JP2016138872A - Pressure sensor element, pressure sensor, altimeter, electronic apparatus and moving body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensor element capable of reducing transmission of unnecessary vibration and reducing the lowering of pressure detection accuracy, and also to provide a pressure sensor equipped with this pressure sensor element, an altimeter, an electronic apparatus, and a moving body.SOLUTION: A pressure sensor element 1 includes a substrate 2 having a recess 25 in which a bendable and deformable diaphragm 24 is arranged in a bottom part, and a step part 26 having irregularity is arranged on a side surface of the substrate 2. Moreover, the step part 26 includes: a first side surface 261; a second side surface 262 which is arranged in a position deviated from the first side surface 261 in a thickness direction and positioned in an inner peripheral side of the substrate 2 than the first side surface 261; and a third side surface 263 for connecting the first side surface 261 and the second side surface 262.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure sensor element, a pressure sensor, an altimeter, an electronic device, and a moving object.

  Conventionally, as a pressure sensor, a sensor chip that detects pressure and generates an electrical signal corresponding to the detected value, a package that houses the sensor chip, and surrounds the sensor chip in the package and propagates the pressure to the sensor chip The structure provided with the inert liquid is known (for example, refer patent document 1). Such a pressure sensor includes a diaphragm in which a sensor chip bends by receiving pressure and a pressure reference chamber provided on the diaphragm, and pressure outside the package acts on the diaphragm via an inert liquid. Then, the pressure applied to the pressure sensor is detected from the amount of deflection of the diaphragm caused by the pressure applied to the diaphragm.

  However, in the pressure sensor having such a configuration, since the side surface of the sensor chip is a substantially vertical flat surface, unnecessary vibration applied to the package is easily transmitted to the diaphragm. For this reason, the diaphragm is bent by stresses other than pressure, and pressure detection accuracy is lowered. In particular, in recent years, such pressure sensors are often mounted on wearable terminals such as mobile phones (including smartphones), glasses, and watches. In such a terminal, since the vibration is likely to occur due to the walking of the wearer, the above problem becomes particularly significant.

JP-A-9-126920

  An object of the present invention is to provide a pressure sensor element that can reduce transmission of unnecessary vibration and reduce pressure detection accuracy, a pressure sensor including the pressure sensor element, an altimeter, an electronic device, and a moving body. It is in.

  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 application examples.

[Application Example 1]
The pressure sensor element of this application example includes a substrate having a recess in which a deformable diaphragm is disposed at the bottom,
A step portion having irregularities is disposed on a side surface of the substrate.
Thereby, stress (external force other than pressure) such as unnecessary vibration can be attenuated by the stepped portion, and the unnecessary vibration is hardly transmitted to the diaphragm. Therefore, a pressure sensor element that can reduce a decrease in pressure detection accuracy is obtained.

[Application Example 2]
In the pressure sensor element of this application example, it is preferable that the step portion has the unevenness along the thickness direction of the substrate.
This makes it difficult for unnecessary vibrations to be transmitted by the diaphragm.

[Application Example 3]
In the pressure sensor element of this application example, the stepped portion has a first side surface,
A second side surface disposed at a position shifted in the thickness direction from the first side surface, and positioned closer to the center side of the substrate than the first side surface in a plan view of the substrate;
It is preferable to have a third side surface connecting the first side surface and the second side surface.
Thereby, the configuration of the stepped portion is simplified.

[Application Example 4]
In the pressure sensor element of this application example, it is preferable that at least a part of the surface of the step portion is a cutting surface.
Since minute irregularities are formed on the cut surface, unnecessary vibration can be absorbed and alleviated more effectively at the stepped portion.

[Application Example 5]
In the pressure sensor element of this application example, it is preferable that the third side surface is a cutting surface.
Since minute irregularities are formed on the cut surface, unnecessary vibration can be absorbed and alleviated more effectively at the stepped portion.

[Application Example 6]
In the pressure sensor element of this application example, it is preferable that the diaphragm is disposed between the two stepped portions in a plan view of the substrate.
Thus, by arranging the stepped portion with the diaphragm interposed therebetween, unnecessary vibration is hardly transmitted by the diaphragm.

[Application Example 7]
In the pressure sensor element of this application example, it is preferable that the stepped portion is disposed so as to surround the diaphragm in a plan view of the substrate.
This makes it difficult for unnecessary vibrations to be transmitted by the diaphragm.

[Application Example 8]
The pressure sensor of this application example includes the pressure sensor element of the above application example,
And a package having an internal space for accommodating the pressure sensor element.
Thereby, a highly reliable pressure sensor is obtained.

[Application Example 9]
In the pressure sensor of this application example, it has a resin material arranged to surround the pressure sensor element in the package,
The resin material preferably includes at least a first resin and a second resin different from the first resin along a direction in which the unevenness of the pressure sensor element is arranged.
Thus, the pressure sensor element can be protected by the resin material, and the pressure can be efficiently transmitted to the diaphragm. Further, by using at least two kinds of resin materials, for example, it becomes easy to achieve both an excellent protection function and an excellent pressure transmission function.

[Application Example 10]
In the pressure sensor of this application example, it is preferable that a boundary between the first resin and the second resin is located at the stepped portion.
Thereby, for example, it becomes easy to achieve both an excellent protection function and an excellent pressure transmission function.

[Application Example 11]
An altimeter according to this application example includes the pressure sensor element according to the application example described above.
Thereby, a highly reliable altimeter can be obtained.

[Application Example 12]
An electronic apparatus according to this application example includes the pressure sensor element according to the application example described above.
As a result, a highly reliable electronic device can be obtained.

[Application Example 13]
The moving body of this application example includes the pressure sensor element of the above application example.
Thereby, a mobile body with high reliability is obtained.

It is sectional drawing of the pressure sensor element which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the modification of the pressure sensor element shown in FIG. It is a top view which shows the pressure sensor part which the pressure sensor element shown in FIG. 1 has. FIG. 3 is a diagram illustrating a bridge circuit including a pressure sensor unit. It is sectional drawing explaining the manufacturing method of the pressure sensor element shown in FIG. It is sectional drawing explaining the manufacturing method of the pressure sensor element shown in FIG. It is sectional drawing explaining the manufacturing method of the pressure sensor element shown in FIG. It is sectional drawing of the pressure sensor element which concerns on 2nd Embodiment of this invention. It is sectional drawing of the pressure sensor which concerns on 3rd Embodiment of this invention. FIG. 10 is an enlarged view of the pressure sensor shown in FIG. 9. It is sectional drawing of the pressure sensor which concerns on 4th Embodiment of this invention. It is sectional drawing of the pressure sensor which concerns on 5th Embodiment of this invention. It is a perspective view which shows an example of the altimeter of this invention. It is a front view which shows an example of the electronic device of this invention. It is a perspective view which shows an example of the moving body of this invention.

  Hereinafter, a pressure sensor element, a pressure sensor, an altimeter, an electronic device, and a moving body of the present invention will be described in detail based on embodiments shown in the accompanying drawings.

<First Embodiment>
First, the pressure sensor element according to the first embodiment of the present invention will be described.

  FIG. 1 is a cross-sectional view of a pressure sensor element according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing a modification of the pressure sensor element shown in FIG. FIG. 3 is a plan view showing a pressure sensor unit included in the pressure sensor element shown in FIG. FIG. 4 is a diagram showing a bridge circuit including the pressure sensor unit in FIG. 5 to 7 are cross-sectional views illustrating a method for manufacturing the pressure sensor element shown in FIG. In the following description, the upper side in FIG. 1 is also referred to as “upper” and the lower side is also referred to as “lower”.

  A pressure sensor element 1 shown in FIG. 1 is an element that can detect a received pressure. The pressure sensor element 1 includes a substrate 2, a pressure sensor part 3, an element surrounding structure 4, a cavity part S, and a semiconductor circuit (not shown).

Hereinafter, each of these units will be described in order.
The substrate 2 has a first insulating film 22 made of a silicon oxide film (SiO ₂ film) and a second insulation made of a silicon nitride film (SiN film) on a semiconductor substrate 21 that is a Si (silicon) substrate. The film 23 is laminated in this order. However, the semiconductor substrate 21 is not limited to the Si substrate, and for example, an SOI substrate (a substrate in which the first Si layer, the SiO ₂ layer, and the second Si layer are stacked in this order) can be used. . Further, the material of the first insulating film 22 and the second insulating film 23 is not particularly limited as long as the etching resistance and the insulating property can be exhibited. Further, the first insulating film 22 and the second insulating film 23 may be arranged as necessary and may be omitted.

  In addition, the semiconductor substrate 21 is provided with a diaphragm 24 that is thinner than the surrounding portion and bends and deforms by receiving pressure. The diaphragm 24 is formed at the bottom of the recess 25 by providing a bottomed recess 25 opened on the lower surface of the semiconductor substrate 21, and the lower surface of the diaphragm 24 (the bottom surface of the recess 25) serves as a pressure receiving surface 241.

  Further, a stepped portion 26 having unevenness 260 is provided on the side surface of the semiconductor substrate 21. The thickness of the edge of the semiconductor substrate 21 becomes discontinuous by such a stepped portion 26, and unnecessary vibration (stress other than pressure) applied to the pressure sensor element 1 can be effectively attenuated. Therefore, it can reduce that the diaphragm 24 bends (or vibrates) by stresses other than pressures, such as an unnecessary vibration, As a result, the pressure detection accuracy of the pressure sensor element 1 can be improved.

  The step portion 26 will be described in detail. As shown in FIG. 1, in the stepped portion 26, irregularities 260 are formed along the thickness direction of the semiconductor substrate 21. As described above, by forming the unevenness 260 along the thickness direction of the semiconductor substrate 21, unnecessary vibrations can be absorbed and relaxed more effectively. Further, the step portion 26 can be more easily formed by a manufacturing method described later. Further, as will be described later with reference to the pressure sensor 10, the stepped portion 26 can also function as a wraparound prevention portion that prevents the first resin material 81 from wrapping around the diaphragm 24.

  In addition, the step portion 26 is positioned on the upper end side of the first side surface 261 located on the lower end side of the semiconductor substrate 21 and on the inner peripheral side of the first side surface 261. 2 side surfaces 262, and a third side surface 263 connecting the first side surface 261 and the second side surface 262. The first side surface 261 and the second side surface 262 are surfaces substantially parallel to the main surface of the semiconductor substrate 21, and the third side surface 263 is a surface perpendicular to the main surface of the semiconductor substrate 21. . By adopting such a configuration, the configuration of the stepped portion 26 becomes simple and the formation thereof becomes easy.

  Moreover, it is preferable that at least the third side surface 263 of the step portion 26 is a cutting surface. The cutting surface refers to a surface formed by cutting with a cutting device such as a dicing saw, for example, so that minute irregularities can be formed on the third side surface 263. In this manner, by forming minute irregularities on the third side surface 263, unnecessary vibration can be absorbed and relaxed more effectively. In addition, the function as the wraparound prevention unit described above can be more effectively exhibited. In addition to the third side surface 263, the first side surface 261 and the second side surface 262 are preferably cut surfaces. Thereby, the above effect becomes more remarkable.

  Here, the height (length in the thickness direction) t1 of the first side surface 261 is not particularly limited. For example, when the thickness T of the semiconductor substrate 21 is about 100 μm to 300 μm, 0.1T ≦ t1 It is preferable to satisfy the relationship of ≦ 0.9T, and it is preferable to satisfy the relationship of 0.4T ≦ t1 ≦ 0.6T. Thereby, the intensity | strength (strength of a convex part) of the level | step-difference part 26 is fully securable. The distance between the first side surface 261 and the second side surface 262 (the length of the third side surface 263) is not particularly limited, but is preferably about 10 μm or more and 100 μm or less. Thereby, unnecessary vibration can be effectively absorbed and reduced by the step portion 26, and excessive protrusion of the step portion 26 (convex portion) can be prevented.

  The shape of the stepped portion 26 is not limited to the shape of the present embodiment, and for example, as shown in FIG. 2, the third side surface 263 may be a curved surface. Thereby, since a corner | angular part is not formed in the boundary of the 2nd side 262 and the 3rd side 263, in the structure of the pressure sensor 10 mentioned above, the bubble remaining in the said part is reduced.

  Further, the step portion 26 is provided over the entire circumference of the side surface of the semiconductor substrate 21. In other words, the step portion 26 is provided so as to surround the periphery (entire circumference) of the diaphragm 24 in a plan view of the semiconductor substrate 21. Thereby, the unnecessary vibration can be absorbed and alleviated more effectively, regardless of where the unnecessary vibration is transmitted. The step portion 26 may not be provided on the entire circumference of the side surface of the semiconductor substrate 21. For example, a pair may be provided at positions facing each other across the diaphragm 24 in a plan view of the semiconductor substrate 21. In this manner, unnecessary vibration can be absorbed and alleviated more effectively by sandwiching the diaphragm 24 between the pair of stepped portions 26.

  A semiconductor circuit (circuit) (not shown) is formed on and above the semiconductor substrate 21. This semiconductor circuit includes circuit elements such as active elements such as MOS transistors, capacitors, inductors, resistors, diodes, and wirings formed as necessary.

  As shown in FIG. 3, the pressure sensor unit 3 includes four piezoresistive elements 31, 32, 33, and 34 provided in the diaphragm 24. Further, the piezoresistive elements 31 to 34 are electrically connected to each other through wiring or the like, and constitute a bridge circuit 30 (Wheatstone bridge circuit) shown in FIG. 4 and are connected to the semiconductor circuit. The bridge circuit 30 is connected to a drive circuit (not shown) that supplies a drive voltage AVDC. The bridge circuit 30 outputs a signal (voltage) corresponding to a change in resistance value of the piezoresistive elements 31, 32, 33, and 34 based on the deflection of the diaphragm 24. The piezoresistive elements 31, 32, 33, and 34 are configured by, for example, doping (diffusing or implanting) impurities such as phosphorus and boron into the semiconductor substrate 21. The wiring connecting these piezoresistive elements 31 to 34 is constituted by doping (diffusing or injecting) impurities such as phosphorus and boron into the semiconductor substrate 21 at a higher concentration than the piezoresistive elements 31 to 34, for example. Has been.

  As shown in FIG. 1, the element surrounding structure 4 defines a cavity S between itself and the substrate 2. The element surrounding structure 4 includes an interlayer insulating film 41, a wiring layer 42 formed on the interlayer insulating film 41, an interlayer insulating film 43 formed on the wiring layer 42 and the interlayer insulating film 41, and an interlayer insulating film 43. It has a wiring layer 44 formed thereon, a surface protective film 45 formed on the wiring layer 44 and the interlayer insulating film 43, and a sealing layer 46. The wiring layer 44 has a coating layer 441 having a plurality of pores 442 communicating with the inside and outside of the cavity S, and the sealing layer 46 disposed on the coating layer 441 seals the pores 442. doing. Note that the wiring layers 42 and 44 include a wiring layer formed so as to surround the cavity S and a wiring layer constituting wiring of a semiconductor circuit (not shown). The semiconductor circuit is drawn to the upper surface by the wiring layers 42 and 44, and a part of the wiring layer 44 becomes the connection terminal 443 and is exposed from the surface protective film 45.

As the interlayer insulating films 41 and 43, for example, an insulating film such as a silicon oxide film (SiO ₂ film) can be used. In addition, as the wiring layers 42 and 44, for example, a metal film such as an aluminum film can be used. Moreover, as the sealing layer 46, metal films, such as Al, Cu, W, Ti, TiN, can be used, for example. Further, as the surface protection film 45, for example, a silicon oxide film, a silicon nitride film, a polyimide film, an epoxy resin film, or the like having resistance to protect from moisture, dust, scratches, or the like can be used.

A cavity S defined by the substrate 2 and the element surrounding structure 4 is a sealed space, and functions as a pressure reference chamber serving as a reference value of pressure detected by the pressure sensor element 1. Such a cavity S is located on the side opposite to the pressure receiving surface 241 of the diaphragm 24, and is disposed so as to overlap the diaphragm 24. In addition, it is preferable that the cavity part S is a vacuum state (for example, 10 Pa or less). Thus, the pressure sensor element 1 can be used as a so-called “absolute pressure sensor element” that detects a pressure with reference to a vacuum. However, the cavity S may not be in a vacuum state as long as it is maintained at a constant pressure. For example, the cavity S may be in an atmospheric pressure state or in a reduced pressure state where the atmospheric pressure is lower than the atmospheric pressure. It may be in a pressurized state where the atmospheric pressure is higher than the atmospheric pressure.
The pressure sensor element 1 has been described above.

Next, a manufacturing method of the pressure sensor element 1 will be described.
The manufacturing method of the pressure sensor element 1 includes a first step of integrally forming a plurality of pressure sensor elements 1A (pressure sensor elements 1 having no stepped portion 26) on a single silicon wafer 20, and the plurality of pressure sensor elements A second step of dicing 1A.

[First step]
First, as shown in FIG. 5A, a silicon wafer 20 is prepared. Next, as shown in FIG. 5B, after forming the pressure sensor portion 3, the first insulating film 22 and the second insulating film 23, the interlayer insulating film 41, the wiring layer 42, and the interlayer are formed on the substrate 2. An insulating film 43, a wiring layer 44, and a surface protective film 45 are formed in this order. Next, as shown in FIG. 6A, after the cavity S is formed by wet etching, the cavity S is brought into a vacuum state, and the cavity S is sealed with the sealing layer 46. Finally, the recess 25 is formed by wet etching or the like to form the diaphragm 24. As described above, a plurality of pressure sensor elements 1 </ b> A (pressure sensor elements 1 having no stepped portion 26) are integrally formed on the silicon wafer 20.

[Second step]
Next, the plurality of pressure sensor elements 1A are separated into pieces. The step of dividing into pieces has a first cutting step and a second cutting step. In the first cutting step, as shown in FIG. 6B, the first dicing saw DS1 is used to cut from the upper surface side to the middle of the silicon wafer 20 (that is, half-dicing), so that the upper surface is opened. A recess 51 is formed. The width W1 of the recess 51 is not particularly limited, and can be, for example, 30 μm or more and 100 μm or less. In the second cutting step, as shown in FIG. 7A, from the center in the width direction of the bottom surface of the recess 51 to the lower surface using the second dicing saw DS2 having a width smaller than that of the first dicing saw DS1. Cut to penetrate. As a result, the plurality of pressure sensor elements 1A are singulated, and stepped portions 26 are formed in each pressure sensor element 1A.
Thus, the pressure sensor element 1 is obtained.

  In the first cutting step, by using the first dicing saw DS1 having a rounded tip, the concave portion 51 as shown in FIG. 7B can be formed. Therefore, the step portion 26 shown in FIG. It can be easily formed by the above method.

Second Embodiment
Next, a pressure sensor element according to a second embodiment of the present invention will be described.
FIG. 8 is a cross-sectional view of a pressure sensor element according to the second embodiment of the present invention.

  Hereinafter, although the pressure sensor element of 2nd Embodiment is demonstrated, it demonstrates centering around difference with embodiment mentioned above, and abbreviate | omits the description about the same matter.

  The pressure sensor element 1 ′ shown in FIG. 8 includes a plate-shaped pedestal 61, a plate-shaped substrate 62 bonded to the pedestal 61, the pressure sensor unit 3, and the cavity S. The pedestal 61 is made of, for example, a glass substrate, and the substrate 62 is made of, for example, a single crystal silicon substrate. And the base 61 and the board | substrate 62 are joined by anodic bonding, for example.

  Further, the substrate 62 is provided with a diaphragm 621 that is thinner than the surrounding portion and bends and deforms by receiving pressure. The diaphragm 621 is formed at the bottom of the recess 622 by providing a bottomed recess 622 opened on the upper surface of the substrate 62, and the lower surface of the diaphragm 621 is a pressure receiving surface 621a. The diaphragm 621 is provided with the same pressure sensor unit 3 (piezoresistive elements 31 to 34) as in the first embodiment described above. Further, the recess 622 is hermetically sealed by the pedestal 61, thereby forming a cavity S. A stepped portion 63 is formed on the side surface of the substrate 62. The configuration of the step portion 63 is the same as, for example, the step portion 26 of the first embodiment described above.

  In the pressure sensor element 1 having such a configuration, the diaphragm 621 is bent and deformed according to the pressure received by the pressure receiving surface 621a. And the magnitude | size of the pressure received by the pressure receiving surface 621a can be calculated | required based on the resistance value of the piezoresistive elements 31-34 changing with the deformation | transformation of the diaphragm 621. FIG.

  Also according to the second embodiment, the same effects as those of the first embodiment described above can be exhibited.

<Third Embodiment>
Next, a pressure sensor according to a third embodiment of the present invention will be described.

  FIG. 9 is a cross-sectional view of a pressure sensor according to a third embodiment of the present invention. FIG. 10 is an enlarged view of the pressure sensor shown in FIG.

  A pressure sensor 10 shown in FIG. 9 includes a pressure sensor element 1, a package (container) 7 that houses the pressure sensor element 1, and a resin material 8 that is disposed in the package 7 so as to surround the pressure sensor element 1. Have. The pressure sensor element 1 has the same configuration as that of the first embodiment described above.

  The package 7 has a box shape (a bowl shape), and a recess (internal space) 71 is formed on the upper surface. A stepped portion 72 is provided inside the recess 71. A terminal 73 is provided on the upper surface of the stepped portion 72. The number of terminals 73 corresponds to the number of connection terminals 443 included in the pressure sensor element 1. Each terminal 73 is electrically connected to an external connection terminal 74 disposed on the bottom surface of the package 7 through a through electrode (not shown) formed in the stepped portion 72. The external connection terminal 74 includes, for example, a drive circuit for driving the pressure sensor element 1, a temperature compensation circuit for temperature compensation based on the temperature detected by the temperature sensor, and a post-compensation An IC chip having a pressure detection circuit for obtaining a pressure from the output of is connected.

  The constituent material of the package 7 is not particularly limited, for example, various ceramics such as oxide ceramics such as alumina, silica, titania and zirconia, nitride ceramics such as silicon nitride, aluminum nitride and titanium nitride, Examples thereof include insulating materials such as various resin materials such as polyethylene, polyamide, polyimide, polycarbonate, acrylic resin, ABS resin, and epoxy resin, and one or more of these can be used in combination. Among these, various ceramics are preferable. Thereby, the package 7 having excellent mechanical strength can be obtained.

  In such a package 7, the pressure sensor element 1 is accommodated in a posture in which the pressure receiving surface 241 of the diaphragm 24 faces the opening. With this arrangement, the pressure receiving surface 241 can be directed to the opening of the package 7 and can be brought close to the opening of the package 7, so that the pressure applied to the pressure sensor 10 acts on the pressure receiving surface 241 more efficiently. .

  Further, the connection terminal 443 of the pressure sensor element 1 and the terminal 73 of the package are electrically connected via a bonding wire 75. Note that the connection method of the connection terminal 443 and the terminal 73 is not limited to a method using a bonding wire. For example, the connection terminal 443 and the terminal 73 may be connected via a flying lead (tab tape) or bump. You may connect via (metal bump or conductive resin).

  Further, as shown in FIGS. 9 and 10, the package 7 is filled with a resin material 8 so as to surround the pressure sensor element 1. Such a resin material 8 includes a first resin material 81 and a second resin material 82. The first resin material 81 is filled from the bottom of the recess 71 to an intermediate depth, and the second resin material 82 is filled on the first resin material 81. That is, the first resin material 81 and the second resin material 82 are filled side by side in the thickness direction of the package 7. Further, the first resin material 81 and the second resin material 82 are in close contact with each other. Therefore, it is possible to reduce the generation of bubbles (voids) between the first resin material 81 and the second resin material 82, and the propagation of pressure to the pressure receiving surface 241 is hindered by the generation of the bubbles. Or the bubbles can be prevented from moving onto the pressure receiving surface 241.

  The pressure sensor element 1 is embedded in such a resin material 8. More specifically, the first resin material 81 is embedded up to the third side surface 263 of the pressure sensor element 1, and the second resin material 82 is above the third side surface 263 of the pressure sensor element 1. The side is buried. In other words, the boundary 80 between the first resin material 81 and the second resin material 82 is located in the middle of the step portion 26. Therefore, the first resin material 81 is disposed so as to contact the outer peripheral surface of the element surrounding structure 4 and cover the element surrounding structure 4, and the second resin material 82 includes the diaphragm 24 (pressure receiving surface 241). It is arranged so as to contact and cover the diaphragm 24. The boundary 80 may not be located on the third side surface 263 as long as it is located in the middle of the stepped portion 26.

  The first resin material 81 functions as a support member that supports (fixes) the pressure sensor element 1 to the package 7. Thereby, the pressure sensor element 1 can be stably supported by the package 7, and the fluctuation | variation of the position of the pressure sensor element 1 in the recessed part 71 can be reduced. On the other hand, the second resin material 82 protects the pressure sensor element 1 (dustproof and waterproof) and propagates the pressure applied to the pressure sensor 10 to the pressure receiving surface 241 of the pressure sensor element 1 through the opening of the package 7. .

  The first resin material 81 is made of a material harder than the second resin material 82 and has a function of supplementing the rigidity of the element surrounding structure 4 of the pressure sensor element 1, particularly the sealing layer 46. The presence of the first resin material 81 can reduce the pressure propagated from the second resin material 82 from being propagated to the element surrounding structure 4, particularly the sealing layer 46. Therefore, it can reduce that the sealing layer 46 bends toward the cavity part S side by receiving pressure. Thereby, it can prevent or reduce that the reference pressure of the pressure sensor 10 changes.

  Such a first resin material 81 is, for example, in the form of a gel or a solid. In such a state, the bending of the sealing layer 46 toward the cavity S side is more reliably reduced. In particular, when the first resin material 81 is solid, the first resin material 81 preferably has, for example, a Young's modulus (longitudinal elastic modulus) of 0.1 GPa to 50 GPa, preferably 1 GPa to 10 GPa. The following is more preferable. Moreover, when the 1st resin material 81 is a gel form, the 1st resin material 81 should just have smaller penetration than the 2nd resin material 82, For example, penetration is 1 or more It is preferably 200 or less, more preferably 10 or more and 100 or less. In addition, the said penetration can be calculated | required by measuring by the method based on the test method prescribed | regulated to JISK2207. When the Young's modulus or the penetration is within the above range, the first resin material 81 can ensure the necessary rigidity (hardness), and exhibits the function of supplementing the rigidity of the sealing layer 46 more remarkably. be able to.

  The first resin material 81 has an insulating property. Thereby, even if the 1st resin material 81 is contacting the bonding wire 75 and the terminal 73, the short circuit between the some bonding wires 75 and between the some terminals 73 can be prevented.

  Examples of the constituent material of the first resin material 81 include a silicon-based resin, a fluorine-based resin, an epoxy-based resin, and a polyimide-based resin, and one or a combination of two or more of these may be used. Can be used. Thereby, the 1st resin material 81 can ensure required rigidity (hardness) more easily. Silicon-based resins, fluorine-based resins, epoxy resins, and polyimide resins have a relatively small heat shrinkage rate. For this reason, it is possible to reduce the deformation (deflection) of the sealing layer 46 due to the stress caused by the thermal contraction of the first resin material 81.

  Moreover, it is preferable that the 1st resin material 81 contains the filler in addition to the said resin. Examples of the filler include inorganic fillers containing inorganic substances such as metals, metal oxides, and ceramics, and organic fillers containing organic substances such as graphite, carbon black, and resins. Among these, it is particularly preferable to include an inorganic filler. Thereby, the rigidity of the 1st resin material 81 can be improved and the deformation | transformation of the sealing layer 46 by pressure receiving can be reduced further. Further, as the filler, among inorganic fillers, those having insulating properties such as ceramic are more preferable. Thereby, the short circuit between the some bonding wire 75 and between the some terminals 73 can be prevented more reliably.

  On the other hand, the second resin material 82 has characteristics (flexibility) that are softer than, for example, the pressure sensor element 1 and the package 7. The second resin material 82 is, for example, liquid or gel. In particular, since the gel-like second resin material 82 has low fluidity, fluctuations in the position of the pressure sensor element 1 in the recess 71 can be reduced. Therefore, the pressure sensor 10 can be detected with high accuracy without being affected by the change in posture. When the 2nd resin material 82 is a gel form, it is preferable that the 2nd resin material 82 is 50-250, for example, and it is more preferable that it is 150-250. Thereby, the second resin material 82 can be sufficiently softened, and the pressure applied to the pressure sensor 10 acts on the pressure receiving surface 241 efficiently. Moreover, the fluctuation | variation of the position of the pressure sensor element 1 in the recessed part 71 can be suppressed more appropriately.

  Examples of the constituent material of the second resin material 82 include a fluorine-based resin and a silicone resin, and one or more of these can be used in combination. Thereby, the second resin material 82 becomes sufficiently soft, and the pressure applied to the pressure sensor 10 can be efficiently transmitted to the pressure receiving surface 241.

  By having the resin material 8 as described above, the pressure applied to the pressure sensor 10 can be efficiently propagated to the pressure receiving surface 241 and the sealing layer 46 is bent by the pressure receiving, whereby the cavity S A change in pressure can be avoided. For this reason, the pressure detection accuracy of the pressure sensor 10 can be increased.

  Further, in the pressure sensor 10 having such a configuration, the step portion 26 of the pressure sensor element 1 exhibits the following effects. That is, the pressure sensor 10 is obtained by placing the pressure sensor element 1 in the package 7, connecting the pressure sensor element 1 and the package 7 with the bonding wire 75, and then filling the resin material 8 in the recess 71. .

  Filling the recess 71 with the resin material 8 is performed by filling the first resin material 81 from the bottom of the recess 71 and filling the second resin material 82 from above the first resin material 81. And a second filling step. In the first filling step, the first resin material 81 must be filled so as to cover the element surrounding structure 4 and not to contact the pressure receiving surface 241 of the diaphragm 24. In this respect, the pressure sensor element 1 is provided with a step portion 26, and when the concave portion 71 is filled with the first resin material 81, the step portion 26 (particularly the third side surface 263) is the first resin. It functions as a stopper for the material 81. Therefore, even if the filling amount of the first resin material 81 is somewhat increased, it is possible to prevent the first resin material 81 from entering the pressure receiving surface 241. In particular, in the case of the stepped portion 26 having the shape shown in FIG. 4, since there is no corner at the boundary between the second side surface 262 and the third side surface 263, it is more effective for bubbles to remain at the stepped portion 26. Can be reduced.

  Also according to the third embodiment, the same effects as those of the first embodiment described above can be exhibited.

<Fourth embodiment>
Next, a pressure sensor according to a fourth embodiment of the present invention will be described.
FIG. 11 is a cross-sectional view of a pressure sensor according to the fourth embodiment of the present invention.

  Hereinafter, although the pressure sensor of 4th Embodiment is demonstrated, it demonstrates centering around difference with embodiment mentioned above, and abbreviate | omits the description about the same matter.

  The pressure sensor of the fourth embodiment is the same as the third embodiment described above except that it further includes an IC chip.

  As shown in FIG. 11, the pressure sensor 10 of this embodiment includes a pressure sensor element 1, an IC chip 9, a package 7 that houses the pressure sensor element 1 and the IC chip 9, and the pressure sensor element 1 in the package 7. And a resin material 8 arranged so as to surround the IC chip 9.

  The IC chip 9 is disposed below the pressure sensor element 1. Further, the IC chip 9 and the pressure sensor element 1 are electrically connected by a connecting member 91 and mechanically fixed. The IC chip 9 is connected to the terminal 73 via the bonding wire 75. The IC chip 9 includes, for example, a drive circuit for driving the pressure sensor element 1, a temperature compensation circuit for temperature compensation based on the temperature detected by the temperature sensor, and a post-compensation circuit. A pressure detection circuit for obtaining the pressure from the output is provided.

  The arrangement of the IC chip 9 is not particularly limited, and may be located above the pressure sensor element 1 or may be arranged side by side.

  According to the fourth embodiment, the same effect as that of the first embodiment described above can be exhibited.

<Fifth Embodiment>
Next, a pressure sensor according to a fifth embodiment of the invention will be described.
FIG. 12 is a cross-sectional view of a pressure sensor according to the fifth embodiment of the present invention.

  Hereinafter, although the pressure sensor of 5th Embodiment is demonstrated, it demonstrates centering around difference with embodiment mentioned above, and abbreviate | omits the description about the same matter.

  The pressure sensor of the fifth embodiment is the same as that of the fourth embodiment described above except that the arrangement of the first resin material is different.

  As shown in FIG. 12, in the pressure sensor 10 of the present embodiment, the first resin material 81 is provided between the pressure sensor element 1 and the IC chip 9. A second resin material 82 is provided around the entire structure including the pressure sensor element 1 and the IC chip 9. With such a structure, the pressure receiving surface 241 and the IC chip 9 are both connected to the second resin material 82. That is, unlike the fourth embodiment described above, the pressure receiving surface 241 and the IC chip 9 are covered with the same material. For this reason, in the pressure sensor 10 of this embodiment, a difference in heat conduction between the pressure receiving surface 241 and the IC chip 9 hardly occurs, and problems such as temperature hysteresis hardly occur.

  Further, since the second resin material 82 is provided not only on the upper side of the structure but also on the side and lower sides, the stress caused by the distortion of the package 7 can be absorbed. By acting on the structure, it is possible to reduce a decrease in detection performance of the pressure sensor element 1 and the IC chip 9.

  According to the fifth embodiment, the same effect as that of the first embodiment described above can be exhibited.

[Altimeter]
Next, an example of an altimeter provided with the pressure sensor (pressure sensor element) of the present invention will be described. FIG. 13 is a perspective view showing an example of an altimeter according to the present invention.

  As shown in FIG. 13, the altimeter 200 can be worn on the wrist like a wristwatch. In addition, the pressure sensor 10 (pressure sensor element 1) is mounted inside the altimeter 200, and the altitude from the sea level of the current location, the atmospheric pressure of the current location, or the like can be displayed on the display unit 201. The display unit 201 can display various information such as the current time, the user's heart rate, and weather.

[Electronics]
Next, a navigation system to which an electronic device including the pressure sensor (pressure sensor element) of the present invention is applied will be described. FIG. 14 is a front view showing an example of an electronic apparatus of the present invention.

  As shown in FIG. 14, the navigation system 300 includes a map information (not shown), position information acquisition means from a GPS (Global Positioning System), a gyro sensor, an acceleration sensor, and vehicle speed data. Means, a pressure sensor 10 (pressure sensor element 1), and a display 301 for displaying predetermined position information or course information.

  According to this navigation system, altitude information can be acquired in addition to the acquired position information. By obtaining altitude information, for example, when traveling on an elevated road that shows approximately the same position as a general road, if you do not have altitude information, you are traveling on an ordinary road or on an elevated road The navigation system was unable to determine whether or not the vehicle was being used, and the general road information was provided to the user as priority information. Therefore, in the navigation system 300 according to the present embodiment, the altitude information can be acquired by the pressure sensor 10, and a change in altitude caused by entering the elevated road from a general road is detected, and the navigation information in the traveling state of the elevated road is obtained. Can be provided to the user.

  The electronic device provided with the pressure sensor (pressure sensor element) of the present invention is not limited to the above-mentioned ones. For example, personal computers, mobile phones, medical devices (for example, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiogram measuring devices) The present invention can be applied to ultrasonic diagnostic apparatuses, electronic endoscopes), various measuring instruments, instruments (for example, instruments for vehicles, aircraft, ships), flight simulators, and the like.

[Moving object]
Next, a moving body including a pressure sensor (pressure sensor element) will be described. FIG. 15 is a perspective view showing an example of the moving body of the present invention.

  As shown in FIG. 15, the moving body 400 has a vehicle body 401 and four wheels 402, and is configured to rotate the wheels 402 by a power source (engine) (not shown) provided in the vehicle body 401. ing. Such a moving body 400 incorporates a navigation system 300 (pressure sensor element 1).

  As described above, the pressure sensor element, pressure sensor, altimeter, electronic device, and moving body of the present invention have been described based on the illustrated embodiments, but the present invention is not limited to these, and the configuration of each part is the same. It can be replaced with any configuration having the above function. Moreover, other arbitrary structures and processes may be added. Moreover, you may combine each embodiment suitably.

  In the above-described embodiment, the sensor chip has a sensor element that uses a piezoresistive element. However, the pressure sensor is not limited to this, for example, a configuration using a flap-type vibrator, Other MEMS vibrators such as comb electrodes, and vibration elements such as crystal vibrators can also be used.

DESCRIPTION OF SYMBOLS 1, 1 ', 1A ... Pressure sensor element 10 ... Pressure sensor 2 ... Substrate 20 ... Silicon wafer 21 ... Semiconductor substrate 22 ... 1st insulating film 23 ... 2nd insulating film 24 ... Diaphragm 241 ... …… Pressure receiving surface 25 …… Concave portion 26 …… Step portion 260 …… Concavity and convexity 261 …… First side surface 262 …… Second side surface 263 …… Third side surface 3 …… Pressure sensor portion 30 …… Bridge circuit 31, 32, 33, 34 ... Piezoresistive element 4 ... Element surrounding structure 41 ... Interlayer insulating film 42 ... Wiring layer 43 ... Interlayer insulating film 44 ... Wiring layer 441 ... Covering layer 442 ... Pore 443 …… Connection terminal 45 …… Surface protection film 46 …… Sealing layer 51 …… Recess 61 …… Pedestal 62 …… Substrate 621 …… Diaphragm 621a …… Pressure receiving surface 622 …… Depression 63 …… Step part 71 ...... Recessed portion 72 ...... Stepped portion 73 ...... Terminal 74 ...... External connection terminal 75 ...... Bonding wire 8 ...... Resin material 80 ...... Boundary 81 ...... First resin material 82 ...... Second resin material 9. ... IC chip 91 ... Connection member 200 ... Altimeter 201 ... Display part 300 ... Navigation system 301 ... Display part 400 ... Mobile body 401 ... Car body 402 ... Wheel DS1 ... First dicing saw DS2 ... ... Second dicing saw S ... Cavity t1 ... Height T ... Thickness W1 ... Width

Claims (13)

A substrate having a recess with a deformable diaphragm disposed at the bottom;
A pressure sensor element, wherein a step portion having unevenness is disposed on a side surface of the substrate.   The pressure sensor element according to claim 1, wherein the step portion has the unevenness along a thickness direction of the substrate. The step portion includes a first side surface,
A second side surface disposed at a position shifted in the thickness direction from the first side surface, and positioned closer to the center side of the substrate than the first side surface in a plan view of the substrate;
The pressure sensor element according to claim 2, further comprising a third side surface that connects the first side surface and the second side surface.   The pressure sensor element according to any one of claims 1 to 3, wherein at least a part of the surface of the step portion is a cutting surface.   The pressure sensor element according to claim 3, wherein the third side surface is a cutting surface.   The pressure sensor element according to any one of claims 1 to 5, wherein the diaphragm is disposed between the two stepped portions in a plan view of the substrate.   The pressure sensor element according to any one of claims 1 to 6, wherein the step portion is disposed so as to surround the diaphragm in a plan view of the substrate. The pressure sensor element according to any one of claims 1 to 7,
And a package having an internal space for accommodating the pressure sensor element. A resin material disposed around the pressure sensor element in the package;
The said resin material has at least 1st resin and 2nd resin different from said 1st resin along the alignment direction of the said unevenness | corrugation of the said pressure sensor element. pressure sensor.   The pressure sensor according to claim 9, wherein a boundary between the first resin and the second resin is located at the stepped portion.   An altimeter comprising the pressure sensor element according to any one of claims 1 to 7.   An electronic apparatus comprising the pressure sensor element according to claim 1.   A moving body comprising the pressure sensor element according to claim 1.

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