JP2013170975A - Physical quantity induction base, physical quantity detection device, physical quantity detector, manufacturing method thereof, and electronic apparatus - Google Patents

Abstract

To solve a problem that a support portion used for positioning when a physical quantity sensitive base is assembled in a package causes a decrease in sensitivity of a physical quantity detector.
A base portion, a plate-like movable portion having a base end connected to a distal end of the base portion via a joint portion, and a portion extending from the base portion along the movable portion in a plan view. The other portion between the intermediate portion of the support portion corresponding to the center position between the base end and the other end of the movable portion 12 and the base end of the base portion 10. The first easy-to-break portion 15 that is easier to break is provided.
[Selection] Figure 2

Description

  The present invention relates to a physical quantity sensitive base, a physical quantity detection device, a physical quantity detector, a method of manufacturing a physical quantity detector, and an electronic apparatus.

For example, an acceleration detector as a physical quantity detector uses a phenomenon in which the resonance frequency of the piezoelectric vibration element changes when a force in the detection axis direction acts on the piezoelectric vibration element. Some are configured to detect applied acceleration.
Patent Document 1 includes a base, a pendulum-type rotating mass that is connected to the base by a hinge joint and can rotate about the hinge joint as a rotation axis, and sensor means that bridges the rotating mass to the base. A pendulum accelerometer (hereinafter referred to as an acceleration detection device) is disclosed.
In the acceleration detecting device, a rotating mass (hereinafter referred to as a movable portion) rotates (hereinafter referred to as a displacement) in accordance with an applied acceleration, whereby a tensile stress or a compressive stress is applied to the sensor means (hereinafter referred to as an acceleration detecting element). The acceleration is detected based on the change in the resonance frequency of the acceleration detecting element.
Further, the base of the acceleration detection device includes a base portion that supports one end of the acceleration detection element, two arms that extend in parallel from both longitudinal ends of the base portion along both sides of the movable portion, and extend in parallel. It is a rectangular frame comprising a connecting piece that connects the ends of the two arms.
The U-shaped frame portion composed of the two arms and the connecting piece in Patent Document 1 is effectively used to maintain the mounting accuracy and levelness when the acceleration detecting device is housed in the package. The In other words, a mounting step is provided on the inner wall of the box-shaped package so as to project in a U shape in plan view, and a U-shaped frame is placed on the supporting step and bonded to any part, thereby mounting accuracy. It is possible to maintain a high level of level.

  However, when an acceleration detector with a rectangular frame base bonded and fixed in the package is built, the two arms cause mechanical resonance due to vibration of the acceleration detection element or external vibration, and various vibration modes are induced. These vibration modes become noises that hinder normal resonance of the acceleration detecting element. Moreover, if the arm, which is made of a material different from the package, is rigidly fixed to the package over a wide bonding area, it will cause a problem due to thermal stress due to the difference in linear expansion coefficient, specifically, change in external temperature. This leads to an undesirable result that the thermal stress generated by is transmitted to the acceleration detecting element via the arm and causes fluctuations in the resonance frequency.

JP-A-1-302166

  If the bonding area and the number of bonding points between the two arms and the package are minimized to cope with such a problem, the arm can vibrate relatively freely with respect to the package. However, if free vibration of the arm is allowed, the two arms cause mechanical resonance due to the vibration of the acceleration detection element or external vibration, inducing various harmful vibration modes, affecting the sensitivity of the acceleration detection element. Will be.

  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 sensitive base according to this application example is aligned with a base portion and the base substrate along a direction orthogonal to the width direction of the base portion, and a joint portion is provided at the tip of the base portion. A physical quantity sensitive base having a plate-like movable part having a base end connected thereto, and a support part provided with a portion extending from the base part along the movable part in plan view, It is easier to break than other parts between the intermediate part of the support part and the base part of the base part, which are arranged along the width direction with the center position between the base end and the other end of the movable part. The first easy-to-break part is provided.

  According to this, since the portion close to the base portion of the support portion or the base portion is configured to be easily broken, the breakable portion is broken to support the physical quantity detection element supported by the base portion. Unnecessary vibrations propagated to the physical quantity detection element from other parts and other parts can be blocked, and a decrease in sensitivity of the physical quantity detection element can be prevented.

  Application Example 2 The support unit includes an extension that extends in the width direction along the distal end of the movable unit.

  When the physical quantity detection device is accommodated in the package, the extension portion functions as a stopper that regulates the movable range of the movable portion.

  Application Example 3 A second easy-to-break part that is easier to break than other parts is provided between the intermediate part of the support part and the tip of the extension part of the support part.

  A part of the support part remains on the physical quantity sensitive base side only by breaking the first easy-to-break part, but a part that causes unnecessary mechanical vibration by breaking the second broken part Can be removed.

  Application Example 4 In the first and second breakable parts, at least one of the width, thickness, or thickness of the support part, the base part, or the extension part is partially other part. It has the structure formed smaller than this.

  The easily breakable portion can be easily formed by reducing the width and thickness of an arbitrary portion of the physical quantity sensitive base.

  Application Example 5 The support portion includes a first arm and a second arm that protrude from the base portion with the movable portion interposed therebetween, and tip portions of the first and second arms. It is the substantially U-shaped body which has the said extension part which connects between, It is characterized by the above-mentioned.

  By configuring the physical quantity sensitive base in this way, it is possible to maintain the stability of the shape when assembled in the package, and to ensure good positioning accuracy and levelness.

  Application Example 6 A physical quantity detection device according to this application example includes the physical quantity sensitive base according to any one of application examples 1 to 5, a physical quantity detection element spanned between the base unit and the movable unit, It is provided with.

  Since the portion that causes unnecessary vibration when assembled in the package is cut off from the easily breakable portion, it is possible to effectively prevent a decrease in sensitivity.

  Application Example 7 Mass portions are arranged on both main surfaces of the movable portion, and the extension portion of the support portion is in a non-contact state in a gap between the end portions of the mass portions protruding from the tip of the movable portion. It is arranged by these.

  The extension portion of the support portion does not interfere with the mass portion when the movable portion vibrates within an appropriate range, but functions as a stopper by interfering with the mass portion when exceeding the appropriate range.

  Application Example 8 A physical quantity detector according to this application example includes the physical quantity detection device according to Application Example 6 or 7, and a package that accommodates the physical quantity detection device, and the physical quantity sensitive device includes the first physical quantity detection device. The easy-to-break part or the first and second easy-to-break parts are provided.

  A physical quantity detector is configured by incorporating a physical quantity detection device in a package. By removing a part of the support part or the base part that causes unnecessary vibrations by using the easily breakable part or by blocking it from the physical quantity detection element, it is possible to prevent the sensitivity of the detector from being lowered.

  Application Example 9 The physical quantity detection device is broken at the first breakable portion, and the base portion and the support portion are fixed in the package.

  By breaking at the first easily breakable portion, the support portion and the physical quantity detection element can be blocked, and a decrease in detection sensitivity due to unnecessary vibration propagating from the support portion can be prevented.

  Application Example 10 The physical quantity detection device is characterized in that the first and second breakable parts are broken and the base part and the support part are fixed in the package.

  By breaking at the first easily breakable portion and the second easily breakable portion, the support portion and the physical quantity detection element can be blocked, and the detection sensitivity is reduced due to unnecessary vibration propagating from the support portion. Can be prevented.

  [Application Example 11] A part of the support part located between the broken first easily breakable part and the second easily breakable part, or a part of the support part and the base part It is characterized by having removed.

  By breaking both easily breakable parts and removing the member located between them, the possibility of unnecessary vibrations adversely affecting the physical quantity detection element can be greatly reduced.

  [Application Example 12] The method of manufacturing a physical quantity detector according to any one of Application Examples 9 to 11, wherein the base part, the joint part, the movable part, and the support part are integrated. Forming the physical quantity sensing base, forming the physical quantity detecting element by fixing the physical quantity detecting element across the base part and the movable part, and fixing the mass part to the movable part. A step of fixing the physical quantity detection device in the package, and a step of breaking the first easily breakable portion or the first and second easily breakable portions. To do.

  A physical quantity detector is configured by incorporating a physical quantity detection device in a package. By removing a part of the support part or the base part that causes unnecessary vibrations by using the easily breakable part or by blocking it from the physical quantity detection element, it is possible to prevent the sensitivity of the detector from being lowered.

  Application Example 13 An electronic apparatus according to this application example includes the physical quantity detector according to any one of Application Examples 9 to 11.

  It is possible to provide an electronic device having the above-described effects of the physical quantity detector.

It is a partial expansion model perspective view showing a schematic structure of an acceleration detection device as an example of a physical quantity detection device of this embodiment. It is a schematic diagram which shows schematic structure of the acceleration detection device of this embodiment, (a) is a top view, (b) is sectional drawing in the AA of (a). It is a schematic cross-sectional view explaining the operation of the acceleration detection device, (a) shows a state where the movable part is displaced downward on the paper surface, (b) is a diagram showing a state where the movable part is displaced above the paper surface. . It is a flowchart which shows an example of the manufacturing process of an acceleration detection device. (A) And (b) is a schematic diagram explaining the main manufacturing process of an acceleration detection device. (A) And (b) is a schematic diagram explaining the main manufacturing process of an acceleration detection device. (A) And (b) is a schematic diagram explaining the main manufacturing process of an acceleration detection device. It is a model plane sectional view which shows schematic structure of the acceleration detector as an example of a physical quantity detector, (a) is a top view seen from the lid (lid body) side, (b) is C of (a). It is sectional drawing in the -C line. It is a top view of the acceleration detector which shows the state which fractured | ruptured the easy breakable part and removed the excision required part. It is a top view which shows the structure of the modification of the acceleration sensitive base (physical quantity sensitive base) 2 of this invention. It is a model perspective view which shows the inclinometer which concerns on one Embodiment of this invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.
(Embodiment)
First, an example of the configuration of the physical quantity detector will be described.
FIG. 1 is a partially developed schematic perspective view showing a schematic configuration of an acceleration detection device as an example of a physical quantity detection device of the present embodiment. 2A and 2B are schematic cross-sectional views showing a schematic configuration of the acceleration detection device of the present embodiment. FIG. 2A is a plan view, and FIG. 2B is a line AA in FIG. FIG. In addition, each wiring is abbreviate | omitted and the dimension ratio of each component differs from actual.

As shown in FIGS. 1 and 2, the acceleration detection device (physical quantity detection device) 1 includes an acceleration sensitive base 2 as a physical quantity sensitive base, an acceleration detection element 30 as a physical quantity detection element, and a mass unit 40. ing.
The acceleration sensitive base 2 has a substantially rectangular, flat plate-like base portion 10 and a flat plate shape in which one end portion (base end, fixed end) 12A is connected to a distal end edge 10B of the base portion 10 via a joint portion 11. The movable part 12 and the support part 14 (14A, 14B, 14C) provided with the site | part extended along a movable part from a base part in planar view are provided.
The range of the base portion 10 is a region located between a line L1 obtained by linearly extending both end portions of the distal end edge 10B and the base end portion 10A of the base portion. Therefore, the base end of the support portion 14 is located along the line L1.

The movable portion 12 can be displaced in a direction intersecting the main surface with the joint portion 11 as a fulcrum according to an acceleration applied in a direction intersecting the main surfaces 12a and 12b or a gravitational acceleration.
The support portion 14 includes a first arm 14A and a second arm 14B that protrude from the both ends in the longitudinal direction of the base portion 10 with the movable portion 12 therebetween, and a first arm and a second arm. And a connecting portion (extension portion) 14 </ b> C that connects the tip portions of each other. The first and second arms extend in parallel with each other on both side edges of the movable portion 12 in a non-contact state.
Furthermore, each arm 14A, 14B is located on a center line CL extending in the width direction from a center position C between at least a base end (right end) 12A of the movable portion 12 and a front end (left end) 12B facing the base end. A first easily breakable portion 15 (which is less rigid than other portions and easy to break) between the intermediate portion of the support portion 14 (arms 14A and 14B) positioned and the base end (right end) 10A of the base portion 10. 15A, 15B) and between the intermediate portion of the support portion 14 (arms 14A, 14B) located on the center line CL and the distal end edge 14C of the connection portion (extension portion) 14C of the support portion. A second easy-to-break portion 17 is provided which is weaker than the portion and easy to break.

The easy breakable portions 15 and 17 may be configured to be easily broken by partially narrowing the width of the arms 14A and 14B or the base portion 10 as in the illustrated example, or by thinning them. You may comprise easily to fracture | rupture. Alternatively, the width may be reduced and the wall thickness may be reduced. In any case, when a mechanical force is applied in the thickness direction and other directions, the easily breakable portion breaks and other portions of the arm (including the connecting portion 14C and the base portion 10) are folded from that portion. It is configured to be easy to take. Further, the breakable portions 15 and 17 may be provided only on the arms 14A and 14B, may extend over the arms and the base portion 10, or may be provided only on the base portion.
The base portion 10 and the support portion 14 have a plurality of (four in this case) fixing portions 14a, 14b, 14c, and 14d that are portions fixed to an external member such as a package and a substrate, and are adjacent in plan view. Within a range surrounded by connecting fixed portions (for example, a range surrounded by non-crossing lines connecting adjacent fixed portions as in the range surrounded by a two-dot chain line in FIG. 2A) Inner), the fixing portions 14a to 14d are arranged so that the center of gravity G of the acceleration detection device 1 is located. In addition, when there are two fixing portions, it is only necessary that the two fixing portions are arranged so that the center of gravity G is positioned on a straight line connecting the fixing portions.

The acceleration detection element 30 is bridged across the joint portion 11 between the base portion 10 and the movable portion 12.
A pair of mass parts that partially overlap the region on the other end (tip, free end) 12B side of the movable part 12 in plan view on both main surfaces 12a, 12b corresponding to the front and back surfaces of the flat plate of the movable part 12 (Weights) 40 are arranged by bonding. Each mass portion 40 is bonded to the same position on each main surface 12a, 12b via a bonding material 42. 14 C of support parts are arrange | positioned in the non-contact state in the space between the edge parts of each mass part which protrudes from the front-end edge of the movable part 12. FIG. As will be described later, the connecting portion 14C separated from the arms 14A and 14B is left in the package to function as a stopper that regulates the movable range in the thickness direction of the movable portion 12 including the mass portion. To do.

The base part 10, the joint part 11, the movable part 12, and the support part 14 are integrally formed in a substantially flat plate shape, for example, using a quartz substrate cut out from a quartz crystal or the like at a predetermined angle. A slit-like hole that separates the movable portion 12 and the support portion 14 (14A, 14B, 14C) except for one end side (tip side) connected by the joint portion 11 is provided. SL is provided.
The outer shapes of the base portion 10, the joint portion 11, the movable portion 12, and the support portion 14 are accurately formed using techniques such as photolithography and etching.
As described above, the base portion 10 and the support portion 14 are continuous with the line L1 as a boundary.

The joint portion 11 is a direction (Y-axis direction) that connects the base portion 10 and the movable portion 12 so as to separate the base portion 10 and the movable portion 12 by half-etching from both the main surfaces 12a and 12b side of the movable portion. It is comprised from the bottomed groove part 11a formed along the direction (X-axis direction) orthogonal to.
The cross-sectional shape (shape of FIG. 2B) along the Y-axis direction of the joint portion 11 is formed in a substantially H shape by the groove portion 11a.
By this joint portion 11, the movable portion 12 intersects the main surface 12a with the joint portion 11 as a fulcrum (rotation axis) according to the acceleration applied in the direction (Z-axis direction) intersecting the main surface 12a (12b). It can be displaced (rotated) in the direction (Z-axis direction).

Each mass portion 40 has a columnar (disk-shaped) convex portion 40a that protrudes toward the main surfaces 12a and 12b of the movable portion 12, and the tip of the convex portion 40a is the main surface 12a of the movable portion 12. , 12b through a bonding material 42.
In addition, it is preferable that the convex part 40a makes plane size as small as possible, ensuring the area required for joining to the movable part 12, from a viewpoint of suppression of thermal stress. Moreover, it is preferable that the gravity center of the mass part 40 is settled in the convex part 40a in planar view from a viewpoint of the inclination avoidance at the time of joining.
The mass portion 40 avoids the acceleration detecting element 30 from the free end 12B side opposite to the joint portion 11 side in the movable portion 12 in order to increase the plane size as much as possible in order to improve the sensitivity of the acceleration detecting device 1. It is bifurcated and extends to the vicinity of the joint portion 11 and is formed in a substantially U shape in plan view.
For the mass part 40, for example, a material having a relatively large specific gravity represented by a metal such as Cu or Au is used.
For the bonding material 42, for example, a silicone-based thermosetting adhesive is used as an adhesive including a silicone-based resin (such as a modified silicone resin) having excellent elasticity.
In the region B where the mass portion 40 and the support portion 14 (connecting portion 14C) overlap (the hatched portion in FIG. 2A), there is a gap between the end portions of both mass portions as shown in FIG. 2B. A gap C is provided between the mass portions 40 and the connecting portion 14C. In the present embodiment, the gap C is managed by the thickness (projection height) of the convex portion 40a.

The acceleration detection element 30 has at least one or more (two in this case) prismatic shape extending along the direction connecting the base portion 10 and the movable portion 12 (Y-axis direction), and flexurally vibrates in the X-axis direction. An acceleration detection unit 30c having vibration beams 30a and 30b and a pair of bases 30d and 30e connected to both ends of the acceleration detection unit 30c are provided.
The acceleration detecting element 30 uses a piezoelectric material to form two sets of tuning forks with two vibrating beams 30a and 30b and a pair of bases 30d and 30e. It is also called a tuning fork type resonator element.
The acceleration detection element 30 is formed, for example, by using a quartz substrate cut out at a predetermined angle from a quartz crystal or the like, and the acceleration detection unit 30c and the bases 30d and 30e are integrally formed in a substantially flat plate shape. Further, the outer shape of the acceleration detecting element 30 is accurately formed by using techniques such as photolithography and etching.
In the acceleration detecting element 30, one base 30d is fixed to the main surface 12a side of the movable portion 12 via a bonding member 31 such as a low melting point glass or an Au / Sn alloy coating capable of eutectic bonding, and the other The base 30 e is fixed to the main surface 10 a side of the base portion 10 (the same side as the main surface 12 a of the movable portion 12) via the joining member 31.

In addition, between the acceleration detection element 30 and the main surface 10a of the base part 10 and the main surface 12a of the movable part 12, when the movable part 12 is displaced, the acceleration detection element 30, the base part 10 and the movable part 12 are mutually connected. A predetermined gap is provided to prevent contact. This gap is managed by the thickness of the joining member 31 in this embodiment.
Specifically, for example, the base portion 10 and the movable portion 12 are sandwiched between the base portion 10 and the movable portion 12 and the acceleration detecting element 30 with a spacer formed in a thickness corresponding to a predetermined gap. By fixing the acceleration detecting element 30 and the acceleration detecting element 30 with the joining member 31, the gap can be managed within a predetermined range. The method for manufacturing the acceleration detection device 1 will be described later.

The acceleration detecting element 30 includes conductive electrodes such as a metal filler mixed with conductive electrodes such as metal fillers, which are extracted from excitation electrodes (drive electrodes) (not shown) of the vibration beams 30a and 30b to the base 30e. The connection terminals 10 b and 10 c provided on the main surface 10 a of the base portion 10 are connected by an agent (for example, a silicone-based conductive adhesive) 32.
More specifically, the extraction electrode 30f is connected to the connection terminal 10b, and the extraction electrode 30g is connected to the connection terminal 10c.
The connection terminals 10b and 10c of the base portion 10 are connected to external connection terminals 10e and 10f provided on a main surface 10d which is a surface opposite to the main surface 10a of the base portion 10 by wiring not shown. Specifically, the connection terminal 10b is connected to the external connection terminal 10e, and the connection terminal 10c is connected to the external connection terminal 10f.

The excitation electrodes, extraction electrodes 30f and 30g, connection terminals 10b and 10c, and external connection terminals 10e and 10f have a structure in which, for example, Cr is used as a base layer and Au is stacked thereon.
The first and second breakable portions 15 and 17 are broken after the acceleration detecting device 1 is assembled in the package by bonding the fixing portions 14a, 14b, 14c, and 14d. The arm piece 18 located between the easily breakable part 15 and the second easily breakable part 17 can be removed from the acceleration sensitive base 2.
If a part (arm piece) 18 of the arms 14A and 14B removed by breaking both breakable parts is left on the package side, the arm piece left by normal vibration of the acceleration detecting element 30 is left. Causes mechanical resonance, and this vibration component adversely affects the original resonance frequency of the acceleration detecting element. For this reason, it is ideal that the arm piece is not left on the package side.

In this example, the first and second easily breakable portions 15 and 17 are both broken, and the arm piece 18 (the surplus portion) located between the both easily breakable portions is removed. In this way, a configuration in which the arm piece 18 is left on the package side without breaking the second breakable portion 17 is also possible. In this case, by fixing the arm piece in the package using a flexible adhesive, the stress due to the difference in linear expansion coefficient between the package and the arm piece may be alleviated while preventing free vibration. .
Therefore, in the present invention, the first easily breakable portion 15 is essential, and the second easily breakable portion 17 is not essential.

The first breakable portion 15 may be formed anywhere between the center line CL of the movable portion 12 and the base end portion 10A of the base portion. Specifically, the base portion 10 and the arms 14A and 14B may be formed. It may be on the line L1 which is a boundary line, or may be on the support part side or the base part side from the line L1.
The second easily breakable portion 17 is formed on the arms 14A and 14B on the distal end side (left side) with respect to the center line CL of the movable portion. Moreover, you may form the 2nd breakable part 17 in the both ends except the longitudinal direction center part (part which functions as a stopper with respect to a mass part) of the connection part 14C.
In other words, as long as the first easily breakable portion 15 can divide the arm from the base portion by breaking this portion, a part of the first breakable portion 15 may be applied to the base portion. The arm piece (including a part of the base part in some cases) separated from the base part by breaking the first easy-to-break part 15 causes the acceleration sensitive base 2 to break by breaking the second easy-to-break part 17. It is preferable to completely remove a portion that causes an unnecessary vibration mode by cutting away the material. In addition, you may leave on the package side by devising the adhesion part of an arm piece and a package.
Since the connecting part 14C is a part that functions as a stopper of the movable part, the connecting part 14C is adhered and fixed to the package side. However, within the range that does not interfere with the function of the mass part 40 as a stopper, the connecting part 14C is located near both ends of the connecting part 14C. A second easy break portion 17 may be provided.

Next, the operation of the acceleration detection device 1 will be described.
FIG. 3 is a schematic cross-sectional view for explaining the operation of the acceleration detection device 1. FIG. 3A shows a state where the movable part is displaced downward (−Z direction) in the drawing, and FIG. 3B shows a state where the movable part is displaced upward (+ Z direction) in the drawing.
As shown in FIG. 3A, when the movable portion 12 is displaced in the −Z direction with the joint portion 11 as a fulcrum by an inertial force corresponding to the acceleration + α applied in the Z-axis direction, In addition, a tensile force is applied in a direction in which the base 30d and the base 30e are separated from each other in the Y-axis direction, and tensile stress is generated in the vibrating beams 30a and 30b of the acceleration detection unit 30c.
Thereby, for example, the vibration frequency of the vibration beams 30a and 30b of the acceleration detection unit 30c (hereinafter also referred to as the resonance frequency) is changed to be higher like a string of a wound string instrument.

On the other hand, as shown in FIG. 3B, when the movable portion 12 is displaced in the + Z direction with the joint portion 11 as a fulcrum by an inertial force corresponding to the acceleration −α applied in the Z-axis direction, the acceleration detecting element 30. Is applied with a compressive force in a direction in which the base 30d and the base 30e approach each other in the Y-axis direction, and compressive stress is generated in the vibrating beams 30a and 30b of the acceleration detector 30c.
Thereby, for example, the resonance frequency of the vibrating beams 30a and 30b of the acceleration detecting unit 30c is changed to be lower like a string of a rewinded string instrument.
The acceleration detection device 1 is configured to detect this change in resonance frequency. The acceleration (+ α, −α) applied in the Z-axis direction is derived by converting the acceleration (+ α, −α) into a numerical value determined by a lookup table or the like according to the detected change rate of the resonance frequency.

Here, as shown in FIG. 3A, when the acceleration + α applied in the Z-axis direction is larger than a predetermined magnitude, the connecting portion 14C in the plan view of the mass portion 40 fixed to the main surface 12a of the movable portion 12 is obtained. The part which overlaps with the main surface 14Ca of a connection part contacts.
Accordingly, the connecting portion 14C restricts the displacement of the movable portion 12 that is displaced in the −Z direction according to the acceleration + α within a predetermined range (corresponding to the gap C, see FIG. 2B).
On the other hand, as shown in FIG. 3B, when the acceleration −α applied in the Z-axis direction is larger than a predetermined magnitude, the connecting portion 14C in the plan view of the mass portion 40 fixed to the main surface 12b of the movable portion 12 is obtained. The portion overlapping with the main surface 14Cb of the connecting portion 14C comes into contact. Thereby, the displacement of the movable portion 12 that is displaced in the + Z direction according to the acceleration −α is restricted within a predetermined range (corresponding to the gap C, see FIG. 2B).

Next, an example of a method for manufacturing the acceleration detection device 1 will be described.
FIG. 4 is a flowchart showing an example of the manufacturing process of the acceleration detecting device, and FIGS. 5 to 7 are schematic diagrams for explaining each main manufacturing process.
As shown in FIG. 4, the manufacturing method of the acceleration detecting device 1 includes an acceleration sensitive base (physical quantity sensitive base) forming step S1, an acceleration detecting element (physical quantity detecting element) joining step S2, a mass part joining step S3, an acceleration. And a detection device (physical quantity detection device) separation step S4.

[Acceleration-sensitive base forming step S1]
First, as shown in the schematic diagram for explaining the acceleration-sensitive base forming process in FIG. 5, for example, using a quartz substrate (wafer) 100 cut out from a quartz crystal or the like at a predetermined angle, photolithography, wet etching, etc. With this technique, the acceleration sensitive base 2 in which the base portion 10, the joint portion 11, the movable portion 12, and the support portions 14 (14A, 14B, 14C) are integrated is formed.
The acceleration sensitive base 2 is connected to another acceleration sensitive base 2 adjacent in the vertical and horizontal directions via a connecting beam (corresponding to a separation tab) 120, so that a plurality of acceleration sensitive bases 2 are taken on one quartz substrate 100.

At this time, first and second easily breakable portions 15 and 17 are formed in a part of the support portion 14, in the present example, in the vicinity of both ends in the longitudinal direction of the arms 14A and 14B, respectively. The easy breakable portions 15 and 17 according to this example are narrow portions formed by removing a part of two opposing edges in the width direction of each arm in a concave shape in a plan view by etching. It is good also as a thin part which made the thickness of the arm thin locally. In order to make the thin part, for example, one side or both sides of the arm are processed by wet etching or the like to form a thinner part than the other part. In addition, each easy-to-break part may be provided in part or all in the base part 10, or may be provided in the connecting part 14C.
In addition, as an example of the thickness of each part of the acceleration sensitive base 2, the base part 10 and the movable part 12 are about 100 micrometers-200 micrometers, and the joint part 11 is about 20 micrometers. When the easily breakable portions 15 and 17 are thin portions, the thickness is about 40 μm. The joint portion 11 is formed by half etching from both the main surfaces 12a and 12b.

[Acceleration element joining step S2]
Next, as shown in the schematic diagram for explaining the acceleration detecting element joining step in FIG. 6, the acceleration detecting element 30 is bridged between the base portion 10 and the movable portion 12 and fixed.
Specifically, one base portion 30d of the acceleration detection element 30 is fixed to the main surface 12a of the movable portion 12 via a joining member 31 such as, for example, low melting point glass or Au / Sn alloy coating capable of eutectic bonding. Then, the other base portion 30e is fixed to the main surface 10a of the base portion 10 via the bonding member 31.
Note that the acceleration detection element 30 is fixed so that the center line 30h along the direction connecting the movable portion 12 and the base portion 10 overlaps the center line 12c of the movable portion 12 in plan view. From the viewpoint of improving detection characteristics such as sensitivity and accuracy.
At this time, as described above, when the movable portion 12 is displaced in the thickness direction between the acceleration detecting element 30 and the main surface 10a of the base portion 10 and the main surface 12a of the movable portion 12, A predetermined gap is provided so that the base portion 10 and the movable portion 12 do not contact each other. This gap is managed by the thickness of the joining member 31 in this embodiment.

Specifically, for example, the base portion 10 and the movable portion 12 are sandwiched between the base portion 10 and the movable portion 12 and the acceleration detecting element 30 with a spacer formed in a thickness corresponding to a predetermined gap. And the acceleration detecting element 30 are fixed by the joining member 31 and the spacer is removed after the joining member 31 is cured, thereby managing the gap within a predetermined range.
Subsequently, the lead electrodes 30f and 30g of the acceleration detecting element 30 are connected to the base portion 10 via a conductive adhesive (for example, a silicone-based conductive adhesive) 32 mixed with a conductive material such as a metal filler. The connection terminals 10b and 10c provided on the main surface 10a are connected.
More specifically, first, the conductive adhesive 32 is applied so as to straddle the extraction electrode 30f and the connection terminal 10b, and the conductive adhesive 32 is applied so as to straddle the extraction electrode 30g and the connection terminal 10c.
Next, the conductive adhesive 32 is heated and cured, the lead electrode 30f and the connection terminal 10b are electrically connected, and the lead electrode 30g and the connection terminal 10c are electrically connected.
In this step, instead of the conductive adhesive 32, a metal wire may be used to electrically connect the lead electrodes 30f, 30g and the connection terminals 10b, 10c by wire bonding.

[Mass part bonding step S3]
Next, as shown in the schematic diagram for explaining the mass part joining step in FIG. 7, each mass part 40 is fixed (joined) to both main surfaces 12 a and 12 b of the movable part 12 via the joining material 42.
Specifically, first, bonding using, for example, a silicone-based thermosetting adhesive that includes a silicone-based resin (such as a modified silicone resin) excellent in elasticity on the top surface of the convex portion 40a of the mass unit 40. A predetermined amount of the material 42 is applied by an application device such as a dispenser.
Next, the mass portions 40 are aligned so that the convex portions 40 a are on the main surfaces 12 a and 12 b side of the movable portion 12, and arranged on the movable portion 12.
Next, the bonding material 42 is heated and cured to fix (join) the mass portions 40 to the main surfaces 12 a and 12 b of the movable portion 12.

At this time, as described above, from the viewpoint of avoiding the inclination of each mass portion 40, it is preferable that the center of gravity of the mass portion 40 is within the convex portion 40a in plan view.
The acceleration detection device 1 is formed by assembling the mass portions 40 to the acceleration sensitive base 2.

[Acceleration detection device separation step S4]
Next, the connecting beam 120 is cut using a cutting device (not shown), and the acceleration sensitive base 2 is separated from the quartz substrate 100 and separated into individual pieces, whereby the acceleration detecting device 1 as shown in FIGS. 1 and 2 is obtained.
In addition, you may replace the order of said each process suitably in the range which does not have trouble. For example, the mass part bonding step S3 may be performed individually after the acceleration detection device 1 is separated into pieces in the acceleration detection device separation step S4.
Moreover, processes other than the above, such as a preparation process, an inspection process, and an adjustment process, are appropriately performed before and after each of the above processes.

As described above, the method of manufacturing the acceleration detecting device 1 includes the acceleration sensitive base forming step S1 in which the base portion 10, the joint portion 11, the movable portion 12, and the support portion 14 are integrally formed, and the acceleration detecting element. It includes an acceleration detection element joining step S2 that spans and fixes 30 to the base portion 10 and the movable portion 12, a mass portion joining step S3, and an acceleration detection device separation step S4.
The arms 14A and 14B of the acceleration detection device 1 formed in this way are in an unseparated state from the breakable portions 15 and 17, and are assembled and stored in the package in this state. The support portion 14 serves as a clue to ensure assembly accuracy and levelness when assembled into the package.

Next, an acceleration detector configured by housing the acceleration detection device according to the embodiment in a package will be described.
FIG. 8 is a schematic plan sectional view showing a schematic configuration of an acceleration detector as an example of a physical quantity detector according to one embodiment. FIG. 8A is a plan view seen from the lid (lid body) side, and FIG. 8B is a cross-sectional view taken along line CC in FIG. 8A. In the plan view, the lid is omitted. Each wiring is omitted. In addition, the same code | symbol is attached | subjected to a common part with the acceleration detection device which concerns on the said embodiment, detailed description is abbreviate | omitted, and it demonstrates centering on a different part from the said embodiment. FIG. 9 is a plan view of the acceleration detector showing a state in which the easily breakable portion is broken and the excision required portion is removed.

  As shown in FIG. 8, the acceleration detector (physical quantity detector) 5 includes the acceleration detection device 1 described in the above embodiment and the package 50 that houses the acceleration detection device 1. The package 50 includes a package base 51 having a substantially rectangular planar shape and a recess, and a lid 52 having a substantially rectangular and flat shape covering the recess of the package base 51, and is formed in a substantially rectangular parallelepiped shape. Yes. The package base 51 is made of an aluminum oxide sintered body, crystal, glass, silicone or the like obtained by forming, laminating and firing ceramic green sheets. The lid 52 is made of the same material as the package base 51 or a metal such as Kovar, 42 alloy, stainless steel.

The package base 51 is provided with internal terminals 54 and 55 on two stepped portions 53a protruding from the outer peripheral portion of the inner bottom surface (the bottom surface inside the recess) 53 along the inner wall of the recess. The internal terminals 54 and 55 are provided at positions facing the external connection terminals 10e and 10f provided on the acceleration sensitive base 2 (positions overlapping in plan view). The external connection terminal 10 e is connected to the connection terminal 10 b of the base portion 10, and the external connection terminal 10 f is connected to the connection terminal 10 c of the base portion 10. In addition, it is preferable that the external connection terminals 10e and 10f are provided at positions that overlap with the fixing portions 14b and 14c of the support portion 14 in plan view.
A pair of external terminals 57 and 58 used for mounting on an external member such as an electronic device is formed on the outer bottom surface (the surface opposite to the inner bottom surface 53, the outer bottom surface) 56 of the package base 51. . The external terminals 57 and 58 are connected to the internal terminals 54 and 55 by an internal wiring (not shown). For example, the internal terminals 54 and 55 and the external terminals 57 and 58 are made of a metal film in which a film such as Ni or Au is laminated on a metallized layer such as W by a method such as plating.
The package base 51 is provided with a sealing portion 59 that seals the inside of the package 50 at the bottom of the recess. The sealing portion 59 is formed in a stepped through hole 59a formed in the package base 51, the hole diameter on the outer bottom surface 56 side being larger than the hole diameter on the inner bottom surface 53 side, and a sealing material 59b made of Au / Ge alloy, solder, or the like. The inside of the package 50 is hermetically sealed by charging and solidifying after heating and melting.

  In the acceleration detector 5, the fixing portions 14 a, 14 b, 14 c, and 14 d of the support portion 14 of the acceleration detection device 1 are fixed on the stepped portion 53 a of the package base 51 through the adhesive 60. Here, since the fixing portions 14b and 14c are portions for connecting the external connection terminals 10e and 10f and the internal terminals 54 and 55, the adhesive 60 is mixed with a conductive substance such as a metal filler, for example. Silicone resin-based conductive adhesives are used. In addition, you may use the silicone resin type adhesive agent which does not contain electroconductive substances, such as a metal filler, for fixation of the fixing | fixed part 14a, 14d.

The acceleration detecting device 1 is fixed in a horizontal posture in the package by fixing the fixing portions 14a, 14b, 14c, and 14d of the support portion 14 on the stepped portion 53a without breaking the easily breakable portions 15 and 17. The so-called leveling operation can be facilitated and made efficient. Moreover, it becomes easy to ensure the positional accuracy of the acceleration detection device 1 in the package.
In a state where the acceleration detection device 1 is connected to the internal terminals 54 and 55 of the package base 51, the recesses of the package base 51 are covered with the lid 52, and the package base 51 and the lid 52 are seam ring, low melting point glass, adhesive Are joined by a joining member 50a. After the lid 52 is bonded, the sealing material 59b is put into the through hole 59a of the sealing portion 59 in a state where the inside of the package 50 is decompressed (high vacuum state), and is solidified after being heated and melted. The inside of the package 50 is hermetically sealed. Note that the inside of the package 50 may be filled with an inert gas such as nitrogen, helium, or argon. The package may have a recess in both the package base and the lid.
The vibration of the acceleration detection device 1 is driven by a drive signal applied to the excitation electrode of the acceleration detection device 1 via the external terminals 57 and 58, the internal terminals 54 and 55, the external connection terminals 10e and 10f, the connection terminals 10b and 10c, and the like. The beams 30a and 30b oscillate (resonate) at a predetermined frequency. And the acceleration detector 5 outputs the resonance frequency of the acceleration detection device 1 which changes according to the applied acceleration as an output signal.

  At this time, the easily breakable portions 15 and 17 are not broken, so that the arms 14A and 14B are fixed on the stepped portion 53a of the package by the fixing portions 14a, 14b, 14c, and 14d. In this state, mechanical resonance occurs in the arms 14A and 14B due to the vibration of the acceleration detecting element 30 or the vibration from the outside, which causes a decrease in sensitivity of the acceleration detector.

On the other hand, in the present invention, as shown in FIG. 9, the first and second easily breakable portions 15 and 17 are broken, and an arm serving as a cut-away portion located between the first and second easily breakable portions. The piece 18 (which may include a part of the base part and a part of the connecting part 14C) 18 is removed after being separated from the remaining support part and base part fixed to the package side. For this reason, the portion 18 that causes harmful mechanical vibration due to vibration of the acceleration detecting element 30 and external vibration is eliminated, and a decrease in sensitivity of the acceleration detector can be prevented.
The first breakable portion 15 is better as it is closer to the base portion 10. For example, a part of the base part may be cut off by breaking the first easy breakable part. Further, the shorter the protruding length of the portion remaining on the base portion side or the connecting portion 14C side by breaking each breakable portion, the better. That is, it is preferable that the protrusion length of the remaining portion is shortened so that the frequency becomes higher than the frequency when the movable portion 12 vibrates. Specifically, the protrusion length in the X-axis direction or the Y-axis direction is made zero or short.
The connecting part 14C has spring properties because both ends are bonded by two fixing parts 14a and 14d, and two mass parts arranged opposite to each other with the intermediate part of the connecting part 14C interposed therebetween. When it contacts with 40 and the movement range is regulated, a cushion effect (damper function) is exhibited and damage to the movable part is prevented.

In other words, since the connecting portion 14C fixed in the package is disposed in the gap formed between the two mass portions 40, the connecting portion 14C can function as a stopper that regulates the vibration range of the mass portion. For this reason, it is possible to avoid damage to the acceleration detection device 1 due to collision with the inner surface of the package 50 or displacement exceeding the limit of strength.
In the above embodiment, the configuration example of the acceleration sensitive base 2 in which the tip portions of the arms 14A and 14B are connected and integrated by the connecting portion 14C is shown. However, the presence of the connecting portion 14C is essential as the configuration of the acceleration sensitive base 2. Absent. That is, the support portion 14 is composed of two parallel arms 14A and 14B in which the connecting portion 14C does not exist, while a separate stopper piece (on the connecting portion 14C) on the two stepped portions 53a facing the package. (Corresponding) may be adhered. If it does in this way, the structure of a support part can be simplified and the process process by an etching can be simplified. Moreover, the stopper piece separately bonded to the package exhibits the function as a stopper.

Next, FIG. 10 is a plan view showing a configuration of a modification of the acceleration sensitive base (physical quantity sensitive base) 2 of the present invention.
The acceleration sensitive base 2 according to this embodiment is different from the above embodiment in that there is one arm. Leveling when the acceleration sensitive base 2 is assembled in the package can be carried out by using one arm 14B, and the function as a stopper of the mass portion after the assembly can be exhibited by the connecting portion 14C. .
As described above, in the acceleration detector according to the present invention, when the acceleration detection device is fixed in the package, the base portion 10 and the support portion 14 are bonded on the step portion 53a to perform horizontal positioning (leveling). After being surely performed, the excess portion 18 that causes generation of spurious due to mechanical resonance is removed. At this time, a part of the acceleration sensitive base 2, specifically a part of the support part 14 (14 </ b> A, 14 </ b> B, 14 </ b> C) or a part of the base part that is easier to break than other parts (narrow width). A portion (constricted portion) or a thin-walled portion is provided, and the easily breakable portions 15 and 17 are broken by a mechanical force so that the excess portion 18 can be easily cut (broken or cut).

  The surplus portion 18 can be adhered in the package. In this case, the adhesive used for bonding, the bonding site, and the bonding area are devised so as not to cause unnecessary vibration modes to be excited. By leaving a surplus portion in the package, the amount of dust generated can be reduced.

Further, it is only necessary to provide at least one easy break portion near the base portion 10, that is, only the first easy break portion 15. Other portions of the support portion remaining by breaking the first easily breakable portion are removed or bonded and fixed to the package side so as not to cause spurious generation due to mechanical resonance.
The easy breakable portions 15 and 17 may extend over the base portion 10 or the connecting portion (extension portion) 14C beyond the arm portions 14A and 14B, or the base portion 10 or the connecting portion 14C. You may arrange only.
Further, in the support portion 14 of the acceleration sensitive base 2, the connecting portion (extension portion) 14C is not essential, and if only the arms 14A and 14B are provided, the positioning in the horizontal direction when housed in the package is possible. At this time, a connecting portion (stopper member) 14C functioning as a stopper for restricting displacement in the thickness direction of the mass portion 40 fixed to the movable portion 12 may be separately bonded and fixed to a predetermined location in the package. .

Next, an inclinometer as an electronic apparatus including the physical quantity detection device and the acceleration detector described in the embodiment and the modification will be described. FIG. 11 is a schematic perspective view showing an inclinometer according to an embodiment of the present invention. An inclinometer 70 shown in FIG. 11 uses the physical quantity detection device (gravity acceleration detection device) 1 described in the above embodiment as an inclination sensor. The inclinometer 70 is installed at a place to be measured such as a mountain slope, road slope, embankment retaining wall, or the like. The inclinometer 70 is supplied with power from the outside via a cable 71 or has a built-in power supply, and a drive signal is sent to the acceleration detection device 1 by a drive circuit (not shown). Then, the inclinometer 70 changes the attitude of the inclinometer 70 (change in the direction in which the gravitational acceleration is applied to the inclinometer 70) from a resonance frequency that changes according to the gravitational acceleration applied to the acceleration detection device 1 by a detection circuit (not shown). Is converted into an angle, and data is transferred to the base station by radio, for example. Thereby, the inclinometer 70 can contribute to the early detection of abnormality.
The physical quantity detection device and the acceleration detector described above are not limited to the inclinometer, but can be suitably used as an acceleration sensor, an inclination sensor, and the like used for a seismometer, a navigation device, an attitude control device, a game controller, a mobile phone, and the like. In any case, it is possible to provide an electronic device that exhibits the effects described in the embodiment and the modification.

In addition, in the physical quantity detection device 1 (physical sensitive base 2) according to each of the above embodiments, the material of the base portion, the joint portion, the movable portion, and the support portion is not limited to quartz, but is made of glass or silicone. It may be a semiconductor material. The base material of the acceleration detecting element is not limited to quartz, but lithium tantalate (LiTaO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ ), lithium niobate (LiNbO ₃ ), zirconate titanate Piezoelectric materials such as lead oxide (PZT), zinc oxide (ZnO), and aluminum nitride (AlN), or semiconductor materials such as silicone provided with a piezoelectric material such as zinc oxide (ZnO) and aluminum nitride (AlN) as a coating. May be.
The configurations of the detection devices and detectors shown in the above embodiments can also be applied to detection devices and detectors that detect physical quantities other than acceleration, for example, gravitational acceleration. That is, all the above-described configurations of the acceleration detection device or the acceleration detector can be replaced with other physical quantity detection means such as a gravity acceleration detection device or a gravity acceleration detector.

The material of the acceleration detecting element 30 is not limited to quartz, but lithium tantalate (LiTaO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ ), lithium niobate (LiNbO ₃ ), zirconate titanate. Piezoelectric materials such as lead oxide (PZT), zinc oxide (ZnO), and aluminum nitride (AlN), or semiconductor materials such as silicone provided with a piezoelectric material such as zinc oxide (ZnO) and aluminum nitride (AlN) as a coating. May be.
The present invention has been described above by taking the acceleration detector as an example of the physical quantity detector. However, the present invention is not limited to this, and the present invention is also applicable to a physical quantity detector that detects force, speed, distance, etc. from the acceleration detection result. it can.

  DESCRIPTION OF SYMBOLS 1 ... Acceleration detection device (physical quantity detection device), 2 ... Acceleration sensitive base (physical quantity sensitive base), 5 ... Acceleration detector (physical quantity detector), 10 ... Base part, 10A ... Base end part, 10B ... Leading edge, 10a ... main surface, 10b, 10c ... connection terminal, 10d ... main surface, 10e, 10f ... external connection terminal, 11 ... joint, 11a ... groove, 12 ... movable part, 12B ... free end, 12a, 12b ... main surface, 12c ... center line, 14 ... support part, 14A, 14B ... arm, 14C ... coupling part, 14C ｀ ... tip edge, 14Ca ... main surface, 14Cb ... main surface, 14a, 14b, 14c, 14d ... fixed part, 10e, 10f: external connection terminals, 15, 17: breakable part, 18: arm piece (excess part), 30: acceleration detecting element, 30a, 30b ... vibrating beam, 30c: acceleration detecting part, 30d, 30e ... base 30f, 30g ... electrode, 30h ... center line, 31 ... joining member, 32 ... conductive adhesive, 40 ... mass part, 40a ... convex part, 42 ... joining material, 50 ... package, 50a ... joining member, 51 ... package Base, 52 ... Lid, 53 ... Inner bottom surface, 53a ... Stepped portion, 54, 55 ... Internal terminal, 56 ... Outer bottom surface, 57, 58 ... External terminal, 59 ... Sealing portion, 59a ... Through hole, 59b ... Sealing Material 60 ... Adhesive 70 ... Inclinometer 71 ... Cable 100 ... Quartz substrate 120 ... Connecting beam

Claims (13)

A plate-like movable portion that is aligned with the base substrate along a direction orthogonal to the width direction of the base portion and has a base end connected to the distal end of the base portion via a joint portion; A physical quantity sensitive base having a support part having a portion extending along the movable part from the base part in plan view,
At least the center position between the base end and the other end of the movable part and the intermediate part of the support part arranged along the width direction, and the base part of the base part is broken more than other parts A physical quantity sensitive base comprising an easy first breakable part.   The physical quantity sensitive base according to claim 1, wherein the support part has an extension part extending in a width direction along a distal end of the movable part.   The second breakable part that is easier to break than other parts is provided between the intermediate part of the support part and the tip of the extension part of the support part. Physical quantity sensitive base.   The first and second breakable portions are formed such that at least one of the support portion, the base portion, or the extension portion has a width or thickness that is partially smaller than the other portions. The physical quantity sensitive base according to claim 1, wherein the physical quantity sensitive base has a configuration.   The support portion connects the first arm and the second arm respectively protruding from the base portion with the movable portion interposed therebetween, and connects between the tip portions of the first and second arms. The physical quantity sensitive base according to claim 2, 3 or 4, wherein the physical quantity sensitive base is an approximately U-shaped body having an extension.   A physical quantity detection device comprising: the physical quantity sensitive base according to claim 1; and a physical quantity detection element stretched between the base part and the movable part. Mass parts are arranged on both main surfaces of the movable part,
The physical quantity detection device according to claim 6, wherein an extension portion of the support portion is disposed in a non-contact state in a gap between the end portions of the mass portions protruding from the tip of the movable portion. A physical quantity detection device according to claim 6 or 7, and a package for housing the physical quantity detection device,
The physical quantity detector has a configuration in which the first easily breakable part or the first and second easily breakable parts are broken.   The physical quantity detector according to claim 8, wherein the physical quantity detection device is broken at the first breakable part, and the base part and the support part are fixed in the package.   9. The physical quantity detector according to claim 8, wherein the physical quantity detection device is broken at the first and second breakable parts, and the base part and the support part are fixed in the package. .   Removing a part of the support part or a part of the support part and the base part located between the first easy breakable part and the second easy breakable part. The physical quantity detector according to claim 10, wherein It is a manufacturing method of the physical quantity detector according to any one of claims 9 to 11,
A physical quantity sensitive base forming step of integrally forming the base portion, the joint portion, the movable portion, and the support portion;
Spanning and fixing the physical quantity detection element between the base portion and the movable portion;
Forming the physical quantity detection device by fixing the mass part to the movable part;
Fixing the physical quantity detection device in the package;
Breaking the first easily breakable part or the first and second easily breakable parts;
A method of manufacturing a physical quantity detector, comprising:   An electronic apparatus comprising the physical quantity detector according to any one of claims 9 to 11.

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