JP2019020169A - Acceleration sensor - Google Patents

Abstract

To suppress a reduction in detection accuracy.SOLUTION: In an electrode composing unit 32 in a movable unit 20, when it is assumed that a portion passing through a torsion beam 33 and located closer to one side in the longitudinal direction than a virtual line V1 extending along the extension direction of the torsion beam 33 is a first portion 34 and a portion located closer to the other side in the longitudinal direction than the virtual line V1 is a second portion 35, the first portion 34 is constituted to have a main part 34a whose length L1 along the longitudinal direction between the virtual line V1 and an end opposite the virtual line V1 is made equal to a length L2 along the longitudinal direction between the virtual line V1 and an end opposite the virtual line V1 in the second portion 35 and a weight part 34b provided in the main part 34a and protruding in a direction that is the surface direction of the electrode composing unit 32 and crosses the longitudinal direction.SELECTED DRAWING: Figure 4

Description

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

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

  Specifically, in such an acceleration sensor, the electrode component portion has an opening formed on the inner edge side, and is supported by the anchor portion via a torsion beam. Then, the electrode component is configured such that one first part divided by the virtual line and the other second part are divided with respect to the virtual line passing through the torsion beam so that the torsion beam can be rotated about the 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 portion on the imaginary line side and the end portion opposite to the end portion are different from each other.

  In the first and second fixed electrodes, 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. As a result, the first movable electrode is configured in the portion of the electrode configuration portion that faces the first fixed electrode, and the second movable electrode is configured in the portion of the electrode configuration portion that faces the second fixed electrode. The

  In such an acceleration sensor, when an 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 around the rotation axis. As shown in FIG. 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, acceleration is detected based on these changes in capacitance.

  The first fixed electrode and the second fixed electrode have the same planar shape so that an equal capacitance is formed between the first movable electrode and the second movable electrode when no acceleration is applied. It is said that.

JP, 2014-16175, A

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

  For this reason, when an electrode structure part is distorted, it will be distorted on the basis of the part connected with a torsion beam, but the way of distortion will differ in the 1st part and the 2nd part. That is, the method of changing 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 are different. Therefore, the detection accuracy may be reduced.

  An object of this invention is to provide the acceleration sensor which can suppress that detection accuracy falls in view of the said point.

  In order to achieve the above object, the first movable electrode portion (36) and the first fixed electrode portion (71a) are arranged to face each other, and the second movable electrode portion (37) and the first fixed electrode portion (71a) are arranged to face each other. In the acceleration sensor arranged to face the two fixed electrode portions (72a), the first fixed portion (71) having the first fixed electrode portion and the second fixed portion (72) having the second fixed electrode portion. And the first movable electrode portion is configured at a portion facing the first fixed electrode portion, and the second movable electrode portion is configured at a portion facing the second fixed electrode portion (32). And the electrode constituent part and the anchor part (21) are connected, along the arrangement direction of the first fixed electrode part and the first movable electrode part and the arrangement direction of the second fixed electrode part and the second movable electrode part A torsion beam (33) that moves the electrode component by twisting when acceleration is applied The electrode component is in the form of a plate having a longitudinal direction, and an opening (31) is formed on the inner edge side, and intersects with the longitudinal direction at a facing portion in the opening. A torsion beam extending in the direction to be supported is supported by the anchor portion and passes through the torsion beam and extends along the extending direction of the torsion beam on one side in the longitudinal direction. If the part located in the first part (34) and the part located on the other side in the longitudinal direction from the imaginary line are the second part (35), the first part is opposed to the first fixed electrode part and the second part The part is arranged to face the second fixed electrode part, and the first part has a length (L1) along the longitudinal direction between the imaginary line and the end opposite to the imaginary line side, Between the imaginary line and the end opposite to the imaginary line A main portion (34a) equal to the length (L2) along the longitudinal direction, and a weight portion provided in the main portion and projecting in a direction perpendicular to the longitudinal direction of the electrode constituent portion (surface direction) 34b) and is heavier than the second part.

  According to this, the electrode configuration part includes a length along the longitudinal direction between the virtual line in the first part and the end opposite to the virtual line side, and the virtual line in the second part and the virtual line side. And the length in the longitudinal direction between the opposite end and the opposite end. For this reason, it can suppress that the way of distortion of the 1st part and the 2nd part varies, and it can control that detection accuracy falls.

  In addition, the code | symbol in the bracket | parenthesis in the said and the claim shows the correspondence of the term described in the claim, and the concrete thing etc. which illustrate the said term described in embodiment mentioned later. .

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

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

(First embodiment)
A first embodiment will be described with reference to FIGS. The acceleration sensor of the present embodiment is configured such that a first substrate 10 and a second substrate 50 are stacked and a sensing unit 80 that outputs a detection signal corresponding to the acceleration is accommodated therein.

  1 corresponds to a cross section taken along line I-I in FIGS. 4 to 6, and FIG. 2 corresponds to a cross section taken along line II-II in FIGS. 4 to 6. Corresponds to a cross section taken along line III-III in FIGS. In the following, one direction in the surface direction of the first substrate 10 and the second substrate 50 is defined as the x-axis direction, which is one direction in the surface direction of the first substrate 10 and the second substrate 50 and is orthogonal to the x-axis direction. The direction will be described as the y-axis direction. In addition, the direction orthogonal to the x-axis direction and the y-axis direction is described as the z-axis direction. In each figure, 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 (ie, silicon on insulator) structure in which the first semiconductor layer 13 is disposed on the first support substrate 11 via the first insulating film 12. Yes. The first substrate 10 is configured such that one 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 made of a silicon substrate, and the first insulating film 12 is made of an oxide film, a nitride film, or the like.

  As shown in FIGS. 1 to 4, the first semiconductor layer 13 is subjected to micromachining to form a groove portion 14, and the movable portion 20 and the peripheral region 40 are partitioned by the groove portion 14. Note that FIG. 4 is a plan view of the first 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 indicated by dotted lines.

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

  As shown in FIGS. 1 and 4, the movable portion 20 is responsive to acceleration along the stacking direction of the anchor portion 21 and the first substrate 10 and the 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 first surface 10 a of the first substrate 10. Further, the anchor portion 21 is formed to have a substantially square shape when viewed from the normal direction to the one 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 portion 21, and a plate-like electrode constituent portion 32 whose longitudinal direction is the x-axis direction, the electrode constituent portion 32, and the anchor portion 21 And a torsion beam 33 to be connected.

  The torsion beam 33 is a member that serves as a rotation axis that is the rotation center of the electrode component 32 (that is, the movable region 22) when 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 imaginary line V <b> 1 along the extending direction of the torsion beam 33 intersects the center of the anchor portion 21.

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

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

  Moreover, the 1st site | part 34 has the weight part 34b integrated with the main part 34a with the main part 34a. Specifically, the weight part 34b is provided in the main part 34a so as to protrude in the y-axis direction, which is the surface direction of the electrode component part 32. That is, the weight portion 34b is provided in the main portion 34a so as to form the same plane as the main portion 34a. In the present embodiment, two weight portions 34b are provided, and the main portion 34a is provided so as to protrude in opposite directions with the main portion 34a interposed therebetween.

  Here, the end portion of the first portion 34 opposite to the first virtual line V1 side is one end portion of the first portion 34, and the end portion of the second portion 35 opposite to the first virtual line V1 side is the second portion. One end of 35. In this case, in the present embodiment, the first part 34 and the second part 35 have a length L1 from the first virtual line V1 to one end of the first part 34 (hereinafter, also simply referred to as a length L1), It can be said that the length L2 from the first imaginary line V1 to one end of the second portion 35 (hereinafter, also simply referred to as length L2) is made equal. Here, “equal” includes a slight manufacturing error in addition to the case where the length L1 and the length L2 are completely equal.

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

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

  Although not particularly shown, the electrode component 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 14. For this reason, the main part 34a and the weight part 34b in the 1st site | part 34 of the electrode structure part 32 are formed so that the same plane may be comprised. Further, since the weight part 34b is formed integrally with the torsion beam 33 and the like, the manufacturing process is not particularly increased by providing the weight part 34b.

  As shown in FIGS. 1 to 3, the second substrate 50 includes a cap substrate 60. 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 via the second insulating film 62. The one surface 50 a of the second substrate 50 is configured by 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 composed of a silicon substrate, and the second insulating film 62 is composed of an oxide film, a nitride film, or the like.

  As shown in FIGS. 1 to 3 and 5, the second semiconductor layer 63 of the second substrate 50 is subjected to micromachining to form a groove 64. 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 partitioned by the groove portion 64.

  Specifically, the first fixing portion 71 is formed in a portion of the electrode configuration portion 32 that faces the first portion 34, and forms a predetermined capacitance with the first portion 34. It has a fixed electrode portion 71a and a first fixed wiring portion 71b drawn from the first fixed electrode portion 71a. Further, the second fixed portion 72 is formed in a portion of the electrode configuration portion 32 that faces the second portion 35, and forms a predetermined capacitance between the second fixed portion 72 and the second portion 35. 72a and a second fixed wiring portion 72b drawn from the second fixed electrode portion 72a.

  The first and second fixed electrode portions 71a and 72a have the same planar shape so that the same capacitance is formed between the first and second portions 34 and 35 when no acceleration is applied. It is said that. More specifically, the first and second fixed electrode portions 71a and 72a are symmetrical with respect to the first virtual line V1 and the second virtual line V2 when viewed from the normal direction to the one surface 10a of the first substrate 10. It is formed to become. In the electrode configuration portion 32, as shown in FIG. 4, the portion of the first portion 34 that faces the first fixed electrode portion 71 a becomes the first movable electrode portion 36, and the second portion 35 has the first portion. The portion facing the two fixed electrode portions 72 a becomes 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 way. When acceleration is applied in the stacking direction, the electrode component 32 rotates about the torsion beam 33 as a rotation axis, and therefore, 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 arranged so as to face the electrode configuration portion 32 (that is, the first movable electrode portion 36 and the second movable electrode portion 37). That is, the acceleration is applied in the stacking direction in the present embodiment, 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. The acceleration along the direction of arrangement with the portion 72a is applied.

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

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

  Moreover, the 2nd board | substrate 50 has the other surface insulating film 90 formed in the opposite side to the 1st board | substrate 10 side in the cap board | substrate 60 as FIG. 1-3 shows. 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 on the side opposite to the cap substrate 60.

  The second substrate 50 thus configured is bonded to the first substrate 10 via the bonding member 100 so that the one surface 50a faces the one surface 10a of the first substrate 10. More specifically, the second substrate 50 is bonded to the first substrate 10 so that the sensing unit 80 is hermetically sealed. In the present embodiment, the joining member 100 is made of an oxide film or the like.

  Further, in the present embodiment, first to fifth through electrode portions 111 to 115 having first to fifth wiring portions 111f to 115f for connecting an external circuit and a predetermined region are formed. First, the structure of the 1st-5th penetration electrode parts 111-115 is demonstrated with reference to FIGS. 1-3 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 that is a metal material.

  As shown in FIGS. 1 and 6, the first through electrode portion 111 penetrates the second substrate 50 in the stacking direction, and is formed 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. The first through electrode portion 111 has a first through wiring layer 111 c that is formed on the first wall surface insulating film 111 b and is electrically connected to the anchor portion 21, that is, the movable portion 20. Further, the first through electrode portion 111 electrically connects the first pad portion 111d formed on the other surface insulating film 90 and connected to an external circuit, the first pad portion 111d, and the first through wiring layer 111c. The first lead wiring layer 111e is connected. For this reason, the first wiring part 111f in the first through electrode part 111 is configured to include a first through wiring layer 111c, a first pad part 111d, and a first lead wiring layer 111e.

  As shown in FIGS. 2 and 6, the second through electrode portion 112 penetrates the other surface insulating film 90, the second support substrate 61, and the second insulating film 62 in the stacking direction, and the second through electrode portion 112 in the second semiconductor layer 63. It has the 2nd wall surface insulating film 112b formed in the wall surface of the 2nd through-hole 112a which exposes 1 fixed wiring part 71b. The second through electrode portion 112 has a second through wiring layer 112c formed on the second wall insulating film 112b and electrically connected to the first fixed wiring portion 71b. Further, the second through electrode portion 112 is formed on the other surface insulating film 90 and electrically connects the second pad portion 112d connected to the external circuit, the second pad portion 112d, and the second through wiring layer 112c. And a second lead wiring layer 112e to be connected. Therefore, the second wiring portion 112f in the second through electrode portion 112 is configured to include a second through wiring layer 112c, a second pad portion 112d, and a second lead wiring layer 112e.

  The third through electrode portion 113 has the same configuration as the second through electrode portion 112. That is, it is formed on the wall surface of the third through hole 113a that 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. The third wall surface insulating film 113b is formed. In addition, the third through electrode portion 113 includes a third through wiring layer 113c that is formed on the third wall insulating film 113b and is electrically connected to the second fixed wiring portion 72b. Further, the third through electrode portion 113 is electrically connected to the third pad portion 113d formed on the other surface insulating film 90 and connected to the external circuit, the third pad portion 113d, and the third through wiring layer 113c. And a third lead wiring layer 113e to be connected. For this reason, the third wiring part 113f in the third through electrode part 113 is configured to include a third through wiring layer 113c, a third pad part 113d, and a third lead wiring layer 113e.

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

  The fifth through electrode portion 115 penetrates the other surface insulating film 90, the second support substrate 61, and the second insulating film 62 in the stacking direction, and has a fifth through hole 115 a that exposes the peripheral region 73 in the second semiconductor layer 63. It has the 5th wall surface insulating film 115b formed in the wall surface. The fifth through-electrode portion 115 has a fifth through-wiring layer 115 c that is formed on the fifth wall surface insulating film 115 b and is 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 wiring layer 115e to be connected. Therefore, the fifth wiring portion 115f in the fifth through electrode portion 115 is configured to include a fifth through wiring layer 115c, a fifth pad portion 115d, and a 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. That is, the first to fifth through wiring layers 111c to 115c are formed in a state where the first to fifth through holes 111a to 115a are not embedded.

  In the present embodiment, the first through fifth through holes 111a to 115a have the same opening shape and size. Specifically, each of the first to fifth through holes 111a to 115a has a circular opening and has the same diameter.

  The above is the configuration of the first to fifth through electrode portions 111 to 115 in the present embodiment. And each pad part 111d-115d is each connected with an external circuit, The movable part 20, the 1st fixing | fixed part 71, the 2nd fixing | fixed part 72, the peripheral region 40 in the 1st semiconductor layer 13, and the 2nd semiconductor layer 63 Peripheral regions 73 are respectively 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. Thereby, it is suppressed that the parasitic capacitance formed between the sensing unit 80 and the peripheral regions 40 and 73 is changed, and a reduction in detection accuracy is suppressed.

  Next, the arrangement | positioning location of the 1st-5th penetration electrode parts 111-115 in this embodiment is demonstrated.

  First, as shown in FIG. 6, when viewed from the normal direction to the other surface 50 b of the second substrate 50, the first and second portions extending in the y-axis direction pass through a portion located on the outermost edge side of the movable portion 20. A rectangular virtual region surrounded by the three-part virtual lines K1, K3 and the second and fourth sub-particulate virtual lines K2, K4 extending in the x-axis direction is defined as a virtual region A.

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

  The first to fifth through electrode portions 111 to 115 are formed so as to be located in the virtual region A when viewed from the normal direction with respect to the other surface 50 b of the second substrate 50. The fact that the first to fifth through electrode portions 111 to 115 are arranged in the virtual region A means that the first to fifth pad portions 111d to 111d constituting the first to fifth through electrode portions 111 to 115 are used. 115d and the like are also arranged in the virtual area A.

  More specifically, in the present embodiment, the anchor portion 21 is formed at the center of the one surface 10a of the first substrate 10 as described above. For this reason, 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 symmetric with respect to the center of the second surface 50 b of the second substrate 50 in the virtual region A. That is, the second to fifth wiring portions 112f to 115f are formed so as to be rotationally symmetric with respect to the center of the second 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 shapes. Has been pulled from.

  The above is the arrangement | positioning location of the 1st-5th penetration electrode parts 111-115 in this embodiment. As shown in FIGS. 1 to 3, a protective film 120 covering the first to fifth through electrode portions 111 to 115 is formed on the other surface 50 b of the second substrate 50. Although not specifically shown, the protective film 120 has openings for exposing the first to fifth pad portions 111d to 115d so that an external circuit can be electrically connected to the 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, whereby the length L1 and the length L2 are made equal. The first portion 34 and the second portion 35 have different masses. For this reason, it can suppress that the distortion of the 1st site | part 34 and the 2nd site | part 35 varies, and it can suppress that detection accuracy 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, compared with the case where the mass of the 1st site | part 34 and the 2nd site | part 35 is varied by arrange | positioning another weight part on the main part 34a which comprises the 1st site | part 34, it is a simple structure. Thus, the mass of the first part 34 and the second part 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 a mask such as dry etching performed on the first semiconductor layer 13, and the manufacturing process is complicated. It does not become.

  Furthermore, in the present embodiment, the first to fifth through electrode portions 111 to 115 are disposed in the virtual region A when viewed from the normal direction to the other surface 50 b of the second substrate 50. For this reason, the area | region which becomes wide by providing the weight part 34b can be utilized effectively, 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 portion 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 symmetric with respect to the center of the second surface 50 b of the second substrate 50 in the virtual region A. For this reason, the stress caused by the second to fifth through wiring layers 112c to 115c is easily equalized. Therefore, in this embodiment, it is possible to further suppress the acceleration sensor from being easily distorted and the detection accuracy from being lowered.

  Further, 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 communicate with each other. That is, the first to fifth through wiring layers 111c to 115c are formed in a state where the first to fifth through holes 111a to 115a are not embedded. For this reason, compared with the case where the 1st-5th through-holes 111a-115a are embedded by the 1st-5th through-wiring layer 111c-115c, it is the 1st-5th through-wiring in the part which is not embedded. The stress caused by the layers 111c to 115c can be relaxed. Therefore, the magnitude of the stress itself that distorts the acceleration sensor can be reduced.

  The first to fifth through holes 111a to 115a have the same opening diameter. For this reason, compared with the case where the diameter of the 1st-5th through-holes 111a-115a differs, it can suppress that the magnitude | size of the stress relieve | moderated especially when not burying each through-hole 111a-115a. Therefore, it is possible to further suppress distortion of the acceleration sensor.

(Second Embodiment)
A second embodiment will be described. In the present embodiment, a reinforcing portion is added to the electrode configuration portion 32 with respect to the first embodiment, and the other portions are the same as those in the first embodiment, and thus the description thereof is omitted here.

  In the present embodiment, as shown in FIG. 7, the electrode constituting portion 32 is provided with a reinforcing portion 38 at each portion opposite to the anchor portion 21 side with respect to the portion connected to the torsion beam 33. Yes. In the present embodiment, the reinforcing portions 38 are provided so as to protrude along the y-axis direction.

  Specifically, each reinforcing portion 38 is provided so as to be symmetrical with respect to the first imaginary 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. Yes. The reinforcing portions 38 are provided such that the lengths L5 and L6 in the y-axis direction are equal to each other. That is, each reinforcement part 38 is provided so that it may become line symmetrical with respect to the 2nd virtual line V2. Furthermore, each reinforcement part 38 is made into length below the length L3 of the y-axis direction of the weight part 34b, and L4. That is, the reinforcing portion 38 is provided so as to be located in the virtual area A.

  In the case of such a configuration, although not particularly illustrated, when viewed from the other surface 50b of the second substrate 50, the second and fourth through holes 112a and 114a are located between the weight portion 34b and the reinforcing portion 38. It can be said that it is formed. The third through hole 113a is formed symmetrically 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 constituting portion 32 is provided with the reinforcing portion 38. For this reason, it can suppress that the electrode structure part 32 bends. That is, the electrode component 32 moves when the torsion beam 33 is twisted, but a large stress is generated at the connecting 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 the electrode constituting portion 32 can be prevented from being bent.

(Third embodiment)
A third embodiment will be described. In the present embodiment, the length of the torsion beam 33 is changed with respect to the second embodiment, and the other aspects are the same as those in the second embodiment, and thus the description thereof is omitted here.

  In the present embodiment, as shown in FIG. 8, the electrode component 32 has a recess 31 a formed in a portion connected to the torsion beam 33. Specifically, in the electrode component 32, a recess 31 a is formed in a portion of the wall surface constituting the opening 31 that is connected to the torsion beam 33. And the torsion beam 33 is arrange | positioned so that the bottom face of the hollow part 31a and the anchor part 21 may be connected. That is, the torsion beam 33 of the present embodiment is longer than the torsion beam 33 of the second embodiment.

  Moreover, the electrode structure part 32 is a part located in the y-axis direction with respect to the anchor part 21 in the first part 34 and the second part 35, and is an anchor in a part different from the part where the recessed part 31a is formed. The interval a1 along the y-axis direction between the end on the part 21 side and the end opposite to the end is the narrowest. That is, in the electrode component 32, the interval a1 is such that the interval a2 between the side surface of the opposing recessed portion 31a and the side surface of the reinforcing portion 38, the interval a3 between the bottom surface of the recessed portion 31a and the distal end portion in the protruding direction of the reinforcing portion 38 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 31a. For this reason, the freedom degree of the spring constant of the torsion beam 33 can be improved. That is, the degree of design freedom can be improved.

  Moreover, it forms so that the space | interval a1 may become the shortest. For this reason, the design of the portion that exhibits the necessary function as the movable portion 20 can be used as it is, and it is not necessary to redesign the movable portion 20 by forming the recessed portion 31a. Therefore, the degree of freedom in design can be improved.

(Fourth embodiment)
A fourth embodiment will be described. In this embodiment, the arrangement location of the weight part 34b is changed with respect to the third embodiment, and the other parts are the same as those in the third embodiment, and thus 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 portion side of the first portion 34, and is disposed integrally with the reinforcing portion 38. Thus, even if the weight part 34b is integrated with the reinforcement part 38, the effect similar to the said 3rd Embodiment can be acquired.

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

(Fifth embodiment)
A fifth embodiment will be described. This embodiment is different from the first embodiment in the shape of the recess 15 formed in the first support substrate 11 and the first insulating film 12, and is otherwise the same as the first embodiment. Therefore, the description is omitted here.

  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 extends along the y-axis direction with respect to the third virtual line V3. It is formed in line symmetry. Further, the recess 15 is formed symmetrically with respect to the fourth imaginary line V4 that passes through the center of the support region 11a and extends along the x-axis direction. In other words, the first support substrate 11 is symmetrical with respect to the third virtual line V3 and the fourth virtual line V4 by forming the dummy recess 15a in addition to the portion facing the movable part 20. A recess 15 is formed.

  In the present embodiment, the dummy hollow portion 15a is formed at a position that is line-symmetric with respect to the portion of the movable portion 20 that faces the weight portion 34b of the support substrate 11 with respect to the third virtual line V3. Although not particularly shown, 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 that 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 so as to be symmetric with respect to the third virtual line V3 and the fourth virtual line V4. For this reason, the distortion of the first support substrate 11 and the first insulating film 12 is symmetric with respect to the third virtual line V3 and the fourth virtual line V4. For this reason, 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. This can be suppressed and further reduction in detection accuracy can be suppressed.

(Other embodiments)
The present invention is not limited to the embodiment described above, and can be appropriately changed within the scope described in the claims.

  For example, in each said embodiment, you may change the arrangement place of the 1st-5th penetration electrode part 111-115. For example, a part or all of the first to fifth through electrode portions 111 to 115 may be arranged outside the virtual region 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 to be rotationally symmetric outside the virtual region A. . Even with such a configuration, it is possible to suppress a decrease in detection accuracy by configuring the movable unit 20 to have the same configuration as that of each of the above embodiments.

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

  Furthermore, the second to fifth through electrode portions 112 to 115 are formed rotationally symmetric with respect to the center of the other surface 50b of the second substrate 50 when viewed from the normal direction to the other surface 50b of the second substrate 50. However, it may be formed as follows. For example, when viewed from the normal direction to the other surface 50b of the second substrate 50, the second and fourth through electrode portions 112 and 114 and the third and fifth through electrode portions 113 and 115 with respect to the first virtual line V1. And the second and third through electrode portions 112 and 113 and the fourth and fifth through electrode portions 114 and 115 are line symmetric with respect to the second virtual line K2. Good. Further, the second to fifth through electrodes 112 to 115 may be formed so as to be symmetric with respect to only one virtual line with respect to 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 in this way, each of the through electrode portions 112 is compared with the case where the second to fifth through electrode portions 112 to 115 are irregularly formed. Stress due to ˜115 is easily equalized.

  Moreover, in each said embodiment, the 1st-5th penetration electrode parts 111-115 may not be rotationally symmetrical or line symmetrical, and may be arrange | positioned irregularly. Even in such an acceleration sensor, when the movable unit 20 has the same configuration as that of each of the embodiments described above, it is possible to suppress a decrease in detection accuracy.

  Furthermore, in each said embodiment, the 4th, 5th penetration electrode part 114,115 does not need to be provided.

  Moreover, in each said embodiment, you may make it provide the penetration electrode part which has a wiring part electrically connected with the 1st support substrate 11, for example. According to this, since the 1st support substrate 11 is also maintained at predetermined potential, it can suppress that detection accuracy falls further.

  Then, for example, a contact hole that exposes the second support substrate 61 is formed in the vicinity of the fourth through hole 114a or the fifth through hole 115a in the other surface insulating film 90, and the fourth lead wiring portion 114e or the fifth The lead wiring part 115e may be embedded in the contact hole. According to this, since the 2nd support substrate 61 is also maintained at predetermined potential, it can suppress that detection accuracy falls further.

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

  Furthermore, in each said embodiment, the two weight parts 34b are not provided, but only one may be sufficient. The two weight portions 34b may have different lengths L3 and L4 along the y-axis direction. And in the said 2nd-4th embodiment, the reinforcement part 38 may be only one, and length L5 and L6 along a y-axis direction may mutually differ. Further, the reinforcement portion 38 may have lengths L5 and L6 longer than the lengths L3 and L4 of the weight portion 34b.

  In the first to third and fifth embodiments, the weight portion 34b is not one end portion of the first portion 34, for example, at an intermediate position between the one end portion of the first portion 34 and the first virtual line V1. It may be provided. That is, the location where the weight portion 34b 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, you may make it enlarge the length of the torsion beam 33 by forming the hollow part 31a in the anchor part 21 side. Even 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 that is directly connected to the first through wiring layer 111c. 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 decreases. there is a possibility. That is, an electrical connection failure may occur. For this reason, it is preferable that the recess 31a is formed on the electrode component 32 side.

  Furthermore, in each said embodiment, a through-hole may be formed in the 2nd site | part 35, and you may make it make the mass of the 2nd site | part 35 small. According to this, for example, even if the mass of the weight portion 34b is made smaller than in the above embodiments, the same mass difference between the first portion 34 and the second portion 35 as in the above 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 embodiments, it is possible to suppress the mass difference between the first part 34 and the second part 35 from being reduced. For this reason, the effect similar to each said embodiment can be acquired, aiming at size reduction in the plane direction of an acceleration sensor.

  Further, in each of the above-described embodiments, the dummy pad portion and the dummy lead that are symmetrical with the first pad portion 111d and the first lead wiring layer 111e around the first through hole 111a on the other surface 50b of the second substrate 50. A wiring layer may be formed. According to this, the stress generated in the first pad portion 111d and the first lead wiring layer 111e and the stress generated in the dummy pad portion and the dummy lead wiring layer are equalized. For this reason, it can also suppress that an acceleration sensor is distorted by the stress resulting from the 1st wiring part 111f.

  And it is good also as an acceleration sensor which combined each said embodiment suitably. For example, the fifth embodiment is combined with the second to fourth embodiments, and the first support substrate 11 and the first insulating film 12 are dents that are symmetrical with respect to the third virtual line V3 and the fourth virtual line V4. The part 15 may be formed.

DESCRIPTION OF SYMBOLS 20 Movable part 21 Anchor part 31 Opening part 32 Electrode structure part 33 Torsion beam 34 1st site | part 34a Main part 34b Weight part 35 2nd site | part 36 1st movable electrode 37 2nd movable electrode 71 1st fixed part 71a 1st fixed electrode 72 2nd fixed part 72a 2nd fixed electrode V1 1st virtual line

Claims (10)

The first movable electrode part (36) and the first fixed electrode part (71a) are arranged opposite to each other, and the second movable electrode part (37) and the second fixed electrode part (72a) are opposed to each other. In the arranged acceleration sensor,
A first fixed portion (71) having the first fixed electrode portion;
A second fixed portion (72) having the second fixed electrode portion;
The first movable electrode portion is configured at a portion facing the first fixed electrode portion, and the second movable electrode portion is configured at a portion facing the second fixed electrode portion (32 ), The electrode constituent portion and the anchor portion (21), and the arrangement 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 torsion beam (33) for moving the electrode component by twisting when an acceleration along the arrangement direction is applied, and a movable part (20).
The electrode component is a plate having a longitudinal direction, and an opening (31) is formed on the inner edge side, and the torsion beam is extended in a direction intersecting the longitudinal direction at a facing portion in the opening. Is provided at the anchor portion, and a portion located on one side in the longitudinal direction from the imaginary line (V1) passing through the torsion beam and extending along the extending direction of the torsion beam is provided. Assuming that one part (34), a part located on the other side in the longitudinal direction from the imaginary line is a second part (35), the first part faces the first fixed electrode part and the second part Is disposed opposite to the second fixed electrode portion,
The first part has a length (L1) along the longitudinal direction between the imaginary line and an end opposite to the imaginary line side, and the imaginary line and the imaginary line side in the second part A main portion (34a) equal to a length (L2) along the longitudinal direction between the end portion on the opposite side and the end portion, and provided in the main portion, in the surface direction of the electrode constituent portion, An acceleration sensor having a weight portion (34b) protruding in a direction crossing the longitudinal direction and having a mass heavier than that of 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 equal lengths (L3, L4) in the protruding direction.   The electrode constituent part is a reinforcing part that protrudes in a surface direction of the electrode constituent part in a direction crossing the longitudinal direction at a part opposite to the anchor part with respect to a part provided with the torsion beam. 38) The acceleration sensor according to any one of claims 1 to 3.   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 shorter than the length (L3, L4) in the protruding direction of the weight portion. The acceleration sensor according to claim 4. The electrode component is formed with a depression (31a) in a portion located in a direction intersecting the longitudinal direction with respect to the anchor portion of the first portion and the second portion,
The acceleration sensor according to any one of claims 1 to 5, wherein the torsion beam is provided so as to connect a bottom surface of the hollow portion and the anchor portion.   The electrode constituent portion is a portion located in a direction intersecting the longitudinal direction with respect to the anchor portion of the first portion and the second portion, and is different from a portion where the hollow portion is formed. The acceleration sensor according to claim 6, wherein an interval (a1) in a direction intersecting the longitudinal direction between the end portion on the anchor portion side in the portion and the end portion on the opposite side to the end portion is the narrowest. A first substrate (10);
A second substrate (50b) that is laminated on the first substrate and hermetically seals the movable portion, the first fixed portion, and the second fixed portion, and has the other surface (50b) opposite to the first substrate. 50),
It is formed from the other surface of the second substrate along the stacking direction of the first substrate and the second substrate, and is made of a metal material disposed on the wall surface of the through hole (111a to 115a) exposing a predetermined region. Through wiring layers (111c to 115c), pad portions (111d to 115d) formed on the other surface of the second substrate, and lead wiring layers (111e) 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 located on the outermost edge side of the movable portion, and extend along two imaginary lines (K1) extending along one direction of the surface direction. , K3) and the acceleration according to any one of claims 1 to 7 arranged in a rectangular virtual region (A) surrounded by two virtual lines (K2, K4) orthogonal to the one direction. Sensor.   The plurality of through electrode portions are provided with three or more, and when viewed from the other surface of the second substrate, one through electrode portion is formed at a position including the center on the other surface of the second substrate. The acceleration sensor according to claim 8, wherein the remaining through electrode portions are formed so as to be rotationally symmetric with respect to the center. The first substrate is configured by laminating a support substrate (11), an insulating film (12), and a semiconductor layer (13) in this order,
The movable part is formed in the semiconductor layer,
The support substrate has a support region (11a) for supporting the anchor portion;
In the support substrate and the insulating film, a depression (15) is formed in a region including a portion facing the movable portion,
The hollow portion is line-symmetric with respect to a virtual line (V3) extending in one direction in the surface direction of the first substrate and a virtual line (V4) orthogonal to the virtual line through the support region. The acceleration sensor according to any one of claims 1 to 9, wherein the acceleration sensor has a shape.

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