JP2013104868A - Physical quantity sensor element and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor element that can improve a cushioning effect to a movable portion of a base substrate at the time of impact such as a drop of the physical quantity sensor element while preventing the base substrate and the movable portion from being stuck together, and an electronic apparatus provided with the physical quantity sensor element.SOLUTION: A sensor element 1 comprises: a base substrate 2; and a movable portion 33 that is provided on the base substrate 2 and is movable in response to physical quantity applied thereto. A bottom surface of a cavity portion 21 of the base substrate 2 is provided with projections, 25a, 25b, 25c, etc., at positions overlapping with the movable portion 33 in planar view. The projections, 25a, 25b, 25c, etc., are provided integrally with the base substrate 2.

Description

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

A fixed electrode disposed in a fixed manner, and a movable electrode that is disposed so as to be opposed to and displaceable with respect to the fixed electrode, and based on the capacitance between the fixed electrode and the movable electrode, acceleration A physical quantity sensor element that detects a physical quantity such as angular velocity is known.
For example, the physical quantity sensor element described in Patent Document 1 is arranged at positions spaced apart from each other on the upper surface of the substrate, receives a working force that is displaced by a mechanical quantity, and is fixed to the upper surface of the substrate. A semiconductor dynamic quantity sensor comprising a fixed electrode disposed opposite to at least a part of the body, wherein the structure is provided on a top surface of the substrate and corresponding to a lower part of the structure. A lower electrode electrically connected to the beam structure is disposed, and a protrusion is formed on the beam structure side surface of the lower electrode.

JP 2002-148278 A

In the physical quantity sensor element, for example, when the substrate is made of a glass material, the beam structure is made of a semiconductor material, and both are joined by anodic bonding, the semiconductor material is etched to form the beam structure. There is a problem that the two adhere to each other due to the charge generated on the surface of the structure. Further, for example, the beam structure may come into contact with the substrate due to an impact when the physical quantity sensor element is dropped, and the beam structure may be damaged.
For such a problem, for example, as in the physical quantity sensor element of Patent Document 1, by forming a protrusion at the lower part of the beam structure, the adhesion area between the beam structure and the substrate is reduced. While being able to prevent sticking between both at the time of formation, the buffering effect in the case of a drop impact can be acquired.

However, the physical quantity sensor element described in Patent Document 1 has a problem that since the protrusion is formed from the lower electrode, an electrode processing step for forming the protrusion is required separately, and the efficiency of the manufacturing process is poor. In the physical quantity sensor element, it is difficult to control the thickness of the electrode serving as a protrusion, and there is a possibility that the height of the protrusion may vary.
As a result, the physical quantity sensor element may be insufficient in the prevention of sticking of the beam structure to the substrate and the buffering effect in the case of a drop impact.
An object of the present invention is to provide a physical quantity sensor element capable of preventing sticking of a movable part (beam structure) or the like to a substrate in a manufacturing process or the like, and improving a buffering effect against an impact such as dropping, and the physical quantity sensor element It is providing the electronic device provided with.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A physical quantity sensor element according to this application example includes a base substrate and a movable portion provided on the base substrate and movable in accordance with the physical quantity. A protrusion is provided at a position overlapping with the movable portion, and the protrusion is provided integrally with the base substrate.

As a conventional problem in the physical quantity sensor element, for example, after a base substrate made of a glass material (corresponding to the substrate of Patent Document 1) and a plate-like member made of a semiconductor material are joined by anodic bonding, the plate-like member is etched. When the movable part (corresponding to the beam structure of Patent Document 1) is formed, there is a problem that the two adhere to each other due to the charges generated on the surface of the base substrate and the surface of the movable part.
In response to this problem, the physical quantity sensor element of this application example provides a protrusion on the base substrate so as to overlap the movable portion in plan view, so that the contact range with the movable portion on the base substrate becomes only the protrusion portion, The contact area can be significantly reduced. Thereby, the physical quantity sensor element can prevent sticking between the base substrate and the movable part.

Further, the physical quantity sensor element can form the movable region (for example, the concave portion) and the protrusion of the movable portion in the base substrate in one step by etching, for example, by providing the protrusion integrally with the base substrate.
As a result, the physical quantity sensor element can improve the manufacturing efficiency and can reduce the variation in the thickness of the protrusion as compared with the case where the protrusion is formed with an electrode as in the prior art (for example, Patent Document 1). Thereby, the physical quantity sensor element can improve the buffering effect with respect to the movable part of the base substrate at the time of impact such as dropping.
As a result, the physical quantity sensor element can be more reliable than the conventional one.

  Application Example 2 In the physical quantity sensor element according to the application example, the movable portion includes a spring portion, a mass portion connected to the base substrate via the spring portion, and a movable electrode provided on the mass portion. It is preferable that a fixed electrode part is provided on the base substrate so as to face the movable electrode part.

  According to this, the physical quantity sensor element includes a movable portion having a spring portion, a mass portion connected to the base substrate via the spring portion, and a movable electrode portion provided on the mass portion, and is provided on the base substrate. Since the fixed electrode portion is provided facing the movable electrode portion, physical quantities such as acceleration and angular velocity can be detected with high sensitivity and accuracy based on the capacitance between the fixed electrode portion and the movable electrode portion. Can do.

  Application Example 3 In the physical quantity sensor element according to the application example described above, it is preferable that the protrusion is provided at a position overlapping the mass portion in plan view.

  According to this, since the physical quantity sensor element is provided at a position where the protrusion overlaps with the mass portion in plan view, the mass portion having a large mass and the base substrate are effectively prevented from sticking in the movable portion. be able to.

  Application Example 4 In the physical quantity sensor element according to the application example described above, it is preferable that a plurality of the protrusions are provided so as to be symmetric with respect to the center of the mass portion.

  According to this, since the plurality of physical quantity sensor elements are provided so that the projections are symmetrical with respect to the center of the mass portion, the mass portion having a large mass and the base substrate are more effectively attached to the movable portion. Can be prevented in a well-balanced manner.

  Application Example 5 In the physical quantity sensor element according to the application example, it is preferable that the protrusion is provided at a position overlapping with at least one of the movable electrode portion and the spring portion in a plan view.

  According to this, since the physical quantity sensor element is provided at a position where the protrusion overlaps at least one of the movable electrode part and the spring part in plan view, at least one of the movable electrode part and the spring part of the movable part and the base Sticking to the substrate can be effectively prevented.

  Application Example 6 In the physical quantity sensor element according to the application example described above, it is preferable that an insulating material is used for the base substrate and a semiconductor material is used for the movable part.

  According to this, since the insulating material is used for the base substrate and the semiconductor material is used for the movable part, the physical quantity sensor element can reliably perform the insulation separation between the base substrate and the movable part.

  Application Example 7 An electronic apparatus according to this application example includes the physical quantity sensor element according to any one of the application examples described above.

  According to this, since the electronic device of this configuration includes the physical quantity sensor element described in any of the above application examples, the highly reliable electronic device reflecting the effect described in any of the above application examples Can be provided.

The perspective view which shows the sensor element concerning this embodiment. The top view of the sensor element shown in FIG. The elements on larger scale of FIG. 2 (partial enlarged plan view). FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. The elements on larger scale of FIG. 4 (partial expanded sectional view). BB sectional drawing of FIG. FIG. 7 is a partial cross-sectional view (partial enlarged cross-sectional view) of FIG. 6. (A)-(e) is a figure for demonstrating the manufacturing method of the sensor element shown in FIG. (A)-(c) is a figure for demonstrating the manufacturing method of the sensor element shown in FIG. (A)-(d) is a figure for demonstrating the process shown in FIG.8 (c). The perspective view which shows the structure of the mobile type (or notebook type) personal computer as an electronic device provided with the sensor element. The perspective view which shows the structure of the mobile telephone (PHS is also included) as an electronic device provided with the sensor element. The perspective view which shows the structure of the digital still camera as an electronic device provided with the sensor element.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. In the following drawings, the scale of each layer and each member is made different from the actual scale so that each layer and each member can be recognized.

<Embodiment>
1 is a perspective view showing a sensor element according to this embodiment, FIG. 2 is a plan view of the sensor element shown in FIG. 1, FIG. 3 is a partially enlarged view (partially enlarged plan view) of FIG. 2, and FIG. 2 is a sectional view taken along line AA in FIG. 2, FIG. 5 is a partially enlarged view (partially enlarged sectional view) of FIG. 4, FIG. 6 is a sectional view taken along line BB of FIG. It is sectional drawing (partial expanded sectional view).
In the following, for convenience of explanation, the front side of the sheet in FIG. 2 is referred to as “upper”, the rear side of the sheet is referred to as “lower”, the right side is referred to as “right”, and the left side is referred to as “left”. 1 to 4 and 6, 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 4, 6, 8, and 9, for convenience of explanation, illustration of an insulating film 6 described later and the corresponding film (insulating films 106 and 106 </ b> A) is omitted. In FIG. 2, some of the symbols are omitted to avoid complication. In the present embodiment, an example in which the sensor element is used as a physical quantity sensor element for measuring physical quantities such as acceleration and angular velocity will be described.

(Sensor element)
A sensor element 1 shown in FIG. 1 includes an insulating substrate 2 as a base substrate, an element piece 3 bonded and supported on the insulating substrate 2, a conductor pattern 4 electrically connected to the element piece 3, and an element piece. 3 and a lid member 5 provided so as to cover 3.

Hereinafter, each part which comprises the sensor element 1 is demonstrated sequentially.
(Insulated substrate)
The insulating substrate 2 has a function of supporting the element piece 3.
The insulating substrate 2 has a flat plate shape, and a cavity (concave portion) 21 is provided on the upper surface (one surface). The cavity 21 constitutes an escape area (avoidance region) that prevents the movable portion 33 of the element piece 3 to be described later from coming into contact with the insulating substrate 2 when the insulating substrate 2 is viewed in plan view. Thereby, the insulating substrate 2 can tolerate the displacement of the movable portion 33 of the element piece 3.
The escape field may be an opening that penetrates the insulating substrate 2 in the thickness direction (Z-axis direction) instead of the cavity 21. In the present embodiment, the shape of the cavity 21 in plan view is a quadrangle (specifically, a rectangle), but is not limited thereto.

As shown in FIG. 3, prismatic protrusions 25 a, 25 b, 25 c, 25 d, 25 e, 25 f, 25 g, 25 h, 25 i, and 25 j are provided on the bottom surface of the cavity portion 21 at positions overlapping the movable portion 33 in plan view. , 25k, 25l, and 25m are provided integrally with the insulating substrate 2.
Thereby, when the movable part 33 of the element piece 3 to be described later comes into contact with the insulating substrate 2, the sensor element 1 has a flat contact area between the movable part 33 and the insulating substrate 2 and the bottom surface of the cavity 21 is flat. Since this is smaller than the case of, permanent sticking between the movable portion 33 and the insulating substrate 2 can be prevented. Hereinafter, when there is no need to distinguish individual protrusions, they are referred to as protrusions 25 for convenience.
The details of the position of the protrusion 25 will be described in the element piece 3 described later.

  On the upper surface of the insulating substrate 2, recesses 22, 23, and 24 are provided along the outer periphery of the cavity 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.

Thus, by deepening the depth of a part of the recesses 22, 23, 24, when the substrate 103 before the element piece 3 is formed is bonded to the substrate 102 </ b> A in manufacturing the sensor element 1 described later (FIG. 8), it is possible to prevent the substrate 103 from being bonded to the electrodes 44, 45, and 46.
As a constituent material of such an insulating substrate 2, for example, it is preferable to use an insulating material such as a high-resistance silicon material or a glass material. In particular, when the element piece 3 is configured with a silicon material as a main material, It is preferable to use a glass material containing alkali metal ions (mobile ions) (for example, borosilicate glass such as Pyrex (registered trademark) glass). Thereby, the sensor element 1 can perform anodic bonding of the insulating substrate 2 and the element piece 3 when the element piece 3 is made of silicon as a main material.

  In addition, the constituent material of the insulating substrate 2 preferably has as little difference in thermal expansion coefficient as that of the constituent material of the element piece 3. Specifically, the heat between the constituent material of the insulating substrate 2 and the constituent material of the element piece 3 is preferable. The difference in expansion coefficient is preferably 3 ppm / ° C. or less. Thereby, even if the sensor element 1 is exposed to a high temperature, for example, when the insulating substrate 2 and the element piece 3 are joined, 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, and fixed electrode portions 38 and 39. The movable portion 33 includes connecting portions 34 and 35 as spring portions, mass portions (mass portions) 33a connected to the insulating substrate 2 via the connecting portions 34 and 35, and fixed portions 31 and 32, and mass portions 33a. Movable electrode portions 36 and 37 are provided.
Such an element piece 3 has an X-axis direction (+ X) while the mass portion 33a 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 element piece 3 changes in 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, respectively. To do. That is, along with such displacement, the element piece 3 has a capacitance between the movable electrode portion 36 and the fixed electrode portion 38 and a capacitance between the movable electrode portion 37 and the fixed electrode portion 39. The size of each changes. Therefore, the sensor element 1 can detect physical quantities such as acceleration and angular velocity based on these capacitances.

The fixed portions 31 and 32 and the movable portion 33 (the coupling portions 34 and 35, the mass portion 33a, 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 joined to a portion of the upper surface of the insulating substrate 2 on the −X direction side (left side in the drawing) with respect to the cavity portion 21, and the fixing portion 32 is bonded to 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. The fixed 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 mass portion 33 a of the movable portion 33 is provided between the two fixed portions 31 and 32. In the present embodiment, the mass portion 33a has a prismatic shape extending in the X-axis direction. The shape of the mass portion 33a is determined according to the shape, size, and the like of each portion constituting the element piece 3, and is not limited to the above.

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

  Specifically, the connecting portion 34 is composed of 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 mass portion 33a 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 mass portion 33a. 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 (Y-axis direction) of the mass portion 33a supported so as to be displaceable in the X-axis direction with respect to the insulating substrate 2. A movable electrode portion 37 is provided on the other side (−Y direction side).
The movable electrode portion 36 includes a plurality of movable electrode fingers 361 to 365 that protrude from the mass portion 33a in the + Y direction and are arranged in a comb-like shape. The movable electrode fingers 361, 362, 363, 364, 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 to 375 that protrude in the −Y direction from the mass portion 33a and are arranged in a comb-teeth shape. The movable electrode fingers 371, 372, 373, 374, and 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 mass portion 33a is displaced (that is, the X-axis direction).
As a result, the sensor element 1 has a capacitance between fixed electrode fingers 382, 384, 386, and 388 and the movable electrode portion 36, which will be described later, and fixed electrode fingers 381, 383, 385, 387, and the movable electrode portion 36. Can be efficiently changed according to the displacement of the mass portion 33a.
Similarly, the sensor element 1 includes a capacitance between fixed electrode fingers 392, 394, 396, 398 and the movable electrode portion 37, which will be described later, and fixed electrode fingers 391, 393, 395, 397 and the movable electrode portion 37. Can be efficiently changed according to the displacement of the mass portion 33a. Thereby, the sensor element 1 can be made excellent in detection sensitivity and detection accuracy when used as a physical quantity sensor element.

Here, the positional relationship between the protrusion 25 of the insulating substrate 2 and the movable portion 33 of the element piece 3 will be described in detail.
As shown in FIG. 3, the protrusions 25a, 25b, and 25c are provided at positions overlapping the mass portion 33a in plan view. Specifically, the protrusion 25a is provided at a position overlapping the center O of the mass portion 33a, and the protrusions 25b and 25c are positions that are symmetric with respect to the center line B parallel to the Y axis of the mass portion 33a. Is preferably provided. Moreover, it is preferable that the protrusions 25b and 25c are provided at positions overlapping the center line C parallel to the X axis of the mass portion 33a.
The protrusion 25d is a movable electrode finger 361, the protrusion 25e is a movable electrode finger 362, the protrusion 25f is a movable electrode finger 363, the protrusion 25g is a movable electrode finger 364, the protrusion 25h is a movable electrode finger 365, and the protrusion 25i is a movable electrode. The finger 371, the protrusion 25j are provided at the overlapping positions of the movable electrode finger 372, the protrusion 25k at the movable electrode finger 373, the protrusion 25l at the movable electrode finger 374, and the protrusion 25m at the overlapping position in the plan view. It has been.

The protrusions 25d, 25e, 25f, 25g, and 25h and the protrusions 25i, 25j, 25k, 25l, and 25m are preferably provided at positions that are symmetrical with respect to the center line C of the mass portion 33a. .
Further, the protrusion 25 may be provided at a position overlapping the connecting portions 34 and 35 in plan view. In this case, it is preferable that the protrusion 25 is provided at a position that overlaps with the easily bent portion of the beams 341, 342, 351, and 352. More specifically, the protrusion 25 is preferably provided at a position overlapping the + Y-side folded portion with respect to the beams 341 and 351, and with respect to the beams 342 and 352, a position overlapping with the −Y-side folded portion. Is preferably provided.

It should be noted that the height of the protrusion 25 does not hinder the detection of physical quantities such as acceleration and angular velocity according to the distance from the movable part 33, the size of the movable part 33, the degree of displacement (deflection) of the movable part, and the like. Set as appropriate. The planar shape of the protrusion 25 is not limited to a rectangle, and may be any shape such as a circle, a triangle, a pentagon or more polygon, and an ellipse.
Further, the surface facing the movable portion 33 at the tip of the protrusion 25 may be provided with fine irregularities in order to further reduce the contact area with the movable portion 33 and is a porous having a large number of holes (dents). You may be covered with the film which consists of a quality material.

  The fixed electrode portion 38 is provided on the insulating substrate 2 so as to face the movable electrode portion 36 with a space therebetween. In addition, the fixed electrode portion 39 is provided on the insulating substrate 2 so as to face the movable electrode portion 37 with a gap.

  The fixed electrode unit 38 includes a plurality of fixed electrode fingers 381 to 388 arranged so as to form a comb tooth 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 opposite to the mass portion 33a side are respectively joined to portions on the + Y direction side with respect to the cavity portion 21 on the upper surface of the insulating substrate 2. . 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 form a pair, and the above-mentioned movable electrode fingers 361 and 362 form a pair, and the fixed electrode fingers 383 and 384 form a pair and the movable electrode fingers 362 and 363 form a fixed electrode. The fingers 385 and 386 make a pair and are provided between the movable electrode fingers 363 and 364, and the fixed electrode fingers 387 and 388 make a pair and are sandwiched between the movable electrode fingers 364 and 365.

  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. On the other hand, it is a second fixed electrode finger provided through 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 arranged on one side of the movable electrode finger, and the second fixed electrode finger is arranged on the other side.

The first fixed electrode fingers 382, 384, 386, and 388 and the second fixed electrode fingers 381, 383, 385, and 387 are separated from each other on the insulating substrate 2. In other words, the first fixed electrode fingers 382, 384, 386, 388 and the second 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. .
Accordingly, the sensor element 1 can electrically insulate the first fixed electrode fingers 382, 384, 386, and 388 from the second fixed electrode fingers 381, 383, 385, and 387.
As a result, the sensor element 1 includes the capacitance between the first fixed electrode fingers 382, 384, 386, 388 and the movable electrode portion 36, and the second fixed electrode fingers 381, 383, 385, 387 and the movable electrode. The capacitance between the unit 36 and the unit 36 can be measured separately, and the physical quantity can be detected with high accuracy based on the measurement results.

  Similarly, the fixed electrode portion 39 includes a plurality of fixed electrode fingers 391 to 398 arranged in a comb-like shape that meshes with the plurality of movable electrode fingers 371 to 375 of the movable electrode portion 37 described above at intervals. ing. The ends of the plurality of fixed electrode fingers 391 to 398 on the side opposite to the movable portion 33 are respectively joined to portions on the −Y direction side of the upper surface of the insulating substrate 2 with respect to the cavity portion 21. . 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 form a pair, and the above-mentioned movable electrode fingers 371 and 372 form a pair, and the fixed electrode fingers 393 and 394 form a pair and the movable electrode fingers 372 and 373 form a fixed electrode. The fingers 395 and 396 form a pair, and are provided between the movable electrode fingers 373 and 374, and the fixed electrode fingers 397 and 398 form a pair and are sandwiched between the movable electrode fingers 374 and 375.

  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 the first fixed electrode fingers on the insulating substrate 2, respectively. On the other hand, it is a second fixed electrode finger provided through 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 arranged on one side of the movable electrode finger, and the second fixed electrode finger is arranged on the other side.

  The first fixed electrode fingers 392, 394, 396, 398 and the second fixed electrode fingers 391, 393, 395, 397 are separated from each other on the insulating substrate 2 like the fixed electrode portion 38 described above. . As a result, the sensor element 1 includes the capacitance between the first fixed electrode fingers 392, 394, 396, 398 and the movable electrode portion 37, and the second fixed electrode fingers 391, 393, 395, 397 and the movable electrode. The capacitance between the unit 37 and the unit 37 can be measured separately, and the physical quantity can be detected with high accuracy based on the measurement results.

Such an element piece 3 is formed by etching one substrate 103 described later.
Thereby, the sensor element 1 includes the fixed portions 31 and 32, the mass portion 33a, 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. The thickness can be increased. In addition, the sensor element 1 can easily and accurately align these thicknesses. As a result, the sensor element 1 can achieve high sensitivity and can improve impact resistance.

The constituent material of the element piece 3 is not particularly limited as long as it can detect a physical quantity based on the change in capacitance as described above, but is preferably a semiconductor material, specifically, for example, single crystal silicon, It is preferable to use a silicon material such as polysilicon.
That is, the fixed portions 31 and 32, the mass portion 33a, 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 to be configured as a material.

Silicon can be processed with high precision by etching. Therefore, the element piece 3 is made of silicon as a main material, whereby the dimensional accuracy of the element piece 3 is improved, and as a result, the sensitivity of the sensor element 1 that is a physical quantity sensor element can be increased. Moreover, since silicon hardly deteriorates, the durability of the sensor element 1 can be improved.
Further, it is preferable that the silicon material constituting the element piece 3 is doped with impurities such as phosphorus and boron. Thereby, the sensor element 1 can make the conductivity of the element piece 3 excellent.

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. Thereby, the sensor element 1 can firmly bond 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) to the insulating substrate 2.
As a result, the sensor element 1 can improve the impact resistance, and 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 provided on the insulating substrate 2 as desired. It is possible to join to the position with high accuracy. Thereby, the sensor element 1 can achieve high sensitivity.

(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 is composed of 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, and 388 and the fixed electrode fingers 392, 394, 396, and 398, which are the first fixed electrode fingers of the element piece 3 described above. Yes.
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 (the outer portion of the lid member 5 on the insulating substrate 2) on the upper surface of the insulating substrate 2 so as to be arranged at a distance from the electrode 44 described above. It is connected to the.

  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 portion of the wiring 43 opposite to the fixed portion 31 is arranged on the outer peripheral portion of the upper surface of the insulating substrate 2 (the lid member 5 on the insulating substrate 2 so as to be arranged at a distance from the electrodes 44 and 45 described above. The electrode 46 is connected to the outer portion of the electrode 46.

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.

  Especially, as a constituent material of the wirings 41 to 43, it is preferable to use a transparent electrode material (particularly ITO). In the sensor element 1, 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 Can be easily seen from the side of the insulating substrate 2 opposite to the fixed electrode portions 38 and 39. Thereby, the sensor element 1 becomes easy to detect a defective product, and can improve reliability.

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 the present embodiment, the same material as that of the joint protrusions 471, 472, 481, and 482 described later is used as the constituent material of the electrodes 44 to 46.
The sensor element 1 is movable with the capacitance between the first fixed electrode fingers 382, 384, 386 and 388 and the movable electrode portion 36 and the first fixed electrode fingers 392, 394, 396 and 398 via the wiring 41. The capacitance between the electrode part 37 and the electrode part 37 can be measured. The sensor element 1 includes the capacitance between the second fixed electrode fingers 381, 383, 385, 387 and the movable electrode portion 36 via the wiring 42, and the second fixed electrode fingers 391, 393, 395, 397. And 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 first fixed electrode fingers 382, 384, 386, 388 and the movable electrode portion 36, and the first fixed electrode fingers 392, 394, The capacitance between 396 and 398 and the movable electrode portion 37 can be measured. Further, by using the electrode 45 and the electrode 46, the capacitance between the second fixed electrode fingers 381, 383, 385, 387 and the movable electrode portion 36, and the second fixed electrode fingers 391, 393, 395, 397 are obtained. And the movable electrode part 37 can be measured.
Further, since the 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 and positioning with respect to the fixed electrode portions 38 and 39 are easy. As a result, the sensor element 1 can improve reliability (particularly, impact resistance and detection accuracy).

Further, the wiring 41 and the electrode 44 are provided in the concave portion 22 of the insulating substrate 2 described above, the wiring 42 and the electrode 45 are provided in the concave portion 23 of the insulating substrate 2 described above, and the wiring 43 and the electrode 46 are described above. The insulating substrate 2 is provided in the recess 24. Thereby, it is possible to prevent the wirings 41 to 43 from protruding from the upper surface of the insulating substrate 2. Therefore, the fixed electrode fingers 382 to 388, 391 to 398 and the insulating substrate 2 are securely joined (fixed), and the fixed electrode fingers 382, 384, 386, 388, 392, 394, 396, and 398 are connected to the wiring. 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 wiring 41 is provided.

  In particular, a plurality of conductive protrusions 481 and 482 having conductivity are provided on the wiring 41. The plurality of bonding protrusions 481 are provided corresponding to the fixed electrode fingers 382, 384, 386, and 388, and the plurality of bonding protrusions 482 are provided corresponding to the fixed electrode fingers 392, 394, 396, and 398. .

The fixed electrode fingers 382, 384, 386, and 388 are electrically connected to the wiring 41 through the plurality of joint protrusions 481, and the fixed electrode fingers 392, 394, through the plurality of joint protrusions 482. 396, 398 and the wiring 41 are electrically connected.
Thus, the electrical connection between each fixed electrode finger 382, 384, 386, 388, 392, 394, 396, 398 and the wiring 41 is prevented while preventing unnecessary electrical connection (short circuit) between the wiring 41 and other parts. Connection can be made.

  Similarly, a plurality of conductive protrusions 471 and 472 are provided on the wiring 42. The plurality of bonding protrusions 471 are provided corresponding to the fixed electrode fingers 381, 383, 385, 387, and the plurality of bonding protrusions 472 are provided corresponding to the fixed electrode fingers 391, 393, 395, 397. Yes.

The fixed electrode fingers 381, 383, 385, 387 and the wiring 42 are electrically connected to each other through the plurality of joint protrusions 471, and the fixed electrode fingers 391, 393, through the plurality of joint protrusions 472. 395 and 397 and the wiring 42 are electrically connected.
Thereby, the electrical connection between each fixed electrode finger 381, 383, 385, 387, 391, 393, 395, 397 and the wiring 42 is prevented while preventing unnecessary electrical connection (short circuit) between the wiring 42 and other parts. Connection can be made.

  The material of the joint protrusions 471, 472, 481, 482 is not particularly limited as long as it has conductivity, and various electrode materials can be used. For example, Au, Pt Metals such as simple metals such as Ag, Cu, and Al or alloys containing them are preferably used. By forming the joint protrusions 471, 472, 481, 482 using such a metal, the sensor element 1 can reduce the contact resistance between the wirings 41, 42 and the fixed electrode portions 38, 39. it can.

The thicknesses of the wirings 41 to 43 are t, and the depths of the portions of the recesses 22 to 24 where the wirings 41 to 43 are provided are d. The heights of the joint protrusions 471, 472, 481, and 482 are high. When each is h, the relationship d≈t + h is satisfied.
Further, as shown in FIGS. 5 and 7, an insulating film 6 is provided on the wirings 41 to 43. The insulating film 6 is not formed on the above-described joint protrusions 471, 472, 481, 482, 50, and the surfaces of the joint protrusions 471, 472, 481, 482, 50 are exposed. The insulating film 6 has a function of preventing unnecessary electrical connection (short circuit) between the conductor pattern 4 and the element piece 3.

As a result, the sensor element 1 more reliably prevents unnecessary electrical connection (short circuit) between the wirings 41 and 42 and other parts, and the fixed electrode fingers 382, 384, 386, 388, 392, 394, and 396. , 398 and the wiring 41, and the fixed electrode fingers 381, 383, 385, 385, 387, 391, 393, 395, 397 and the wiring 42 can be connected.
In addition, the sensor element 1 can perform electrical connection between the fixed portion 31 and the wiring 43 while more reliably preventing unnecessary 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 formation regions of the bonding protrusions 471, 472, 481, 482, 50 and the electrodes 44 to 46 described later. Yes. 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 thickness of the wirings 41 to 43 is t, and the depth of the portions where the wirings 41 to 43 of the recesses 22 to 24 are provided is d, the relationship of d> t is satisfied. Thereby, for example, as shown in FIG. 5, 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 102 and the substrate 103 in the manufacture of the sensor element 1 to be described later, and gas generated during anodic bonding can be discharged.

  Further, as shown in FIG. 7, 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 (222 and the like) can be used when the lid member 5 is decompressed or filled with an inert gas. Note that these gaps (222, etc.) may be closed by an adhesive when the lid member 5 and the insulating substrate 2 are bonded by an 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, unnecessary electrical connection as described above can be 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 joint portion with the element piece 3 on the upper surface of the insulating substrate 2. Anodic bonding is possible.

  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 sensor element 1 can prevent unnecessary electrical connection as described above. 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, the sensor element 1 is connected to the element piece 3 on the upper surface of the insulating substrate 2. Even if the insulating film 6 is present at the bonding site, 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 flat 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 (the mass portion 33a, the connecting portions 34 and 35, 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 sensor element)
Next, a method for manufacturing the sensor element of this embodiment will be described. Hereinafter, an example of manufacturing the above-described sensor element 1 will be described.
8 and FIG. 9 are diagrams for explaining the method of manufacturing the sensor element shown in FIG. 1, and FIG. 10 is a process shown in FIG. 8C (process for forming a wiring, a contact, and an insulating film). It is a figure for demonstrating. 8 and 9 show cross sections along the Y axis in FIG. 2, respectively.
In the following description, an example in which the insulating substrate 2 is made of a glass material containing alkali metal ions and the element piece 3 is made of a silicon material will be described.

[1]
First, as shown in FIG. 8A, a substrate 102 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 alkali metal ions.
[2]
Next, as shown in FIG. 8B, the upper surface of the substrate 102 is etched to form the cavity 21, the recesses 22, 23, and the protrusions 25. At this time, although not shown in FIG. 8B, the recess 24 is also formed by the etching. As a result, the substrate 102A on which the cavity portion 21, the recesses 22 to 24, and the protrusions 25 are formed is obtained.

  A method (etching method) for forming the cavity 21, the recesses 22 to 24, and the protrusions 25 is not particularly limited. For example, physical etching such as plasma etching, reactive ion etching, beam etching, and optically assisted etching. Or a combination of two or more of chemical etching methods such as wet etching and the like 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. Further, the cavity 21, the recesses 22 to 24, and the protrusions 25 can be formed in order by repeating a plurality of mask formations, etchings, and mask removals. 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, the recessed parts 22-24 (several recessed parts from which depth differs), and the processus | protrusion 25 by using a gray scale mask, for example.

[3]
Next, 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 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.
Then, as shown in FIG. 10B, a plurality of joint protrusions 472 are formed (film formation) on the wiring 42. At this time, although not shown in FIG. 10B, a plurality of joint protrusions 471 and electrodes 45 are formed on the wiring 42 simultaneously with the joint protrusions 472.
In addition, a plurality of bonding protrusions 481, a plurality of bonding protrusions 482, and an electrode 44 are formed on the wiring 41 at the same time as the bonding protrusions 472. Further, the joint protrusion 50 and the electrode 46 are formed on the wiring 43 simultaneously with the joint protrusion 472.

Next, as shown in FIG. 10C, an insulating film 106 is formed (deposited) on the upper surface of the substrate 102A so as to cover the wirings 41, 42 and the like.
Next, as shown in FIG. 10D, portions of the insulating film 106 corresponding to the respective joint protrusions 472 are removed. Although not shown in FIG. 10D, the portions corresponding to the bonding protrusions 471, 481, 482, the bonding protrusion 50, and the electrodes 44 to 46 of the insulating film 106 are also removed. Thereby, the electrodes 44 to 46 are exposed, and the insulating film 106 </ b> A through which the respective joint protrusions 471, 472, 481, 482 and 50 penetrate is obtained.
As described above, the conductor pattern 4 and the insulating film 106A are obtained.

[4]
Next, returning to FIG. 8, as shown in FIG. 8D, the substrate 103 is bonded to the upper surface of the substrate 102A by an anodic bonding method. Thereby, the board | substrate 103 and each joining protrusion 471,472,481,482,50 are connected.
The substrate 103 becomes the element piece 3 through thinning, patterning, and individualization, which will be described later.
The substrate 103 is a silicon substrate.
Further, the thickness of the substrate 103 is larger than the thickness of the element piece 3. Thereby, the handleability of the substrate 103 can be improved. The thickness of the substrate 103 may be the same as the thickness of the element piece 3. In this case, the thinning step [5] described later may be omitted.

[5]
Next, the substrate 103 is thinned to obtain a substrate 103A as shown in FIG.
This thinning is performed so that the thickness of the substrate 103A is the same as the thickness of the element piece 3.
Further, a method for thinning the substrate 103 is not particularly limited, but for example, a CMP method or a dry polishing method can be preferably used.

[6]
Next, by etching the substrate 103A, the element piece 3 is obtained as shown in FIG.
[7]
Next, as shown in FIG. 9B, a lid member 105 having a recess 51 is bonded 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.
[8]
Next, as shown in FIG. 9C, the sensor element 1 is obtained by dividing the joined body 101 into pieces (dicing).

  As described above, in the sensor element 1 according to the first embodiment, the protrusion 25 is provided on the bottom surface of the cavity portion 21 of the insulating substrate 2 at a position overlapping the movable portion 33 in plan view. Thereby, when the movable part 33 is displaced and contacts the bottom surface (including the protrusion 25) of the cavity part 21, the sensor element 1 has a contact range with the movable part 33 on the bottom surface of the cavity part 21. Only part. Thereby, the sensor element 1 can reduce the contact area between the movable portion 33 and the bottom surface of the cavity portion 21, and can prevent permanent sticking between the movable portion 33 and the bottom surface of the cavity portion 21.

In addition, the sensor element 1 can form the cavity 21 and the protrusion 25 of the insulating substrate 2 together by, for example, etching using a photolithography technique by providing the protrusion 25 integrally with the insulating substrate 2. it can.
Thereby, the sensor element 1 can improve manufacturing efficiency, and can reduce the variation in the thickness of the protrusions 25 as compared with the case where the protrusions 25 are formed with electrodes as in the related art (for example, Patent Document 1). Thereby, the sensor element 1 can improve the buffering effect with respect to the movable part 33 of the cavity 21 of the insulating substrate 2 at the time of impact such as dropping.
As a result, the sensor element 1 can improve reliability.

  The sensor element 1 includes a movable portion 33 connected to the insulating substrate 2 via the connecting portions 34 and 35, the connecting portions 34 and 35, a movable electrode portion 36 provided on the mass portion 33a, 37, and the fixed electrode portions 38, 39 are provided on the insulating substrate 2 so as to face the movable electrode portions 36, 37, so that the fixed electrode portions 38, 39 and the movable electrode portions 36, 37 are connected to each other. Based on the capacitance between them, physical quantities such as acceleration and angular velocity can be detected with high sensitivity and accuracy.

  Further, since the sensor element 1 is provided with the projections 25a, 25b, and 25c overlapping with the mass portion 33a in plan view, the mass portion 33a having a large mass in the movable portion 33 and the cavity portion of the insulating substrate 2 are provided. Adhesion with the bottom surface of 21 can be effectively prevented.

  The sensor element 1 is provided at a position where the projection 25a overlaps the center O of the mass portion 33a in plan view, and the projection 25b and the projection 25c are located with respect to the center line B along the Y axis of the mass portion 33a. Since they are provided so as to be symmetrical with each other, it is possible to more effectively prevent the mass portion 33a having a large mass and the bottom surface of the cavity portion 21 of the insulating substrate 2 from sticking to each other more effectively. .

  The sensor element 1 has protrusions 25d, 25e, 25f, 25g, 25h, 25i, 25j, 25k, 25l, and 25m, and movable electrode fingers 361, 362, 363, 364, 365, 371, 372, 373, and 374. Since it is provided at a position overlapping with 375 in plan view, sticking of the movable electrode fingers 361 to 365 and 371 to 375 of the movable portion 33 and the bottom surface of the cavity portion 21 of the insulating substrate 2 is effectively prevented. can do.

  In the sensor element 1, the protrusions 25 d, 25 e, 25 f, 25 g, 25 h and the protrusions 25 i, 25 j, 25 k, 25 l, 25 m are symmetric with respect to the center line C along the X axis of the movable part 33. Therefore, sticking between the movable electrode fingers 361 to 365 and 371 to 375 of the movable portion 33 and the bottom surface of the cavity portion 21 of the insulating substrate 2 can be prevented in a more balanced manner.

  Further, the sensor element 1 is provided at a position where the projection 25 overlaps with the connecting portions 34 and 35 of the movable portion 33 in plan view, so that the connecting portions 34 and 35 of the movable portion 33 (beams 341, 342 and 351) , 352) and the bottom surface of the cavity 21 of the insulating substrate 2 can be effectively prevented.

In the sensor element 1, the insulating substrate 2 is made of glass containing alkali metal ions as an insulating material, and the movable portion 33 (element piece 3) is made of silicon as a semiconductor material. And the movable part 33 (element piece 3) can be reliably separated.
Thereby, the sensor element 1 can improve reliability.

(Electronics)
Next, an electronic device including the sensor element described above will be described.
FIG. 11 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer as an electronic apparatus including a sensor element.
As shown in FIG. 11, the personal computer 1100 includes a main body portion 1104 having a keyboard 1102 and a display unit 1106 having a display portion 1101. The display unit 1106 is connected to the main body portion 1104 via a hinge structure portion. And is rotatably supported.
Such a personal computer 1100 incorporates the sensor element 1.

FIG. 12 is a perspective view illustrating a configuration of a mobile phone (including PHS) as an electronic device including a sensor element.
As shown in FIG. 12, the mobile phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 1201 is disposed between the operation buttons 1202 and the earpiece 1204. .
Such a cellular phone 1200 incorporates the sensor element 1.

FIG. 13 is a perspective view illustrating a configuration of a digital still camera as an electronic apparatus including a sensor element. In FIG. 13, the connection with external devices is also shown in a simplified manner.
Here, a normal 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 image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.
A display unit 1310 is provided on the back surface (front side in the figure) of the case (body) 1302 in the digital still camera 1300, and the display unit 1310 is configured to perform display based on an imaging signal from the CCD. Functions as a viewfinder that displays images as electronic images.
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 1310 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. 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, if 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 sensor element 1.

Since such an electronic device includes the sensor element 1 having excellent reliability, the electronic device can exhibit excellent performance.
In addition to the personal computer of FIG. 11 (mobile personal computer), the mobile phone of FIG. 12, and the digital still camera of FIG. Inkjet printers), laptop personal computers, televisions, video cameras, video tape recorders, various navigation devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game devices, word processors, workstations, televisions Telephone, crime prevention TV monitor, electronic binoculars, POS terminal, medical equipment (for example, electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measuring devices, Instruments (eg, vehicles, navigation Aircraft, gauges of a ship), can be applied to a flight simulator or the like.

  DESCRIPTION OF SYMBOLS 1 ... Sensor element, 2 ... Insulating substrate as a base substrate, 3 ... Element piece, 4 ... Conductor pattern, 5 ... Cover member, 6 ... Insulating film, 21 ... Hollow part, 22, 23, 24 ... Recessed part, 25, 25a , 25b, 25c, 25d, 25e, 25f, 25g, 25h, 25i, 25j, 25k, 25l, 25m ... projections, 31, 32 ... fixed parts, 33 ... movable parts, 33a ... mass parts, 34, 35 ... spring parts Connecting part, 36, 37 ... movable electrode part, 38, 39 ... fixed electrode part, 41, 42, 43 ... wiring, 44, 45, 46 ... electrode, 50 ... joining protrusion, 51 ... recessed part, 101 ... joining Body, 102, 102A, 103, 103A ... substrate, 105 ... lid member, 106, 106A ... insulating film, 221, 222 ... gap, 341, 342, 351, 352 ... beam, 361, 362, 363, 364, 365 3 1,372,373,374,375 ... movable electrode fingers, 382, 384, 386, 388, 392, 394, 396, 398 ... fixed electrode fingers (first fixed electrode fingers), 381, 383, 385, 385, 387 , 391, 393, 395, 397 ... fixed electrode fingers (second fixed electrode fingers), 471, 472, 481, 482 ... joint protrusions, 1100 ... personal computer as an electronic device, 1101 ... display unit, 1102 ... keyboard, DESCRIPTION OF SYMBOLS 1104 ... Main-body part, 1106 ... Display unit, 1200 ... Mobile telephone as an electronic device, 1201 ... Display part, 1202 ... Operation button, 1204 ... Earpiece, 1206 ... Mouthpiece, 1300 ... Digital still camera as an electronic device, 1302 ... Case, 1304 ... Light receiving unit, 1306 ... Shutter button, 1308 ... Me Lee, 1310 ... the display unit, 1312 ... the video signal output terminal, 1314 ... input and output terminals, 1430 ... TV monitors, 1440 ... personal computer.

Claims (7)

A base substrate;
A movable portion provided on the base substrate and movable in accordance with a physical quantity;
The base substrate is provided with a protrusion at a position overlapping the movable portion in plan view,
The physical quantity sensor element, wherein the protrusion is provided integrally with the base substrate. The movable part includes a spring part, a mass part connected to the base substrate via the spring part, and a movable electrode part provided on the mass part,
The physical quantity sensor element according to claim 1, wherein a fixed electrode portion is provided on the base substrate so as to face the movable electrode portion.   The physical quantity sensor element according to claim 2, wherein the protrusion is provided at a position overlapping the mass portion in plan view.   The physical quantity sensor element according to claim 3, wherein a plurality of the protrusions are provided so as to be symmetric with respect to a center of the mass portion.   5. The physical quantity sensor element according to claim 2, wherein the protrusion is provided at a position overlapping with at least one of the movable electrode part and the spring part in a plan view. .   6. The physical quantity sensor element according to claim 1, wherein the base substrate is made of an insulating material, and the movable part is made of a semiconductor material.   An electronic apparatus comprising the physical quantity sensor element according to any one of claims 1 to 6.

Images