JP5982889B2 - Physical quantity sensor module and electronic device - Google Patents

Description

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

  Conventionally, as a physical quantity sensor module including a physical quantity sensor for detecting a physical quantity such as acceleration or angular velocity, a sensor block including a plurality of sensor chips each having a semiconductor substrate on which a detection unit is formed, and the semiconductor substrate of each sensor chip is A sensor block that is electrically joined to and supported by a common base block is known (see, for example, Patent Document 1).

JP 2007-127607 A

However, Patent Document 1 does not describe or suggest a mounting form of the sensor block on an external component (external member).
If the sensor block is mounted as it is, the sensor block directly transmits changes in the ambient temperature. As the ambient temperature changes, the temperature of the base block that supports the sensor chip and the sensor chip increases. May change.
As a result, the sensor block is distorted due to the thermal stress generated due to the difference in linear expansion coefficient between the glass base block supporting the sensor chip, the semiconductor substrate constituting the sensor chip, and the glass substrate. For this reason, there is a possibility that detection characteristics (particularly temperature characteristics) such as detection sensitivity and detection accuracy of physical quantities may deteriorate.

  In addition, since the sensor block requires electrical connection between the contact hole (electrode) of the sensor chip and the external member by aerial wiring using lead wires, workability is poor and productivity is improved. There are challenges.

  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 module according to this application example includes a first substrate having a first connection terminal on the main surface and attachable to an external member, and the main surface of the first substrate via a resin spacer. A metal block attached to the side, a second substrate provided with a second connection terminal at the end, and a wiring pattern attached to the second substrate and provided on the second substrate. A physical quantity sensor connected to the second connection terminal, and a case attached to the main surface side of the first substrate and covering at least the resin spacer, the metal block, the second substrate, and the physical quantity sensor; The second substrate is erected on the main surface side of the first substrate, and is connected to the first connection terminal of the first substrate via the second connection terminal, Physics Sensor is characterized in that through the conductive bonding member is bonded to the metal block.

According to this, the physical quantity sensor module includes a first substrate, a metal block attached to the first substrate via a resin spacer, a second substrate provided with a second connection terminal at an end, and a second substrate. And a physical quantity sensor (corresponding to a sensor chip) that is electrically connected to the second connection terminal, and a case that is attached to the first substrate and covers the above-described components.
In the physical quantity sensor module, the second board is erected on the first board, and is electrically connected to the first connection terminal of the first board via the second connection terminal. It is joined to the metal block via.

Thus, the physical quantity sensor module is such that the physical quantity sensor is bonded to a metal block having a large heat capacity and a relatively gentle temperature change through a conductive joining member having a relatively high thermal conductivity (the physical quantity sensor and the metal The heat conduction to the metal block due to contact from the first substrate is delayed (suppressed) by a resin spacer having a relatively low thermal conductivity, and the physical quantity sensor The temperature of the physical quantity sensor that accompanies changes in the ambient temperature is greatly reduced by the fact that the heat conduction to the physical quantity sensor due to convection of the surrounding atmosphere and external radiant heat (radiant heat) is covered with the case. The change can be remarkably suppressed as compared with the prior art (for example, Patent Document 1) (in other words, the temperature change can be made gentle. That).
As a result, the physical quantity sensor module can improve detection characteristics (particularly temperature characteristics) such as detection sensitivity and detection accuracy of the physical quantity, as compared with the prior art (for example, Patent Document 1).

In addition, in the physical quantity sensor module, the physical quantity sensor is attached to the second board, and is electrically connected to the second connection terminal via the wiring pattern provided on the second board, and the second board has the second connection terminal. Since the first connection terminal of the first substrate is electrically connected to the first substrate and the physical quantity sensor, aerial wiring as in the prior art (for example, Patent Document 1) is used for electrical connection between the first substrate and the physical quantity sensor. It becomes unnecessary.
As a result, the physical quantity sensor module has good workability for electrical connection between the first substrate and the physical quantity sensor, and can improve productivity.

  Application Example 2 In the physical quantity sensor module according to the application example, it is preferable that the case is made of resin.

According to this, since the case of the physical quantity sensor module is made of resin, for example, the thermal conductivity of the case is lower than that of a case made of metal, and convection in the atmosphere around the physical quantity sensor or radiant heat from the outside Heat conduction to the physical quantity sensor due to (radiant heat) can be almost blocked.
As a result, the physical quantity sensor module can further suppress the temperature change of the physical quantity sensor due to the change of the ambient temperature, and therefore, detection characteristics such as physical quantity detection sensitivity and detection accuracy compared to the prior art (for example, Patent Document 1). (Especially temperature characteristics) can be further improved.

  Application Example 3 In the physical quantity sensor module according to the application example, it is preferable that the wiring pattern includes a plurality of folded portions.

  According to this, in the physical quantity sensor module, since the wiring pattern of the second substrate has a plurality of folded portions, the wiring pattern from the second connection terminal to the physical quantity sensor becomes long, and the physical quantity sensor is connected to the physical quantity sensor by the wiring pattern. Heat conduction can be suppressed (delayed).

  Application Example 4 In the physical quantity sensor module according to the application example, the physical quantity sensor module includes a plurality of the second substrates to which the physical quantity sensors are attached, and the physical quantity detection axes of the physical quantity sensors cross each other on the second boards. Further, it is preferable that the first substrate is erected.

According to this, the physical quantity sensor module is erected on the first board such that the plurality of second boards on which the physical quantity sensors are attached so that the physical quantity detection axes of the respective physical quantity sensors intersect each other.
Thereby, the physical quantity sensor module of this structure can provide the physical quantity sensor module provided with the several detection axis from which one detection direction differs.

  Application Example 5 In the physical quantity sensor module according to the application example described above, it is preferable that the physical quantity sensor module further includes a drive circuit that drives the physical quantity sensor, and the drive circuit is provided on the second substrate.

  According to this, since the physical quantity sensor module further includes a drive circuit for driving the physical quantity sensor, and this drive circuit is provided on the second substrate, for example, when the drive circuit is provided on the first substrate. In addition, it is possible to reduce the size and noise superimposed on the drive signal, and to suppress heat conduction from the first substrate to the drive circuit.

  Application Example 6 In the physical quantity sensor module according to the application example, the physical quantity sensor includes a base part, a plate-like movable part connected to the base part via a joint part, the base part, and the movable part. A physical quantity detection element that is stretched over the part, and a package that accommodates at least the above-described components inside and is attached to the second substrate, wherein the movable part includes the first main surface and the second main surface. A mass portion is disposed on at least one of the main surfaces, and is configured to be displaceable in the first direction with the joint portion as a fulcrum according to a physical quantity applied in a first direction intersecting the first main surface. Is preferred.

According to this, in the physical quantity sensor module, since the main components of the physical quantity sensor are accommodated in the package, the conventional technology (for example, a configuration in which the sensor chip is exposed as in Patent Document 1) and In comparison, the temperature change of the physical quantity sensor accompanying the change of the ambient temperature can be remarkably suppressed.
As a result, the physical quantity sensor module can improve detection characteristics (particularly temperature characteristics) such as physical quantity detection sensitivity and detection accuracy as compared with the above-described conventional technique.

  In addition, the physical quantity sensor module includes a physical quantity sensor in which a mass part is disposed on at least one of the first main surface and the second main surface of the movable part, and the physical quantity applied in the first direction in which the movable part intersects the first main surface. Accordingly, the physical quantity can be detected with high sensitivity and accuracy because it is configured to be displaceable in the first direction with the joint portion as a fulcrum.

  Application Example 7 In the physical quantity sensor module according to the application example, the physical quantity detection element includes a physical quantity detection unit including at least one vibration beam extending along a direction connecting the base unit and the movable unit, and the physical quantity And a pair of bases connected to both ends of the detection unit, wherein one of the bases is fixed to the base unit and the other base is fixed to the movable unit.

According to this, the physical quantity sensor module has a physical quantity detection element of the physical quantity sensor connected to the physical quantity detection section having at least one vibrating beam extending along a direction connecting the base portion and the movable portion, and both ends of the physical quantity detection portion. A pair of base parts, one base part being fixed to the base part and the other base part being fixed to the movable part.
Thereby, the physical quantity sensor module is configured such that, for example, the vibrating beam expands and contracts according to the displacement of the movable part due to the applied physical quantity, and changes in the vibration frequency of the vibrating beam due to the tensile stress and compressive stress generated at this time are converted into physical quantities. Is possible.
By suppressing the temperature change of the physical quantity sensor, the physical quantity detection element of this configuration can exhibit excellent performance in detection characteristics such as physical quantity detection sensitivity and detection accuracy.

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

  According to this, since the electronic device of this configuration includes the physical quantity sensor module described in any of the above application examples, the electronic device reflecting the effect described in any of the above application examples is provided. be able to.

The model perspective view which shows schematic structure of a physical quantity sensor module. FIG. 2 is a schematic side view of the main part viewed from the direction of arrow A or arrow B in FIG. It is a schematic diagram which shows schematic structure of a physical quantity sensor, (a) is a schematic top view seen from the lid (lid body) side, (b) is a schematic cross section in CC line of (a). It is a schematic cross-sectional view for explaining the operation of the physical quantity sensor, (a) is a schematic cross-sectional view showing a state where the movable part is displaced downward on the paper surface, (b) is a schematic cross-sectional view showing a state where the movable part is displaced upward on the paper surface. . (A), (b) is a model perspective view which shows the variation of a resin spacer. The model perspective view which shows the inclinometer as an example of the electronic device provided with the physical quantity sensor module.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.

(Embodiment)
<Physical quantity sensor module>
First, the physical quantity sensor module will be described.
FIG. 1 is a schematic perspective view showing a schematic configuration of the physical quantity sensor module of the present embodiment. FIG. 2 is a schematic side view of the main part viewed from the direction of arrow A or the direction of arrow B in FIG. In FIG. 1, some parts are expanded. In the following drawings, the dimensional ratios of the constituent elements are different from the actual ones for easy understanding.

  As shown in FIGS. 1 and 2, the physical quantity sensor module 1 includes a first substrate 101, a resin spacer 102, a metal block 103, two second substrates 104, two physical quantity sensors 2, and a case 105. It is equipped with.

The first substrate 101 is formed in a substantially rectangular flat plate shape, and has a plurality of first connection terminals 101b on the main surface 101a. In addition, the first substrate 101 includes a plurality of (four in this case) notch-shaped attachment portions 101c used for attachment to an external member such as an electronic device.
The first substrate 101 is provided with a plurality of external connection terminals 101d for electrical connection with external members at both ends. The external connection terminal 101d and the first connection terminal 101b are electrically connected by a wiring pattern (not shown).

For the first substrate 101, glass fiber (thermal conductivity: about 1 W / (m · K)) and epoxy resin (such as FR-4 (epoxy resin substrate with glass cloth)) having relatively low thermal conductivity are used. Substrates excellent in heat resistance, moisture resistance, electrical characteristics, etc., which are mainly composed of thermal conductivity: about 0.21 W / (m · K)), are used.
Thereby, in the physical quantity sensor module 1, the heat conduction to the entire first substrate 101 due to the contact from the external member is delayed (suppressed) more than other materials.
The first connection terminal 101b and the external connection terminal 101d are made of, for example, a metal film in which respective films such as nickel and gold are laminated on a copper foil by plating or the like.

A substantially rectangular parallelepiped metal block 103 is attached to a substantially central portion of the first substrate 101 on the main surface 101 a side via a substantially rectangular flat plate-like resin spacer 102.
Examples of the resin spacer 102 include fluororesin such as tetrafluoroethylene (polytetrafluoroethylene) (thermal conductivity: about 0.25 W / (m · K)), PBT (polybutylene terephthalate) (thermal conductivity: About 0.27 W / (m · K)), LCP (liquid crystal polymer) (thermal conductivity: about 0.5 W / (m · K)), polyimide (thermal conductivity: about 0.29 W / (m · K)) ) And other resins having a relatively low thermal conductivity and excellent heat resistance, electrical characteristics, dimensional stability, and the like.

Examples of the metal block 103 include a metal having a relatively high thermal conductivity such as aluminum (thermal conductivity: about 240 W / (m · K)) and copper (thermal conductivity: about 400 W / (m · K)). Is used. The metal block 103 is formed in a substantially rectangular parallelepiped shape by cutting or the like from the metal bar or the like. Thereby, the metal block 103 can enlarge heat capacity compared with the hollow block processed by sheet metal processing.
The resin spacer 102 is made of, for example, an adhesive having a relatively low thermal conductivity, such as an epoxy resin type, a silicone resin (thermal conductivity: about 0.15 W / (m · K)) type, or a polyimide resin type. It is bonded and fixed to a substantially central portion of the main surface 101a of one substrate 101.
The metal block 103 is bonded and fixed on the resin spacer 102 using an adhesive having a relatively low thermal conductivity such as the epoxy resin system, the silicone resin system, or the polyimide resin system described above.

Each second substrate 104 is formed in a substantially rectangular flat plate shape smaller than the first substrate 101, and a plurality of (four in this case) side through holes 104a as second connection terminals are provided at one end.
Similar to the first substrate 101, the second substrate 104 has, for example, heat resistance, moisture resistance, electrical characteristics, and the like mainly composed of glass fiber and epoxy resin having relatively low thermal conductivity such as FR-4. An excellent substrate is used.
The second substrate 104 is provided with a wiring pattern 104b that electrically connects the side through hole 104a and a physical quantity sensor 2 described later. The wiring pattern 104b includes a plurality of folded portions 104c. The side through hole 104a and the wiring pattern 104b are made of, for example, a metal film in which films such as nickel and gold are laminated on a copper foil by plating or the like. Note that the wiring pattern 104b is preferably formed as thin as possible to the extent that there is no problem in electrical connection, in order to suppress heat conduction by the wiring pattern 104b.

On the main surface 104d side of the second substrate 104, for example, a physical quantity sensor 2 that detects a physical quantity such as acceleration or angular velocity is attached. The physical quantity sensor 2 is electrically connected to the wiring pattern 104b by attaching external terminals 27 and 28 provided on the second substrate 104 side to the land portion of the wiring pattern 104b with solder or the like.
In addition, as shown in FIG. 2, on the main surface 104 d side of the second substrate 104, an IC chip 106 having a built-in transmission circuit as a drive circuit for driving the physical quantity sensor 2 is located near one side of the physical quantity sensor 2. It is provided (attached).
In addition, on the main surface 104d side of the second substrate 104, a temperature detection element 107 such as a thermistor for detecting the ambient temperature of the physical quantity sensor 2 is provided in the vicinity of the other side of the physical quantity sensor 2 ( Are preferably attached). In this case, the IC chip 106 preferably includes a temperature compensation circuit that corrects the temperature characteristics of the physical quantity sensor 2 based on the ambient temperature detected by the temperature detection element 107.

In the present embodiment, since the IC chip 106 for driving the physical quantity sensor 2 is provided on the second substrate 104, the physical quantity sensor 2 is connected to the side through hole 104a via the wiring pattern 104b and the IC chip 106. Are electrically connected to each other.
Here, even in this embodiment, the physical quantity sensor 2 is defined as being electrically connected to the side through hole 104a via the wiring pattern 104b.
When the IC chip 106 is not provided on the second substrate 104, the physical quantity sensor 2 is directly connected to the side through hole 104a directly via the wiring pattern 104b.

The second substrate 104 is erected on the main surface 101a side of the first substrate 101 (fixed in an upright state), and the first connection terminal 101b of the first substrate 101 is soldered or the like through the side through hole 104a. And are electrically connected.
The physical quantity sensor 2 attached to the second substrate 104 is an epoxy resin type whose thermal conductivity is increased by mixing a metal filler such as silver (thermal conductivity: about 420 W / (m · K)). It is bonded (adhered and fixed) to the metal block 103 using a conductive adhesive 108 as a conductive bonding member such as a silicone resin type or a polyimide resin type. Thereby, the physical quantity sensor 2 is easily thermally coupled to the metal block 103.

Here, in the two second substrates 104, the physical quantity detection axes of the two physical quantity sensors 2 (here, the axes substantially orthogonal to the main surface 104d of the second substrate 104) intersect with each other (here, substantially orthogonal). In other words, in other words, the first substrate 101 is erected so that the angle formed by the principal surfaces 104d of each other is substantially a right angle.
As a result, the two physical quantity sensors 2 are joined to the side surfaces of the metal block 103 that are adjacent to each other (the surface that is substantially perpendicular to the main surface 101a of the first substrate 101).

The case 105 is formed in a box shape with one surface opened, and covers at least the resin spacer 102, the metal block 103, the second substrate 104, the physical quantity sensor 2, the IC chip 106, and the temperature detection element 107 described above. The opening side is attached to the main surface 101 a side of the first substrate 101.
Case 105 has a relatively low thermal conductivity such as fluororesin such as tetrafluoroethylene (polytetrafluoroethylene), PBT (polybutylene terephthalate), and LCP (liquid crystal polymer), and has heat resistance and dimensional stability. It is preferable to use an excellent resin.
The case 105 is first formed by an adhesive fixing method using an adhesive having a relatively low thermal conductivity such as an epoxy resin system, a silicone resin system, or a polyimide resin system, or an adhesive fixing method using a double-sided adhesive tape or the like. Attached to the substrate 101.

Here, the physical quantity sensor 2 will be described in detail.
FIG. 3 is a schematic diagram illustrating a schematic configuration of the physical quantity sensor. 3A is a schematic plan view seen from the lid (lid body) side, and FIG. 3B is a schematic cross-sectional view taken along the line CC in FIG. 3A. In the plan view, the lid is omitted. Each wiring is omitted.

Here, an acceleration sensor that detects acceleration will be described as an example of the physical quantity sensor.
As shown in FIG. 3, the physical quantity sensor 2 includes a flat base portion 10, a substantially rectangular flat plate-like movable portion 12 connected to the base portion 10 via a joint portion 11, and the base portion 10 and the movable portion 12. And an acceleration detection element 13 as a physical quantity detection element, and a package 20 that houses at least each of the above-described components and is attached to the second substrate 104.

The physical quantity sensor 2 extends from the base portion 10 along both sides of the movable portion 12 in a plan view (FIG. 3A), and is formed in a substantially rectangular frame shape surrounding the movable portion 12 with the base portion 10. A flat support 14 is further provided.
The movable portion 12 has a mass portion (weight) 15 disposed on at least one (here both) of the first main surface 12a and the second main surface 12b, and the Z-axis as a first direction intersecting the first main surface 12a. It is configured to be able to be displaced (rotated) in the Z-axis direction with the joint portion 11 as a fulcrum according to acceleration as a physical quantity applied in the direction.

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 is provided between the movable portion 12 and the support portion 14 to divide both.
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.

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 the first main surface 12a and the second main surface 12b. A bottomed groove portion 11a is formed along a direction (X-axis direction) orthogonal to ().
The cross-sectional shape (shape of FIG.3 (b)) along the Y-axis direction of the joint part 11 is formed in the substantially H shape by the groove part 11a.

The mass portion 15 is formed so that a part (left side of the paper surface) overlaps the support portion 14 in plan view (FIG. 3A), and the convex portion has the first main surface 12 a and the second main surface via the bonding material 16. It is joined (attached) to the main surface 12b.
In order to increase the plane size as much as possible in order to improve the sensitivity of the physical quantity sensor 2, the mass portion 15 is bifurcated from the free end side of the movable portion 12 opposite to the joint portion 11 side, avoiding the acceleration detecting element 13. It extends to the vicinity of the joint 11 and is formed in a substantially U shape in plan view. For the mass portion 15, for example, a material having a relatively large specific gravity represented by a metal such as copper and a copper alloy is used.
For the bonding material 16, for example, a silicone resin adhesive is used.

The acceleration detecting element 13 includes at least one (here, two) vibrating beams 13a and 13b that bend and vibrate in the X-axis direction extending along the direction connecting the base portion 10 and the movable portion 12 (Y-axis direction). And an acceleration detection unit 13c as a physical quantity detection unit, and a pair of bases 13d and 13e connected to both ends of the acceleration detection unit 13c.
The acceleration detecting element 13 is also called a double tuning fork element (double tuning fork type vibrating piece) because the two vibrating beams 13a and 13b and the pair of base portions 13d and 13e constitute two sets of tuning forks.
For example, the acceleration detection element 13 is formed of a quartz substrate cut out at a predetermined angle from a quartz crystal or the like, and the acceleration detection unit 13c and the bases 13d and 13e are integrally formed in a substantially flat plate shape. Further, the outer shape of the acceleration detecting element 13 is accurately formed by using techniques such as photolithography and etching.

  In the acceleration detecting element 13, one base portion 13d is fixed to the first main surface 12a side of the movable portion 12 via a bonding member 17 such as a low melting point glass or a gold / tin alloy coating capable of eutectic bonding, for example. The other base portion 13e is fixed to the main surface 10a side of the base portion 10 (the same side as the first main surface 12a of the movable portion 12) via the joining member 17.

The acceleration detecting element 13 includes base electrodes 10 having lead electrodes 13f and 13g drawn out from excitation electrodes (drive electrodes) (not shown) of the vibrating beams 13a and 13b to the base portion 13e by metal wires 18 made of, for example, gold or aluminum. Are connected to connection terminals 10b and 10c provided on the main surface 10a.
Specifically, the lead electrode 13f is connected to the connection terminal 10b, and the lead electrode 13g is connected to the connection terminal 10c.
The connection terminals 10b and 10c of the base part 10 are connected to the external connection terminals 14e and 14f of the support part 14 by wiring (not shown). Specifically, the connection terminal 10b is connected to the external connection terminal 14e, and the connection terminal 10c is connected to the external connection terminal 14f.
The excitation electrodes, lead electrodes 13f and 13g, connection terminals 10b and 10c, and external connection terminals 14e and 14f are, for example, metal films in which chromium is used as a base layer and gold is stacked thereon.

The support portion 14 has a plurality of (four in this case) fixing portions 14a, 14b, 14c, and 14d that are portions fixed to the package 20 at four corners.
Note that the fixing portions 14 b and 14 c may be formed on the base portion 10.

The package 20 includes a package base 21 having a substantially rectangular planar shape and a recess, and a substantially rectangular parallelepiped lid (cover) 22 having a substantially rectangular planar shape covering the recess of the package base 21. Is formed.
The package base 21 includes an aluminum oxide sintered body, a mullite sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a glass ceramic sintered body, etc., which are formed by stacking and firing ceramic green sheets. Ceramic-based insulating materials, quartz, glass, silicon and the like are used.
The lid 22 is made of the same material as the package base 21 or a metal such as Kovar, 42 alloy, or stainless steel.

The package base 21 is provided with internal terminals 24 and 25 at two step portions 23a protruding from the outer peripheral portion of the inner bottom surface (the bottom surface inside the recess) along the inner wall of the recess.
The internal terminals 24 and 25 are provided at positions facing the external connection terminals 14e and 14f provided on the support portion 14 (positions overlapping in plan view). The external connection terminals 14e and 14f are provided at positions that overlap the fixing portions 14b and 14c of the support portion 14 in plan view.

A pair of external terminals 27 and 28 that are used when the package base 21 is attached to the second substrate 104 are formed on the outer bottom surface (surface opposite to the inner bottom surface 23, outer bottom surface) 26. The external terminals 27 and 28 are connected to the internal terminals 24 and 25 by internal wiring (not shown). For example, the external terminal 27 is connected to the internal terminal 24, and the external terminal 28 is connected to the internal terminal 25.
The internal terminals 24 and 25 and the external terminals 27 and 28 are made of a metal film obtained by laminating various films such as nickel and gold on a metallized layer such as tungsten by plating.

The package base 21 is provided with a sealing portion 29 that seals the inside of the package 20 at the bottom of the recess.
The sealing portion 29 is formed in a stepped through hole 29a formed in the package base 21 with a hole diameter on the outer bottom surface 26 side larger than that on the inner bottom surface 23 side, and a sealing material 29b made of gold / germanium alloy, solder, or the like. The inside of the package 20 is hermetically sealed by charging and solidifying after heating and melting.

The fixing portions 14 a, 14 b, 14 c, and 14 d of the support portion 14 are fixed to the step portion 23 a of the package base 21 through the adhesive 30.
Here, since the fixing portions 14b and 14c are portions connecting the external connection terminals 14e and 14f and the internal terminals 24 and 25, the adhesive 30 is mixed with a conductive material such as a metal filler, for example. A conductive adhesive (for example, a silicone resin conductive adhesive) is used. In addition, you may use the adhesive agent (for example, 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.

In the physical quantity sensor 2, the recesses of the package base 21 are covered with the lid 22 in a state where the external connection terminals 14e and 14f are connected to the internal terminals 24 and 25 of the package base 21, and the package base 21 and the lid 22 are seamed. Further, they are joined by a joining member 22a such as low melting glass or adhesive.
In the physical quantity sensor 2, after the lid 22 is joined, the sealing material 29 b is put into the through hole 29 a of the sealing portion 29 in a state where the inside of the package 20 is decompressed (high vacuum state), and after heating and melting, By solidifying, the inside of the package 20 is hermetically sealed.
Note that the inside of the package 20 may be filled with an inert gas such as nitrogen, helium, or argon. The package 20 may have a recess in both the package base 21 and the lid 22.

The physical quantity sensor 2 is accelerated by a drive signal applied to the excitation electrode of the acceleration detecting element 13 via the external terminals 27 and 28, the internal terminals 24 and 25, the external connection terminals 14e and 14f, the connection terminals 10b and 10c, and the like. The vibrating beams 13a and 13b of the detection element 13 oscillate (resonate) at a predetermined frequency.
Then, the physical quantity sensor 2 outputs the resonance frequency of the acceleration detecting element 13 that changes according to the applied acceleration as an output signal.

Here, the operation of the physical quantity sensor 2 will be described.
FIG. 4 is a schematic cross-sectional view for explaining the operation of the physical quantity sensor. FIG. 4A is a schematic cross-sectional view showing a state where the movable part is displaced downward (−Z direction) in the drawing, and FIG. 4B shows a state where the movable part is displaced upward (+ Z direction) in the drawing. It is a schematic cross section shown.

As shown in FIG. 4A, when the physical quantity sensor 2 is displaced in the −Z direction by the inertial force corresponding to the acceleration + α applied in the Z-axis direction, the movable part 12 is displaced in the −Z direction with the joint part 11 as a fulcrum. A tensile force is applied to the detection element 13 in a direction in which the base portion 13d and the base portion 13e are separated from each other in the Y-axis direction, and tensile stress is generated in the vibration beams 13a and 13b of the acceleration detection portion 13c.
As a result, the physical quantity sensor 2 changes such that the vibration frequencies (hereinafter also referred to as resonance frequencies) of the vibration beams 13a and 13b of the acceleration detection unit 13c become higher, for example, like a string of a wound string instrument.

On the other hand, as shown in FIG. 4B, the physical quantity sensor 2 is configured such that the movable part 12 is displaced in the + Z direction with the joint part 11 as a fulcrum by an inertial force corresponding to the acceleration −α applied in the Z-axis direction. The acceleration detecting element 13 is applied with a compressive force in the direction in which the base portion 13d and the base portion 13e approach each other in the Y-axis direction, and compressive stress is generated in the vibrating beams 13a and 13b of the acceleration detecting portion 13c.
Thereby, the physical quantity sensor 2 changes so that the resonant frequency of the vibration beams 13a and 13b of the acceleration detection part 13c becomes low like the string of the rewinded stringed instrument, for example.

  The physical quantity sensor 2 detects 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. 4A, the physical quantity sensor 2 is configured such that when the acceleration + α applied in the Z-axis direction is larger than a predetermined magnitude, the mass part 15 fixed to the first main surface 12a of the movable part 12 The portion overlapping the support portion 14 in plan view comes into contact with the support portion 14.
As a result, the physical quantity sensor 2 regulates the displacement of the movable portion 12 that is displaced in the −Z direction in accordance with the acceleration + α within a predetermined range.

On the other hand, as shown in FIG. 4B, the physical quantity sensor 2 has the mass portion 15 fixed to the second main surface 12 b of the movable portion 12 when the acceleration −α applied in the Z-axis direction is larger than a predetermined magnitude. The portion overlapping the support portion 14 in plan view comes into contact with the support portion 14.
Thereby, the physical quantity sensor 2 regulates the displacement of the movable part 12 that is displaced in the + Z direction according to the acceleration −α within a predetermined range.

As described above, the physical quantity sensor module 1 includes the first substrate 101, the metal block 103 attached to the first substrate 101 via the resin spacer 102, and the second substrate provided with the side through hole 104a at the end. 104, a physical quantity sensor 2 attached to the second substrate 104 and electrically connected to the side through-hole 104a, and a case 105 attached to the first substrate 101 and covering the above-described components.
In the physical quantity sensor module 1, the second substrate 104 is erected on the first substrate 101 and is electrically connected to the first connection terminal 101b of the first substrate 101 through the side through hole 104a. The sensor 2 is bonded to the metal block 103 via the conductive adhesive 108.

As a result, the physical quantity sensor module 1 is such that the physical quantity sensor 2 is bonded to the metal block 103 having a large heat capacity and a relatively gentle temperature change via the conductive adhesive 108 having a relatively high thermal conductivity ( The physical quantity sensor 2 and the metal block 103 are thermally coupled), and heat conduction to the metal block 103 due to contact from the first substrate 101 is delayed (suppressed) by the resin spacer 102 having relatively low thermal conductivity. And heat conduction to the physical quantity sensor 2 due to convection of the atmosphere around the physical quantity sensor 2 and radiant heat (radiant heat) from the outside is greatly suppressed by the case 105 being covered. As a result, the temperature change of the physical quantity sensor 2 accompanying the change in the ambient temperature can be remarkably suppressed as compared with the prior art (for example, Patent Document 1). Kill.
As a result, the physical quantity sensor module 1 can improve detection characteristics (particularly temperature characteristics) such as acceleration detection sensitivity and detection accuracy as compared with the conventional technique (for example, Patent Document 1).

In addition, in the physical quantity sensor module 1, the physical quantity sensor 2 is attached to the second substrate 104, and is electrically connected to the side through hole 104a via the wiring pattern 104b provided on the second substrate 104 (via the IC chip 106). The second substrate 104 is electrically connected to the first connection terminal 101b of the first substrate 101 through the side through hole 104a.
Thereby, the physical quantity sensor module 1 does not require an aerial wiring as in the prior art (for example, Patent Document 1) for electrical connection between the first substrate 101 and the physical quantity sensor 2.
As a result, in the physical quantity sensor module 1, workability of electrical connection between the first substrate 101 and the physical quantity sensor 2 is improved, and productivity can be improved.

In addition, since the case 105 is made of resin, the physical quantity sensor module 1 has a lower thermal conductivity than the case of metal, for example, convection of the atmosphere around the physical quantity sensor 2 and radiation from the outside. Heat conduction to the physical quantity sensor 2 due to heat (radiant heat) can be almost blocked.
As a result, since the physical quantity sensor module 1 can further suppress the temperature change of the physical quantity sensor 2 due to the change in the ambient temperature, the acceleration detection sensitivity, the detection accuracy, etc. are compared with the prior art (for example, Patent Document 1). Detection characteristics (particularly temperature characteristics) can be further improved.
The case 105 may be made of stainless steel (thermal conductivity: about 20 W / (m · K)) having a relatively low thermal conductivity among metals such as SUS316 and SUS304.

  Further, in the physical quantity sensor module 1, since the wiring pattern 104b of the second substrate 104 includes a plurality of folded portions 104c, the wiring pattern 104b from the side through hole 104a to the physical quantity sensor 2 (via the IC chip 106). Thus, heat conduction to the physical quantity sensor 2 (via the IC chip 106) by the wiring pattern 104b can be suppressed (delayed).

In the physical quantity sensor module 1, the two second substrates 104 to which the physical quantity sensor 2 is attached are erected on the first substrate 101 so that the acceleration detection axes of the two physical quantity sensors 2 are substantially orthogonal to each other. .
Thereby, the physical quantity sensor module 1 of this structure can provide the physical quantity sensor module provided with two detection axes from which one detection direction differs.

  In addition, the physical quantity sensor module 1 includes an IC chip 106 that drives the physical quantity sensor 2. Since the IC chip 106 is provided on the second substrate 104, for example, the IC chip 106 is provided on the first substrate 101. This makes it possible to reduce the size and reduce the noise superimposed on the drive signal, and to suppress the heat conduction from the first substrate 101 to the IC chip 106.

Further, the physical quantity sensor module 1 includes the main components of the physical quantity sensor 2 housed in the package 20, so that the conventional technology (for example, a configuration in which a sensor chip is exposed as in Patent Document 1) is used. In comparison, the temperature change of the physical quantity sensor 2 accompanying the change in the ambient temperature can be remarkably suppressed.
As a result, the physical quantity sensor module 1 can improve detection characteristics (particularly temperature characteristics) such as acceleration detection sensitivity and detection accuracy as compared with the conventional technique.

  In addition, in the physical quantity sensor module 1, the physical quantity sensor 2 includes a mass part 15 disposed on both the first main surface 12a and the second main surface 12b of the movable part 12, and the movable part 12 intersects the first main surface 12a. According to the acceleration applied in the Z-axis direction, it is configured to be displaceable in the Z-axis direction with the joint portion 11 as a fulcrum, so that the acceleration can be detected with high sensitivity and accuracy.

In addition, the physical quantity sensor module 1 includes an acceleration detection unit 13c in which the acceleration detection element 13 of the physical quantity sensor 2 includes two vibrating beams 13a and 13b extending along a direction connecting the base unit 10 and the movable unit 12. A pair of base portions 13 d and 13 e connected to both ends of the portion 13 c, one base portion 13 d is fixed to the movable portion 12, and the other base portion 13 e is fixed to the base portion 10.
Thereby, in the physical quantity sensor module 1, for example, the vibrating beams 13a and 13b expand and contract according to the displacement of the movable part 12 due to the applied acceleration, and the vibration frequency of the vibrating beams 13a and 13b caused by the tensile stress and the compressive stress generated at this time is increased. A configuration for converting the change into acceleration is possible.
By suppressing the temperature change of the physical quantity sensor 2, the acceleration detection element 13 of this configuration can exhibit excellent performance in detection characteristics such as acceleration detection sensitivity and detection accuracy.

In addition, as shown in the model perspective view which shows the variation of the resin spacer of FIG. 5, the resin spacer 102 is not limited to simple flat form, A some through-hole as shown to Fig.5 (a) is shown. A shape provided with a grid shape 102a, or a shape in which a plurality of leg portions 102b and stepped portions 102c are provided at four corners as shown in FIG.
As a result, the physical quantity sensor module 1 reduces the contact area between the first substrate 101 and the resin spacer 102 and the contact area between the resin spacer 102 and the metal block 103. Heat conduction can be further suppressed.

  When the resin spacer 102 has a shape as shown in FIG. 5B, the physical quantity sensor module 1 is provided with a through hole at a position corresponding to the leg portion 102b in the first substrate 101, and a leg is formed in the through hole. The resin spacer 102 can be fixed to the first substrate 101 without using an adhesive by inserting the portion 102b and welding (thermally caulking) the tip of the leg portion 102b protruding from the through hole. .

In the above embodiment, the drive circuit of the physical quantity sensor 2 is not limited to the IC chip 106, and may be configured by combining discrete components such as an inverter, a capacitor, and a resistor. The drive circuit for the physical quantity sensor 2 may be provided on the first substrate 101.
Further, the second connection terminal of the second substrate 104 is not limited to the side through hole 104a, but a normal wiring pattern provided at the end of the surface opposite to the main surface 104d of the second substrate 104. It may be a land part.

Moreover, the main material of the base part 10, the joint part 11, the movable part 12, and the support part 14 of the physical quantity sensor 2 is not limited to quartz, but may be a semiconductor material such as glass or silicon.
Further, the main material of the acceleration detecting element 13 of the physical quantity sensor 2 is not limited to quartz, and for example, lithium tantalate (LiTaO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ ), lithium niobate. It may be a piezoelectric material such as (LiNbO ₃ ), lead zirconate titanate (PZT), zinc oxide (ZnO), aluminum nitride (AlN), or a semiconductor material such as silicon.
The physical quantity sensor 2 is not limited to the acceleration sensor having the above-described configuration, but an angular velocity sensor (gyro sensor) having an angular velocity detection element as a physical quantity detection element, a pressure sensor having a pressure detection element, and a weight detection element. A weight sensor or the like may be used.

<Electronic equipment>
Next, an electronic device including the above-described physical quantity sensor module 1 will be described.
FIG. 6 is a schematic perspective view illustrating an inclinometer as an example of an electronic apparatus including a physical quantity sensor module.

As shown in FIG. 6, the inclinometer 5 includes the physical quantity sensor module 1 described above as an inclination sensor module.
The inclinometer 5 is installed at a place to be measured such as a mountain slope, a road slope, or a retaining wall. The inclinometer 5 is supplied with power from the outside via a cable 40 or has a built-in power source, and a drive signal is sent to the physical quantity sensor module 1 (tilt sensor module) by a drive circuit (not shown).
Then, the inclinometer 5 changes the attitude of the inclinometer 5 (gravitational acceleration with respect to the inclinometer 5 is applied) from the resonance frequency of the physical quantity sensor 2 that changes according to the gravitational acceleration applied to the physical quantity sensor module 1 by a detection circuit (not shown). Direction change) is detected, converted into an angle by a look-up table or the like, and data is transferred to the base station by radio or cable 40, for example.
Thus, since the inclinometer 5 includes the physical quantity sensor module 1 having excellent detection characteristics (particularly temperature characteristics), it can contribute to daily management (maintenance) of the measurement location and early detection of abnormalities. it can.

  The physical quantity sensor module 1 described above is not limited to the inclinometer 5, but is suitable as an acceleration sensor, an angular velocity sensor, an inclination sensor, a pressure sensor, a weight sensor, etc. In any case, it is possible to provide an electronic device in which the above-described effects are reflected.

  DESCRIPTION OF SYMBOLS 1 ... Physical quantity sensor module, 2 ... Physical quantity sensor, 5 ... Inclinometer as electronic equipment, 10 ... Base part, 10a ... Main surface, 10b, 10c ... Connection terminal, 11 ... Joint part, 11a ... Groove part, 12 ... Movable part , 12a ... first main surface, 12b ... second main surface, 13 ... acceleration detection element as physical quantity detection element, 13a, 13b ... vibrating beam, 13c ... acceleration detection part as physical quantity detection unit, 13d, 13e ... base, 13f, 13g ... extraction electrode, 14 ... support part, 14a, 14b, 14c, 14d ... fixed part, 14e, 14f ... external connection terminal, 15 ... mass part, 16 ... bonding material, 17 ... bonding member, 18 ... metal wire 20 ... package, 21 ... package base, 22 ... lid, 22a ... joining member, 23 ... inner bottom surface, 23a ... stepped portion, 24,25 ... internal terminal, 26 ... outer bottom surface, 2 28 ... external terminal, 29 ... sealing portion, 29a ... through hole, 29b ... sealing material, 30 ... adhesive, 40 ... cable, 101 ... first substrate, 101a ... main surface, 101b ... first connection terminal, DESCRIPTION OF SYMBOLS 101c ... Attachment part, 101d ... External connection terminal, 102 ... Resin spacer, 102a ... Through-hole, 102b ... Leg part, 102c ... Step part, 103 ... Metal block, 104 ... 2nd board | substrate, 104a ... As 2nd connection terminal Side through hole, 104b ... wiring pattern, 104c ... folded portion, 104d ... main surface, 105 ... case, 106 ... IC chip as drive circuit, 107 ... temperature detection element, 108 ... conductive adhesive as conductive bonding member .

Claims (9)

A first substrate having a first connection terminal on the main surface and further having a mounting portion to an external member ;
A metal block attached to the main surface of the first substrate;
A resin spacer disposed between the first substrate and the metal block;
A wiring pattern electrically connected to the second connection terminal and the second connection terminal, and an end portion on which the second connection terminal is provided is attached to the main surface side of the first substrate; A second substrate,
A physical quantity sensor attached to the second substrate and electrically connected to the wiring pattern;
A case attached to the main surface side of the first substrate and covering at least the resin spacer, the metal block, the second substrate, and the physical quantity sensor;
With
The second connection terminal is electrically connected to the first connection terminal;
The physical quantity sensor module, wherein the physical quantity sensor is joined to the metal block via a conductive joining member. The physical quantity sensor module according to claim 1,
The physical quantity sensor
It has a package that houses the physical quantity detection element,
A physical quantity sensor module, wherein the package has a first surface attached to the second substrate and a second surface opposite to the first surface connected to the conductive bonding member. The physical quantity sensor module according to claim 1 or 2,
The physical quantity sensor module, wherein the resin spacer includes a plurality of through holes. In the physical quantity sensor module according to any one of claims 1 to 3,
The physical quantity sensor module, wherein the case is made of resin. In the physical quantity sensor module according to any one of claims 1 to 4,
The physical quantity sensor module, wherein the wiring pattern includes a plurality of folded portions. In the physical quantity sensor module according to any one of claims 1 to 5,
A plurality of the second substrates to which the physical quantity sensor is attached;
Each of the second substrates is attached to the first substrate so that the physical quantity detection axes of the physical quantity sensors intersect with each other. In the physical quantity sensor module according to any one of claims 1 to 6,
A drive circuit for driving the physical quantity sensor;
The physical quantity sensor module, wherein the drive circuit is provided on the second substrate. In the physical quantity sensor module according to any one of claims 1 to 7,
The physical quantity sensor
A base part;
A plate-like movable part connected to the base part via a joint part;
A physical quantity detection element spanned between the base part and the movable part;
With
The movable portion has a mass portion disposed on at least one of the first main surface and the second main surface, and the joint portion serves as a fulcrum according to a physical quantity applied in a first direction intersecting the first main surface. A physical quantity sensor module configured to be displaceable in a first direction.   An electronic apparatus comprising the physical quantity sensor module according to any one of claims 1 to 8.

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