WO2019013295A1 - Acceleration sensor - Google Patents

Abstract

In an electrode configuration portion (32) of a movable portion (20), a part positioned to one side, in a longitudinal direction, of a virtual line (V1) which passes through a torsion beam (33) and extends in the direction in which the torsion beam (33) extends is defined as a first part (34), and a part positioned to the other side, in the longitudinal direction, of the virtual line (V1) is defined as a second part (35). Furthermore, the first part (34) has a configuration comprising: a main portion (34a) in which a length (L1) in the longitudinal direction between the virtual line (V1) and an end portion on the opposite side to the virtual line (V1) side is equal to a length (L2) of the second part (35) in the longitudinal direction between the virtual line (V1) and an end portion thereof on the opposite side to the virtual line (V1) side; and a weight portion (34b) with which the main portion (34a) is provided, and which projects in a surface direction of the electrode configuration portion (32), which is a direction intersecting the longitudinal direction thereof.

Description

Acceleration sensor CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on Japanese Patent Application No. 2017-136541 filed on Jul. 12, 2017, the contents of which are incorporated herein by reference.

The present disclosure relates to an acceleration sensor that has a movable electrode and a fixed electrode, and detects an acceleration along the arrangement direction of the movable electrode and the fixed electrode.

Conventionally, for example, in Patent Document 1, a plate-like electrode configuration portion has a movable portion supported by an anchor portion via a torsion beam, and the first and second fixed electrodes are opposed to the movable portion. An acceleration sensor in which is disposed is proposed.

Specifically, in such an acceleration sensor, the electrode configuration portion has an opening formed on the inner edge side, and is supported by the anchor portion via the torsion beam. Then, with respect to the virtual line passing through the torsion beam, the electrode configuration portion has one first portion divided by the virtual line and the other second portion so as to be able to rotate around the torsion beam as a rotation axis. It has an asymmetric shape. More specifically, the first portion and the second portion are configured such that the lengths between the end on the phantom line side and the end on the opposite side are different from each other.

The first fixed electrode is disposed so as to face the first portion, and the second fixed electrode is disposed so as to face the second portion. Thus, the first movable electrode is configured in a portion facing the first fixed electrode in the electrode configuration portion, and the second movable electrode is configured in a portion facing the second fixed electrode in the electrode configuration portion. Ru.

In such an acceleration sensor, when acceleration is applied along the arrangement direction of the first movable electrode and the first fixed electrode, and the arrangement direction of the second movable electrode and the second fixed electrode, the torsion beam is rotated about the rotation axis. As an electrode configuration part rotates. As a result, the capacitance between the first movable electrode and the first fixed electrode and the capacitance between the second movable electrode and the second fixed electrode change. Therefore, the acceleration is detected based on the change in capacitance.

Note that the first fixed electrode and the second fixed electrode have the same planar shape as each other so that an equal capacitance is formed between the first movable electrode and the second movable electrode when no acceleration is applied. It is assumed.

JP, 2014-16175, A

However, in the acceleration sensor, the first portion and the second portion are configured such that the lengths between the end on the imaginary line side and the end on the other side are different from each other. That is, the first portion and the second portion are configured such that the lengths between the end on the rotation shaft side and the end on the opposite side are different from each other.

For this reason, in the above acceleration sensor, when the electrode configuration portion is distorted, the portion connected with the torsion beam is distorted on the basis, but the distortion is different between the first portion and the second portion. That is, the method of changing the electrostatic capacitance between the first movable electrode and the first fixed electrode differs from the method of changing the electrostatic capacitance between the second movable electrode and the second fixed electrode. Therefore, detection accuracy may be reduced.

An object of the present disclosure is to provide an acceleration sensor that can suppress a decrease in detection accuracy.

According to one aspect of the present disclosure, the acceleration sensor includes a first fixed portion having a first fixed electrode portion, a second fixed portion having a second fixed electrode portion, and a portion facing the first fixed electrode portion. A first movable electrode portion, and a second movable electrode portion formed in a portion facing the second fixed electrode portion, and connecting the electrode portion and the anchor portion; A torsion beam for moving an electrode configuration portion by twisting when acceleration is applied along the arrangement direction of the fixed electrode portion and the first movable electrode portion and the arrangement direction of the second fixed electrode portion and the second movable electrode portion; And a movable portion having The electrode configuration portion is a plate having a longitudinal direction, and an opening is formed on the inner edge side, and the opposing portion in the opening is provided with a torsion beam extending in a direction intersecting the longitudinal direction. A portion which is supported by the anchor portion, passes through the torsion beam, and is located on one side in the longitudinal direction of the virtual line extending along the extension direction of the torsion beam is a first portion, and the other in the longitudinal direction than the virtual line Assuming that the portion located on the side is the second portion, the first portion faces the first fixed electrode portion and the second portion faces the second fixed electrode portion, and the first portion is a virtual line. And a length along the longitudinal direction between the virtual line side and the opposite end portion is a length along the longitudinal direction between the virtual line and the virtual line side and the opposite end at the second portion An equalized main part and an electrode configuration provided in the main part A surface direction, and a spindle portion which projects in a direction intersecting the longitudinal direction, mass than the second portion is heavy.

According to this, the electrode configuration portion has a length along the longitudinal direction between the imaginary line at the first portion and the end opposite to the imaginary line side, the imaginary line at the second portion, and the imaginary line side And the end along the longitudinal direction between the opposite end and the same. For this reason, it can suppress that the distortion method of a 1st site | part and a 2nd site | part disperses, and it can suppress that a detection precision falls.

The reference numerals in parentheses attached to each component, etc., shows an example of a relationship of the specific component such as described in the following embodiments and their components, and the like.

It is a sectional view of an acceleration sensor in a 1st embodiment. It is sectional drawing of an acceleration sensor different from FIG. 1 in 1st Embodiment. It is sectional drawing of an acceleration sensor different from FIG. 1 in 1st Embodiment. FIG. 5 is a plan view of one surface side of a first substrate. It is a top view of the one side of the 2nd substrate. It is a top view of the other side of a 2nd substrate. It is a top view on the 1 side of the 1st substrate in a 2nd embodiment. It is a top view on the 1 side of the 1st substrate in a 3rd embodiment. It is a top view of the 1 side of the 1st substrate in a 4th embodiment. It is a top view of the 1st support substrate in a 5th embodiment.

Hereinafter, embodiments of the present disclosure will be described based on the drawings. In the following embodiments, parts that are the same as or equivalent to each other will be described with the same reference numerals.

First Embodiment
The first embodiment will be described with reference to FIGS. 1 to 6. The acceleration sensor of the present embodiment is configured such that the first substrate 10 and the second substrate 50 are stacked, and a sensing unit 80 that outputs a detection signal according to the acceleration is accommodated inside.

1 corresponds to the cross section along the line II in FIG. 4 to FIG. 6, and FIG. 2 corresponds to the cross section along the line II-II in FIG. Corresponds to a cross section taken along the line III-III in FIGS. 4 to 6. In the following, one direction in the surface direction of the first substrate 10 and the second substrate 50 is taken as an x-axis direction, one direction in the surface direction of the first substrate 10 and the second substrate 50, and orthogonal to the x-axis direction. The direction is described as the y-axis direction. Further, a direction orthogonal to the x-axis direction and the y-axis direction will be described as the z-axis direction. In each of the drawings, the x-axis direction, the y-axis direction, and the z-axis direction are indicated by arrows.

In the present embodiment, the first substrate 10 is configured using an SOI (that is, Silicon on Insulator) structure in which the first semiconductor layer 13 is disposed on the first support substrate 11 with the first insulating film 12 interposed therebetween. There is. The first substrate 10 is configured such that the first surface 10 a is a surface of the first semiconductor layer 13 opposite to the first insulating film 12 side. In the present embodiment, the first support substrate 11 and the first semiconductor layer 13 are formed of a silicon substrate, and the first insulating film 12 is formed of an oxide film, a nitride film, or the like.

Then, as shown in FIGS. 1 to 4, the first semiconductor layer 13 is micromachined to form a groove 14, and the groove 14 divides the movable portion 20 and the peripheral region 40. 4 is a plan view of one surface 10a side of the first substrate 10, but in order to facilitate understanding, a first fixed electrode portion 71a and a second fixed electrode portion 72a described later are shown by dotted lines.

Further, in the first support substrate 11 and the first insulating film 12, as shown in FIGS. 1 to 3, the movable portion 20 is prevented from coming into contact with the first support substrate 11 and the first insulating film 12. The recess 15 is formed in a portion facing the movable portion 20. In addition, this recessed part 15 is formed so that it may become a shape corresponding to the movable part 20 in the part different from the support area | region 11a which supports the anchor part 21 mentioned later.

As shown in FIGS. 1 and 4, movable portion 20 responds to acceleration along the stacking direction of anchor portion 21, first substrate 10 and second substrate 50 (hereinafter simply referred to as the stacking direction). And a movable region 22 supported by the anchor portion 21 in a movable state.

In the present embodiment, the anchor portion 21 is formed such that the center of the anchor portion 21 coincides with the center of the surface 10 a of the first substrate 10. Further, the anchor portion 21 is formed to be substantially square when viewed in the normal direction to the surface 10 a of the first substrate 10.

In the movable region 22, an opening 31 is formed on the inner edge side along the outer shape of the anchor 21, and the plate-like electrode component 32 having the x-axis direction as the longitudinal direction, the electrode component 32 and the anchor 21 And a torsion beam 33 connected thereto.

The torsion beam 33 is a member serving as a rotation axis serving as a rotation center of the electrode configuration portion 32 (that is, the movable region 22) when an acceleration in the stacking direction is applied. In the present embodiment, the torsion beam 33 is provided at a pair of opposing portions in the opening 31 and extends along the y-axis direction so as to connect the anchor portion 21 and the electrode configuration portion 32. Specifically, the torsion beam 33 is formed such that the first virtual line V1 along the extending direction of the torsion beam 33 intersects the center of the anchor portion 21.

The electrode configuration portion 32 has a first portion 34 located on one side in the longitudinal direction of the first virtual line V1 and a second portion 35 located on the other side of the first virtual line V1. . In other words, it can be said that the torsion beam 33 is connected to the boundary between the first portion 34 and the second portion 35 of the electrode configuration portion 32. In FIG. 4, the portion on the left side in the drawing of the electrode configuration portion 32 is the first portion 34, and the portion on the right side in the drawing of the electrode configuration portion 32 is the second portion 35.

The second portion 35 is substantially U-shaped to form a half of the opening 31 formed along the outer shape of the anchor portion 21. The first portion 34 has a main portion 34 a that is line-symmetrical to the second portion 35 with respect to the first virtual line V1. That is, the first portion 34 has the main portion 34 a which has the same planar shape as the second portion 35.

The first portion 34 has a main portion 34a and a weight portion 34b integrated with the main portion 34a. Specifically, the weight portion 34 b is provided in the main portion 34 a so as to protrude in the y-axis direction in the surface direction of the electrode configuration portion 32. That is, the weight portion 34 b is provided in the main portion 34 a so as to constitute the same plane as the main portion 34 a. In the present embodiment, two weight portions 34 b are provided in the main portion 34 a so as to protrude in opposite directions with respect to the main portion 34 a.

Here, an end of the first portion 34 opposite to the first virtual line V1 is one end of the first portion 34, and an end of the second portion 35 opposite to the first virtual line V1 is the second portion. Let it be one end of 35. In this case, in the present embodiment, the first portion 34 and the second portion 35 have a length L1 from the first virtual line V1 to one end of the first portion 34, and the first virtual line V1 to the second portion 35. It can be said that the length L2 to one end is equal. In the following, the length L1 from the first virtual line V1 to one end of the first portion 34 is simply referred to as the length L1, and the length L2 from the first virtual line V1 to one end of the second portion 35 is It is also simply referred to as the length L2. Moreover, being equal here includes a slight manufacturing error in addition to the case where the length L1 and the length L2 are completely equal.

In this embodiment, as described above, the first portion 34 is configured to include the main portion 34 a having the same shape as the second portion 35 and the weight portion 34 b provided in the main portion 34 a. The mass is made heavier than the second portion 35. Thus, when acceleration in the stacking direction is applied, the electrode configuration portion 32 rotates with the torsion beam 33 as a rotation axis.

In the present embodiment, the two weight portions 34b are provided such that the lengths L3 and L4 along the y-axis direction are equal to each other. That is, the electrode configuration portion 32 passes the center of the anchor portion 21 and is formed in line symmetry with respect to the second virtual line V2 along the x-axis direction. Further, in the present embodiment, the lengths L3 and L4 of the weight portion 34b are shorter than the length of the main portion 34a in the y-axis direction.

In addition, although not particularly illustrated, the electrode configuration portion 32, the torsion beam 33, and the anchor portion 21 are integrally formed by performing dry etching or the like on the first semiconductor layer 13 to form the groove portion 14. For this reason, the main portion 34a and the weight portion 34b in the first portion 34 of the electrode configuration portion 32 are formed to constitute the same plane. Further, since the weight portion 34 b is integrally formed with the torsion beam 33 or the like, the manufacturing process is not particularly increased by providing the weight portion 34 b.

The second substrate 50 has a cap substrate 60, as shown in FIGS. In the present embodiment, the cap substrate 60 is configured using an SOI structure in which the second semiconductor layer 63 is disposed on the second support substrate 61 with the second insulating film 62 interposed therebetween. The one surface 50 a of the second substrate 50 is formed of the surface of the second semiconductor layer 63 opposite to the second insulating film 62 side. In the present embodiment, the second support substrate 61 and the second semiconductor layer 63 are formed of a silicon substrate, and the second insulating film 62 is formed of an oxide film, a nitride film, or the like.

As shown in FIG. 1 to FIG. 3 and FIG. 5, the groove portion 64 is formed in the second semiconductor layer 63 of the second substrate 50 by micromachining. In the second semiconductor layer 63, the first fixing portion 71, the second fixing portion 72, the peripheral region 73, the first bonding region 74, and the second bonding region 75 are formed by the groove 64.

Specifically, the first fixing portion 71 is formed in a portion facing the first portion 34 in the electrode configuration portion 32 and forms a predetermined capacitance with the first portion 34. The fixed electrode portion 71a and a first fixed wiring portion 71b drawn from the first fixed electrode portion 71a are provided. In addition, the second fixed portion 72 is formed in a portion facing the second portion 35 of the electrode configuration portion 32 and forms a predetermined capacitance with the second portion 35. It has 72a and the 2nd fixed wiring part 72b drawn out from the 2nd fixed electrode part 72a.

The first and second fixed electrode portions 71a and 72a have the same planar shape as each other so that equal capacitance is formed between the first and second portions 34 and 35 in the state where acceleration is not applied. It is assumed. More specifically, the first and second fixed electrode portions 71a and 72a are formed to be line symmetrical with respect to the first virtual line V1 when viewed from the normal direction to the surface 10a of the first substrate 10. There is. Then, in the electrode configuration portion 32, as shown in FIG. 4, the portion of the first portion 34 facing the first fixed electrode portion 71a becomes the first movable electrode portion 36, and the portion of the second portion 35 The portion facing the second fixed electrode portion 72 a is the second movable electrode portion 37. In the present embodiment, the sensing unit 80 is configured by forming the movable unit 20 and the first and second fixed units 71 and 72 in this manner. Then, when an acceleration is applied in the stacking direction, the electrode configuration portion 32 rotates about the torsion beam 33 as a rotation axis, and thus, the capacitance between the first movable electrode portion 36 and the first fixed electrode portion 71a, The capacitance between the second movable electrode portion 37 and the second fixed electrode portion 72a changes. Therefore, a detection signal corresponding to the change in capacitance is output. The first fixed electrode portion 71a and the second fixed electrode portion 72a are disposed to face the electrode configuration portion 32 (that is, the first movable electrode portion 36 and the second movable electrode portion 37). That is, that acceleration is applied in the stacking direction in the present embodiment means, in other words, the arrangement direction of the first movable electrode portion 36 and the first fixed electrode portion 71a, and the second movable electrode portion 37 and the second fixed electrode Acceleration is applied along the direction of arrangement with the portion 72a.

The first fixed wiring portion 71b is electrically connected to the second through wiring layer 112c disposed in the second through hole 112a, as described later. The second fixed wiring portion 72b is electrically connected to the third through wiring layer 113c disposed in the third through hole 113a, as described later. Therefore, from the first and second fixed electrode portions 71a and 72a, the first and second fixed wiring portions 71b and 72b are electrically connected to the second and third through wiring layers 112c and 113c, respectively. It is pulled out to a predetermined position.

The first bonding region 74 is a region for causing the first through electrode unit 111 described later to reach the anchor portion 21, and is a region to be bonded to the anchor portion 21. The second bonding region 75 is a region for causing the fourth through electrode unit 114 described later to reach the peripheral region 40 in the first semiconductor layer 13.

Further, as shown in FIGS. 1 to 3, the second substrate 50 has the other surface insulating film 90 formed on the opposite side of the cap substrate 60 to the first substrate 10 side. In the present embodiment, the other surface 50 b of the second substrate 50 is configured by the surface of the other surface insulating film 90 opposite to the cap substrate 60.

The second substrate 50 configured in this manner is bonded to the first substrate 10 via the bonding member 100 such that the first surface 50 a faces the first surface 10 a of the first substrate 10. More specifically, the second substrate 50 is bonded to the first substrate 10 such that the sensing unit 80 is hermetically sealed. In the present embodiment, the bonding member 100 is formed of an oxide film or the like.

Further, in the present embodiment, the first to fifth through electrode portions 111 to 115 having the first to fifth wiring portions 111f to 115f for connecting the external circuit to the predetermined region are formed. First, the configuration of the first to fifth through electrode units 111 to 115 will be described with reference to FIGS. 1 to 3 and FIG. In FIG. 6, a protective film 120 described later is omitted. The first to fifth wiring portions 111f to 115f are configured using aluminum or the like which is a metal material.

As shown in FIGS. 1 and 6, the first through electrode unit 111 penetrates the second substrate 50 in the stacking direction, and is provided on the wall surface of the first through hole 111 a that exposes the anchor portion 21 in the first semiconductor layer 13. The first wall insulating film 111b is formed. In addition, the first through electrode unit 111 is formed on the first wall surface insulating film 111 b and has a first through wiring layer 111 c electrically connected to the anchor unit 21, that is, the movable unit 20. Furthermore, the first through electrode unit 111 electrically connects the first pad unit 111d formed on the other surface insulating film 90 and connected to the external circuit, the first pad unit 111d, and the first through wiring layer 111c. And a first lead-out wiring layer 111e to be connected. Therefore, the first wiring portion 111f in the first through electrode unit 111 is configured to have the first through wiring layer 111c, the first pad portion 111d, and the first lead wiring layer 111e.

As shown in FIGS. 2 and 6, the second through electrode unit 112 has the following second wall insulating film 112 b. That is, the second through electrode unit 112 penetrates the other surface insulating film 90, the second support substrate 61, and the second insulating film 62 in the stacking direction to expose the first fixed wiring portion 71b in the second semiconductor layer 63. The second wall insulating film 112b is formed on the wall surface of the second through hole 112a. In addition, the second through electrode unit 112 includes a second through wiring layer 112c which is formed on the second wall surface insulating film 112b and electrically connected to the first fixed wiring portion 71b. Furthermore, the second through electrode unit 112 electrically connects the second pad unit 112d formed on the other surface insulating film 90 and connected to the external circuit, the second pad unit 112d, and the second through wiring layer 112c. And a second lead-out wiring layer 112e to be connected. For this reason, the second wiring portion 112f in the second through electrode portion 112 is configured to have the second through wiring layer 112c, the second pad portion 112d, and the second lead wiring layer 112e.

The third through electrode unit 113 has a configuration similar to that of the second through electrode unit 112. That is, it is formed on the wall surface of the third through hole 113a which penetrates the other surface insulating film 90, the second support substrate 61, and the second insulating film 62 in the stacking direction and exposes the second fixed wiring portion 72b in the second semiconductor layer 63. And the third wall insulating film 113b. Further, the third through electrode unit 113 includes a third through wiring layer 113c which is formed on the third wall insulating film 113b and electrically connected to the second fixed wiring portion 72b. Further, the third through electrode unit 113 electrically connects the third pad unit 113d formed on the other surface insulating film 90 and connected to the external circuit, the third pad unit 113d and the third through wiring layer 113c. And a third lead-out wiring layer 113e to be connected. Therefore, the third wiring portion 113f in the third through electrode unit 113 is configured to have the third through wiring layer 113c, the third pad portion 113d, and the third lead wiring layer 113e.

As shown in FIGS. 3 and 6, the fourth through electrode unit 114 penetrates the second substrate 50 in the stacking direction, and is provided on the wall surface of the fourth through hole 114a that exposes the peripheral region 40 in the first semiconductor layer 13. The fourth wall insulating film 114 b is formed. Further, the fourth through electrode unit 114 includes a fourth through wiring layer 114 c which is formed on the fourth wall insulating film 114 b and electrically connected to the peripheral region 40 in the first semiconductor layer 13. Further, the fourth through electrode portion 114 electrically connects the fourth pad portion 114d formed on the other surface insulating film 90 and connected to the external circuit, the fourth pad portion 114d and the fourth through wiring layer 114c. And a fourth lead-out wiring layer 114e to be connected. Therefore, the fourth wiring portion 114f in the fourth through electrode unit 114 is configured to have the fourth through wiring layer 114c, the fourth pad portion 114d, and the fourth lead wiring layer 114e.

The fifth through electrode unit 115 penetrates the other surface insulating film 90, the second support substrate 61, and the second insulating film 62 in the stacking direction to expose the peripheral region 73 in the second semiconductor layer 63. The fifth wall insulating film 115 b is formed on the wall surface. Further, the fifth through electrode unit 115 includes a fifth through wiring layer 115 c which is formed on the fifth wall surface insulating film 115 b and electrically connected to the peripheral region 73 in the second semiconductor layer 63. Further, the fifth through electrode portion 115 electrically connects the fifth pad portion 115d formed on the other surface insulating film 90 and connected to the external circuit, the fifth pad portion 115d and the fifth through wiring layer 115c. And a fifth lead-out wiring layer 115e to be connected. Therefore, the fifth wiring portion 115f in the fifth through electrode unit 115 is configured to have the fifth through wiring layer 115c, the fifth pad portion 115d, and the fifth lead wiring layer 115e.

In the present embodiment, the first to fifth through wiring layers 111c to 115c are formed in a state in which the communication between the inside and the outside of the first to fifth through holes 111a to 115a is maintained, respectively. That is, the first to fifth through wiring layers 111c to 115c are formed in a state in which the first to fifth through holes 111a to 115a are not embedded, respectively.

Further, in the present embodiment, the first to fifth through holes 111a to 115a respectively have the same shape and size of the opening. Specifically, the openings of the first to fifth through holes 111a to 115a are circular, and the diameters thereof are equal to each other.

The above is the configuration of the first to fifth through electrode units 111 to 115 in the present embodiment. Then, the pad portions 111 d to 115 d are respectively connected to the external circuit, whereby the movable portion 20, the first fixing portion 71, the second fixing portion 72, the peripheral region 40 of the first semiconductor layer 13, and the second semiconductor layer 63. The peripheral regions 73 in each are connected to external circuits. In the present embodiment, the peripheral region 40 in the first semiconductor layer 13 and the peripheral region 73 in the second semiconductor layer 63 are connected to an external circuit and maintained at a predetermined potential. As a result, a change in parasitic capacitance formed between sensing unit 80 and peripheral regions 40 and 73 is suppressed, and a decrease in detection accuracy is suppressed.

Next, the locations of the first to fifth through electrode units 111 to 115 in the present embodiment will be described.

First, as shown in FIG. 6, when viewed from the normal direction to the other surface 50 b of the second substrate 50, an imaginary line extending in the y-axis direction passes through the portion positioned on the outermost edge side of the movable portion 20. It is assumed that the first and third section virtual lines K1 and K3. Further, when viewed in a direction normal to the other surface 50b of the second substrate 50, a virtual line extending in the x-axis direction passing through a portion positioned on the outermost edge side of the movable portion 20 is a second, fourth section virtual line K2 , K4. Then, a rectangular virtual area surrounded by the first to fourth section virtual lines K1 to K4 is set as a virtual area A.

Specifically, in the present embodiment, a virtual line extending from one end of the first portion 34 along the y-axis direction is the first section virtual line K1, and a virtual line extending from one end of the second portion 35 along the y-axis The line is the third section imaginary line K3. In addition, imaginary lines extending along the x-axis direction from end portions on the opposite side to the main portion 34a side in the weight portion 34b become second and fourth section imaginary lines K2 and K4. A virtual region A is a rectangular virtual region surrounded by the first to fourth section virtual lines K1 to K4.

The first to fifth through electrode portions 111 to 115 are formed to be located in the virtual area A when viewed in the normal direction to the other surface 50b of the second substrate 50. The fact that the first to fifth through electrode portions 111 to 115 are arranged in the virtual area A means that the first to fifth pad portions 111d to 111 which constitute the first to fifth through electrode portions 111 to 115 are formed. It means that 115d etc. are arrange | positioned in the virtual area A, too.

In more detail, in the present embodiment, the anchor portion 21 is formed at the center of the surface 10 a of the first substrate 10 as described above. Therefore, as shown in FIG. 6, when viewed from the normal direction to the other surface 50b of the second substrate 50, the first through hole 111a in which the first through wiring layer 111c in the first through electrode portion 111 is disposed. Is formed at the center of the other surface 50 b of the second substrate 50.

The second to fifth through electrode portions 112 to 115 are formed so as to be rotationally symmetrical with respect to the center of the other surface 50 b of the second substrate 50 in the virtual area A. That is, the second to fifth wiring parts 112f to 115f are formed to be rotationally symmetrical with respect to the center of the other surface 50b of the second substrate 50. As described above, the first and second fixed wiring portions 71b and 72b have the first and second fixed electrode portions 71a and 72a, respectively, so that the second and third through holes 112a and 113a have the above-described shape. Are drawn from

The above is the arrangement places of the first to fifth through electrode portions 111 to 115 in the present embodiment. Then, as shown in FIGS. 1 to 3, on the other surface 50b of the second substrate 50, a protective film 120 covering the first to fifth through electrode portions 111 to 115 is formed. Although not shown in the figure, the protective film 120 is provided with openings for exposing the first to fifth pad portions 111d to 115d so that an external circuit can be electrically connected to the respective pad portions 111d to 115d. It has become.

As described above, in the present embodiment, the electrode configuration portion 32 includes the weight portion 34b that protrudes along the y-axis direction in the first portion 34, so that the length L1 and the length L2 are equalized. The first portion 34 and the second portion 35 have different masses. For this reason, it can suppress that the distortion method of the 1st site | part 34 and the 2nd site | part 35 varies, and it can suppress that a detection precision falls.

Further, the weight portion 34 b is provided so as to constitute the same plane as the main portion 34 a constituting the first portion 34. For this reason, for example, by arranging another weight part on the main part 34a which comprises the 1st part 34, compared with the case where the mass of the 1st part 34 and the 2nd part 35 is made to differ, simple composition. The mass of the first portion 34 and the second portion 35 can be made different. Further, since the weight portion 34b is provided in the same plane as the main portion 34a constituting the first portion 34, for example, it is only necessary to change the mask such as dry etching performed on the first semiconductor layer 13 and the manufacturing process is complicated. There is no need to

Furthermore, in the present embodiment, the first to fifth through electrode units 111 to 115 are disposed in the virtual area A when viewed from the normal direction to the other surface 50b of the second substrate 50. For this reason, the area | region which becomes wide can be effectively utilized by providing the weight part 34b, and it can suppress that an acceleration sensor enlarges.

Further, when viewed from the normal direction to the other surface 50 b of the second substrate 50, the first through electrode unit 111 is formed at a position including the center of the second substrate 50. The second to fifth through electrode portions 112 to 115 are formed so as to be rotationally symmetrical with respect to the center of the other surface 50 b of the second substrate 50 in the virtual area A. Therefore, stress caused by the second to fifth through wiring layers 112c to 115c can be easily equalized. Therefore, in the present embodiment, the acceleration sensor is less likely to be distorted, and it is possible to further suppress the decrease in detection accuracy.

Furthermore, the first to fifth through wiring layers 111c to 115c are formed in a state where the inside and the outside of the first to fifth through holes 111a to 115a are in communication. That is, the first to fifth through wiring layers 111c to 115c are formed in a state in which the first to fifth through holes 111a to 115a are not embedded. Therefore, compared to the case where the first to fifth through holes 111a to 115a are embedded by the first to fifth through wiring layers 111c to 115c, the first to fifth through wirings in the portion not embedded Stress caused by the layers 111c to 115c can be relieved. Therefore, the magnitude of the stress itself that distorts the acceleration sensor can be reduced.

Further, the diameters of the openings of the first to fifth through holes 111a to 115a are equal. Therefore, as compared with the case where the diameters of the first to fifth through holes 111a to 115a are different, it is possible to suppress the dispersion of the magnitude of the stress to be relaxed particularly when the through holes 111a to 115a are not embedded. Therefore, distortion of the acceleration sensor can be further suppressed.

Second Embodiment
The second embodiment will be described. The present embodiment is the same as the first embodiment except that a reinforcing portion is added to the electrode configuration portion 32 with respect to the first embodiment, and thus the description thereof is omitted here.

In the present embodiment, as shown in FIG. 7, in the electrode configuration portion 32, reinforcing portions 38 are provided in respective portions on the side opposite to the anchor portion 21 side with respect to portions connected with the torsion beam 33. There is. In the present embodiment, the reinforcing portions 38 are provided to project along the y-axis direction.

Specifically, each reinforcing portion 38 is provided so as to be line symmetrical with respect to the first virtual line V1 so that the mass relationship between the first portion 34 and the second portion 35 is not changed by the reinforcing portion 38. There is. Further, each reinforcing portion 38 is provided such that the lengths L5 and L6 in the y-axis direction are equal to each other. That is, each reinforcing portion 38 is provided so as to be line symmetrical with respect to the second virtual line V2. Furthermore, each reinforcing portion 38 has a length equal to or less than the length L3 in the y-axis direction of the weight portion 34b, and a length L4 or less. That is, the reinforcing portion 38 is provided so as to be located in the virtual area A.

In addition, although it does not show in particular when it is comprised in this way, when it sees from the other surface 50b of the 2nd board | substrate 50, 2nd, 4th through-hole 112a, 114a is between the weight part 34b and the reinforcement part 38. It can be said that it is formed in The third through hole 113a is formed in line symmetry with the second through hole 112a with respect to the first virtual line V1, and the fifth through hole 115a is formed with the fourth through hole 114a with respect to the first virtual line V1. It can be said that it is formed in line symmetry.

As described above, in the present embodiment, the electrode configuration portion 32 is provided with the reinforcing portion 38. For this reason, it can suppress that the electrode structure part 32 bends. That is, although the electrode configuration portion 32 is moved by twisting the torsion beam 33, a large stress is generated in the connection portion with the torsion beam 33. Therefore, by providing the reinforcing portion 38 on the side opposite to the portion connected to the torsion beam 33, the rigidity of the portion connected to the torsion beam 33 can be increased, and bending of the electrode configuration portion 32 can be suppressed.

Third Embodiment
A third embodiment will be described. The present embodiment is the same as the second embodiment except that the length of the torsion beam 33 is changed with respect to the second embodiment, and the description thereof is omitted here.

In the present embodiment, as shown in FIG. 8, the electrode configuration portion 32 is formed with a recess 31 a in a portion connected to the torsion beam 33. Specifically, in the electrode configuration portion 32, a recess 31a is formed in a portion connected to the torsion beam 33 in the wall surface constituting the opening 31. The torsion beam 33 is disposed to connect the bottom surface of the recess 31 a and the anchor 21. That is, the torsion beam 33 of the present embodiment is longer than the torsion beam 33 of the second embodiment.

In addition, the electrode configuration portion 32 is formed such that an interval a1 of a predetermined region of a portion located in the y-axis direction with respect to the anchor portion 21 of the first portion 34 and the second portion 35 is the narrowest. Specifically, electrode configuration portion 32 has a space a1 along the y-axis direction between the end portion on the side of anchor portion 21 and the end portion on the opposite side of the portion different from the portion where recess 31a is formed. Is formed to be the narrowest. That is, in the electrode configuration portion 32, the distance a1 is the distance a2 between the side surface of the opposing recess 31a and the side surface of the reinforcing portion 38, the distance a3 between the bottom of the recess 31a and the tip of the reinforcing portion 38 in the projecting direction, It is formed to be shorter than the lengths L1 to L6.

As described above, in the present embodiment, the length of the torsion beam 33 is increased by forming the recess 31 a. Therefore, the degree of freedom of the spring constant of the torsion beam 33 can be improved. That is, the degree of freedom in design can be improved.

Also, the space a1 is formed to be the shortest. For this reason, the design of the part which exhibits the necessary function as the movable part 20 can be diverted as it is, and there is no need to newly design the movable part 20 by forming the depressed part 31 a. Therefore, the freedom of design can be improved.

Fourth Embodiment
A fourth embodiment will be described. The present embodiment is the same as the third embodiment except that the place where the weight 34 b is disposed is changed with respect to the third embodiment, and therefore the description thereof is omitted here.

In the present embodiment, as shown in FIG. 9, the weight portion 34 b is not disposed on one end side of the first portion 34, and is disposed integrally with the reinforcing portion 38. Thus, even if the weight portion 34b is integrated with the reinforcing portion 38, the same effect as that of the third embodiment can be obtained.

In such a configuration, compared to the case where the weight 34b is provided on one end side of the first portion 34, the weight 34b is disposed near the first virtual line V1 (that is, the rotation axis) It becomes. Therefore, for example, in order to have the same detection sensitivity as that of the first embodiment, the depression 31a described in the third embodiment is made larger, and the length of the torsion beam 33 is made longer. The spring constant of the torsion beam 33 may be reduced.

Fifth Embodiment
A fifth embodiment will be described. The present embodiment is the same as the first embodiment except that the shapes of the depressions 15 formed in the first support substrate 11 and the first insulating film 12 are modified with respect to the first embodiment. The description is omitted here because it is present.

In the present embodiment, as shown in FIG. 10, the recess 15 formed in the first support substrate 11 passes through the center of the support region 11a and with respect to the third imaginary line V3 extending along the y-axis direction, It is formed in line symmetry. Further, the recess 15 is formed in line symmetry with respect to a fourth imaginary line V4 extending along the x-axis direction, passing through the center of the support region 11a. That is, in addition to the portion facing the movable portion 20, the first recessed portion 15a is formed in the first support substrate 11 to be line symmetrical with respect to the third virtual line V3 and the fourth virtual line V4. A recess 15 is formed.

In the present embodiment, the dummy recessed portion 15 a is formed at a position that is line symmetrical with the third imaginary line V 3 with the portion of the movable portion 20 of the first support substrate 11 facing the weight portion 34 b. Although not shown in the drawings, the recess 15 formed in the first insulating film 12 has the same shape as the recess 15 formed in the first support substrate 11.

The third virtual line V3 is a virtual line that coincides with the first virtual line V1 when viewed from the other surface 50b of the second substrate 50. Similarly, the fourth virtual line V4 is a virtual line which coincides with the second virtual line V2 when viewed from the other surface 50b of the second substrate 50.

As described above, in the present embodiment, the recess 15 is formed to be line symmetrical with respect to the third virtual line V3 and the fourth virtual line V4. Therefore, the distortions of the first support substrate 11 and the first insulating film 12 are symmetrical with respect to the third virtual line V3 and the fourth virtual line V4. Therefore, the difference between the capacitance between the first movable electrode portion 36 and the first fixed electrode portion 71a and the capacitance between the second movable electrode portion 37 and the second fixed electrode portion 72a changes. Can be suppressed, and the decrease in detection accuracy can be further suppressed.

(Other embodiments)
Although the present disclosure has been described in accordance with the embodiment, it is understood that the present disclosure is not limited to the embodiment or the structure. The present disclosure also includes various modifications and variations within the equivalent range. In addition, various combinations and forms, and further, other combinations and forms including only one element, or more or less than these elements are also within the scope and the scope of the present disclosure.

For example, in each of the above embodiments, the arrangement locations of the first to fifth through electrode units 111 to 115 may be changed. For example, a part or all of the first to fifth through electrode units 111 to 115 may be disposed outside the virtual area A. In this case, for example, when viewed from the other surface 50b side of the second substrate 50, the second to fifth through electrode portions 112 to 115 may be formed so as to be rotationally symmetric outside the virtual area A. . Even with such a configuration, by setting the movable portion 20 to the same configuration as each of the above-described embodiments, it is possible to suppress a decrease in detection accuracy.

Further, the anchor portion 21 may not be formed so that the center thereof coincides with the center of the surface 10 a of the first substrate 10.

Furthermore, the second to fifth through electrode portions 112 to 115 are formed in rotational symmetry with respect to the center of the other surface 50 b of the second substrate 50 when viewed from the normal direction to the other surface 50 b of the second substrate 50. It may be formed as follows. For example, the second and fourth through silicon vias 112 and 114 and the third and fifth through silicon vias 113 and 115 may be line symmetrical with respect to the first virtual line V1. Then, the second and third through silicon vias 112 and 113 and the fourth and fifth through silicon vias 114 and 115 may be line symmetrical with respect to the second virtual line K2. In addition, the second to fifth through electrodes 112 to 115 may be formed to be line symmetrical with respect to only one of the first virtual line V1 and the second virtual line V2.

Even if the second to fifth through electrode portions 112 to 115 are formed as described above, each through electrode portion 112 is compared with the case where the second to fifth through electrode portions 112 to 115 are formed irregularly. Stresses caused by ̃115 are likely to be equalized.

In each of the above embodiments, the first to fifth through silicon vias 111 to 115 may be arranged irregularly without being rotationally symmetrical or axisymmetric. Also as such an acceleration sensor, when the movable portion 20 has the same configuration as that of each of the above-described embodiments, it is possible to suppress a decrease in detection accuracy.

Furthermore, in the above embodiments, the fourth and fifth through electrode units 114 and 115 may not be provided.

In each of the above embodiments, for example, a through electrode unit having a wiring unit electrically connected to the first support substrate 11 may be provided. According to this, since the first support substrate 11 is also maintained at the predetermined potential, it is possible to suppress further decrease in detection accuracy.

Furthermore, for example, a contact hole for exposing the second support substrate 61 may be formed in the vicinity of the fourth through hole 114 a or the fifth through hole 115 a of the other surface insulating film 90. Then, the fourth lead wiring portion 114e or the fifth lead wiring portion 115e may be embedded in the contact hole. According to this, since the second support substrate 61 is also maintained at the predetermined potential, it is possible to suppress further decrease in detection accuracy.

In each of the above embodiments, in the second semiconductor layer 63, the peripheral region 73, the first bonding region 74, and the second bonding region 75 may not be partitioned by the groove 64. Even in such a configuration, since the first, fourth, and fifth through wiring layers 111c, 114, and 115c are disposed via the wall surface insulating films 111b, 114b, and 115b, respectively, insulation in each region is maintained. .

Furthermore, in each of the above-described embodiments, two weight parts 34b may not be provided, and only one weight part 34b may be provided. The two weights 34b may have different lengths L3 and L4 along the y-axis direction. In the second to fourth embodiments, only one reinforcing portion 38 may be provided, or the lengths L5 and L6 along the y-axis direction may be different from each other. Furthermore, in the reinforcing portion 38, the lengths L5 and L6 may be longer than the lengths L3 and L4 of the weight portion 34b.

In the first to third and fifth embodiments, the weight 34 b is not at one end of the first portion 34 but, for example, at an intermediate position between one end of the first portion 34 and the first virtual line V1. It may be provided. That is, the place where the weight 34 b is provided is not particularly limited.

And in the said 3rd, 4th embodiment, the hollow part 31a may be formed in the anchor part 21 side. That is, the length of the torsion beam 33 may be increased by forming the recess 31 a on the anchor 21 side. Also in this case, the spring constant of the torsion beam 33 can be changed, and the degree of freedom in design can be improved. However, the anchor portion 21 is a portion directly connected to the first through wiring layer 111c, and when the recessed portion 31a is formed in the anchor portion 21, the contact area between the anchor portion 21 and the first through wiring layer 111c is reduced. there is a possibility. That is, there is a possibility that an electrical connection failure may occur. For this reason, the recess 31a is preferably formed on the side of the electrode component 32.

Furthermore, in each of the above embodiments, a through hole may be formed in the second portion 35, and the mass of the second portion 35 may be reduced. According to this, even if, for example, the mass of the weight portion 34 b is made smaller than in the above-described embodiments, the mass difference between the first portion 34 and the second portion 35 similar to those in the above-described embodiments can be maintained. That is, even if the lengths L3 and L4 in the y-axis direction of the weight portion 34b are made shorter than in the above-described embodiments, it is possible to suppress a decrease in mass difference between the first portion 34 and the second portion 35. For this reason, it is possible to obtain the same effects as those of the above-described embodiments while achieving downsizing of the acceleration sensor in the planar direction.

Further, in each of the above embodiments, on the other surface 50b of the second substrate 50, a dummy pad portion and a dummy lead portion symmetrical to the first pad portion 111d and the first lead wiring layer 111e with the first through hole 111a as the center. A wiring layer may be formed. According to this, the stress generated in the first pad portion 111d and the first lead-out wiring layer 111e and the stress generated in the dummy pad portion and the dummy lead-out wiring layer are equalized. For this reason, distortion of the acceleration sensor due to the stress caused by the first wiring portion 111 f can also be suppressed.

And it is good also as an acceleration sensor which combined each above-mentioned embodiment suitably. For example, a combination of the fifth embodiment with the second to fourth embodiments, in the first support substrate 11 and the first insulating film 12, depressions that are line symmetrical with respect to the third virtual line V3 and the fourth virtual line V4. The portion 15 may be formed.

Claims (10)

The first movable electrode portion (36) and the first fixed electrode portion (71a) are disposed to face each other, and the second movable electrode portion (37) and the second fixed electrode portion (72a) are disposed to face each other. An acceleration sensor being arranged,
A first fixed portion (71) having the first fixed electrode portion;
A second fixed portion (72) having the second fixed electrode portion;
An electrode configuration portion in which the first movable electrode portion is configured in a portion facing the first fixed electrode portion and the second movable electrode portion is configured in a portion facing the second fixed electrode portion 32) connecting the electrode configuration portion and the anchor portion (21), arranging direction of the first fixed electrode portion and the first movable electrode portion, and the second fixed electrode portion and the second movable electrode portion A movable portion (20) having a torsion beam (33) for moving the electrode component by twisting when an acceleration is applied along the arrangement direction of
The said electrode structure part is plate shape which has a longitudinal direction, Comprising: Opening part (31) is formed in the inner edge side, The said torsion beam extended in the direction which intersects the said longitudinal direction in the opposing site | part in the said opening part A portion located on one side in the longitudinal direction with respect to a virtual line (V1) which is supported by the anchor portion by being provided, passes through the torsion beam, and extends along the extension direction of the torsion beam; Assuming that one portion (34), a portion located on the other side in the longitudinal direction with respect to the virtual line is a second portion (35), the first portion faces the first fixed electrode portion and the second portion Is disposed opposite to the second fixed electrode portion,
In the first portion, a length (L1) along the longitudinal direction between the virtual line and an end opposite to the virtual line side is the virtual line and the virtual line side in the second portion. And a main portion (34a) equal to the length (L2) along the longitudinal direction between the end and the opposite end, and the main portion is provided with the electrode configuration in the plane direction, An acceleration sensor, comprising: a weight portion (34b) protruding in a direction intersecting the longitudinal direction, wherein the mass is made heavier than the second portion. The acceleration sensor according to claim 1, wherein two weight parts are provided and protrude in opposite directions with respect to the main part. The acceleration sensor according to claim 2, wherein the two weight portions have the same length (L3, L4) in the projecting direction. The electrode configuration portion is a reinforcing portion that protrudes in the surface direction of the electrode configuration portion in a direction that intersects the longitudinal direction at a portion on the side opposite to the anchor portion with respect to the portion where the torsion beam is provided The acceleration sensor according to any one of claims 1 to 3, further comprising 38). The reinforcing portion protrudes along the protruding direction of the weight portion, and the length (L5, L6) in the protruding direction is equal to or less than the length (L3, L4) in the protruding direction of the weight portion The acceleration sensor according to claim 4. In the electrode configuration portion, a recess (31a) is formed in a portion of the first portion and the second portion located in a direction intersecting the longitudinal direction with respect to the anchor portion,
The acceleration sensor according to any one of claims 1 to 5, wherein the torsion beam is provided to connect the bottom surface of the recess and the anchor. The electrode configuration portion is a portion of the first portion and the second portion which is located in a direction intersecting the longitudinal direction with respect to the anchor portion, and is different from a portion in which the recess portion is formed. The acceleration sensor according to claim 6, wherein a distance (a1) in a direction intersecting the longitudinal direction between an end on the anchor portion side and an end opposite to the end in the portion is the narrowest. A first substrate (10),
A second substrate (laminated on the first substrate to hermetically seal the movable portion, the first fixed portion, and the second fixed portion) and having the other surface (50b) opposite to the first substrate 50),
The metal material is formed along the stacking direction of the first substrate and the second substrate from the other surface of the second substrate and is disposed on the wall surface of the through holes (111a to 115a) exposing a predetermined region Lead wiring layers (111c to 115c), pad portions (111d to 115d) formed on the other surface of the second substrate, and a lead wiring layer (111e) for connecting the pad portions and the through wiring layers A plurality of through electrode portions (111 to 115) having
When viewed from the other surface of the second substrate, the plurality of through electrode portions pass through a portion positioned on the outermost edge side of the movable portion, and extend along two virtual lines (K1 along the one surface direction) , K3) and the two-dimensional virtual line (K2, K4) orthogonal to the one direction, the acceleration according to any one of claims 1 to 7, arranged in a rectangular virtual area (A). Sensor. Three or more of the plurality of through electrode units are provided, and when viewed from the other surface of the second substrate, one through electrode unit is formed at a position including the center of the other surface of the second substrate. 9. The acceleration sensor according to claim 8, wherein the remaining through electrode parts are formed to be rotationally symmetrical with respect to the center. A first substrate (10) in which a support substrate (11), an insulating film (12), and a semiconductor layer (13) are sequentially stacked;
The movable portion is formed in the semiconductor layer,
The support substrate has a support area (11a) for supporting the anchor portion,
In the support substrate and the insulating film, a recessed portion (15) is formed in a region including a portion facing the movable portion,
The hollow portion passes through the support region and is line symmetrical with respect to an imaginary line (V3) extending in one direction in the surface direction of the first substrate and an imaginary line (V4) orthogonal to the imaginary line. 10. An acceleration sensor as claimed in any one of the preceding claims, which is shaped.

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