JPWO2011111540A1 - Physical quantity sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor capable of suppressing an electrical short circuit between a movable part (movable electrode) and a fixed electrode layer. A base member having an anchor part 29 and a movable part 34 supported by the anchor part via a spring part so as to be displaceable in the height direction, and the base part facing the base material in the height direction and fixing the anchor part. A facing portion 20 that supports and opposes the movable portion with a gap in the height direction, a fixed electrode layer 28 formed on the surface of the facing portion, a protrusion 23 whose surface is a stopper surface for the movable portion, and a facing portion The fixed support portion 22 provided on the surface of the metal plate and the joint portion 26 made of a metal layer that joins between the fixed support portion and the anchor portion are configured. The protruding portion 23 protrudes from the surface of the facing portion 20, and the fixed electrode layer 28 is disposed on the surface of the recessed facing portion, and the surface of the protruding portion 23 is higher in the height direction than the surface of the fixed electrode layer 28. It protrudes. [Selection] Figure 1

Description

  The present invention relates to a physical quantity sensor that detects a displacement amount of a movable part formed by cutting out from a silicon substrate, and thereby enables measurement of a physical quantity such as acceleration acting from the outside.

  For example, the physical quantity sensor disclosed in Patent Document 1 includes a movable portion that can be displaced in the height direction, and a fixed electrode layer that is disposed at an interval in the height direction with respect to the movable portion. The physical quantity is detected based on the capacitance change between the fixed electrode layer and the electrode layer.

  In the physical quantity sensor having such a configuration, as shown in the comparative example of the present invention shown in FIG. Part 4 is formed. FIG. 10 is a schematic diagram showing a longitudinal section in a state where the base material 9 having the movable portion 1 and the like constituting the physical quantity sensor and the facing portion 3 with respect to the base material 9 are vertically separated.

  As shown in FIG. 10, a protruding support portion 5 is provided on the surface 3 a of the facing portion 3. A first connection metal layer 6 is formed on the surface (upper surface) 5 a of the fixed support portion 5.

  On the other hand, the base material 9 with respect to the height direction with respect to the facing part 3 has an anchor part 7 and a movable part 1 connected to the anchor part 7 via a spring part 8. As shown in FIG. 10, the movable portion 1 is at a position facing the fixed electrode layer 2 and the protruding portion 4. As shown in FIG. 10, the second connection metal layer 10 is provided on the surface (lower surface) of the anchor portion 7. The first connection metal layer 6 and the second connection metal layer 10 are joined by being heated under pressure.

  As shown in FIG. 10, a gap A is formed between the movable portion 1 and the protruding portion 4. A gap B is formed between the movable part 1 and the fixed electrode layer 2. Note that the gaps A and B shown in FIG. 10 are shown in a state where the base material 9 and the facing portion 3 are separated from each other, but actually, the gap between the first connection metal layer 6 and the second connection metal layer 10 is shown. It is defined in the joined state.

JP 2005-283393 A JP 2008-197113 A JP-A-9-127151

  In the comparative example with respect to the present invention shown in FIG. 10, the height of the surface 2 a of the fixed electrode layer 2 is equal to or higher than the height of the surface 4 a of the protrusion 4. In such a case, the movable part 1 is displaced downward in FIG. 10, and comes into contact with the surface 4 a of the protrusion 4 serving as a stopper surface and also easily comes into contact with the surface 2 a of the fixed electrode layer 2. Therefore, there is a risk of an electrical short between the movable part 1 and the fixed electrode layer 2.

  In the comparative example shown in FIG. 10, the fixed electrode layer 2 is formed in the same process as the first connection metal layer 6 formed on the surface 5 a of the fixed support portion 5 of the facing portion 3. Therefore, the fixed electrode layer 2 and the first connection metal layer 6 are formed with the same film thickness. The first connection metal layer 6 is formed to a certain degree of thickness in order to ensure good bondability with the second connection metal layer 10. For this reason, the fixed electrode layer 2 is also formed with a thick film thickness. For example, the fixed electrode layer 2 is Al. When a thick Al layer is formed in this way, hillocks 11 are formed on the surface 2a of the fixed electrode layer 2 by heat treatment in the bonding process between the first connection metal layer 6 and the second connection metal layer 10, and the fixed electrode layer 2 The film thickness becomes thicker than the film formation stage. For this reason, electrical shorting between the movable part 1 and the fixed electrode layer 2 is more likely to occur.

  Therefore, the present invention solves the above-described conventional problems, and has an object to provide a physical quantity sensor that can suppress an electrical short circuit between a movable part (movable electrode) and a fixed electrode layer.

The physical quantity sensor in the present invention is
An anchor part, a base material having a movable part supported by the anchor part so as to be displaceable in a height direction via a spring part, and fixedly supporting the anchor part facing the base material in the height direction. A facing portion opposed to the movable portion at an interval in the height direction; a fixed electrode layer formed on a surface of the facing portion facing the movable portion; and a projection portion whose surface is a stopper surface for the movable portion; A fixed support portion provided on a surface of the facing portion facing the anchor portion, and a joint portion made of a metal layer that joins between the fixed support portion and the anchor portion,
The protruding portion protrudes from the surface of the facing portion, the fixed electrode layer is disposed on the surface of the facing portion that is recessed from the surface of the protruding portion, and the surface of the protruding portion is the fixed electrode layer It protrudes in the height direction from the surface of this.

  As a result, it is possible to appropriately suppress an electrical short between the movable portion and the fixed electrode layer when the movable portion comes into contact with the surface of the protruding portion serving as the stopper surface.

  In this invention, it is preferable that the surface of the said fixed support part in which the said junction part is formed protrudes in the height direction rather than the surface of the said fixed electrode layer.

  In the present invention, the joining portion is configured by joining a first connection metal layer formed on the surface of the fixed support portion and a second connection metal layer formed on the surface of the anchor portion, It is preferable that the film thickness of the fixed electrode layer is smaller than the film thickness of the first connection metal layer. Thereby, the production | generation of the hillock in the surface of a fixed electrode layer can be suppressed also by the heat processing in the joining process between a 1st connection metal layer and a 2nd connection metal layer. Therefore, it is possible to more effectively suppress an electrical short between the movable part and the fixed electrode layer.

  In the above configuration, it is preferable that the surface of the fixed support portion on which the first connection metal layer is formed be formed at the same height as the surface of the protrusion. Thereby, it can adjust appropriately so that the space | interval in the height direction between a fixed part and a movable part may remain the same, and the space | interval in the height direction between a projection part and a movable part may spread. Thereby, the amount of displacement of the movable part can be increased, and the anti-sticking property can be improved.

  In the present invention, it is preferable that the film thickness of the fixed electrode layer is smaller than the distance in the height direction from the surface of the protrusion to the surface of the fixed electrode layer. Thereby, even if the movable part comes into contact with the protrusion due to a strong physical quantity change or the like and further bends and deforms, an electrical short circuit between the movable part which is a movable electrode and the fixed electrode layer can be appropriately prevented.

  According to the configuration of the present invention, it is possible to appropriately suppress an electrical short between the movable portion and the fixed electrode layer when the movable portion (movable electrode) comes into contact with the surface of the protruding portion that is the stopper surface.

The schematic diagram which shows the longitudinal cross-section of the physical quantity sensor of 1st Embodiment in this invention, The schematic diagram which shows the longitudinal cross-section of the physical quantity sensor of 2nd Embodiment in this invention, A schematic diagram showing a longitudinal section of a physical quantity sensor of a third embodiment of the present invention, 1 is a longitudinal sectional view showing a more specific structure of a physical quantity sensor to which the embodiment shown in FIGS. 1 to 3 can be applied; 1 is a longitudinal sectional view showing a more specific structure of a physical quantity sensor to which the embodiment shown in FIGS. 1 to 3 can be applied; FIG. 6 is a perspective view showing a state where the physical quantity sensor of FIG. 5 is stationary. The perspective view which shows the state which the physical quantity sensor of FIG. 5 is operate | moving. The perspective view which shows the state which the physical quantity sensor of FIG. 5 is operate | moving. FIG. 6 is a partially enlarged longitudinal sectional view showing a state in which a leg portion and a movable portion provided in the physical quantity sensor of FIG. The schematic diagram which shows the longitudinal cross-section of the physical quantity sensor of the comparative example with respect to this invention.

  FIG. 1 is a schematic diagram showing a longitudinal section of the physical quantity sensor of the first embodiment of the present invention, FIG. 2 is a schematic diagram showing a longitudinal section of the physical quantity sensor of the second embodiment of the present invention, and FIG. It is a schematic diagram which shows the longitudinal cross-section of the physical quantity sensor of 3rd Embodiment. Each drawing separately shows the first base material 21 and the facing portion 20 located on the lower side of the first base material 21.

  In the embodiment shown in FIG. 1, a fixed support portion 22 and a protruding portion 23 are formed to protrude on the surface 20 a of the facing portion 20 (the surface facing the first base material 21; the upper surface) 20 a. The surface 23 a of the protrusion 23 forms a stopper surface for the movable portion 34. The surface 23 a indicates the surface that is at the highest position in the protrusion 22. As shown in FIG. 1, the highest surface 22 a of the fixed support portion 22 and the surface 23 a of the protruding portion 23 are formed at the same height. As shown in FIG. 1, the fixed support portion 22 is formed with a surface 22b that is one step lower than the surface 22a. This surface 22b and the one-step lower surface 23b provided on the protrusion 23 have the same height.

  As shown in FIG. 1, the first connection metal layer 24 is formed on the surface 22b of the fixed support portion 22 by an existing method such as sputtering. For example, the first connection metal layer 24 is formed of Al or an Al alloy (AlCu, AlSiCu, AlSi, AlScCu, etc.). Further, an underlying Ti layer, Ta layer, or the like may be formed on the lower surface of the first connection metal layer 24. A thin surface layer made of the same material (for example, Ge) as the second connection metal layer 25 described later may be formed on the surface of the first connection metal layer 24.

  The facing portion 20 shown in FIG. 1 has a configuration in which an insulating layer such as silicon oxide or silicon nitride is formed on the surface of a Si base material, for example. The surface 20a of the facing portion 20 is the surface of the insulating layer, and the surface of the insulating layer is formed into an uneven shape by etching.

  As shown in FIG. 1, a concave portion 27 is formed between the fixed support portion 22 and the protruding portion 23, and a fixed electrode layer 28 is formed on a surface 27 a of the concave portion 27. The fixed electrode layer 28 is formed by an existing method such as sputtering. As shown in FIG. 1, the surface 28 a of the fixed electrode layer 28 is formed at a position lower than the surface 23 a of the protrusion 23 and the surfaces 22 a and 22 b of the fixed support portion 22.

  As shown in FIG. 1, the first base material 21 positioned above the facing portion 20 is supported by an anchor portion 29 and the anchor portion 29 so as to be displaceable in the height direction (Z) via a spring portion 30. The movable portion 34 is configured.

  As shown in FIG. 1, a second connection metal layer 25 is formed on the surface of the anchor portion 29 (opposing surface facing the opposing portion 20; lower surface) 29 a. The second connection metal layer 25 is, for example, Ge.

  As shown in FIG. 1, the first connecting metal layer 24 formed on the facing portion 20 side and the second connecting metal layer 25 formed on the anchor portion 29 side are in contact with each other under pressure. Through the heat treatment, eutectic bonding is performed between the first connection metal layer 24 and the second connection metal layer 25. As a result, the anchor portion 29 and the fixed support portion 22 are fixedly bonded via the bonding portion 26 including the first connection metal layer 24 and the second connection metal layer 25.

  As shown in FIG. 1, a gap (gap) C is provided in the height direction (Z) between the fixed electrode layer 28 and the movable portion 34, and a height direction (Z) is provided between the protrusion 23 and the movable portion 34. An interval (gap) D is formed. In FIG. 1, the gaps C and D are illustrated in a state where the facing portion 20 and the first base material 21 are separated from each other. However, in practice, the gaps C and D are separated from the facing portion 20 and the first base 21. It is defined in a state where the material 21 is joined.

  In the embodiment shown in FIG. 1, the surface 28 a of the fixed electrode layer 28 is formed at a position lower than the surface 23 a of the protrusion 23. As a result, the movable portion 34 is displaced downward, and in a state where the movable portion 34 is in contact with the surface 23 a that is the stopper surface of the protrusion 23, the electric power between the movable portion 34 that is a movable electrode and the fixed electrode layer 28 is obtained. It is possible to appropriately suppress a short circuit.

  Further, as shown in FIG. 1, when the hillock 31 is generated on the surface 28a of the fixed electrode layer 28, the surface of the fixed electrode layer 28 is defined by the surface 31a of the hillock 31. At this time, the fixed electrode layer 28 and the movable part 34 The distance (gap) in the height direction between the two is E. As described above, even when the hillock 31 is formed, the surface 31 a of the hillock 31 that is the surface of the fixed electrode layer 28 is regulated to be lower than the surface 23 a of the protrusion 23. In the embodiment shown in FIG. 1, the fixed electrode layer 28 can be formed in a separate process from the first connection metal layer 24, or can be formed in the same process.

  On the other hand, in the embodiment shown in FIG. 2, the fixed electrode layer 32 is formed with a film thickness thinner than that of the first connection metal layer 24 formed on the surface 22 b of the fixed support portion 22 of the facing portion 20.

  In the embodiment shown in FIG. 2, the fixed electrode layer 32 is formed in a separate process from the first connection metal layer 24. At this time, the fixed electrode layer 32 can be formed of a material in which hillocks are not easily formed even by heat treatment in the bonding process between the first connection metal layer 24 and the second connection metal layer 25. Alternatively, even if the fixed electrode layer 32 is formed of the same Al or Al alloy as the first connection metal layer 24, the generation of hillocks can be appropriately suppressed by forming the fixed electrode layer 32 thin. is there. The fixed electrode layer 32 shown in FIG. 2 can be formed of Al, Al alloy (AlCu, AlSiCu, AlSi, AlScCu, etc.), Si, Cu, Au, Ru, Pt or the like. As an example, the fixed electrode layer 32 can be formed with a laminated structure of Ti layer (about 0.02 μm) / AlCu layer (about 0.3 μm). On the other hand, the first connection metal layer 24 can be formed, for example, with a stacked structure of Ta layer (about 0.02 μm) / AlCu layer (about 0.8 μm) / Ge layer (about 0.03 μm).

  In the embodiment shown in FIG. 2, the film thickness of the fixed electrode layer 32 is formed to be smaller than the distance in the height direction (gap F) between the surface 23 a of the protrusion 23 and the surface 32 a of the fixed electrode layer 32. . The fixed electrode layer 32 can be formed with a film thickness of 1 μm or less, preferably 0.5 μm or less. On the other hand, the gap F can be adjusted to about 1 μm to about 2 μm.

  As a result, after the movable part 34 comes into contact with the surface 23a of the protrusion 23, even if a stronger physical quantity change acts, the movable part 34 is bent downward and deformed as shown by the dotted line G in FIG. Contact between the movable portion 34 and the protrusion 23 can be suppressed, and an electrical short circuit can be prevented.

  In the embodiment shown in FIG. 3, the surface 32 a of the fixed electrode layer 32 is at a lower position than the surface 23 a of the protrusion 23, as in the embodiment shown in FIGS. 1 and 2. 3, the fixed electrode layer 32 is formed thinner than the first connection metal layer 24 as in FIG. 2.

  In FIG. 3, unlike FIGS. 1 and 2, the first connection metal layer 24 is formed on the surface 22 a of the fixed support portion 22 at the same height as the surface 23 a of the protrusion 23. In the embodiment shown in FIG. 3, the digging amount of the concave portion 27 between the fixed support portion 22 and the projection portion 23 is set so that the gap C between the fixed electrode layer 32 and the movable portion 34 is the same as in FIGS. It was adjusted. In FIG. 3, the fixed electrode layer 32 is formed thinner than the first connecting metal layer 24 and the first support metal layer 22 has the same height as the surface 23a of the protrusion 23. By providing the connection metal layer 24, the gap C between the fixed electrode layer 32 and the movable portion 34 remains the same, and the height interval (gap) H between the protrusion 23 and the movable portion 34 is as shown in FIG. It is easy to adjust so that it may spread rather than embodiment shown in FIG.

  In FIG. 1, the fixed electrode layer 28 is formed with a film thickness comparable to that of the first connection metal layer 24. In such a case, the fixed electrode layer 28 can be formed in the same process as the connection metal layer 24, but the fixed electrode layer 28 contains Al. Therefore, hillocks 31 are easily formed on the surface 28a of the fixed electrode layer 28 as in the comparative example described in FIG. Therefore, if the concave portion 27 is not formed deeper than necessary in anticipation of the maximum amount of hillock 31 to be generated, the surface 31a of the hillock 31 that becomes the surface of the fixed electrode layer 28 may not be lower than the surface 23a of the protrusion 23. There is sex. On the other hand, by forming the fixed electrode layer 28 in the deep recess 27, the gap C between the movable portion 34 and the fixed electrode layer 28 is easily widened. Further, the variation in the gap C tends to increase due to the variation in the amount of hillock 31 generated. Therefore, in FIG. 1, the spread of the gap C is suppressed as much as possible by forming the surface 22 b that is one step lower on the surface of the fixed support portion 22 and forming the joint portion 26 with the anchor portion 29 thereon. When the gap C widens, it leads to a decrease in sensor sensitivity.

  On the other hand, in the embodiment in which the fixed electrode layer 32 is formed thinner than the first connection metal layer 24 as shown in FIG. 3, no hillock is generated on the surface of the fixed electrode layer 32 as shown in FIG. Alternatively, the amount of hillocks generated can be greatly reduced. Therefore, even if hillocks are generated in the form of FIG. 3, the concave portion 27 can be effectively shallowly formed so that the surface 32 a of the fixed electrode layer 32 is positioned lower than the surface 23 a of the protruding portion 23. Further, since the amount of hillocks generated is very small, the fluctuation of the gap C is small and it is easy to adjust to a predetermined value. For this reason, in FIG. 3, even if the junction part 26 is formed in the highest surface 22a of the fixed support part 22, the gap C can be appropriately adjusted to a small value. The surface 22 a of the fixed support portion 22 is the same height as the surface 23 a of the protruding portion 23. As described above, the joint position between the anchor portion 29 and the fixed support portion 22 moves upward as compared with FIGS. 1 and 2, so that the gap H between the movable portion 34 and the protruding portion 23 can be widened.

  As described above, since the gap H between the movable portion 34 and the protrusion 23 is widened, the amount of displacement of the movable portion 34 in the height direction can be increased. Therefore, when the movable part 34 returns to the original state from the state in contact with the protrusion 23, the restoring force with the same spring constant can be increased, and the sticking resistance can be improved more effectively.

  In the embodiment shown in FIG. 3, the film thickness of the fixed electrode layer 32 is smaller than the gap F between the surface 23 a of the protrusion 23 and the surface 32 a of the fixed electrode layer 32.

  1 and 2, the gap D can be widened by cutting the protrusion 23 to reduce the height. In such a case, the surface 28 a of the fixed electrode layer 28 and the surface 23 a of the protrusion 23 are formed. The gap may approach the height direction and the gap F (see FIG. 2) may not be sufficiently secured. Therefore, as shown in FIG. 3, it is preferable that the surface 22 a of the fixed support portion 22 where the joint portion 26 is formed and the surface 23 a of the projection portion 23 are defined to be the same height.

  In the embodiment shown in FIG. 3, a protrusion 33 having a height lower than that of the protrusion 23 is formed on the surface of the facing portion 20. In the following description of FIG. 3, the protrusion 23 is the first protrusion 23 and the protrusion 33 is the second protrusion 33.

  When the movable portion 34 is displaced downward, the movable portion 34 first comes into contact with the surface 23a of the first protrusion 23 having the highest height in response to a change in physical quantity of a predetermined amount or more. When the movable part 34 is bent downward and deformed as described with reference to FIG. 2 due to a stronger physical quantity change, the movable part 34 comes into contact with the surface 33a of the second protrusion 33 having a low height. Therefore, in the form of FIG. 3 in which the plurality of protrusions 23 and 33 that are different in height and can come into contact with the movable part 34 are formed, the surfaces 23a and 33a of the protrusions 23 and 33 are more than the surface of the fixed electrode layer. It is necessary to be in a high position.

The embodiment shown in FIGS. 1 to 3 is applied to the physical quantity sensor shown in FIG. 4, for example.
As shown in FIG. 4, the physical quantity sensor includes a facing portion 40 and a first base material 41. As shown in FIG. 4, an insulating base layer 43 made of silicon oxide or the like is formed on the surface 42 a of the second substrate 42 made of silicon or the like that constitutes the facing portion 40. As shown in FIG. 4, an internal wiring layer 44 is formed on the surface 43 a of the silicon oxide layer 43.

  As shown in FIG. 4, an insulating layer 45 is formed from the internal wiring layer 44 to the insulating base layer 43. Through holes 46 and 47 are formed in the insulating layer 45 at positions facing the internal wiring layer 44.

  As shown in FIG. 4, protruding fixed support portions 50 and 51 are formed on the surface of the insulating layer 45 at positions facing the anchor portion 48 and the frame body portion 49 constituting the first base material 41.

  Further, as shown in FIG. 4, a protrusion 52 is formed on the surface of the insulating layer 45. The protruding portion 52 is formed at a position facing the movable portion 53 in the height direction, and the surface 52 a constitutes a stopper surface for the movable portion 53.

  As shown in FIG. 4, the first base material 41 provided above the facing portion 40 includes an anchor portion 48, a movable portion 53 connected to the anchor portion 48 via a spring portion 63, and a frame body portion 49. It is comprised. The frame body part 49 has a frame shape surrounding the periphery of the movable part 53.

  As shown in FIG. 4, the anchor portion 48 and the fixed support portion 50 are joined by a joining portion 56 including a first connection metal layer 54 and a second connection metal layer 55. Similarly, the frame body portion 49 and the fixed support portion 51 are also joined by a joint portion 57 including the first connection metal layer 54 and the second connection metal layer 55.

  As shown in FIG. 4, the upper surface of the first base material 41 is fixedly supported by the support base material 59 via an oxide insulating layer (ceremonial layer) 58. An SOI (Silicon on Insulator) substrate can be configured by the first base material 41, the oxide insulating layer 58, and the support base material 59. The support base 59 is made of silicon.

  As shown in FIG. 4, the fixed electrode layer 61 is formed in the recessed portion 60 that is recessed from the fixed support portion 51 and the protruding portion 52 formed on the surface of the insulating layer 45. The fixed electrode layer 61 is electrically connected to the internal wiring layer 44 through a through hole 46 formed in the insulating layer 45 inside the frame body portion 49. On the outside of the frame portion 49, the electrode pad 62 is electrically connected to the internal wiring layer 44 through a through hole 47 formed in the insulating layer 45.

  Also in the embodiment shown in FIG. 4, the surface 61 a of the fixed electrode layer 61 is formed at a position lower than the surface 52 a of the protrusion 52 and the surfaces 50 a and 51 a of the fixed support portions 50 and 51. In the embodiment of FIG. 4, the fixed electrode layer 61 is formed to be thinner than the first connection metal layer 54, and the surface 50 a of the fixed support portion 50 on which the first connection metal layer 54 is formed. 51a and the surface 52a of the projection part 52 are the same height. Further, the film thickness of the fixed electrode layer 61 is smaller than an interval (gap) H in the height direction from the surface 52 a of the protrusion 52 to the surface 61 a of the fixed electrode layer 61.

Alternatively, the embodiment shown in FIGS. 1 to 3 is applied to the physical quantity sensor shown in FIG.
In the physical quantity sensor shown in FIG. 5, the outer frame portion surrounded by the rectangular long sides 70 a and 70 b and the short sides 70 c and 70 d is the movable portion 71.

  As shown in FIG. 5, two support coupling bodies 72 and 73 are provided inside the movable portion 71. The planar shape of the support coupling bodies 72 and 73 is formed in a crank shape.

  As shown in FIG. 5, the 1st support coupling body 72 is integrally formed with the 1st connection arm 72a extended in the front (X1), and the leg part 72b extended in back (X2). As shown in FIG. 5, the second support connection body 73 is formed integrally with a first connection arm 73 a extending rearward (X2) and a leg portion 73 b extending forward (X1).

  As shown in FIG. 5, the first anchor portion 74, the second anchor portion 75, and the third anchor portion 76 are arranged in parallel inside the movable portion 71 with an interval in the Y1-Y2 direction. .

  As shown in FIG. 5, the first connection arm 72 a of the first support connection body 72 and the movable portion 71 are rotatably connected at the spring portion 80 a, and the first connection arm 73 a of the second support connection body 73. And the movable portion 71 are rotatably connected at the spring portion 80b.

  Furthermore, the 1st support coupling body 72 is connected with the spring parts 81a and 81b so that rotation is possible. Moreover, as shown in FIG. 5, the 2nd support connection body 73 is connected with the spring parts 82a and 82b so that rotation is possible.

  Further, as shown in FIG. 5, a second connecting arm 83 and a second connecting arm 84 are provided. The second connecting arms 83 and 84 are formed inside the movable portion 71.

  As shown in FIG. 5, the 2nd connection arm 83 and the movable part 71 are rotatably connected in the spring part 85a. Moreover, the 2nd connection arm 84 and the movable part 71 are rotatably connected in the spring part 85b. Further, as shown in FIG. 5, the second connecting arm 83 and the anchor portion 75 are rotatably connected by a spring portion 87a. Moreover, the 2nd connection arm 84 and the anchor part 76 are rotatably connected in the spring part 87b.

  Further, as shown in FIG. 5, the first connecting arm 72a and the second connecting arm 83 are connected via a spring portion 88a. Moreover, as shown in FIG. 5, between the 1st connection arm 73a and the 2nd connection arm 84 is connected via the spring part 88b.

  In the physical quantity sensor shown in FIG. 5, the movable portion 71 is displaced in the height direction (Z) as shown in FIGS. 6 to 8 due to a change in physical quantity acting in the height direction. At this time, the leg portions 72b and 73b are displaced in the height direction (Z) in the direction opposite to the displacement direction of the movable portion 71.

  Therefore, as shown in FIG. 9 (a), on the surface of the facing portion 90, there are projections 91 that abut against the legs 72b and 73b, and projections 92 that abut against the movable portion 71 as shown in FIG. 9 (b). Both can be provided. The surface 91a of the protrusion 91 is a stopper surface for the legs 72b and 73b, and the surface 92a of the protrusion 92 is a stopper surface for the movable portion 71. As shown in FIG. 9, the surface of the facing portion 90 has a concave portion 94 formed in a portion other than a fixed support portion (not shown) provided at a position facing the protruding portions 91 and 92 and the anchor portions 74 to 76. A fixed electrode layer 93 is formed. The surface 93a of the fixed electrode layer 93 is formed at a position lower than the surface 92a of the protruding portion 92 with which the movable portion 71 can come into contact.

  If the embodiment shown in FIG. 3 is applied to the physical quantity sensor shown in FIG. 5, the gap H can be easily set wider than the embodiment shown in FIGS. 1 and 2, and accordingly, the movable portion 71 and the legs 72b and 73b can be set. The amount of displacement in the height direction can be increased. For this reason, even if the spring constant is the same, it is possible to increase the restoring force when returning from the state of FIG. 9 to the original stationary state, and to effectively improve the sticking resistance. It has been found that the restoring force can be increased to about 1.5 to 2 times by adopting the form of FIG. 3 as compared with the form of FIG.

  The present embodiment can be applied to all physical quantity sensors such as an acceleration sensor, an angular velocity sensor, and an impact sensor.

20, 40 Opposing portions 21, 41 First base member 22, 50, 51 Fixed support portions 22a, 22b, 50a, 51a Surfaces 23, 33, 52 of fixed support portions Projected portions 23a, 33a, 52a Surface 24 of projected portions , 54 First connection metal layer 25, 55 Second connection metal layer 26, 56, 57 Joint 27 Recess 28, 32, 61 Fixed electrode layer 28 a, 32 a Fixed electrode layer surface 29, 48 Anchor part 30 Spring part 31 Hillock 31a Hillock surface 34, 53, 71 Movable part 44 Internal wiring layer 45 Insulating layer 36, 47 Through hole 49 Frame part

Claims (5)

An anchor part, a base material having a movable part supported by the anchor part so as to be displaceable in a height direction via a spring part, and fixedly supporting the anchor part facing the base material in the height direction. A facing portion opposed to the movable portion at an interval in the height direction; a fixed electrode layer formed on a surface of the facing portion facing the movable portion; and a projection portion whose surface is a stopper surface for the movable portion; A fixed support portion provided on a surface of the facing portion facing the anchor portion, and a joint portion made of a metal layer that joins between the fixed support portion and the anchor portion,
The protruding portion protrudes from the surface of the facing portion, the fixed electrode layer is disposed on the surface of the facing portion that is recessed from the surface of the protruding portion, and the surface of the protruding portion is the fixed electrode layer A physical quantity sensor that protrudes in a height direction from the surface of the sensor.   The physical quantity sensor according to claim 1, wherein a surface of the fixed support portion on which the joint portion is formed protrudes in a height direction from a surface of the fixed electrode layer.   The joint portion is configured by joining a first connection metal layer formed on the surface of the fixed support portion and a second connection metal layer formed on the surface of the anchor portion, and the fixed electrode layer The physical quantity sensor according to claim 1, wherein the film thickness is formed smaller than the film thickness of the first connection metal layer.   The physical quantity sensor according to claim 3, wherein the surface of the fixed support portion on which the first connection metal layer is formed is formed at the same height position as the surface of the protrusion.   5. The physical quantity sensor according to claim 1, wherein a film thickness of the fixed electrode layer is smaller than an interval in a height direction from a surface of the protruding portion to a surface of the fixed electrode layer.

Images