor 1, the first movable body 41 moves in the Z1 direction as shown in FIG. At this time, in the detection unit shown in FIG. 8B, the movable electrode 47a of the right mass unit 41A moves in the Z1 direction as indicated by the arrow, and the facing area between the movable electrode 47a and the fixed electrode 51a is reduced. The capacitance between the movable electrode 47a and the fixed electrode 51a is reduced. On the other hand, in the detection unit shown in FIG. 9B, the movable electrode 47b of the left mass unit 41B moves in the Z1 direction, the opposing area between the movable electrode 47b and the fixed electrode 53a increases, and the capacitance increases.

  In a detection circuit (not shown), Z2 is calculated by calculating a difference between an output based on a decrease in capacitance at the detection unit shown in FIG. 8 and an output based on an increase in capacitance at the detection unit shown in FIG. The magnitude and change of acceleration acting in the direction can be recognized with a large output. Conversely, when acceleration in the Z1 direction acts, the first movable body 41 moves in the Z2 direction from the neutral position. At this time, in the detection unit shown in FIG. 8A, the capacitance between the movable electrode 47a and the fixed electrode 51a increases. Conversely, in the detection unit shown in FIG. 9B, the detection unit shown in FIG. The capacitance between the electrode 53a is lowered.

  FIGS. 10A and 10B show another embodiment of the shapes of the fixed electrodes 51a and 53a and the movable electrodes 47a and 47b.

  As shown in FIG. 10A, the length dimension of the movable electrode 47a in the Z1 direction is larger than that of the right fixed electrode 51a. As shown in FIG. 10B, the left fixed electrode 53a has a length dimension in the Z1 direction larger than that of the movable electrode 47b. That is, the right fixed electrode 51a and the left movable electrode 47b have the same dimensions, and the right fixed electrode 53a and the left movable electrode 47a have the same dimensions. When the first movable body 41 is in the neutral position in the Z direction, the fixed electrode 51a, the movable electrode 47a, the fixed electrode 53a, and the movable electrode 47b all have the same height in the Z direction on the Z2 side.

  When the first movable body 41 moves in the Z1 direction, the facing area between the right fixed electrode 51a and the movable electrode 47a shown in FIG. 10A decreases, but the left fixed electrode 53a shown in FIG. 10B. And the movable electrode 47b facing area does not change. Conversely, when the first movable body 41 moves in the Z2 direction, the opposed area between the right fixed electrode 51a and the movable electrode 47a does not change, and the opposed area between the left fixed electrode 53a and the movable electrode 47b decreases. .

  By calculating the difference between the output based on the electrostatic capacitance at the detection unit shown in FIG. 10A and the output based on the electrostatic capacitance at the detection unit shown in FIG. The magnitude and change of the acceleration acting in the direction of FIG. 1 and the Z2 direction can be recognized without being affected by changes in the environmental temperature.

  FIG. 11 is a partial plan view of a detection apparatus including a MEMS sensor according to this embodiment. Note that the MEMS sensor of FIG. 11 is shown through the support substrate. FIG. 11 is created based on the MEMS sensor shown in FIG. 1, and FIG. 11 illustrates the location of the support conduction portion of the MEMS sensor that is important for explanation, and shows the components around each support conduction portion. Omitted. FIG. 11 will be described with reference to FIG. 1 and FIG.

  As already described, as shown in FIG. 1, the first movable body 41 provided in the first operation space 15 detects acceleration in the Z direction, for example, and is provided in the second operation space 16. The second movable body 21 is for detecting acceleration in the Y direction, and the third movable body 21A provided in the third operation space 17 is for detecting acceleration in the X direction.

  The amount of movement is detected as a change in capacitance acting between the movable electrode and the fixed electrode when the movable body moves due to the action of acceleration.

  The support conduction part 52 formed in the 1st operation space 15 shown in FIG. 1, FIG. 11 is integrally formed with the right fixed part 51 provided with the fixed electrode 51a, and the support conduction part 54 is provided with the fixed electrode 53a. It is formed integrally with the left fixing part 53. The support conducting portions 52 and 54 both function as output electrodes, and are connected to the first lead layers 70 and 71 embedded in the second insulating layer 5 (see FIG. 2) provided on the closing member 4 side. It is connected. In FIG. 11, the lead layer is indicated by a solid line in order to clarify the planar position of the lead layer. Further, the first movable body 41 is supported by the two support conducting portions 42 and 42 formed in the first operation space 15. A movable electrode is provided on the first movable body 41. One support conduction portion 42 is connected as an input electrode to the second lead layer 72 in the second insulating layer 5 provided on the closing member 4 side.

  Further, the support conductive portion 33 formed in the second operation space 16 shown in FIGS. 1, 3, and 11 is formed integrally with the first fixed portion 31 including the fixed electrodes 31b and 31c. 34, the second fixed portion 32 including the fixed electrodes 32b and 32c is integrally formed. The support conducting portions 33 and 34 both function as output electrodes and are connected to first lead layers 73 and 74 in the second insulating layer 5 provided on the closing member 4 side. Further, the second movable body 21 is supported by the two support conducting portions 23 and 25 formed in the second operation space 16. A movable electrode is provided on the second movable body 21. One support conduction portion 25 is connected as an input electrode to the second lead layer 75 in the second insulating layer 5 provided on the closing member 4 side.

  Moreover, the support conduction | electrical_connection part 33A formed in the 3rd operation space 17 shown in FIG. 1, FIG. 11 is formed integrally with the 1st fixing | fixed part 31A provided with a fixed electrode, and the support conduction | electrical_connection part 34A is a fixed electrode. Are formed integrally with the second fixing portion 32A. Both of the support conducting portions 33A and 34A function as output electrodes and are connected to first lead layers 76 and 77 in the second insulating layer 5 provided on the closing member 4 side. Further, the third movable body 21A is supported by the two support conduction portions 23A and 25A formed in the third operation space 17. The third movable body 21A is provided with a movable electrode. One support conduction portion 23A is connected as an input electrode to the second lead layer 78 in the second insulating layer 5 provided on the closing member 4 side.

  As shown in FIG. 11, each lead layer is extended in the Y1 direction and electrically connected to each of the external connection pads 80 to 88 disposed at a predetermined interval in the X1-X2 direction on the Y1 side of the closing member 4. Connected.

  The arrangement of the external connection pads 80 to 88 is determined according to the arrangement of the terminal portions 90 to 98 of the integrated circuit (IC) 100 including the detection circuit. In the embodiment shown in FIG. 11, the external connection pads 80 to 88 are spaced apart from each other so that the terminal portions 90 to 98 on the integrated circuit (IC) 100 side are substantially opposed to each other in the Y1-Y2 direction. Arranged in a row.

  The external connection pads 80 to 88 and the terminal portions 90 to 98 that are substantially opposed to each other are electrically connected by wire bonding, for example.

  In the configuration shown in FIG. 11, the external connection pads 80 to 88 are collectively provided on the Y1 side in the vicinity of the first operation space 15 in order to correspond to the terminal portions 90 to 98 on the integrated circuit (IC) 100 side. At this time, the linear distances from the support conductive portions 52 and 54 as output electrodes provided in the first operation space 15 to the external connection pads 83 and 85 are substantially the same, and the pattern lengths of the first lead layers 70 and 71 are the same. Can be adjusted so that does not change.

  On the other hand, in the configuration shown in FIG. 11, the linear distance between the support conductive portions 33 and 34 as output electrodes provided in the second operation space 16 and the external connection pads 86 and 88 is easily different, and the pattern is drawn around. In addition, the first lead layers 73 and 74 are designed with different pattern lengths. The same applies to the third operation space 17.

  In the second operation space 16, when the pattern lengths of the first lead layers 73 and 74 connected to the output electrode are different, the parasitic capacitance generated between the first lead layers 73 and 74 and the closing member 4 is different. Occurs.

  In the present embodiment, the output obtained from the external connection pads 86 and 88 connected to the support conductive portions 33 and 34 that are output electrodes can be obtained as a differential output by the integrated circuit (IC) 100. As described above, if the parasitic capacitance generated between the first lead layers 73 and 74 and the closing member 4 is different, the parasitic capacitance cannot be offset when obtaining the differential output, and a highly accurate differential output is obtained. There was a problem that was not possible. Alternatively, the offset amount must be set on the integrated circuit (IC) 100 side in consideration of the parasitic capacitance.

  Therefore, in the present embodiment, even if the pattern lengths of the first lead layers 73 and 74 are designed to be different, the pattern length is set so that the parasitic capacitance generated between the first lead layers 73 and 74 and the closing member 4 approaches a constant value. The width of the first lead layer 74 having a longer length is reduced, while the width of the first lead layer 73 having a shorter pattern length is increased. As a result, the parasitic capacitance generated between the first lead layers 73 and 74 and the closing member 4 can be made closer to a constant value as compared with the conventional case, and a highly accurate differential output can be obtained.

  The width of the lead layer is adjusted by each detection unit. That is, in the configuration of FIG. 11, the first lead layers 70 and 71 connected to the support conductive portions 52 and 54 as output electrodes provided in the first operation space 15 are adjusted with substantially the same pattern length. , The width can be set almost the same.

  As described above, in the present embodiment, the external connection pads 80 to 88 of the MEMS sensor are arranged in accordance with the positions of the terminal portions 90 to 98 on the integrated circuit (IC) 100 side, so that the first lead layer of each detection unit is arranged. Even if the pattern length is different, it is possible to obtain a highly accurate differential output by adjusting the width of the first lead layer. According to the configuration of the MEMS sensor of the present embodiment, it is possible to appropriately cope with connection with any integrated circuit (IC) 100, and without restricting the integrated circuit (IC) 100 side, It is possible to manufacture a detection device with excellent detection accuracy.

  FIG. 12 is a plan view of an inspection apparatus showing another embodiment. Note that the plan view of FIG. 12 is shown with the lid side of the package removed. FIG. 13 is an enlarged plan view of the MEMS sensor shown in FIG. In addition, the MEMS sensor shown in FIGS. 12 and 13 is seen through the support substrate, and the lead layer is shown by a solid line in order to clarify the formation position of the lead layer.

  The inspection apparatus 110 shown in FIG. 12 has a configuration in which an integrated circuit (IC) 111 and a MEMS sensor 112 are packaged.

  Below, the point from which the structure of the MEMS sensor 112 differs from FIG.1 and FIG.11 is demonstrated. 12 and 13, four support conductive portions 113 to 116 functioning as output electrodes are formed in the first operation space 15 separately, and the fixed portions are supported by the support conductive portions 113 to 116. 117 to 120 are respectively formed. 12 and 13, the support conductive portion 113 and the fixed portions 117 and 120 including the comb-shaped fixed electrode supported by the support conductive portion 116 are in the same positional relationship as the movable electrode. The conductive portion 114 and the fixed portions 118 and 119 each having a comb-shaped fixed electrode supported by the support conductive portion 115 are in the same positional relationship as the movable electrode.

  In the second operation space 16, four support conductive portions 121 to 124 that function as output electrodes are formed separately, and fixed portions 125 to 128 supported by the support conductive portions 121 to 124 are respectively provided. Is formed. 12 and 13, the support conductive portion 121 and the fixed portions 125 and 128 including the comb-shaped fixed electrode supported by the support conductive portion 124 are in the same positional relationship as the movable electrode, and the support The conductive portion 122 and the fixed portions 126 and 127 including the comb-shaped fixed electrode supported by the support conductive portion 123 are in the same positional relationship as the movable electrode.

  In the third operation space 17, four support conductive portions 130 to 133 that function as output electrodes are formed separately, and fixed portions 134 to 137 supported by the support conductive portions 130 to 133 are respectively provided. Is formed. 12 and 13, the support conductive portion 130 and the fixed portions 134 and 137 including the comb-shaped fixed electrodes supported by the support conductive portion 133 are in the same positional relationship as the movable electrode. The conductive portions 131 and the fixed portions 135 and 136 having comb-shaped fixed electrodes supported by the support conductive portions 132 are in the same positional relationship as the movable electrodes.

  As shown in FIG. 12, the external connection pads 80 to 88 on the MEMS sensor 112 side are disposed substantially opposite to the terminal portions 90 to 98 on the integrated circuit (IC) 111 side. External connection pads and terminal portions located on both sides are ground electrodes. And as shown in FIG. 12, each external connection pad 80-88 and each terminal part 90-98 are conduction-connected.

  As shown in FIG. 13, in the first operation space 15, the support conductive portion 113 and the support conductive portion 116 are connected by the first lead layer 140. Further, the support conductive portion 114 and the support conductive portion 115 are connected by the first lead layer 141.

  As shown in FIG. 13, in the second operation space 16, the support conductive portion 121 and the support conductive portion 124 are connected by the first lead layer 142. Further, the support conduction portion 122 and the support conduction portion 123 are connected by the first lead layer 143.

  As shown in FIG. 13, in the third operation space 17, the support conductive portion 130 and the support conductive portion 133 are connected by the first lead layer 144. Further, the support conductive portion 131 and the support conductive portion 132 are connected by the first lead layer 145.

  In the embodiment shown in FIG. 13, the two first lead layers provided in each detector are designed with different pattern lengths. In the first operation space 15, the pattern length of the first lead layer 141 is longer than the pattern length of the first lead layer 140. In FIG. 13, the fixed portion is divided into four, and the fixed portions having the same positional relationship with the movable electrode are arranged in a cross relationship, so that one of the first lead layers 141 is replaced with the other first lead layer 140. On the other hand, there is a difference in length dimension as much as it is routed to make a detour. In the second operation space 16, the pattern length of the first lead layer 143 is longer than the pattern length of the first lead layer 142. In the third operation space 17, the pattern length of the first lead layer 144 is longer than the pattern length of the first lead layer 145.

  In the embodiment of FIG. 13, the width of each first lead layer is not adjusted, but only a part of the width is adjusted, specifically, the width between the connection pattern portions between the support conductive portions of each first lead layer. The parasitic capacitance generated between each first lead layer and the closing member 4 is adjusted by adjusting only the above.

  That is, as shown in FIG. 13, the widths of the first lead layers 140, 141, 142, 143, 144, and 145 extending from the external connection pads 80, 82, 83, 85, 86, and 87 to the support conducting portion located in front are almost equal. In the first operation space 15, the width of the connection pattern portion 140 a between the support conductive portions 113 and 116 of the first lead layer 140 having a short pattern length is set within the first operation space 15. The width of the connection pattern portion 141a between the support conductive portions 114 and 115 of the lead layer 141 is larger. In the second operation space 16, the width of the connection pattern portion 142 a between the support conductive portions 121 and 124 of the first lead layer 142 with a short pattern length is equal to the support conductive property of the first lead layer 143 with a long pattern length. The connection pattern portion 143a between the portions 122 and 123 is thicker than the width. In the third operation space 17, the width of the connection pattern portion 145 a between the support conductive portions 131 and 132 of the first lead layer 145 having a short pattern length is equal to the support conductive property of the first lead layer 144 having a long pattern length. The width of the connection pattern portion 144a between the portions 130 and 133 is larger.

  In the embodiment of FIG. 13, the parasitic capacitance is adjusted by changing only a part of the first lead layer without changing the width of the first lead layer. Therefore, a minute adjustment can be easily and appropriately performed. In the embodiment of FIG. 13, the widths of the wide connection pattern portions 140a, 142a, 145a are substantially constant, and the other narrow portions are also substantially constant in each first lead layer. The pattern length of the layer is adjusted. As a result, each wide pattern portion and each narrow pattern portion can be set to the same value in each first lead layer, so that the pattern formation of each first lead layer can be performed easily and appropriately. .

Next, a manufacturing method of the MEMS sensor will be described.
In the manufacturing method of the MEMS sensor 1, first, the support substrate 2 and the functional layer 10 are manufactured using an SOI layer in which two silicon wafers are bonded via an insulating layer. In order to form the functional layer 10, a resist layer is formed on the surface of one silicon wafer of the SOI layer. The resist layer is formed so as to have a pattern of the frame body layer 11 having the first hole 12, the second hole 13, and the third hole 14. Further, the first movable body 41, the second movable body 21, the third movable body 21A, the movable electrode, and the fixed movement in the first operational space 15, the second operational space 16, and the third operational space 17. The portions that become various functional parts such as electrodes and supporting conductive parts are also covered with a resist layer. A part of the silicon wafer is removed from the resist layer by ion etching means such as deep RIE using high-density plasma, so that the frame body layer 11 and each functional part are separated from each other. The

  At this time, a large number of microscopic RIEs are applied to all regions except the frame layer 11 and the respective supporting conductive portions 23, 25, 33, 34, 23A, 25A, 33A, 34A, 42, 52, 54 by the deep RIE. A hole is formed. 5 and 6 illustrate the fine holes 21e formed in the second movable body 21 and the movable electrodes 21b and 21d and the fine holes 31d and 32d formed in the fixed electrodes 31c and 32c. 8A and 9A, the fine hole 41e formed in the right mass part 41A of the first movable body 41, the fine hole 41e formed in the left mass part 41B, and the fixed electrode 51a The formed fine hole 51d and the fine hole 53d formed in the fixed electrode 53a are respectively illustrated.

After etching the silicon wafer by Fukahori RIE or the like, a selective isotropic etching process that can dissolve the SiO ₂ layer of the insulating layer without dissolving the silicon is performed. At this time, the etching gas or the etching solution penetrates into the groove where the respective parts of the silicon wafer are separated, and further penetrates into the fine hole, and a part of the SiO ₂ layer is removed.

As a result, frame-shaped insulation is provided only between the frame body layer 11 and the respective support conducting portions 23, 25, 33, 34, 23 A, 25 A, 33 A, 34 A, 42, 52, 54 and the surface of the support substrate 2. The layer 3a and the supporting insulating layers 3b, 3c, 3d, and 3e are left, and the insulating layer (SiO ₂ layer) is removed at other portions.

  The support substrate 2 processed using the SOI layer has a thickness dimension of about 0.2 to 0.7 mm, the functional layer 10 has a thickness dimension of about 10 to 30 μm, the frame-shaped insulating layer 3a and the supporting insulating layer 3b, The thicknesses of 3c, 3d, and 3e are about 1 to 3 μm.

The second insulating layer 5 formed on the closing member 4 is an inorganic insulating layer and is formed by a sputtering process or a CVD process. As the inorganic insulating layer, a material having a smaller difference in thermal expansion coefficient from the silicon wafer than the difference in thermal expansion coefficient between the conductive metal constituting the bonding layer 6 and the silicon wafer is selected. Preferably, SiO ₂ or SiN having a relatively small difference in thermal expansion coefficient from the silicon wafer is used.

  The bonding layer 6 forming the seal bonding layer 6a and the support bonding layers 6b, 6c, 6d, and 6e was formed on the surface of the conductive metal layer formed on the surface of the functional layer 10 and the surface of the second insulating layer. It is formed by eutectic bonding or diffusion bonding with a conductive metal layer.

  Examples of the metal combination capable of eutectic bonding or diffusion bonding include aluminum-germanium, aluminum-zinc, gold-silicon, gold-indium, gold-germanium, and gold-tin.

  When the functional layer 10 and the closing member 4 are joined, the interiors of the first operating space 15, the second operating space 16, and the third operating space 17 are evacuated, and a low pressure close to a vacuum state or a vacuum state. Set to Accordingly, the first movable body 41, the second movable body 21, and the third movable body 21A can be operated in the closed operation space without being attenuated by the air damper effect. Alternatively, an inert gas such as argon may be sealed in the first operation space 15, the second operation space 16, and the third operation space 17.

  Here, as shown in FIGS. 1 and 3, a communication path 61 that is a through hole is formed in the frame body layer 11 that partitions the first operating space 15 and the second operating space 16, The inside of the first operation space 15 and the second operation space 16 is communicated. In addition, a communication path 62 that is a through hole is formed in the frame layer 11 that partitions the first operating space 15 and the third operating space 17, and the first operating space 15 and the third operating space 15 are formed. The internal space of the space 17 is communicated.

  Therefore, when each operation space is in a vacuum state or a low pressure state close to a vacuum state, the difference in pressure (pressure difference) in the first operation space 15, the second operation space 16, and the third operation space 17. (Difference) can be avoided. Similarly, when the internal argon gas or the like is sealed, the internal pressure difference in the first operating space 15, the second operating space 16, and the third operating space 17 can be eliminated. By eliminating the internal pressure difference in the first operating space 15, the second operating space 16, and the third operating space 17, it is possible to avoid stress bias and concentration due to internal pressure bias, warping, etc. Can be suppressed.

  The MEMS sensor 1 shown in FIGS. 1 and 2 can detect acceleration in three orthogonal directions as a change in capacitance between the movable electrode and the fixed electrode. Despite being able to detect acceleration in three directions, it has a planar structure, so it can be easily mounted on a mother board and contributes to miniaturization of various devices.

  In addition, the first operation space 15, the second operation space 16, and the third operation space 17 are symmetrical with respect to the first center line O1 shown in FIG. 1, and the frame body layer 11 also has the first center. Since it is the object via the line O1, the bonding stress of each part can be made equal to the left and right, and it is easy to prevent extreme warping of only a part.

  In addition, the mass distribution of the first movable body 41, the second movable body 21, and the third movable body 21A is also a rotational object about the first center line O1 and is symmetrical with respect to the left and right. The part is also balanced as a whole, and stress due to the reaction force can be prevented from being concentrated in one place.

1, 112 MEMS sensor 2 Support substrate 3 First insulating layer 3a Frame-like insulating layers 3b, 3c, 3d, 3e Support insulating layer 4 Closing member 5 Second insulating layer 6 Bonding layer 6a Seal bonding layers 6b, 6c, 6d , 6e Support bonding layer 10 Functional layer 11 Frame layer 12 First hole 13 Second hole 14 Third hole 15 First operation space 16 Second operation space 17 Third operation space 21 Second movable Body 21a, 21b, 21c, 21d Movable electrode 22, 24 Support arm part 23, 25 Support conduction part 31, 32 Fixed part 31b, 31c, 32b, 32c Fixed electrode 21A Third movable body 41 First movable body 42 Conductive portion 43A Right link portion 43B Left link portions 47a, 47b Movable electrodes 51, 53 Fixed portions 51a, 53a Fixed electrodes 70, 71, 73, 74, 76, 77, 140 to 145 First lead layers 80 to 88 Outside Part connection pads 90 to 98 Terminal parts 100 and 111 Integrated circuit (IC)
110 inspection apparatus 113-116, 121-124, 130-133 support conduction | electrical_connection part 117-120, 125-128, 134-137 fixing | fixed part

Claims (7)

A frame layer is provided between the support substrate and a closing member parallel to the support substrate, and a first operation space, a second operation space, and a third operation space that are sealed from the outside and separated from each other are formed. And
A first movable body is housed in the first operation space, a second movable body is housed in the second operation space, and a third movable body is housed in the third operation space. And the second movable body and the third movable body are supported so that the main movement directions are in three different directions orthogonal to each other, and the movable bodies are moved in the respective movement spaces. A detection unit that detects the amount of movement in the main movement direction of the body is provided,
The second operation space is arranged on one side of the first operation space, the third operation space is arranged on the other side, and the three operation spaces are arranged in a row, and the plane of the second operation space The shape and the planar shape of the third motion space are equal, and the planar shape of the three motion spaces is 180 degrees with respect to a center line passing through the center of the first motion space and orthogonal to the surface of the support substrate. A rotationally symmetric shape of
Each detection unit provided in each operation space has an output side electrode and an input side electrode, and a plurality of the output side electrode and the input side electrode are provided in each detection unit,
Each output side electrode is electrically connected to an external connection pad via a first lead layer embedded in an insulating layer formed on the surface of the closing member,
In at least one of the detection units, the pattern lengths of the plurality of first lead layers are different, and the first lead layer having a long pattern length is different from the first lead layer having a short pattern length. A MEMS sensor characterized by being formed narrow. Wherein the second movable member third movable body mass are the same, the first movable body, MEMS sensor of claim 1, wherein the mass across the center line is symmetrical. The main operation direction of the second movable body and the third movable body is a direction parallel to and orthogonal to the substrate surface of the support substrate, and the main operation direction of the first movable body is: The MEMS sensor according to claim 1 , wherein the MEMS sensor is oriented in a direction perpendicular to a substrate surface of the support substrate. Supporting unit and the detection unit for movably supporting the movable body and the frame body layer and the movable body to the main direction of movement, according to claim 1 or 2 is formed separately from a common layer MEMS sensor.   An SOI layer in which two Si layers are bonded via an insulating layer is used, one Si layer is used as the support substrate, and the other Si layer is used as a functional layer. From the functional layer, the frame body is used. The MEMS sensor according to claim 4, wherein the layer, the movable body, and a support portion that supports the movable body so as to be movable in a main operation direction are separated from the detection portion. The MEMS sensor according to any one of claims 1 to 5 , wherein a communication path that connects the adjacent operation spaces is formed in the frame body layer. The MEMS sensor according to claim 1 and an integrated circuit (IC) are provided, and the formation position of each external connection pad is set according to the position of the terminal portion of the integrated circuit (IC),
A detection device, wherein each external connection pad of the MEMS sensor and each terminal portion provided in the integrated circuit are conductively connected to obtain a differential output.

Images