JP2013068450A - Physical quantity sensor element, physical quantity sensor and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor element realizing at least one of high sensitivity, manufacturing efficiency improvement, cost-reduction and high reliability, a physical quantity sensor equipped with the physical quantity sensor element, and an electronic apparatus equipped with the physical quantity sensor element.SOLUTION: A physical quantity sensor element 1 includes: an insulation substrate 2; a movable part 33 provided on an upper side of the insulation substrate 2; movable electrode fingers 361-365, 371-375 provided for the movable part 33; and fixed electrode fingers 381-388, 391-398 provided on the insulation substrate 2 and arranged countering the movable electrode fingers 361-365, 371-375, respectively. The insulation substrate 2 includes: recess portions 22, 23, 24 having wiring 41, 42, 43; protruding portions 471, 472, 481, 482, 50 formed on an element piece 3 at locations overlapping the wiring 41, 42, 43 in planer view. The wiring 41, 42, 43 and the protruding portions 471, 472, 481, 482, 50 are coupled.

Description

  The present invention relates to a physical quantity sensor element, a physical quantity sensor including a physical quantity sensor element, and an electronic device including the physical quantity sensor element.

Conventionally, as a physical quantity sensor element, there is a fixed electrode that is fixedly arranged, and a movable electrode that is opposed to the fixed electrode with a space therebetween and that can be displaced, and is disposed between the fixed electrode and the movable electrode. An element that detects physical quantities such as acceleration and angular velocity based on capacitance is known.
For example, the physical quantity sensor element described in Patent Document 1 uses a single-layer semiconductor substrate or an SOI (Silicon On Insulator) substrate, and a plurality of electrode fingers arranged in a comb-tooth shape with a fixed electrode and a movable electrode, respectively. And are arranged to mesh with each other.

  In addition, in the physical quantity sensor element described in Patent Literature 1, two electrode fingers of the fixed electrode are provided between two adjacent electrode fingers of the movable electrode, and the two electrode fingers of the fixed electrode are provided. Are electrically isolated from each other. Thereby, the electrostatic capacitance between one electrode finger of the two electrode fingers of the fixed electrode and the electrode finger of the movable electrode opposed thereto, and the other electrode finger of the two electrode fingers of the fixed electrode opposed to the electrode finger The electrostatic capacitance between the movable electrode and the electrode finger can be measured separately, and the physical quantity can be detected based on the measurement results (using a so-called differential detection method).

Japanese Patent No. 4238437

  However, in the physical quantity sensor element described in Patent Document 1, it is necessary to insulate and separate the electrode fingers individually so that each of the fixed electrode and the movable electrode does not conduct, and the manufacturing efficiency is poor. In the above-described differential detection method, the sensitivity increases when the thickness of the fixed electrode and the movable electrode is large (the aspect ratio is high). However, in the case of Patent Document 1, it is necessary to perform the first etching in the thickness direction of the substrate and then perform the second etching in the lateral direction, and in order to increase the thickness of the fixed electrode and the movable electrode, It was necessary to increase the thickness, and it was difficult to increase the thickness of the electrode from the viewpoint of manufacturing efficiency. In addition, the SOI substrate is generally expensive, and there is a problem that the product cost increases.

An object of the present invention is to provide a physical quantity sensor element that achieves at least one of high sensitivity, improvement in manufacturing efficiency, low cost, and high reliability, a physical quantity sensor including the physical quantity sensor element, and a physical quantity sensor element. It is to provide an electronic device provided.
Such an object is achieved by the following application examples.

  [Application Example 1] A physical quantity sensor element according to this application example includes an insulating substrate, a movable portion provided above the insulating substrate, a movable electrode finger provided on the movable portion, and the insulating substrate. And a fixed electrode finger disposed opposite to the movable electrode finger, wherein the insulating substrate is provided with a recess, and a wiring is provided in the recess and the fixed The electrode finger is disposed across the concave portion, and a convex portion is provided at a position overlapping the wiring in a plan view, and the wiring and the convex portion are connected.

According to the physical quantity sensor element having such a configuration, since the fixed electrode finger is formed on the insulating substrate, it is not necessary to embed an insulating film in each of the movable electrode finger and the fixed electrode finger to perform insulation separation. The efficiency is very good. Further, it is not necessary to use an expensive SOI substrate, so that the product cost can be suppressed.
In addition, the physical quantity sensor element has a very high manufacturing efficiency because the movable part, the movable electrode finger, and the fixed electrode finger can be formed collectively from a substrate separate from the insulating substrate. Furthermore, since the physical quantity sensor element can form each of the movable electrode finger and the fixed electrode finger only by etching in the thickness direction of the substrate, the electrode finger can be easily made thicker than in Patent Document 1. For example, when a physical quantity sensor element is used as a physical quantity sensor, high sensitivity can be achieved.
The physical quantity sensor element is fixed to the insulating substrate by fitting the concave portion provided on the insulating substrate and the convex portion provided on the fixed electrode finger when the insulating substrate and the fixed electrode finger are brought into contact with each other. Since the alignment accuracy between the electrode fingers is improved, the reliability of electrical connection can be improved.
If the fixed electrode finger is not provided with a convex portion, the wiring provided in the concave portion of the insulating substrate needs to be connected to the movable portion by increasing the thickness.However, in the physical quantity sensor element, the convex portion is provided on the fixed electrode finger. By providing the wiring, the wiring can be thinned and the product cost can be reduced.

  Application Example 2 In the physical quantity sensor element according to the application example described above, it is preferable that the convex portion includes a portion having an electric resistance smaller than that of the fixed electrode finger.

  As a result, even when the electric resistance of the material constituting the fixed electrode finger is large, the resistance value of the convex portion connected to the wiring is reduced, so that the contact resistance is reduced, and a physical quantity sensor element excellent in reliability is provided. be able to.

  [Application Example 3] In the physical quantity sensor element according to the application example, the fixed electrode finger is made of a semiconductor material, and at least a part of the convex portion is doped with a material different from the semiconductor material, Is preferred.

  As a result, even when the fixed electrode finger is made of a semiconductor material, the electrical resistance can be reduced by doping different types of materials, and the contact resistance is greatly reduced, thereby providing a physical quantity sensor element with excellent reliability. can do.

  Application Example 4 In the physical quantity sensor element according to the application example described above, it is preferable that at least a part of the convex portion is made of metal.

  Thereby, the contact resistance is significantly reduced by the metal material having a small electric resistance, and a physical quantity sensor element having excellent reliability can be provided.

  Application Example 5 In the physical quantity sensor element according to the application example described above, it is preferable that the metal of the convex portion and the wiring are made of the same material.

  Thereby, it is not necessary to use a plurality of materials in the manufacturing process, and a physical quantity sensor element having excellent manufacturing efficiency can be provided.

  Application Example 6 In the physical quantity sensor element according to the application example described above, at least a part of the convex portion is gold, platinum, silver, copper, aluminum, tin, titanium, germanium, silicon, zinc, indium, or at least one of these. It is preferably composed of a compound having one as a main component.

  Thereby, since a material which can be obtained relatively easily can be used, a physical quantity sensor element can be manufactured at low cost.

  Application Example 7 A physical quantity sensor according to this application example includes the physical quantity sensor element according to any one of the application examples described above and an integrated circuit.

  Thereby, a physical quantity sensor having the above-described effects can be realized.

  Application Example 8 An electronic apparatus according to this application example includes the physical quantity sensor element according to any one of the application examples described above.

  Thereby, the electronic device provided with the above-mentioned effect is realizable.

It is a perspective view which shows the physical quantity sensor element which concerns on 1st Embodiment of this invention. It is a top view which shows the physical quantity sensor element shown in FIG. It is sectional drawing in the AA in FIG. FIG. 4 is a partially enlarged cross-sectional view of FIG. 3. It is sectional drawing in the BB line in FIG. FIG. 6 is a partially enlarged cross-sectional view of FIG. 5. It is a flowchart which shows the manufacturing method of a physical quantity sensor element. It is sectional drawing for demonstrating the manufacturing method of a physical quantity sensor element. It is sectional drawing for demonstrating the manufacturing method of a physical quantity sensor element. It is sectional drawing for demonstrating the manufacturing process (The process of forming a wiring, a contact, and an insulating film) of a physical quantity sensor element. It is a top view which shows the physical quantity sensor element which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows an example of the physical quantity sensor of this invention. It is a perspective view which shows the electronic device (notebook-type personal computer) of this invention. It is a perspective view which shows the electronic device (cellular phone) of this invention. It is a perspective view which shows the electronic device (digital still camera) of this invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Preferred embodiments of a physical quantity sensor element, a physical quantity sensor, and an electronic apparatus according to the invention will be described below with reference to the accompanying drawings.
<First Embodiment>

  1 is a perspective view showing a physical quantity sensor element according to the first embodiment of the present invention, FIG. 2 is a plan view showing the physical quantity sensor element shown in FIG. 1, and FIG. 3 is taken along the line AA in FIG. 4 is a partially enlarged sectional view of FIG. 3, FIG. 5 is a sectional view taken along line BB in FIG. 2, and FIG. 6 is a partially enlarged sectional view of FIG. In the following, for convenience of explanation, the front side of the paper in FIG. 2 is referred to as “up”, the back side of the paper is referred to as “down”, the right side is referred to as “right”, and the left side is referred to as “left”. 1 to 3 and 5, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other. In the following, the direction parallel to the X axis (left-right direction) is the “X-axis direction”, the direction parallel to the Y-axis is “Y-axis direction”, and the direction parallel to the Z-axis (vertical direction) is “Z-axis direction”. " Also, in FIGS. 1 to 3, 5, 8, and 9, for convenience of explanation, illustration of an insulating film 6 (FIG. 4) described later and a corresponding film (insulating films 106, 106 </ b> A (FIGS. 10B and 10C)) In this embodiment, an example in which a physical quantity sensor element is used as an element for measuring a physical quantity such as acceleration and angular velocity will be described.

(Physical quantity sensor element)
A physical quantity sensor element 1 shown in FIG. 1 covers an insulating substrate 2, an element piece 3 bonded and supported to the insulating substrate 2, a conductor pattern 4 electrically connected to the element piece 3, and the element piece 3. The lid member 5 is provided.

Hereinafter, each part which comprises the physical quantity sensor element 1 is demonstrated in detail sequentially.
(Insulated substrate)
The insulating substrate 2 has a function of supporting the element piece 3.
The insulating substrate 2 has a plate shape, and a cavity 21 is provided on the upper surface (one surface). The cavity 21 is formed so as to include a movable portion 33, movable electrode portions 36 and 37, and connecting portions 34 and 35 of an element piece 3 to be described later when the insulating substrate 2 is viewed in plan view. Have Such a cavity 21 constitutes an escape portion that prevents the movable portion 33, the movable electrode portions 36 and 37, and the coupling portions 34 and 35 of the element piece 3 from contacting the insulating substrate 2. Thereby, the displacement of the movable part 33 of the element piece 3 can be permitted.
The escape portion may be an opening that penetrates the insulating substrate 2 in the thickness direction instead of the cavity portion 21 (concave portion). In the present embodiment, the shape of the cavity 21 in plan view is a quadrangle (specifically, a rectangle), but is not limited thereto.

  On the upper surface of the insulating substrate 2, recesses 22, 23, and 24 are provided along the outer periphery of the cavity portion 21 described above. The recesses 22, 23 and 24 have a shape corresponding to the conductor pattern 4 in plan view. Specifically, the recess 22 has a shape corresponding to a wiring 41 and an electrode 44 of a conductor pattern 4 described later, and the recess 23 has a shape corresponding to a wiring 42 and an electrode 45 of a conductor pattern 4 described later. 24 has a shape corresponding to the wiring 43 and the electrode 46 of the conductor pattern 4 to be described later.

  The depth of the portion of the recess 22 where the electrode 44 is provided is deeper than the portion of the recess 22 where the wiring 41 is provided. Similarly, the depth of the portion of the recess 23 where the electrode 45 is provided is deeper than the portion of the recess 23 where the wiring 42 is provided. The depth of the portion of the recess 24 where the electrode 46 is provided is deeper than the portion of the recess 24 where the wiring 43 is provided.

In this way, by increasing the depth of some of the recesses 22, 23, and 24, when the physical quantity sensor element 1 described later is manufactured, the substrate 103A before the element piece 3 is formed is bonded to the substrate 102A ( 8E), the substrate 103A can be prevented from being bonded to the electrodes 44, 45, and 46.
Specifically, it is preferable to use a high-resistance silicon material or glass material as the constituent material of such an insulating substrate 2. In particular, when the element piece 3 is composed of a silicon material as a main material, an alkali is used. It is preferable to use a glass material containing metal ions (movable ions) (for example, silicon acid glass such as Pyrex (registered trademark) glass). Thereby, when the element piece 3 is composed of silicon as a main material, the insulating substrate 2 and the element piece 3 can be anodically bonded.

  Further, it is preferable that the constituent material of the insulating substrate 2 has as little difference in thermal expansion coefficient as that of the constituent material of the element piece 3. Specifically, the thermal expansion between the constituent material of the insulating substrate 2 and the constituent material of the element piece 3 is preferable. The coefficient difference is preferably 3 ppm / ° C. or less. As a result, even if the insulating substrate 2 and the element piece 3 are exposed to a high temperature during bonding, the residual stress between the insulating substrate 2 and the element piece 3 can be reduced.

(Element piece)
The element piece 3 includes fixed portions 31 and 32, a movable portion 33, connecting portions 34 and 35, movable electrode portions 36 and 37, and fixed electrode portions 38 and 39.
Such an element piece 3 has an X-axis direction (+ X) while the movable portion 33 and the movable electrode portions 36 and 37 elastically deform the connecting portions 34 and 35 according to changes in physical quantities such as acceleration and angular velocity. Direction or -X direction). With such displacement, the size of the gap between the movable electrode portion 36 and the fixed electrode portion 38 and the size of the gap between the movable electrode portion 37 and the fixed electrode portion 39 change. That is, with such a displacement, the capacitance between the movable electrode portion 36 and the fixed electrode portion 38 and the capacitance between the movable electrode portion 37 and the fixed electrode portion 39 are respectively reduced. Change. Therefore, physical quantities such as acceleration and angular velocity can be detected based on these capacitances.

The fixed portions 31 and 32, the movable portion 33, the connecting portions 34 and 35, and the movable electrode portions 36 and 37 are integrally formed.
The fixing portions 31 and 32 are respectively joined to the upper surface of the insulating substrate 2 described above. Specifically, the fixing portion 31 is bonded to a portion on the −X direction side (left side in the drawing) with respect to the cavity portion 21 on the upper surface of the insulating substrate 2, and the fixing portion 32 is formed on the upper surface of the insulating substrate 2. It is joined to the portion on the + X direction side (right side in the figure) with respect to the cavity portion 21. Further, the fixing portions 31 and 32 are provided so as to straddle the outer peripheral edge of the cavity portion 21 when viewed in plan.

  The positions and shapes of the fixing portions 31 and 32 are determined according to the positions and shapes of the connecting portions 34 and 35, the conductor pattern 4, etc., and are not limited to those described above. A movable portion 33 is provided between the two fixed portions 31 and 32. In the present embodiment, the movable part 33 has a longitudinal shape extending in the X-axis direction. The shape of the movable portion 33 is determined according to the shape, size, etc. of each portion constituting the element piece 3 and is not limited to the above-described one.

Such a movable portion 33 is connected to the fixed portion 31 via the connecting portion 34 and is connected to the fixed portion 32 via the connecting portion 35. More specifically, the left end portion of the movable portion 33 is connected to the fixed portion 31 via the connecting portion 34, and the right end portion of the movable portion 33 is connected to the fixed portion 32 via the connecting portion 35. Has been.
The connecting portions 34 and 35 connect the movable portion 33 to the fixed portions 31 and 32 so as to be displaceable. In the present embodiment, the connecting portions 34 and 35 are configured to be able to displace the movable portion 33 in the X-axis direction (+ X direction or −X direction) as indicated by an arrow a in FIG.

  Specifically, the connecting portion 34 includes two beams 341 and 342. Each of the beams 341 and 342 has a shape extending in the X-axis direction while meandering in the Y-axis direction. In other words, each of the beams 341 and 342 has a shape that is folded back a plurality of times (three times in the present embodiment) in the Y-axis direction. Note that the number of times the beams 341 and 342 are folded may be one or two times, or four or more times.

Similarly, the connecting portion 35 is composed of two beams 351 and 352 having a shape extending in the X-axis direction while meandering in the Y-axis direction.
The connecting portions 34 and 35 are not limited to those described above as long as they support the movable portion 33 so as to be displaceable with respect to the insulating substrate 2. For example, the connecting portions 34 and 35 are not limited to those described above from both ends of the movable portion 33. You may be comprised with a pair of beam each extended in a Y direction.

Thus, the movable electrode portion 36 is provided on one side (+ Y direction side) in the width direction of the movable portion 33 supported so as to be displaceable in the X-axis direction with respect to the insulating substrate 2, and the other side (−Y On the direction side, a movable electrode portion 37 is provided.
The movable electrode portion 36 includes a plurality of movable electrode fingers 361, 362, 363, 364, 365 that protrude in the + Y direction from the movable portion 33 and are arranged in a comb-teeth shape. These movable electrode fingers 361 to 365 are arranged in this order from the −X direction side to the + X direction side. Similarly, the movable electrode portion 37 includes a plurality of movable electrode fingers 371, 372, 373, 374, and 375 that protrude in the −Y direction from the movable portion 33 and are arranged in a comb shape. These movable electrode fingers 371 to 375 are arranged in this order from the −X direction side to the + X direction side.

Thus, the plurality of movable electrode fingers 361 to 365 and the plurality of movable electrode fingers 371 to 375 are provided side by side in the direction in which the movable portion 33 is displaced (that is, the X-axis direction). Thereby, the electrostatic capacitance between the fixed electrode fingers 382, 384, 386, and 388, which will be described later, and the movable electrode portion 36, and the electrostatic capacitance between the fixed electrode fingers 381, 383, 385, 387 and the movable electrode portion 36 are described. Can be efficiently changed according to the displacement of the movable portion 33. Similarly, the capacitance between the fixed electrode fingers 392, 394, 396, and 398 and the movable electrode portion 37, which will be described later, and the capacitance between the fixed electrode fingers 391, 393, 395, and 397 and the movable electrode portion 37 are as follows. It can be efficiently changed according to the displacement of the movable portion 33. Therefore, the physical quantity sensor element 1 can be excellent in detection accuracy.
Such a movable electrode part 36 is opposed to the fixed electrode part 38 with an interval. Further, the movable electrode portion 37 faces the fixed electrode portion 39 with a space therebetween.

  The fixed electrode unit 38 includes a plurality of fixed electrode fingers 381 to 388 arranged in a comb-like shape that meshes with the plurality of movable electrode fingers 361 to 365 of the movable electrode unit 36 described above at intervals. The end portions of the plurality of fixed electrode fingers 381 to 388 on the side opposite to the movable portion 33 are joined to the + Y direction side portion with respect to the cavity portion 21 on the upper surface of the insulating substrate 2. At this time, the upper surfaces of the fixed electrode fingers 381 to 388 and the insulating substrate 2 are bonded, and the convex portions 471 and 481 formed on the surface side of the fixed electrode fingers 381 to 388 bonded to the insulating substrate 2 are respectively These are electrically connected to wirings 41 and 42 of a conductor pattern 4 to be described later. The fixed electrode fingers 381 to 388 each have a fixed end as a fixed end and a free end extending in the −Y direction.

  The fixed electrode fingers 381 to 388 are arranged in this order from the −X direction side to the + X direction side. The fixed electrode fingers 381 and 382 make a pair, and the fixed electrode fingers 383 and 384 make a pair between the movable electrode finger 361 and the movable electrode finger 362 described above, and the movable electrode finger 362 and the movable electrode finger 363 have a pair. Between the fixed electrode fingers 385 and 386, the movable electrode finger 363 and the movable electrode finger 364 are paired, and between the fixed electrode fingers 387 and 388, the movable electrode finger 364 and the movable electrode finger 365 are paired. It is provided to face between.

  Here, the fixed electrode fingers 382, 384, 386, and 388 are first fixed electrode fingers, respectively, and the fixed electrode fingers 381, 383, 385, and 387 are the first fixed electrode fingers on the insulating substrate 2, respectively. The second fixed electrode fingers are spaced apart from each other via a gap (gap). As described above, the plurality of fixed electrode fingers 381 to 388 are composed of a plurality of first fixed electrode fingers and a plurality of second fixed electrode fingers arranged alternately. In other words, the first fixed electrode finger is disposed on one side of the movable electrode fingers 362, 363, 364, and the second fixed electrode finger is disposed on the other side. Further, the first fixed electrode finger or the second fixed electrode finger is arranged on either side of the movable electrode fingers 361 and 365.

  The fixed electrode fingers 382, 384, 386, and 388, which are the first fixed electrode fingers, and the fixed electrode fingers 381, 383, 385, and 387, which are the second fixed electrode fingers, are separated from each other on the insulating substrate 2. Yes. In other words, the fixed electrode fingers 382, 384, 386, 388 and the fixed electrode fingers 381, 383, 385, 387 are not connected to each other on the insulating substrate 2 and are isolated in an island shape. Thereby, the fixed electrode fingers 382, 384, 386, 388 and the fixed electrode fingers 381, 383, 385, 387 can be electrically insulated. Therefore, the electrostatic capacitance between the fixed electrode fingers 382, 384, 386, 388 and the movable electrode portion 36, and the electrostatic capacitance between the fixed electrode fingers 381, 383, 385, 387 and the movable electrode portion 36 are increased. It is possible to measure separately and detect physical quantities with high accuracy based on the measurement results.

  In the present embodiment, the fixed electrode fingers 381 to 388 are separated from each other on the insulating substrate 2. In other words, the fixed electrode fingers 381 to 388 are not connected to each other on the insulating substrate 2 and are isolated in an island shape. Thereby, the length of the fixed electrode fingers 381 to 388 in the Y-axis direction can be made uniform. Therefore, it is possible to reduce the size of the fixed electrode fingers 381 to 388 while securing an area necessary for obtaining a sufficient bonding strength of each bonded portion between the fixed electrode fingers 381 to 388 and the insulating substrate 2.

  Similarly, the fixed electrode unit 39 includes a plurality of fixed electrode fingers 391 to 398 arranged in a comb-teeth shape that meshes with the plurality of movable electrode fingers 371 to 375 of the movable electrode unit 37 described above at intervals. Prepare. The ends of the plurality of fixed electrode fingers 391 to 398 on the side opposite to the movable portion 33 are joined to the portion on the −Y direction side with respect to the cavity portion 21 on the upper surface of the insulating substrate 2. At this time, the upper surfaces of the fixed electrode fingers 391 to 398 and the insulating substrate 2 are bonded, and the convex portions 472 and 482 formed on the surface side of the fixed electrode fingers 391 to 398 bonded to the insulating substrate 2 are respectively These are electrically connected to wirings 41 and 42 of a conductor pattern 4 to be described later. Each fixed electrode finger 391 to 398 has a fixed end as a fixed end and a free end extending in the + Y direction.

  The fixed electrode fingers 391, 392, 393, 394, 395, 396, 397, 398 are arranged in this order from the −X direction side to the + X direction side. The fixed electrode fingers 391 and 392 make a pair, and the fixed electrode fingers 393 and 394 make a pair between the movable electrode finger 371 and the movable electrode finger 372 described above. Between the fixed electrode fingers 395 and 396, the movable electrode finger 373 and the movable electrode finger 374 are paired, and between the fixed electrode fingers 397 and 398, the movable electrode finger 374 and the movable electrode finger 375 are paired. It is provided to face between.

  Here, the fixed electrode fingers 392, 394, 396, and 398 are first fixed electrode fingers, respectively, and the fixed electrode fingers 391, 393, 395, and 397 are respectively the first fixed electrode fingers on the insulating substrate 2. The second fixed electrode fingers are spaced apart from each other via a gap (gap). As described above, the plurality of fixed electrode fingers 391 to 398 are composed of a plurality of first fixed electrode fingers and a plurality of second fixed electrode fingers arranged alternately. In other words, the first fixed electrode finger is disposed on one side of the movable electrode fingers 372, 373, and 374, and the second fixed electrode finger is disposed on the other side. Further, the first fixed electrode finger or the second fixed electrode finger is disposed on either side of the movable electrode fingers 371 and 375.

  The fixed electrode fingers 392, 394, 396, and 398 as the first fixed electrode fingers and the fixed electrode fingers 391, 393, 395, and 397 as the second fixed electrode fingers are similar to the fixed electrode portion 38 described above. They are separated from each other on the insulating substrate 2. Thereby, the electrostatic capacitance between the fixed electrode fingers 392, 394, 396, 398 and the movable electrode portion 37, and the electrostatic capacitance between the fixed electrode fingers 391, 393, 395, 397 and the movable electrode portion 37 Can be measured separately, and based on the measurement results, the physical quantity can be detected with high accuracy.

  In the present embodiment, the plurality of fixed electrode fingers 391 to 398 are separated from each other on the insulating substrate 2 in the same manner as the fixed electrode portion 38 described above. Accordingly, it is possible to reduce the size of the fixed electrode fingers 391 to 398 while making the area of each joint portion between the fixed electrode fingers 391 to 398 and the insulating substrate 2 sufficient. Therefore, the physical quantity sensor element 1 can be downsized while the impact resistance of the physical quantity sensor element 1 is excellent.

Such an element piece 3 (that is, fixed portions 31, 32, movable portion 33, connecting portions 34, 35, a plurality of fixed electrode fingers 381-388, 391-398, and a plurality of movable electrode fingers 361-365, 371-375). ) Is formed by etching one substrate 103 to be described later.
Accordingly, the thicknesses of the fixed portions 31 and 32, the movable portion 33, the connecting portions 34 and 35, the plurality of fixed electrode fingers 381 to 388 and 391 to 398, and the plurality of movable electrode fingers 361 to 365 and 371 to 375 are increased. be able to. Also, these thicknesses can be easily and accurately aligned. For this reason, it is possible to increase the sensitivity of the physical quantity sensor element 1 and to improve the impact resistance of the physical quantity sensor element 1.

In addition, the constituent material of the element piece 3 is not particularly limited as long as the physical quantity can be detected based on the change in capacitance as described above, but a semiconductor (semiconductor material) is preferable. It is preferable to use a silicon material such as single crystal silicon or polysilicon.
That is, the fixed portions 31 and 32, the movable portion 33, the connecting portions 34 and 35, the plurality of fixed electrode fingers 381 to 388 and 391 to 398, and the plurality of movable electrode fingers 361 to 365 and 371 to 375 are mainly made of silicon. It is preferable that it is constituted as a material.

Silicon can be processed with high precision by etching. Therefore, by configuring the element piece 3 with silicon as a main material, the dimensional accuracy of the element piece 3 is excellent, and as a result, the physical quantity sensor element 1 can be highly sensitive. Further, since silicon is less fatigued, the durability of the physical quantity sensor element 1 can be improved.
Further, it is preferable that the silicon material constituting the element piece 3 is doped with impurities (different materials) such as phosphorus and boron. Thereby, the electroconductivity of the element piece 3 can be made excellent.

Further, as described above, the element piece 3 is supported by the insulating substrate 2 by bonding the fixed portions 31 and 32 and the fixed electrode portions 38 and 39 to the upper surface of the insulating substrate 2. In the present embodiment, the insulating substrate 2 and the element piece 3 are bonded via an insulating film 6 described later.
The bonding method of the element piece 3 (specifically, the fixing portions 31 and 32 and the fixed electrode fingers 381 to 388 and 391 to 398 described above) and the insulating substrate 2 is not particularly limited, but is an anodic bonding method. Is preferably used. Accordingly, the fixed portions 31 and 32 and the fixed electrode portions 38 and 39 (respective fixed electrode fingers 381 to 388 and 391 to 398) can be firmly bonded to the insulating substrate 2. Therefore, the impact resistance of the physical quantity sensor element 1 can be improved. Further, the fixed portions 31 and 32 and the fixed electrode portions 38 and 39 (the fixed electrode fingers 381 to 388 and 391 to 398) can be bonded to desired positions on the insulating substrate 2 with high accuracy. Therefore, it is possible to increase the sensitivity of the physical quantity sensor element 1. In this case, as described above, the element piece 3 is made of silicon as a main material, and the insulating substrate 2 is made of a glass material containing alkali metal ions.

(Conductor pattern)
The conductor pattern 4 is provided on the upper surface (surface on the fixed electrode portions 38 and 39 side) of the insulating substrate 2 described above.
The conductor pattern 4 includes wirings 41, 42, 43 and electrodes 44, 45, 46.
The wiring 41 is provided outside the cavity 21 of the insulating substrate 2 described above, and is formed along the outer periphery of the cavity 21. One end of the wiring 41 is connected to the electrode 44 on the outer peripheral portion of the upper surface of the insulating substrate 2 (the portion outside the lid member 5 on the insulating substrate 2).

Such wiring 41 is electrically connected to the fixed electrode fingers 382, 384, 386, 388 and the fixed electrode fingers 392, 394, 396, 398, which are the first fixed electrode fingers of the element piece 3 described above. Yes. Here, the wiring 41 is a first wiring electrically connected to the first fixed electrode fingers.
Further, the wiring 42 is provided along the outer peripheral edge inside the wiring 41 described above and outside the hollow portion 21 of the insulating substrate 2 described above. One end portion of the wiring 42 is arranged on the outer peripheral portion of the upper surface of the insulating substrate 2 (the portion outside the lid member 5 on the insulating substrate 2) so as to be arranged with a space from the electrode 44 described above. Connected to the electrode 45. The wiring 42 is a second wiring electrically connected to the second fixed electrode finger.

  The wiring 43 is provided so as to extend from the joint portion with the fixing portion 31 on the insulating substrate 2 to the outer peripheral portion (the outer portion of the lid member 5 on the insulating substrate 2) on the upper surface of the insulating substrate 2. The end of the wiring 43 opposite to the fixed portion 31 is on the outer peripheral portion of the upper surface of the insulating substrate 2 (the portion outside the lid member 5 on the insulating substrate 2) with respect to the electrodes 44 and 45 described above. The electrodes 46 are arranged so as to be arranged at intervals.

The material of the wirings 41 to 43 is not particularly limited as long as it has conductivity, and various electrode materials can be used. For example, ITO (Indium Tin Oxide), IZO (IZO ( Indium Zinc Oxide), In ₃ O ₃ , SnO ₂ , Sb-containing SnO ₂ , oxides (transparent electrode materials) such as Al-containing ZnO, Au, Pt, Ag, Cu, Al or alloys containing these, etc. One or more of these can be used in combination.

  Among these, it is preferable to use a transparent electrode material (particularly ITO) as a constituent material of the wirings 41 to 43. When the wirings 41 and 42 are each made of a transparent electrode material, when the insulating substrate 2 is a transparent substrate, foreign matter or the like existing on the surface of the insulating substrate 2 on the fixed electrode portions 38 and 39 side is removed. It can be easily visually recognized from the surface opposite to the fixed electrode portions 38 and 39. Therefore, the highly sensitive physical quantity sensor element 1 can be provided more reliably.

In addition, the constituent materials of the electrodes 44 to 46 are not particularly limited as long as they have electrical conductivity as in the case of the wirings 41 to 43 described above, and various electrode materials can be used. In this embodiment, the same material as that of convex portions 471, 472, 481, and 482 described later is used as the constituent material of the electrodes 44 to 46.
By providing such wirings 41 and 42 (first wiring and second wiring) on the upper surface of the insulating substrate 2, the fixed electrode fingers 382, 384, which are first fixed electrode fingers, are provided via the wiring 41. The capacitance between the electrodes 386 and 388 and the movable electrode portion 36 and the capacitance between the fixed electrode fingers 392, 394, 396 and 398, which are the first fixed electrode fingers, and the movable electrode portion 37 are measured. At the same time, the capacitance between the fixed electrode fingers 381, 383, 385, 387, which are the second fixed electrode fingers, and the movable electrode portion 36, and the fixed electrode finger 391, which is the second fixed electrode finger, via the wiring 42. , 393, 395, 397 and the capacitance between the movable electrode part 37 can be measured.

In the present embodiment, by using the electrode 44 and the electrode 46, the capacitance between the fixed electrode fingers 382, 384, 386, and 388 and the movable electrode portion 36, and the fixed electrode fingers 392, 394, 396, and 398, The capacitance between the movable electrode portion 37 and the movable electrode portion 37 can be measured. Further, by using the electrode 45 and the electrode 46, the capacitance between the fixed electrode fingers 381, 383, 385, 387 and the movable electrode portion 36, and the fixed electrode fingers 391, 393, 395, 397 and the movable electrode portion The electrostatic capacity between 37 can be measured.
Further, since such wirings 41 and 42 are provided on the upper surface of the insulating substrate 2 (that is, on the surface on the fixed electrode portions 38 and 39 side), electrical connection to the fixed electrode portions 38 and 39 and positioning thereof Is easy. Therefore, the reliability (especially impact resistance and detection accuracy) of the physical quantity sensor element 1 can be improved.

  In addition, the wiring 41 and the electrode 44 are provided in the concave portion (first concave portion) 22 of the insulating substrate 2 described above, and the wiring 42 and the electrode 45 are provided in the concave portion (second concave portion) 23 of the insulating substrate 2 described above. The wiring 43 and the electrode 46 are provided in the concave portion (third concave portion) 24 of the insulating substrate 2 described above. Thereby, it is possible to prevent the wirings 41 to 43 from protruding from the plate surface of the insulating substrate 2. Therefore, the fixed electrode fingers 382, 384, 386, 388, 392, 394, 396, 398 and the wiring are secured while ensuring the bonding (fixing) between the fixed electrode fingers 381-388, 391-398 and the insulating substrate 2. 41, and the fixed electrode fingers 381, 383, 385, 387, 391, 393, 395, 397 and the wiring 42 can be connected. Similarly, the electrical connection between the fixing part 31 and the wiring 43 can be performed while ensuring the bonding (fixing) between the fixing part 31 and the insulating substrate 2. Here, the relationship of t <d is satisfied, where t is the thickness of each of the wirings 41 to 43 and d is the depth of each of the recesses 22 to 24 where the wirings 41 to 43 are provided.

  In particular, a plurality of convex portions 481 and a plurality of convex portions 482 which are first convex portions having conductivity are provided on the wiring 41 which is the first wiring. The plurality of convex portions 481 are provided corresponding to the plurality of fixed electrode fingers 382, 384, 386, and 388 that are first fixed electrode fingers, and the plurality of convex portions 482 are a plurality of fixed electrodes that are first fixed electrode fingers. The electrode fingers 392, 394, 396, and 398 are provided correspondingly.

The fixed electrode fingers 382, 384, 386 and 388 and the wiring 41 are electrically connected via the plurality of convex portions 481, and the fixed electrode fingers 392, 394, and the like are connected via the plurality of convex portions 482. 396 and 398 and the wiring 41 are electrically connected.
Thereby, the electrical connection between each fixed electrode finger 382, 384, 386, 388, 392, 394, 396, and 398 and the wiring 41 is prevented while preventing the unintentional electrical connection (short circuit) between the wiring 41 and other parts. Connection can be made.

  Similarly, a plurality of convex portions 471 and a plurality of convex portions 472 which are second convex portions having conductivity are provided on the wiring 42 which is the second wiring. The plurality of convex portions 471 are provided corresponding to the plurality of fixed electrode fingers 381, 383, 385, and 387 that are second fixed electrode fingers, and the plurality of convex portions 472 are a plurality of fixed electrodes that are second fixed electrode fingers. The electrode fingers 391, 393, 395, and 397 are provided.

The fixed electrode fingers 381, 383, 385, 387 and the wiring 42 are electrically connected via the plurality of convex portions 471, and the fixed electrode fingers 391, 393, 395 and 397 and the wiring 42 are electrically connected.
As a result, the electrical connection between the fixed electrode fingers 381, 383, 385, 387, 391, 393, 395, and 397 and the wiring 42 is prevented while preventing unintentional electrical connection (short circuit) between the wiring 42 and other parts. Connection can be made.

  The constituent materials of the convex portions 471, 472, 481, and 482 are not particularly limited as long as they have conductivity, and various electrode materials can be used. For example, gold, platinum, Silver, copper, aluminum, tin, titanium, germanium, zinc, indium, or a compound containing these as a main component is preferably used. By forming the convex portions 471, 472, 481, and 482 using such a metal, the contact resistance between the wirings 41 and 42 and the fixed electrode portions 38 and 39 can be reduced. That is, the convex portions 471, 472, 481, and 482 include portions having lower electrical resistance than the first fixed electrode fingers and the second fixed electrode fingers. Further, in this case, as described above, since the convex portions 471, 472, 481, 482 and the wirings 41, 42, 43 are formed of the same material, it is necessary to use a plurality of materials in the manufacturing process. The physical quantity sensor element 1 can be manufactured with excellent manufacturing efficiency.

Further, the thickness of each of the wirings 41 to 43 is t, the depth of each of the concave portions 22 to 24 where the wirings 41 to 43 are provided is d, and the heights of the convex portions 471, 472, 481, 482 are set. Satisfying the relation d≈t + h, where h is h.
As shown in FIGS. 4 and 6, an insulating film 6 is provided on the wirings 41 to 43. The insulating film 6 has a function of preventing unintentional electrical connection (short circuit) between the conductor pattern 4 and the element piece 3. The insulating film 6 is not formed on the portions facing the convex portions 471, 472, 481, 482, 50 described above. Thereby, the fixed electrode fingers 382, 384, 386, 388, 392, which are the first fixed electrode fingers, are more reliably prevented while preventing unintentional electrical connection (short circuit) between the wirings 41, 42 and other parts. 394, 396, and 398 are electrically connected to the wiring 41, and the fixed electrode fingers 381, 383, 385, 387, 391, 393, 395, and 397 that are the second fixed electrode fingers are electrically connected to the wiring 42. be able to. In addition, the electrical connection between the fixed portion 31 and the wiring 43 can be performed while more reliably preventing the unintentional electrical connection (short circuit) between the wiring 43 and other parts.

  In the present embodiment, the insulating film 6 is formed over substantially the entire upper surface of the insulating substrate 2 except for the convex regions 471, 472, 481, 482, 50 and the electrodes 44 to 46 described later. . The formation region of the insulating film 6 is not limited to this as long as the wirings 41 to 43 can be covered. For example, a bonding portion with the element piece 3 on the upper surface of the insulating substrate 2 or a bonding portion with the lid member 5 is used. The shape may be excluded.

  Further, when the thicknesses of the wirings 41 to 43 are t and the depths of the portions where the wirings 41 of the recesses 22 to 24 are provided are d, the relationship d> t is satisfied. Thereby, for example, as shown in FIG. 4, a gap 221 is formed between the fixed electrode finger 391 and the insulating film 6 on the wiring 41. Although not shown, a gap similar to the gap 221 is also formed between the other fixed electrode fingers and the insulating film 6 on the wirings 41 and 42. Such a gap is similarly formed between the substrate 102A and the substrate 103A in the production of the physical quantity sensor element 1 to be described later, and gas generated during anodic bonding can be discharged.

  As shown in FIG. 6, a gap 222 is formed between the lid member 5 and the insulating film 6 on the wiring 43. Although not shown, a gap similar to the gap 222 is also formed between the lid member 5 and the insulating film 6 on the wirings 41 and 42. These gaps can be used to depressurize the inside of the lid member 5 or to fill with an inert gas. Note that these gaps may be closed with an adhesive when the lid member 5 and the insulating substrate 2 are joined with the adhesive.

The constituent material of the insulating film 6 is not particularly limited, and various insulating materials can be used. The insulating substrate 2 is a glass material (particularly, a glass material to which alkali metal ions are added). If configured, silicon dioxide (SiO ₂ ) is preferably used. As a result, unintentional electrical connection as described above is prevented, and the insulating substrate 2 and the element piece 3 can be connected to each other even if the insulating film 6 is present at the bonding portion with the element piece 3 on the upper surface of the insulating substrate 2. Can be anodically bonded.

  Moreover, the thickness (average thickness) of the insulating film 6 is not particularly limited, but is preferably about 10 to 1000 nm, and more preferably about 10 to 200 nm. If the insulating film 6 is formed in such a thickness range, the unintentional electrical connection as described above can be prevented. Further, when the insulating substrate 2 is made of a glass material containing alkali metal ions and the element piece 3 is made of silicon as a main material, an insulating film is formed at a bonding portion with the element piece 3 on the upper surface of the insulating substrate 2. Even if 6 is present, the insulating substrate 2 and the element piece 3 can be anodically bonded via the insulating film 6.

(Cover member)
The lid member 5 has a function of protecting the element piece 3 described above.
The lid member 5 has a plate shape, and a concave portion 51 is provided on one surface (lower surface) thereof. The recess 51 is formed to allow displacement of the movable portion 33 and the movable electrode portions 36 and 37 of the element piece 3.

And the part outside the recessed part 51 of the lower surface of the cover member 5 is joined to the upper surface of the insulating substrate 2 mentioned above. In the present embodiment, the insulating substrate 2 and the lid member 5 are bonded via the insulating film 6 described above.
The method for bonding the lid member 5 and the insulating substrate 2 is not particularly limited, and for example, a bonding method using an adhesive, an anodic bonding method, a direct bonding method, or the like can be used.
Further, the constituent material of the lid member 5 is not particularly limited as long as it can exhibit the functions as described above, and for example, a silicon material, a glass material, or the like can be suitably used.

(Manufacturing method of physical quantity sensor element)
Next, the manufacturing method of the physical quantity sensor element of the present invention will be described. In the following, an example of manufacturing the above-described physical quantity sensor element 1 will be described.
FIG. 7 is a flowchart showing a manufacturing method of a physical quantity sensor element, FIGS. 8 and 9 are cross-sectional views for explaining the manufacturing method of the physical quantity sensor element, and FIG. 10 is a manufacturing process (wiring, It is sectional drawing for demonstrating the process of forming a contact and an insulating film. 8 and 9 each show a cross section corresponding to the cross section along the line AA in FIG.
Hereinafter, a case where the insulating substrate 2 is made of a glass material containing alkali metal ions and the element piece 3 is made of silicon will be described as an example.

[1]
First, in step S1, which is the first step in the flowchart shown in FIG. 7, a first substrate is prepared. That is, as shown in FIG. 8A, a substrate 102 as a first substrate is prepared.
This substrate 102 becomes the insulating substrate 2 through the steps described later.
The substrate 102 is made of a glass material containing an alkali metal.

[2]
Next, in step S2, a cavity and a recess are formed. That is, as shown in FIG. 8B, the cavity 21 and the recesses 22 and 23 are formed by etching the upper surface of the substrate 102 which is the first substrate. At this time, although not shown in FIG. 8B, the recess 24 is also formed by the etching. As a result, a substrate 102A in which a plurality of hollow portions 21 and concave portions 22 to 24 are formed is obtained. That is, a plurality of physical quantity sensor elements 1 are formed on the substrate 102A.

  The formation method (etching method) of the cavity 21 and the recesses 22 to 24 is not particularly limited. For example, physical etching methods such as plasma etching, reactive ion etching, beam etching, and light-assisted etching, wet One or a combination of two or more of chemical etching methods such as etching can be used. Note that the same method can be used for etching in the following steps.

In the etching as described above, for example, a mask formed by a photolithography method can be preferably used. In addition, the cavity 21 and the recesses 22 to 24 can be formed in order by repeating mask formation, etching, and mask removal a plurality of times. The mask is removed after etching. As a method for removing the mask, for example, when the mask is made of a resist material, a resist stripping solution is used. When the mask is made of a metal material, a metal stripping solution such as a phosphoric acid solution is used. be able to.
In addition, as a mask, you may form the cavity part 21 and the recessed parts 22-24 (a several recessed part from which depth differs) collectively, for example by using a gray scale mask.

[3]
Next, in step S3, a conductor pattern is formed. That is, as shown in FIG. 8C, the conductor pattern 4 is formed on the upper surface of the substrate 102A. Thereafter, although not shown in FIG. 8C, an insulating film 106A (FIG. 10C) is formed.
Here, the insulating film 106 </ b> A becomes the insulating film 6 through singulation described later.

  Hereinafter, the formation of the conductor pattern 4 and the insulating film 106A will be described in detail with reference to FIG. In FIG. 10, the formation of the conductor pattern 4 and the insulating film 106A in the vicinity of the joint portion between the substrate 102A and the fixed electrode finger 391 is representatively illustrated.

When forming the conductor pattern 4, first, as shown in FIG. 10A, the wiring 41 is formed in the recess 22 and the wiring 42 is formed in the recess 23. At this time, although not shown in FIG. 10, the wiring 43 is formed in the recess 24 simultaneously with the wirings 41 and 42.
A method for forming the wirings 41, 42, and 43 (film forming method) is not particularly limited, and examples thereof include vacuum plating, sputtering (low temperature sputtering), dry plating methods such as ion plating, electrolytic plating, electroless plating, and the like. Examples include wet plating, thermal spraying, and thin film bonding. Note that the same method can be used for film formation in the following steps.

Next, as shown in FIG. 10B, an insulating film 106 is formed (deposited) on the upper surface of the substrate 102A so as to cover the wirings 41 and 42 and the like.
Next, as shown in FIG. 10C, the insulating film 106 corresponding to the portion where each convex portion 472 and the wiring 42 are connected is removed in a bonding step [5] described later. Although not shown in FIG. 10C, the portions corresponding to the convex portions 471, the convex portions 50, and the electrodes 44 to 46 of the insulating film 106 are also removed. As a result, the insulating film 106 </ b> A that exposes the electrodes 44 to 46 and is configured to allow the projections 471, 472, and 50 to penetrate is obtained.
As described above, the conductor pattern 4 and the insulating film 106A are obtained.

[4]
Next, returning to FIG. 7, in step S4, the second substrate is placed. In this step, first, as shown in FIG. 8D, a substrate 103 as a second substrate is prepared.
The substrate 103 becomes the element piece 3 through a process described later.
The substrate 103 is made of a material whose main material is silicon.

Then, as shown in FIG. 8D, convex portions 471 and 472 are formed on the lower surface of the substrate 103. The method for forming the convex portions 471 and 472 is not particularly limited. For example, a resist pattern is formed on the convex portion by using a photolithography technique, and a portion other than the convex portion is formed by dry etching or wet etching. Remove. At this time, the etching time is adjusted so that the height of the convex portion is h. In step S4, the substrate 103A is obtained in this way.
In addition, in the bonding step [5] described later, in order to ensure electrical connection between the convex portions 471, 472, 50 and the wirings 41, 42, 43, the upper surfaces of the convex portions of the convex portions 471, 472, 50. A metal material such as gold, platinum, silver, copper, aluminum, tin, titanium, germanium, zinc, indium, or a compound containing these as a main component may be formed, or a convex material may be doped with a different material. May be.

[5]
Next, in step S5, both the substrates are bonded. That is, as shown in FIG. 8E, the substrate 103A is bonded to the upper surface of the substrate 102A by an anodic bonding method. Thereby, each convex part 471,472,50 of the board | substrate 103A and the wiring 41,42,43 of the board | substrate 102A are connected.
The substrate 103A becomes the element piece 3 through thinning, patterning, and individualization, which will be described later.
Further, the thickness of the substrate 103 </ b> A is thicker than the thickness of the element piece 3. Thereby, the handleability of the substrate 103A can be improved. Note that the thickness of the substrate 103A may be the same as the thickness of the element piece 3, and in this case, a thinning step [6] described later may be omitted.

[6]
Next, in step S6, the substrate serving as the element piece is thinned. That is, the substrate 103A is thinned to obtain a substrate 103B as shown in FIG.
This thinning is performed so that the thickness of the substrate 103B is the same as the thickness of the element piece 3.
Further, a method for thinning the substrate 103A is not particularly limited, but for example, a CMP method or a dry polishing method can be preferably used.

[7]
Next, in step S7, an element piece is formed. That is, as shown in FIG. 9G, the substrate 103B is etched. By this patterning by etching, the fixed electrode fingers 381 to 388 and 391 to 398, the movable electrode portions 36 and 37, and the like can be formed. Thereby, an element piece 3 as shown in FIG. 9G is obtained.

[8]
Next, in step S8, the lid member is joined. That is, as shown in FIG. 9H, the lid member 105 having the recess 51 is joined to the upper surface of the substrate 102A. Thereby, the joined body 101 is obtained in which the substrate 102A and the lid member 105 are joined so as to accommodate the element piece 3.
The lid member 105 becomes the lid member 5 after being separated into individual pieces to be described later.

[9]
Next, in step S9, the joined body is separated into pieces. That is, by dividing the bonded body 101 into pieces (dicing), a plurality of physical quantity sensor elements 1 as shown in FIG. 9I are obtained.

  According to the physical quantity sensor element 1 according to the first embodiment described above, the first fixed electrode fingers (fixed electrode fingers 382, 384, 386, 388, 392, 394, 396, 398) and the second fixed electrode fingers (fixed) Since the electrode fingers 381, 383, 385, 387, 391, 393, 395, 397) are electrically insulated from each other, the capacitance between the first fixed electrode fingers and the movable electrode portions 36, 37, And the electrostatic capacitance of a 2nd fixed electrode finger and the movable electrode parts 36 and 37 can be measured separately, and a physical quantity can be detected with high precision based on those measurement results.

Further, the fixed portions 31 and 32, the movable portion 33, the connecting portions 34 and 35, the plurality of fixed electrode fingers 381 to 388 and 391 to 398, and the plurality of movable electrode fingers 361 to 365 and 371 to 375 are separated from the insulating substrate 2. Since it can be formed from a body substrate (particularly in a lump), the thickness of each movable electrode finger and each fixed electrode finger can be increased to increase the sensitivity of the physical quantity sensor element 1. Moreover, the fixed parts 31 and 32, the movable part 33, and the connection parts 34 and 35 can be made thick so that the impact resistance of the physical quantity sensor element 1 can be made excellent.
Second Embodiment

Next, a second embodiment of the physical quantity sensor element of the present invention will be described.
FIG. 11 is a plan view showing a physical quantity sensor element according to the second embodiment of the present invention.
The physical quantity sensor element 1A according to the present embodiment is the same as the physical quantity sensor element 1 according to the first embodiment described above except that the configuration of the fixed electrode portion is different.
In the following description, the physical quantity sensor element 1A of the second embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted. Moreover, in FIG. 11, the same code | symbol is attached | subjected about the structure similar to 1st Embodiment mentioned above.
In the physical quantity sensor element 1 </ b> A of the present embodiment, an element piece 3 </ b> A is bonded to the upper surface of the insulating substrate 2.

The element piece 3A includes fixed portions 31, 32, a movable portion 33, connecting portions 34, 35, movable electrode portions 36, 37, and fixed electrode portions 38A, 39A.
The fixed electrode portion 38A includes a plurality of fixed electrode fingers 381A to 388A arranged in a comb-tooth shape that meshes with the plurality of movable electrode fingers 361 to 365 of the movable electrode portion 36 at intervals, and a fixed electrode finger 382A, 384A, 386A, 388A and a base 389 formed integrally.

The ends of the plurality of fixed electrode fingers 381 </ b> A to 388 </ b> A on the side opposite to the movable portion 33 and the base portion 389 are respectively joined to the + Y direction side portion with respect to the cavity portion 21 on the upper surface of the insulating substrate 2. Yes. Each fixed electrode finger 381A to 388A has a fixed end as a fixed end and a free end extending in the −Y direction.
The fixed electrode fingers 381A, 382A, 383A, 384A, 385A, 386A, 387A, and 388A are arranged in this order from the −X direction side to the + X direction side. The fixed electrode fingers 381A and 382A are disposed between the movable electrode finger 361 and the movable electrode finger 362, and the fixed electrode fingers 383A and 384A are disposed between the movable electrode finger 362 and the movable electrode finger 363. The fingers 385A and 386A are provided between the movable electrode finger 363 and the movable electrode finger 364, and the fixed electrode fingers 387A and 388A are provided between the movable electrode finger 364 and the movable electrode finger 365.

  Here, the fixed electrode fingers 382A, 384A, 386A, and 388A are the first fixed electrode fingers, respectively, and the fixed electrode fingers 381A, 383A, 385A, and 387A are the first fixed electrode fingers on the insulating substrate 2, respectively. The second fixed electrode fingers are spaced apart from each other via a gap. As described above, the plurality of fixed electrode fingers 381A to 388A are composed of a plurality of first fixed electrode fingers and a plurality of second fixed electrode fingers arranged alternately.

  Similarly, the fixed electrode portion 39A includes a plurality of fixed electrode fingers 391A to 398A arranged in a comb-teeth shape that meshes with the plurality of movable electrode fingers 371 to 375 of the movable electrode portion 37 described above at intervals. A fixed electrode finger 392A, 394A, 396A, 398A and a base 399 formed integrally with the fixed electrode finger 392A, 394A, 396A, 398A; The ends of the fixed electrode fingers 391 </ b> A to 398 </ b> A opposite to the movable portion 33 and the base portion 399 are respectively joined to the −Y direction side portion with respect to the cavity portion 21 on the upper surface of the insulating substrate 2. ing. Each fixed electrode finger 391A to 398A has a fixed end as a fixed end and a free end extending in the + Y direction.

  The fixed electrode fingers 391A, 392A, 393A, 394A, 395A, 396A, 397A, and 398A are arranged in this order from the −X direction side to the + X direction side. The fixed electrode fingers 391A and 392A are disposed between the movable electrode finger 371 and the movable electrode finger 372, and the fixed electrode fingers 393A and 394A are disposed between the movable electrode finger 372 and the movable electrode finger 373. The fingers 395A and 396A are provided between the movable electrode finger 373 and the movable electrode finger 374, and the fixed electrode fingers 397A and 398A are provided so as to face between the movable electrode finger 374 and the movable electrode finger 375.

  Here, the fixed electrode fingers 392A, 394A, 396A, and 398A are first fixed electrode fingers, respectively, and the fixed electrode fingers 391A, 393A, 395A, and 397A are respectively the first fixed electrode fingers on the insulating substrate 2. The second fixed electrode fingers are spaced apart from each other via a gap. As described above, the plurality of fixed electrode fingers 391A to 398A are composed of a plurality of first fixed electrode fingers and a plurality of second fixed electrode fingers arranged alternately.

In such an element piece 3A, fixed electrode fingers 382A, 384A, 386A, 388A, which are first fixed electrode fingers, protrude from the base 389 and are integrally formed. Thereby, the electrical resistance between the fixed electrode fingers 382A, 384A, 386A, 388A can be reduced. As a result, the detection accuracy of the physical quantity sensor element 1A can be increased. Similarly, fixed electrode fingers 392A, 394A, 396A, and 398A, which are first fixed electrode fingers, protrude from the base portion 399 and are integrally formed. Thereby, the electrical resistance between the fixed electrode fingers 392A, 394A, 396A, and 398A can be reduced. As a result, the detection accuracy of the physical quantity sensor element 1A can be increased.
As with the physical quantity sensor element 1 according to the first embodiment described above, the physical quantity sensor element 1A according to the second embodiment as described above also achieves high sensitivity and excellent impact resistance. Can do.

(Physical quantity sensor)
Next, based on FIG. 12, a physical quantity sensor using the physical quantity sensor element 1 of the present invention will be described.
FIG. 12 is a schematic diagram showing an example of the physical quantity sensor of the present invention.
A physical quantity sensor 200 illustrated in FIG. 12 includes the above-described physical quantity sensor element 1 and an electronic component 201 that is an integrated circuit electrically connected to the physical quantity sensor element 1.

The electronic component 201 is an IC (Integrated Circuit) chip, for example, and has a function of driving the physical quantity sensor element 1. By forming an angular velocity detection circuit or an acceleration detection circuit in the electronic component 201, the physical quantity sensor 200 can be configured as a gyro sensor or an acceleration sensor.
FIG. 12 illustrates a case where the physical quantity sensor 200 includes one physical quantity sensor element 1, but the physical quantity sensor 200 may include a plurality of physical quantity sensor elements 1. The physical quantity sensor 200 may include the physical quantity sensor element 1 and a physical quantity sensor element having a configuration different from that of the physical quantity sensor element 1.
Since the physical quantity sensor 200 includes the physical quantity sensor element 1 having excellent sensitivity and impact resistance, the physical quantity sensor 200 has excellent reliability.

(Electronics)
Next, the electronic apparatus of the present invention will be described.
FIG. 13 is a perspective view showing an electronic apparatus (notebook personal computer) of the present invention.
In this figure, a personal computer 1100 includes a main body 1104 having a keyboard 1102 and a display unit 1106. The display unit 1106 is supported by the main body 1104 via a hinge structure so as to be rotatable. Yes.
Such a personal computer 1100 incorporates a physical quantity sensor element 1.

FIG. 14 is a perspective view showing an electronic apparatus (mobile phone) according to the present invention. This mobile phone includes a PHS.
In this figure, a cellular phone 1200 includes an antenna (not shown), a plurality of operation buttons 1202, an earpiece 1204 and a mouthpiece 1206, and a display unit 1207 is provided between the operation buttons 1202 and the earpiece 1204. Has been placed.
Such a cellular phone 1200 incorporates the physical quantity sensor element 1.

  FIG. 15 is a perspective view showing an electronic apparatus (digital still camera) of the present invention. In this figure, connection with an external device is also simply shown. Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an imaging device such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

A display unit 1303 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD. The display unit 1303 displays the subject as an electronic image. Functions as a viewfinder.
A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.

When the photographer confirms the subject image displayed on the display unit 1303 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308.
In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation.

Such a digital still camera 1300 incorporates a physical quantity sensor element 1.
Since the various electronic devices described above include the physical quantity sensor element 1 having excellent sensitivity and impact resistance, the electronic device has excellent reliability.
In addition to the personal computer (notebook (mobile type) personal computer) 1100 of FIG. 13, the mobile phone 1200 of FIG. 14, and the digital still camera 1300 of FIG. Device (for example, inkjet printer), laptop personal computer, TV, video camera, video tape recorder, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, work Station, video phone, security TV monitor, electronic binoculars, POS terminal, medical equipment (eg electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measurements Equipment, instruments For example, gages for vehicles, aircraft, and ships), can be applied to a flight simulator or the like.

The physical quantity sensor element, the physical quantity sensor, and the electronic device of the present invention have been described based on the illustrated embodiments, but the present invention is not limited to these.
For example, if the fixed electrode portion is separated from the other fixed electrode fingers on the insulating substrate by at least one fixed electrode finger of the plurality of fixed electrode fingers arranged in a comb-teeth shape, the embodiment described above It is not limited to.

In addition, the number, arrangement, size, and the like of the plurality of fixed electrode fingers of the fixed electrode portion and the plurality of movable electrode fingers of the movable electrode portion provided so as to mesh with the fixed electrode fingers are limited to the above-described embodiments. Not.
Further, the movable part may be configured to be displaced in the Y-axis direction, or the movable part may be configured to be rotated around an axis parallel to the X-axis. In this case, the physical quantity may be detected based on the change in capacitance due to the change in the facing area between the movable electrode finger and the fixed electrode finger.
Moreover, in the above-mentioned Example, the physical quantity sensor element 1 is not limited to the illustration by each embodiment, For example, by applying a different voltage to a fixed electrode finger and a movable electrode finger, and driving a movable electrode finger by Coulomb force The physical quantity sensor element of the present invention may be used as a resonator that oscillates the natural frequency.

  DESCRIPTION OF SYMBOLS 1 ... Physical quantity sensor element 1A ... Physical quantity sensor element 2 ... Insulation board 3 ... Element piece 3A ... Element piece 4 ... Conductor pattern 5 ... Lid member 6 ... Insulating film 21 ... Hollow part 22 ... Concave part (first concave part) 23 ... concave part (second concave part) 24 ... concave part (third concave part) 31 ... fixed part 32 ... fixed part 33 ... movable part 34 ... connecting part 35 ... connecting part 36 ············································································ Wiring (first wiring) 2 Wiring) 43 ... Wiring 44 ... Electrode 45 ... Electrode 46 ... Electrode 50 ... Convex part 51 ... Concave part 101 ... Bonded body 102 ... Substrate (first substrate) 102A ... Substrate 103 ... Substrate (Second substrate) 103A ... 103B ... Substrate 105 ... Lid member 106 ... Insulating film 106A ... Insulating film 200 ... Physical quantity sensor 201 ... Electronic components 221 ... Gap 222 ... Gap 341, 342 ... Beam 351, 352 ... Beam 361 ˜365... Movable electrode fingers 371 to 375... Movable electrode fingers 381 to 388... Fixed electrode fingers 391 to 398... Fixed electrode fingers 381A to 388A .. Fixed electrode fingers 391A to 398A. ... Base 471 ... Convex part (second convex part) 472 ... Convex part (second convex part) 481 ... Convex part (first convex part) 482 ... Convex part (first convex part) 1100 ... Personal Computer 1102 ... Keyboard 1104 ... Main body 1106 ... Display unit 1200 ... Mobile phone 1202 ... Operation buttons 1204 ... Earpiece 1206 ... Mouthpiece 1300 ... Digital still camera 1302 ... Case 1304 ... Light receiving unit 1306 ... Shutter button 1308 ... Memory 1312 ... Video signal output terminal 1314 ... Input / output terminal 1430 ... TV monitor 1440 Personal computer

Claims (8)

An insulating substrate;
A movable part provided above the insulating substrate;
A movable electrode finger provided in the movable part;
A fixed electrode finger provided on the insulating substrate and disposed to face the movable electrode finger,
The insulating substrate is provided with a recess,
In the recess, wiring is provided,
The fixed electrode finger is disposed across the concave portion, provided with a convex portion at a position overlapping the wiring in a plan view, and the wiring and the convex portion are connected to each other. element.   The physical quantity sensor element according to claim 1, wherein the convex portion includes a portion having an electric resistance smaller than that of the fixed electrode finger.   The physical quantity sensor element according to claim 2, wherein the fixed electrode finger is made of a semiconductor material, and at least a part of the convex portion is doped with a material different from the semiconductor material.   The physical quantity sensor element according to claim 2, wherein at least a part of the convex portion is made of metal.   The physical quantity sensor element according to claim 4, wherein the metal of the convex portion and the wiring are made of the same material.   At least a part of the convex portion is composed of gold, platinum, silver, copper, aluminum, tin, titanium, germanium, silicon, zinc, indium, or a compound mainly containing at least one of these. The physical quantity sensor element according to claim 1, wherein the physical quantity sensor element is characterized in that: The physical quantity sensor element according to any one of claims 1 to 6,
And a physical quantity sensor comprising an integrated circuit.   An electronic apparatus comprising the physical quantity sensor element according to any one of claims 1 to 6.

Images