JP2016133398A - Pressure sensor, method of manufacturing pressure sensor, altimeter, electronic apparatus and moving body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensor in which air bubbles have difficulty to come into contact with a pressure receiving surface of a diaphragm and lowering of pressure detection accuracy can be reduced, and also to provide a method of manufacturing this pressure sensor, an altimeter equipped with this pressure sensor, an electronic apparatus and a moving body.SOLUTION: A pressure sensor 1 includes a pressure sensor element 3 having a pressure receiving surface 541, and a filling material 9 arranged surrounding the pressure sensor element 3. Moreover, the filling material 9 has a first portion 91 in contact with at least the pressure receiving surface 541 and a second portion 92 located around the first portion 91. Then, the hardening ratio of the first portion 91 becomes higher than that of the second portion 92.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure sensor, a pressure sensor manufacturing method, 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, for example, bubbles are easily generated when an inert liquid is filled in the package, and if the bubbles come into contact with the pressure receiving surface of the diaphragm, the pressure detection accuracy decreases. Resulting in.

JP-A-9-126920

  An object of the present invention is to provide a pressure sensor that makes it difficult for bubbles to come into contact with the pressure receiving surface of a diaphragm and can reduce a decrease in pressure detection accuracy, a method for manufacturing the pressure sensor, an altimeter equipped with the pressure sensor, an electronic device, and a moving body Is to provide.

  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 of this application example includes a pressure sensor element having a pressure receiving surface,
A curable resin disposed around the pressure sensor element,
The curable resin has at least a first part disposed on the pressure-receiving surface and a second part different from the first part,
The curing rate of the first part is higher than the curing rate of the second part.
As a result, a pressure sensor can be obtained in which bubbles are unlikely to come into contact with the pressure receiving surface, and a reduction in pressure detection accuracy can be reduced.

[Application Example 2]
In the pressure sensor of this application example, it is preferable that the first part and the second part each contain the same kind of resin material.
Thereby, adjustment of the hardening rate (hardness) of the 1st part and the 2nd part becomes easy.

[Application Example 3]
In the pressure sensor of this application example, the pressure sensor element has a recess whose bottom surface is the pressure receiving surface,
It is preferable that the first portion is disposed so as to be connected to an inner surface connected to the bottom surface in the recess.
This makes it more difficult for bubbles to contact the pressure receiving surface.

[Application Example 4]
In the pressure sensor of this application example, the curable resin is preferably cured by heat.
Thereby, hardening of curable resin can be performed easily.

[Application Example 5]
In the pressure sensor of this application example, the curable resin is preferably cured by light.
Thereby, hardening of curable resin can be performed easily.

[Application Example 6]
The pressure sensor according to this application example preferably includes a package that accommodates the pressure sensor element and the curable resin.
Thereby, while being able to protect a pressure sensor element, curable resin can be collected in a package.

[Application Example 7]
In the pressure sensor of this application example, the package has an opening,
The pressure sensor element is preferably arranged such that the pressure-receiving surface faces a direction different from the opening.
Thereby, a pressure receiving surface can be protected.

[Application Example 8]
In the pressure sensor of this application example, it is preferable that the first portion is subjected to a defoaming process.
This makes it more difficult for bubbles to contact the pressure receiving surface.

[Application Example 9]
The pressure sensor manufacturing method of this application example prepares a pressure sensor element having a pressure receiving surface, a package, a first curable resin, and a second curable resin containing the same components as the first curable resin. Process,
Disposing the first curable resin on the pressure-receiving surface;
Curing the first curable resin;
Disposing the pressure sensor element in the package;
Disposing the second curable resin so as to surround the pressure sensor element and the first curable resin in the package;
Curing the first curable resin and the second curable resin disposed in the package;
It is characterized by including.
As a result, a pressure sensor can be obtained in which bubbles are unlikely to come into contact with the pressure receiving surface, and a reduction in pressure detection accuracy can be reduced.

[Application Example 10]
In the manufacturing method of the pressure sensor of this application example, before the step of curing the first curable resin,
It is preferable that a step of defoaming the first curable resin disposed on the pressure receiving surface is included.
Thereby, since the bubbles in the first curable resin can be removed, the contact between the pressure receiving surface and the bubbles can be more effectively reduced.

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

[Application Example 12]
An electronic apparatus according to this application example includes the pressure sensor 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 of the above application example.
Thereby, a mobile body with high reliability is obtained.

It is sectional drawing of the pressure sensor which concerns on 1st Embodiment of this invention. It is a top view of the flexible wiring board which the pressure sensor shown in FIG. 1 has. It is sectional drawing of the pressure sensor element which the pressure sensor shown in FIG. 1 has. It is a top view which shows the pressure sensor part which the pressure sensor element shown in FIG. 3 has. It is a figure which shows the bridge circuit containing the pressure sensor part shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the pressure sensor shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the pressure sensor shown in FIG. It is sectional drawing of the pressure sensor which concerns on 2nd Embodiment of this invention. It is sectional drawing of the pressure sensor which concerns on 3rd 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, a pressure sensor manufacturing method, an altimeter, an electronic device, and a moving body according to the present invention will be described in detail based on embodiments shown in the accompanying drawings.

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

  FIG. 1 is a cross-sectional view of a pressure sensor according to a first embodiment of the present invention. FIG. 2 is a plan view of a flexible wiring board included in the pressure sensor shown in FIG. FIG. 3 is a sectional view of a pressure sensor element included in the pressure sensor shown in FIG. 4 is a plan view showing a pressure sensor unit included in the pressure sensor element shown in FIG. FIG. 5 is a diagram illustrating a bridge circuit including the pressure sensor unit illustrated in FIG. 4. 6 and 7 are cross-sectional views for explaining a method of manufacturing the pressure sensor shown in FIG. In the following description, the upper side in FIG. 3 is also referred to as “upper” and the lower side is also referred to as “lower”.

  A pressure sensor 1 shown in FIG. 1 includes a pressure sensor element 3, an IC chip 4 electrically connected to the pressure sensor element 3, a package 2 that houses both the pressure sensor element 3 and the IC chip 4, and a package 2. And a filling material 9 surrounding the pressure sensor element 3 and the IC chip 4. Hereinafter, each of these units will be described in order.

≪Package≫
The package 2 has a function of accommodating and fixing the pressure sensor element 3 in an internal space 28 formed therein. The pressure sensor element 3 is protected by the package 2 as described above, and the filler 9 is easily disposed around the pressure sensor element 3.

  As shown in FIG. 1, the package 2 includes a base 21, a housing 22, and a flexible wiring board 25, and the flexible wiring board 25 is sandwiched between the base 21 and the housing 22. These are configured to be joined to each other. Bonding between the base 21 and the flexible wiring board 25 and bonding between the housing 22 and the flexible wiring board 25 are performed via an adhesive layer 26 made of an adhesive.

  The base 21 constitutes the bottom surface of the package 2 and has a box shape (a bowl shape). The constituent material of the base 21 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, polyethylene, Insulating materials such as various resin materials such as polyamide, polyimide, polycarbonate, acrylic resin, ABS resin, and epoxy resin can be used, and one or more of these can be used in combination. Among these, various ceramics are preferable. Thereby, the package 2 having excellent mechanical strength can be obtained. In addition, as the planar view shape of the base 21, for example, a circular shape, a rectangular shape, a polygonal shape of pentagon or more, and the like may be used.

  The housing 22 constitutes a lid portion of the package 2, and in this embodiment, the overall shape is a cylindrical shape. The housing 22 has a first portion where the outer diameter and inner diameter gradually decrease from the lower end toward the upper end to the middle of the package height, and a second portion where the outer diameter and the inner diameter become substantially constant from the middle toward the upper end. Have. As the constituent material of the housing 22, the same materials as those mentioned as the constituent material of the base 21 can be used. The shape of the housing 22 is not particularly limited.

  The flexible wiring board 25 is located between the base 21 and the housing 22, supports the pressure sensor element 3 and the IC chip 4 in the package 2, and receives electric signals from the pressure sensor element 3 and the IC chip 4. It has a function of taking it out of the package 2. Such a flexible wiring board 25 includes a flexible base material 23 and wirings 24 formed on the upper surface side of the base material 23.

  In addition, as shown in FIG. 2, the base material 23 is formed integrally with a frame portion 231 having a substantially rectangular frame shape and having an opening 233 at the center, and protruding on one side of the frame portion 231. A belt body 232 having a belt shape. The constituent material of the base material 23 is not particularly limited as long as it has flexibility, and examples thereof include polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES). Of these, one or two or more of these can be used in combination.

  The wiring 24 has conductivity, and is provided (routed) over the frame portion 231 and the band body 232 as shown in FIG. Such wiring 24 supports the pressure sensor element 3, supports the IC chip 4 and the four wiring parts 241 that electrically connect the pressure sensor element 3 and the IC chip 4, and is attached to the IC chip 4. And four wiring portions 245 that are electrically connected. Then, the four wiring portions 245 are each drawn out of the package 2 through the band body 232.

  Each of the four wiring portions 241 has an end portion on the pressure sensor element 3 side serving as a flying lead 241a, and similarly, an end portion on the IC chip 4 side is also a flying lead 241b. Further, the four flying leads 241a are provided so that the distal end side protrudes into the opening 233, and is electrically connected to the pressure sensor element 3 via the conductive fixing member 14 at the distal end. Yes. The pressure sensor element 3 is supported by the flying lead 241a so as to be separated from the frame portion 231. Similarly, the four flying leads 241b are provided so that the tip side protrudes into the opening 233, and is electrically connected to the IC chip 4 via the conductive fixing member 15 at the tip. Yes. With the configuration as described above, the pressure sensor element 3 and the IC chip 4 are electrically connected via the four wiring portions 241, and communication between them is possible. The fixing members 14 and 15 are not particularly limited as long as they have conductivity. For example, a metal brazing material such as solder, a metal bump such as a gold bump, a conductive adhesive, or the like can be used.

  On the other hand, each of the four wiring portions 245 is provided with the base end side on the band body 232 and the tip end side with the frame portion 231. Moreover, the front-end | tip part of the four wiring parts 245 is the flying lead 245a. Each of the four flying leads 245a is provided such that the tip side protrudes into the opening 233, and is electrically connected to the IC chip 4 via the conductive fixing member 15 at the tip. Yes. Further, the IC chip 4 is supported by being separated from the frame portion 231 by the flying lead 245a and the above-described flying lead 241b.

  According to the package 2 having such a configuration, for example, an electronic device described later or a mother board of a moving body is electrically connected to the end portion of the wiring portion 245 so that the pressure sensor element 3 and the IC chip 4 can be connected. An electric signal can be taken out of the package 2.

The number of wiring portions included in the wiring 24 is not particularly limited, and the number of connection terminals 743 described later provided in the pressure sensor element 3 or the number of connection terminals 42 described later provided in the IC chip 4. It may be set as appropriate in accordance with. Further, the constituent material of the wiring 24 is not particularly limited as long as it has conductivity, and includes, for example, metals such as Ni, Pt, Li, Mg, Sr, Ag, Cu, Co, and Al, and the like. Examples thereof include alloys such as MgAg, AlLi, and CuLi, and oxides such as ITO and SnO ₂ , and one or more of these can be used in combination.

≪Pressure sensor element≫
As shown in FIG. 3, the pressure sensor element 3 includes a substrate 5, a pressure sensor part 6, an element surrounding structure 7, a cavity part 8, and a semiconductor circuit (not shown). Hereinafter, each of these units will be described in order.

The substrate 5 has a plate shape and is formed on a semiconductor substrate 51 formed of an SOI substrate (a substrate in which the first Si layer 511, the SiO ₂ layer 512, and the second Si layer 513 are stacked in this order) The first insulating film 52 made of a silicon oxide film (SiO ₂ film) and the second insulating film 53 made of a silicon nitride film (SiN film) are stacked in this order. However, the semiconductor substrate 51 is not limited to an SOI substrate, and for example, a silicon substrate can be used.

  Further, the semiconductor substrate 51 is provided with a diaphragm 54 that is thinner than the surrounding portion and bends and deforms by receiving pressure. The diaphragm 54 is formed by providing a bottomed recess 55 on the lower surface of the semiconductor substrate 51, and the lower surface (the bottom surface of the recess 55) serves as a pressure receiving surface 541.

  A semiconductor circuit (circuit) (not shown) is formed on and above the semiconductor substrate 51. 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. 4, the pressure sensor unit 6 includes four piezoresistive elements 61, 62, 63, and 64 provided on the diaphragm 54. In addition, the piezoresistive elements 61 to 64 are electrically connected to each other via a wiring or the like, and constitute a bridge circuit 60 (Wheatstone bridge circuit) shown in FIG. 5 and connected to the semiconductor circuit. The bridge circuit 60 is connected to a drive circuit (not shown) that supplies a drive voltage AVDC. The bridge circuit 60 outputs a signal (voltage) corresponding to a change in resistance value of the piezoresistive elements 61, 62, 63, 64 based on the deflection of the diaphragm 54. The piezoresistive elements 61, 62, 63, and 64 are each configured by doping (diffusing or implanting) impurities such as phosphorus and boron into the first Si layer 511, for example. In addition, for example, the wiring connecting these piezoresistive elements 61 to 64 is doped (diffused or implanted) into the first Si layer 511 with impurities such as phosphorus and boron at a higher concentration than the piezoresistive elements 61 to 64. It is composed of that.

  The element surrounding structure 7 is formed so as to define the cavity 8. As shown in FIG. 3, the element surrounding structure 7 includes an interlayer insulating film 71, a wiring layer 72 formed on the interlayer insulating film 71, and an interlayer insulating film formed on the wiring layer 72 and the interlayer insulating film 71. A film 73, a wiring layer 74 formed on the interlayer insulating film 73, a surface protective film 75 formed on the wiring layer 74 and the interlayer insulating film 73, and a sealing layer 76 are included. The wiring layer 74 has a coating layer 741 having a plurality of pores 742 communicating between the inside and the outside of the cavity 8, and the sealing layer 76 disposed on the coating layer 741 has the pores 742. It is sealed. In addition, the wiring layers 72 and 74 include a wiring layer formed so as to surround the cavity 8 and a wiring layer constituting a wiring of the semiconductor circuit. The semiconductor circuit is drawn to the upper surface of the pressure sensor element 3 by the wiring layers 72 and 74, and a part of the wiring layer 74 serves as a connection terminal 743. The connection terminal 743 is electrically connected to the flying lead 241a through the fixing member 14 (see FIG. 2).

The interlayer insulating films 71 and 73 are not particularly limited. For example, an insulating film such as a silicon oxide film (SiO ₂ film) can be used. Further, the wiring layers 72 and 74 are not particularly limited, but for example, a metal film such as an aluminum film can be used. In addition, the sealing layer 76 is not particularly limited, but a metal film such as Al, Cu, W, Ti, TiN, or the like can be used. Further, the surface protective film 75 is not particularly limited, but a film having resistance to protect the element from moisture, dust, scratches, etc., such as a silicon oxide film, a silicon nitride film, a polyimide film, and an epoxy resin film is used. Can do.

  A cavity 8 defined by the substrate 5 and the element surrounding structure 7 is a sealed space, and functions as a pressure reference chamber serving as a reference value of pressure detected by the pressure sensor element 3. Such a cavity portion 8 is located on the side opposite to the pressure receiving surface 541 of the diaphragm 54 and is disposed so as to overlap the diaphragm 54. The cavity 8 is in a vacuum state (for example, 10 Pa or less). As a result, the pressure sensor element 3 can be used as a so-called “absolute pressure sensor element” that detects pressure based on a vacuum state. However, the cavity 8 may not be in a vacuum state, and may be, for example, an atmospheric pressure state, a reduced pressure state where the atmospheric pressure is lower than the atmospheric pressure, or an atmospheric pressure higher than the atmospheric pressure. It may be in a pressurized state.

  As shown in FIG. 1, the pressure sensor element 3 configured as described above is housed in the package 2 in a posture in which the pressure receiving surface 541 of the diaphragm 54 faces the bottom side of the package 2. With such an arrangement, for example, the pressure receiving surface 541 can be protected from foreign matter that has entered through the opening of the package 2. In addition, since the first portion 91 protrudes from the recess 55 and has a curved convex surface 911, when the second curable resin 92A is filled in the package 2, the lower surface of the pressure sensor element 3 is formed. Air bubbles hardly remain (the air bubbles are guided to the surface 911 and are naturally removed). Therefore, the bubbles in the filler 9 can be further suppressed.

≪IC chip≫
For example, a drive circuit for supplying a voltage to the bridge circuit 60, a temperature compensation circuit for temperature compensation of the output from the bridge circuit 60, and a pressure applied from the output from the temperature compensation circuit are applied to the IC chip 4. The pressure detection circuit to be obtained, an output circuit for converting the output from the pressure detection circuit into a predetermined output format (CMOS, LV-PECL, LVDS, etc.) and the like are included. Such an IC chip 4 has a connection terminal 42 connected to the circuit, and the connection terminal 42 is electrically connected to the flying lead 245a via the fixing member 15 (see FIG. 2). . The arrangement of the drive circuit, the temperature compensation circuit, the pressure detection circuit, the output circuit, and the like is not particularly limited. For example, some of these (for example, the drive circuit) are formed in a semiconductor circuit in the pressure sensor element 3. It may be.

≪Filler≫
As shown in FIG. 1, the filler 9 is filled in the internal space 28 of the package 2 and surrounds the pressure sensor element 3 and the IC chip 4 housed in the internal space 28. The filler 9 protects the pressure sensor element 3 and the IC chip 4 (dustproof and waterproof) and can reduce external stress (stress other than pressure) acting on the pressure sensor 1. The pressure applied to the pressure sensor 1 acts on the pressure receiving surface 541 of the pressure sensor element 3 through the opening of the package 2 and the filler 9.

  Such a filler 9 is mainly composed of a curable resin. In particular, the curable resin is preferably a thermosetting resin or a photocurable resin (particularly, an ultraviolet curable resin). Thereby, hardening of curable resin can be performed more easily.

  Moreover, as such a filler 9, what is necessary is just a substance which has sclerosis | hardenability and a softer characteristic than the pressure sensor element 3, the IC chip 4, and the package 2, for example, has comprised the liquid form or the gel form. . As a specific example of such a filler 9, for example, silicone oil, fluorine-based oil, silicone gel, or the like can be used. The filler 9 may be mixed with various fillers, for example, for the purpose of increasing thermal conductivity or adjusting the viscosity.

  The filler 9 has two portions (regions) having different curing rates (resin curing degrees). Specifically, the filler 9 is disposed so as to contact the pressure receiving surface 541 of the pressure sensor element 3 and the inner side surface connected to the periphery of the pressure receiving surface 541 in the recess 55 so as to fill the recess 55. It has the 1st part 91 and the 2nd part 92 which is located in the circumference | surroundings of the 1st part 91 and surrounds the 1st part 91 and the pressure sensor element 3. The curing rate of the first portion 91 is higher than the curing rate of the second portion 92. That is, the first portion 91 is harder (the penetration is lower) than the second portion 92. In addition, the 1st part 91 and the 2nd part 92 have the same kind of resin material as a main component mutually, and only the hardening rate (hardness) differs substantially.

  By adopting such a configuration, it is difficult for bubbles to come into contact with the pressure receiving surface 541, and fluctuation and reduction in pressure detection accuracy can be reduced. Therefore, the pressure sensor 1 can exhibit excellent pressure detection accuracy. Specifically, when the filling material 9 is filled in the internal space 28, bubbles may be generated in the filling material 9, and the bubbles move through the filling material 9 and come into contact with the pressure receiving surface 541. The air bubbles act like a cushion, and the pressure is not properly transmitted to the pressure receiving surface 541 at that portion. For this reason, if air bubbles come into contact with the pressure receiving surface 541, the pressure detection accuracy fluctuates or decreases.

  On the other hand, in the pressure sensor 1 of the present embodiment, since the curing rate of the first portion 91 covering the pressure receiving surface 541 is higher than the curing rate of the second portion 92, for example, the second portion 92 Intrusion of bubbles into the first portion 91 and movement of bubbles within the first portion 91 are effectively suppressed. Therefore, it becomes difficult for bubbles to come into contact with the pressure receiving surface 541, and fluctuations and reductions in pressure detection accuracy can be reduced.

  The curing rate of the first portion 91 and the second portion 92 is not particularly limited as long as the curing rate of the first portion 91 is higher than the curing rate of the second portion 92. For example, the curing rate of the first portion 91 is preferably in the range of 40% or more and 90% or less, and more preferably in the range of 50% or more and 80% or less. The curing rate of the second portion 92 is preferably in the range of 10% or more and 60% or less, and more preferably in the range of 20% or more and 40% or less. By setting the curing rate of the first portion 91 and the second portion 92 in such a range, the viscosity of the second portion 92 can be made not to flow out of the opening of the package 2, and the first portion The portion 91 can have a viscosity such that bubbles do not move inside the portion 91.

  Further, the viscosity of the first portion 91 and the second portion 92 is not particularly limited as long as the viscosity of the first portion 91 is higher than the viscosity of the second portion 92, but for example, the first portion 91 The penetration is preferably in the range of 50 or more and 200 or less, and more preferably in the range of 150 or more and 200 or less. The penetration of the second portion 92 is preferably in the range of 100 or more and 250 or less, and more preferably in the range of 200 or more and 250 or less. Thereby, the filler 9 can be sufficiently softened, and the pressure applied to the pressure sensor 1 acts on the pressure receiving surface 541 efficiently, and the movement of bubbles inside the first portion 91 is effective. Can be suppressed. The curing rate can be measured by measurement using FT-IR or fluorescence measurement. Further, the penetration can be measured by a method based on a test method defined in JIS K 2207.

  In particular, in the present embodiment, since the first portion 91 and the second portion 92 are made of the same type of material (the same resin material), the configuration of the filler 9 becomes simpler and the first Adjustment of the curing rate of the portion 91 and the second portion 92 becomes easier. Further, in the present embodiment, since the first portion 91 is disposed so as to fill the entire area of the recess 55, the second portion 92 can be sufficiently moved away from the pressure receiving surface 541. For this reason, bubbles are less likely to come into contact with the pressure receiving surface 541, and fluctuations and decreases in pressure detection accuracy can be further reduced. Further, in the present embodiment, the first portion 91 is kept to a minimum that can fill the whole area of the recess 55 (as shown in FIG. 3, since the whole area of the lower surface of the substrate 5 is not covered) That is, since only the periphery of the recess 55 except for the edge portion of the lower surface is covered), it is reduced that the pressure is hardly transmitted to the pressure receiving surface 541.

Moreover, it is preferable that the 1st part 91 is defoamed. Thereby, the bubbles in the first portion 91 can be removed. Therefore, it is possible to effectively reduce the bubbles that are originally in the first portion 91 from coming into contact with the pressure receiving surface 541. In addition, although it does not specifically limit as a defoaming process, For example, the method of evacuating which is demonstrated also in the manufacturing method mentioned later is mentioned.
The configuration of the pressure sensor 1 has been described above.

Next, a manufacturing method of the pressure sensor 1 will be described.
The manufacturing method of the pressure sensor 1 includes a step of preparing the pressure sensor element 3, the package 2, the first curable resin 91 </ b> A and the second curable resin 92 </ b> A, and the first curable property on the pressure receiving surface 541 of the pressure sensor 1. A step of disposing the resin 91A, a step of curing (semi-curing) the first curable resin 91A, a step of disposing the pressure sensor element 3 in the package 2, and the pressure sensor element 3 and the first in the package 2. A step of disposing the second curable resin 92A so as to surround the curable resin 91A, and the first curable resin 91A and the second curable resin 92A disposed in the package 2 are cured (semi-cured). And a step of causing.

  Hereinafter, for the sake of convenience of explanation, as the first curable resin 91A and the second curable resin 92A, it is assumed that the same thermosetting resin is used, respectively, and the curing rate before the production is also used. It shall be equal to each other.

  First, as shown in FIG. 6A, the pressure sensor element 3 and the IC chip 4 are connected to the flexible wiring board 25.

  Next, as shown in FIG. 6 (b), the first curable resin 91A is filled to such an extent that the recess 55 is completely filled in the recess 55 with the pressure receiving surface 541 (opening of the recess 55) facing upward in the vertical direction. Supply. Next, the first curable resin 91A is defoamed by placing the pressure sensor element 3 in the vacuum chamber with the pressure-receiving surface 541 (opening of the recess 55) facing upward in the vertical direction, and evacuating the pressure sensor element 3A. To do. Thereby, bubbles are removed from the first curable resin 91A. Next, heat is applied to the first curable resin 91A to semi-cure the first curable resin 91A. For example, when the first curable resin 91 </ b> A is silicone oil (curing rate 0%), it is preferably semi-cured under the condition of 150 ° × 30 minutes, for example. In addition, the curing rate of the first curable resin 91 </ b> A at this time is not particularly limited, but is preferably about 20% or more and about 40% or less, for example.

  Next, as shown in FIG. 6C, the flexible wiring board 25 is sandwiched between the base 21 and the housing 22, and these are bonded to each other with an adhesive. Thereby, the pressure sensor element 3 and the IC chip 4 are accommodated in the package 2.

  Next, as shown in FIG. 7A, the internal space 28 of the package 2 is filled with the second curable resin 92A, and the pressure sensor element 3 and the IC chip 4 are surrounded by the second curable resin 92A. It is assumed that

Next, the first curable resin 91A and the second curable resin 92A are semi-cured by applying heat to the first curable resin 91A and the second curable resin 92A under the same conditions. When the first curable resin 91A and the second curable resin 92A are silicone oils, for example, they are semi-cured under conditions of 150 ° × 30 minutes. The curing rate of the first curable resin 91A at this time is not particularly limited, but is, for example, about 40% or more and 90% or less, and the curing rate of the second curable resin 92A is, for example, 10%. Above, it is about 60% or less. Since the first curable resin 91A and the second curable resin 92A are the same type of resin material, the first curable resin 91A having a longer curing time (curing is performed twice) is more preferable. The curing rate is higher than that of the second curable resin 92A having a short curing time (curing is performed only once). Thereby, the filler 9 which has the 1st part 91 which consists of 1st curable resin 91A, and the 2nd part 92 which consists of 2nd curable resin 92A is obtained.
As described above, as shown in FIG. 7B, the pressure sensor 1 is manufactured.

  According to such a manufacturing method, the pressure sensor 1 can be manufactured by a relatively simple method. In particular, since it includes a step of defoaming the first curable resin 91A before the first curable resin 91A is cured, the bubbles in the first portion 91 are removed, and the pressure detection accuracy is further improved. A high pressure sensor 1 is obtained. In the manufacturing method described above, the second curable resin 92A may be degassed prior to curing the first curable resin 91A and the second curable resin 92A. Thereby, the bubbles in the filler 9 can be sufficiently reduced.

  In the present embodiment, thermosetting resins are used as the first curable resin 91A and the second curable resin 92A, but as the first curable resin 91A and the second curable resin 92A, Alternatively, a photocurable resin may be used. In this case, it can be cured by irradiating light (for example, ultraviolet rays) instead of heat.

  In the above-described embodiment, it is described that “curing” is performed even when the curing rate of the curable resin is less than 100% (for example, semi-cured).

Second Embodiment
FIG. 8 is a sectional view of a pressure sensor according to the second embodiment of the present invention.

  Hereinafter, the second embodiment of the pressure sensor will be described. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.

  The second embodiment is the same as the first embodiment described above except that the direction of the pressure sensor element in the package is different.

  As shown in FIG. 8, in the pressure sensor 1 of the present embodiment, the pressure sensor element 3 is housed in the package 2 in a posture in which the pressure receiving surface 541 of the diaphragm 54 faces the opening side of the package 2. With this arrangement, the pressure receiving surface 541 can be brought close to the opening of the package 2, so that the pressure applied to the pressure sensor 1 acts on the pressure receiving surface 541 more efficiently.

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

<Third Embodiment>
FIG. 9 is a cross-sectional view of a pressure sensor according to a third embodiment of the present invention.

  Hereinafter, the third embodiment of the pressure sensor will be described, but the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.

  The third embodiment is the same as the first embodiment described above except that the arrangement of the pressure sensor element and the IC chip in the package is different.

  As shown in FIG. 9, in the pressure sensor 1 of the present embodiment, the pressure sensor element 3 and the IC chip 4 are disposed so as to overlap in the thickness direction. Thereby, the planar expansion of the pressure sensor 1 can be suppressed, and the pressure sensor 1 can be downsized. In the present embodiment, the pressure sensor element 3 is disposed on the upper side of the IC chip 4, but the pressure sensor element 3 may be disposed on the lower side of the IC chip 4.

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

[Altimeter]
Next, an example of an altimeter provided with the pressure sensor of the present invention will be described.

FIG. 10 is a perspective view showing an example of the altimeter of the present invention.
As shown in FIG. 10, the altimeter 200 can be worn on the wrist like a wristwatch. In addition, the pressure sensor 1 is mounted inside the altimeter 200, and the altitude from the current location above sea level, the atmospheric pressure at 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 of the present invention is applied will be described.

FIG. 11 is a front view showing an example of an electronic apparatus of the present invention.
As shown in FIG. 11, 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 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 1, the altitude change due to the approach from the general road to the elevated 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 of the present invention is not limited to the above-described ones. For example, a personal computer, a mobile phone, a medical device (for example, an electronic thermometer, a blood pressure meter, a blood glucose meter, an electrocardiogram measuring device, an ultrasonic diagnosis) The present invention can be applied to apparatuses, electronic endoscopes), various measuring instruments, instruments (for example, vehicles, aircraft, and ship instruments), flight simulators, and the like.

[Moving object]
Next, a moving body including the pressure sensor of the present invention will be described.

FIG. 12 is a perspective view showing an example of the moving body of the present invention.
As shown in FIG. 12, the moving body 400 includes 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 1).

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

  Further, in the above-described embodiment, the pressure sensor unit using the piezoresistive element is described as the pressure sensor unit, but the pressure sensor unit is not limited to this, for example, a flap type vibrator is used. The structure, other MEMS vibrators such as comb electrodes, and vibration elements such as crystal vibrators can also be used.

  In the above-described embodiment, the wiring portion, the pressure sensor element, and the IC chip are connected by flying leads. However, the connection method is not limited to this, for example, the connection is made through a bonding wire. May be.

  In the above-described embodiment, the pressure sensor includes an IC chip, but the IC chip may be omitted.

DESCRIPTION OF SYMBOLS 1 ... Pressure sensor 14, 15 ... Fixing member 2 ... Package 21 ... Base 22 ... Housing 23 ... Base material 231 ... Frame part 232 ... Strip body 233 ... Opening part 24 ... Wiring 241 ... ... Wiring part 241a, 241b ... Flying lead 245 ... Wiring part 245a ... Flying lead 25 ... Flexible wiring board 26 ... Adhesive layer 28 ... Internal space 3 ... Pressure sensor element 4 ... IC chip 42... Connection Terminal 5... Substrate 51... Semiconductor Substrate 511... First Si Layer 512... SiO2 Layer 513... Second Si Layer 52 ... First Insulating Film 53. …… Diaphragm 541 …… Pressure receiving surface 55 …… Recess 6 …… Pressure sensor portion 60 …… Bridge circuit 61, 62, 63, 64 …… Piezoresistive element 7 …… Element surrounding structure 71… ... Interlayer insulating film 72 ... Wiring layer 73 ... Interlayer insulating film 74 ... Wiring layer 741 ... Cover layer 742 ... Pore 743 ... Connection terminal 75 ... Surface protective film 76 ... Sealing layer 8 ... Cavity 9 ... Filler 91 ... First part 911 ... Surface 91A ... First curable resin 92 ... Second part 92A ... Second curable resin 200 ... Altimeter 201 ... Display unit 300 …… Navigation system 301 …… Display unit 400 …… Moving object 401 …… Car body 402 …… Wheel

Claims (13)

A pressure sensor element having a pressure receiving surface;
A curable resin disposed around the pressure sensor element,
The curable resin has at least a first part disposed on the pressure-receiving surface and a second part different from the first part,
The pressure sensor, wherein a curing rate of the first portion is higher than a curing rate of the second portion.   The pressure sensor according to claim 1, wherein each of the first portion and the second portion includes the same kind of resin material. The pressure sensor element has a recess whose bottom surface is the pressure receiving surface,
3. The pressure sensor according to claim 1, wherein the first portion is connected to an inner surface connected to the bottom surface in the recess.   The pressure sensor according to claim 1, wherein the curable resin is cured by heat.   The pressure sensor according to claim 1, wherein the curable resin is cured by light.   The pressure sensor according to any one of claims 1 to 5, further comprising a package that accommodates the pressure sensor element and the curable resin. The package has an opening;
The pressure sensor according to claim 6, wherein the pressure sensor element is arranged such that the pressure receiving surface faces a direction different from the opening.   The pressure sensor according to any one of claims 1 to 7, wherein the first portion is subjected to a defoaming process. Preparing a pressure sensor element having a pressure-receiving surface, a package, a first curable resin, and a second curable resin containing the same components as the first curable resin;
Disposing the first curable resin on the pressure-receiving surface;
Curing the first curable resin;
Disposing the pressure sensor element in the package;
Disposing the second curable resin so as to surround the pressure sensor element and the first curable resin in the package;
Curing the first curable resin and the second curable resin disposed in the package;
A method for producing a pressure sensor, comprising: Before the step of curing the first curable resin,
The method for manufacturing a pressure sensor according to claim 9, comprising a step of defoaming the first curable resin disposed on the pressure receiving surface.   An altimeter comprising the pressure sensor according to any one of claims 1 to 8.   An electronic apparatus comprising the pressure sensor according to claim 1.   A moving body comprising the pressure sensor according to claim 1.

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