JP2015230237A - Physical quantity sensor, altimeter, electronic equipment, and mobile unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor capable of reducing deformation of a pressure reference chamber by receiving a pressure, and an altimeter, electronic equipment and a mobile unit which include the physical quantity sensor and have high reliability.SOLUTION: A physical quantity sensor 1 includes: a physical quantity sensor chip 3 having a pressure reference chamber 8 and a diaphragm 54 that has a pressure-receiving surface 541 and can bend and deform; a package 2 having an opening and an inner space 28 that houses the physical quantity sensor chip 3; a pressure propagation part 11 that is connected to the diaphragm 54 in the inner space 28; and a protective part 12 that is composed of a material harder than the pressure propagation part 11 and is disposed outside the pressure reference chamber 8.

Description

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

  Conventionally, as a physical quantity sensor, a sensor chip that detects pressure and generates an electrical signal corresponding to the detected value, a package having an opening and containing the sensor chip, and enclosing the sensor chip in the package, the sensor There is known a pressure sensor including an inert liquid that propagates pressure to a chip (see, for example, Patent Document 1).

  In such a pressure sensor, the sensor chip includes a diaphragm that is deflected by pressure reception, and a pressure reference chamber provided on the diaphragm, and the pressure outside the package is detected through the opening of the package and an inert liquid. Acts on the diaphragm of the chip. Then, the deflection of the diaphragm due to the pressure applied to the diaphragm is detected by the sensor chip, and the pressure applied to the pressure sensor is detected based on the detection result.

  However, in the pressure sensor having such a configuration, if the wall portion on the opposite side of the diaphragm of the pressure reference chamber is made thin in order to reduce the size and height, not only the diaphragm but also the wall portion of the pressure reference chamber receives pressure reference. There was a problem that it deformed to bend toward the room. For this reason, the reference pressure of the pressure sensor is changed, and the pressure received by the pressure sensor cannot be accurately detected.

JP-A-9-126920

  An object of the present invention is to provide a physical quantity sensor that can reduce the deformation of a pressure reference chamber due to pressure reception, a highly reliable altimeter, an electronic device, and a moving body including the physical quantity sensor.

  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 physical quantity sensor of this application example includes a physical quantity sensor chip having a pressure reference chamber, a pressure-receiving surface, and a flexible deformable diaphragm.
A package having an opening and having an internal space containing the physical quantity sensor chip;
A pressure propagation part connected to the diaphragm in the internal space;
A protective part which is made of a material harder than the pressure propagation part and is arranged outside the pressure reference chamber;
It is characterized by having.

  Thereby, pressure propagation to the wall can be prevented or reduced, and deformation of the pressure reference chamber due to pressure reception can be reduced. For this reason, a change in the reference pressure of the physical quantity sensor is suppressed, and thus a physical quantity sensor having excellent detection accuracy can be provided.

[Application Example 2]
In the physical quantity sensor of this application example, it is preferable that the physical quantity sensor chip is connected to the package through a wire.

  Since the wire is relatively elastic (flexible), it can absorb the stress caused by the distortion of the package. Therefore, it is possible to further reduce the stress acting on the pressure reference chamber.

[Application Example 3]
The physical quantity sensor of this application example further includes an IC chip,
The sensor chip is preferably fixed to the IC chip.

  With this IC chip, the magnitude of a physical quantity (for example, pressure) applied to the physical quantity sensor can be calculated based on an electrical signal generated by the physical quantity sensor chip. Furthermore, since the physical quantity sensor chip is fixed to the IC chip, it is possible to regulate the relative positional relationship between the physical quantity sensor chip and the IC chip, thereby preventing contact between the physical quantity sensor chip and the IC chip. Or it can be suppressed.

[Application Example 4]
In the physical quantity sensor of this application example, it is preferable that the protection part is surrounded by the pressure propagation part in a plan view in a direction in which the opening and the physical quantity sensor chip overlap.

  Thereby, the stress due to the distortion of the package can be absorbed by the pressure propagation portion on the side surface side of the wall portion of the pressure reference chamber, and the propagation of the stress to the pressure reference chamber can be further reduced. it can.

[Application Example 5]
In the physical quantity sensor of this application example, it is preferable that the protection part is surrounded by the pressure propagation part in a cross-sectional view in a direction in which the opening and the physical quantity sensor chip overlap.

  As a result, the pressure propagation portion on the bottom surface side of the wall portion of the pressure reference chamber can absorb the stress due to the distortion of the package, and the propagation of the stress to the pressure reference chamber can be further reduced. it can.

[Application Example 6]
In the physical quantity sensor of this application example, it is preferable that the protection part includes at least one of a silicon resin, a fluorine resin, an epoxy resin, and a polyimide resin.

  Thereby, a protection part can ensure required rigidity (hardness). Moreover, the epoxy resin and the polyimide resin have a relatively small heat shrinkage rate. For this reason, it can suppress that the wall part of a pressure reference chamber deform | transforms with the stress resulting from the thermal contraction of a protection part.

[Application Example 7]
In the physical quantity sensor of this application example, it is preferable that the physical quantity sensor chip is a pressure sensor chip that generates a signal according to pressure.
Thereby, the pressure can be detected.

[Application Example 8]
The altimeter of this application example includes the physical quantity sensor of the above application example.
Thereby, a highly reliable altimeter can be obtained.

[Application Example 9]
An electronic apparatus according to this application example includes the physical quantity sensor according to the application example described above.
As a result, a highly reliable electronic device can be obtained.

[Application Example 10]
The moving body of this application example includes the physical quantity sensor of the above application example.
Thereby, a mobile body with high reliability is obtained.

It is sectional drawing which shows 1st Embodiment of a physical quantity sensor. It is sectional drawing which shows the physical quantity sensor chip | tip which the physical quantity sensor shown in FIG. 1 has. It is a top view which shows the sensor element which the physical quantity sensor chip shown in FIG. 2 has. It is a figure which shows the bridge circuit containing the sensor element shown in FIG. It is sectional drawing which shows the IC chip and physical quantity sensor chip which the physical quantity sensor shown in FIG. 1 has. It is sectional drawing which shows 2nd Embodiment of a physical quantity sensor. It is sectional drawing which shows 3rd Embodiment of a physical quantity sensor. It is sectional drawing which shows 4th Embodiment of a physical quantity sensor. It is sectional drawing which shows 5th Embodiment of a physical quantity sensor. It is a top view which shows the wiring of the flexible wiring board with which the physical quantity sensor shown in FIG. 9 is provided. It is sectional drawing which shows 6th Embodiment of a physical quantity sensor. It is sectional drawing which shows the physical quantity sensor chip | tip with which the physical quantity sensor of 7th Embodiment is provided. 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 physical quantity 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.

1. Physical Quantity Sensor FIG. 1 is a cross-sectional view showing a first embodiment of a physical quantity sensor. FIG. 2 is a cross-sectional view showing a physical quantity sensor chip included in the physical quantity sensor shown in FIG. FIG. 3 is a plan view showing a sensor element included in the physical quantity sensor chip shown in FIG. FIG. 4 is a diagram showing a bridge circuit including the sensor element shown in FIG. FIG. 5 is a cross-sectional view showing an IC chip and a physical quantity sensor chip included in the physical quantity sensor shown in FIG. In the following description, the upper side in FIGS. 1, 2, and 5 is referred to as “upper” and the lower side is referred to as “lower”.

  A physical quantity sensor 1 shown in FIG. 1 is a pressure sensor that generates a signal according to pressure. Thus, by using the physical quantity sensor 1 as a pressure sensor, the physical quantity sensor can be mounted on various electronic devices.

  As shown in FIG. 1, the physical quantity sensor 1 includes a sensor chip (physical quantity sensor chip) 3 that can detect pressure, an IC chip 4, and a package (container) that houses the sensor chip 3 and the IC chip 4. ) 2 and a pressure propagation part 11 and a protection part 12 provided in the package 2.

Hereinafter, each of these units will be described in order.
≪Package≫
The package 2 includes a base 21 having a square plate shape in plan view, and a wall portion 22 provided on an outer edge portion of the upper surface of the base 21 and having a square frame shape. As a result, the overall shape of the package 2 is a box shape (a bowl shape), and a recess (internal space) 28 that is opened (opened) on the upper side is formed. In the figure, the base 21 and the wall portion 22 are integrated, but they may be formed separately and then joined via an adhesive or the like.

  As shown in FIG. 1, the wall portion 22 is provided with a step portion 26 in which the opening area of the concave portion 28 changes stepwise. On the upper surface of the step portion 26, a terminal 85 is provided for electrically connecting a connection terminal 410 of the IC chip 4 described later via a bonding wire 81. There are four terminals 85 in the present embodiment, and the four terminals 85 are provided near the corners of the package 2, respectively. These terminals 85 are electrically connected to external electrodes 86 provided on the lower surface of the base 21 via through electrodes (not shown) penetrating the wall portion 22 and the base 21, respectively. For example, an electrical signal from the sensor chip 3 or the IC chip 4 can be taken out of the package 2 by electrically connecting, for example, an electronic device described later or a mother board of a moving body to the external electrode 86.

The constituent materials of the terminal 85, the external electrode 86, and the through electrode are not particularly limited as long as they have conductivity. For example, Ni, Pt, Li, Mg, Sr, Ag, Cu, Co, Al Metals such as these, alloys such as MgAg, AlLi, and CuLi containing these, and oxides such as ITO and SnO ₂ can be used, and one or more of these can be used in combination.

  The constituent material of the package 2 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 2 having excellent mechanical strength can be obtained. In addition, the base 21 and the wall part 22 may be comprised with a different material, and may be comprised with the same material.

  Note that the overall shape of the package 2 is not limited to a box shape having a square shape in plan view, and may be, for example, a bottomed cylindrical shape.

≪Sensor chip≫
As shown in FIG. 2, the sensor chip 3 includes a substrate 5, a sensor element 6, an element surrounding structure 7, a cavity 8, and a semiconductor circuit 9. 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 is bent and deformed 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) 9 is formed on and above such a semiconductor substrate 51. This semiconductor circuit 9 includes circuit elements such as active elements such as a MOS transistor 91, capacitors, inductors, resistors, diodes, and wirings formed as necessary. In FIG. 2, only the MOS transistor 91 of the semiconductor circuit 9 is shown for convenience of explanation.

  As shown in FIG. 3, the sensor element 6 includes four piezoresistive elements (deflection amount detecting elements) 61, 62, 63, 64 provided on the diaphragm 54. These four piezoresistive elements 61, 62, 63, and 64 are provided corresponding to the respective sides of the diaphragm 54 that forms a quadrangle in plan view.

  The piezoresistive elements 61 and 62 include piezoresistive portions 611 and 621 provided on the outer edge portion of the diaphragm 54, and wirings 613 and 623 connected to both ends of the piezoresistive portions 611 and 621. Yes. On the other hand, the piezoresistive elements 63 and 64 include a pair of piezoresistive parts 631 and 641 provided on the outer edge of the diaphragm 54 and a connection part 632 that connects the pair of piezoresistive parts 631 and 641 to each other. 642 and wirings 633 and 643 connected to the other ends of the pair of piezoresistive parts 631 and 641.

  The piezoresistive portions 611, 621, 631, and 641 are configured by doping (diffusing or implanting) impurities such as phosphorus and boron into the first Si layer 511 of the semiconductor substrate 51, for example. In addition, the wirings 613, 623, 633, 643 and the connection portions 632, 642 are formed of, for example, phosphorus, boron, etc. at a higher concentration than the piezoresistive portions 611, 621, 631, 641, It is configured by doping impurities (diffusion or implantation).

  Further, the piezoresistive elements 61, 62, 63, 64 are configured so that the resistance values in the natural state are equal to each other. These piezoresistive elements 61, 62, 63, 64 are electrically connected to each other via wirings 613, 623, 633, 643, etc., and as shown in FIG. 4, a bridge circuit 60 (Wheatstone bridge circuit) is provided. ) And is connected to the semiconductor circuit 9. The bridge circuit 60 is connected to a drive circuit (not shown) for supplying a drive voltage AVDC. The bridge circuit 60 outputs a signal (voltage) corresponding to the resistance values of the piezoresistive elements 61, 62, 63, and 64.

  The element surrounding structure 7 is formed so as to define the cavity 8. As shown in FIG. 2, 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 with the inside and outside of the cavity 8, and the sealing layer 76 disposed on the coating layer 741 seals the pores 742. doing. Note that the wiring layers 72 and 74 include wiring layers 72 a and 74 a formed so as to surround the cavity 8, and wiring layers 72 b and 74 b constituting the wiring of the semiconductor circuit 9. Therefore, the semiconductor circuit 9 is drawn to the upper surface of the physical quantity sensor 1 by the wiring layers 72b and 74b, and a part of the wiring layer 74b serves as a connection terminal 74b '.

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 that serves as a reference value of pressure detected by the sensor chip 3. The cavity 8 is arranged so as to overlap the diaphragm 54, and the diaphragm 54 constitutes a part of the wall that defines the cavity 8. Although the state in the cavity part 8 is not specifically limited, It is preferable that it is a vacuum state (for example, 10 Pa or less). As a result, the sensor chip 3 can be used as a so-called “absolute pressure sensor element” that detects pressure based on a vacuum state. However, the state in the cavity 8 may not be 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 a state where the atmospheric pressure is lower than the atmospheric pressure. It may be a pressurized state with a high atmospheric pressure. The cavity 8 may be filled with an inert gas such as nitrogen gas or rare gas.

  In the sensor chip 3 having such a configuration, the diaphragm 54 is deformed according to the pressure received by the pressure receiving surface 541 of the diaphragm 54, thereby distorting the piezoresistive elements 61, 62, 63, 64, and depending on the amount of deflection thereof. The resistance values of the piezoresistive elements 61, 62, 63, 64 change. Along with this, the output of the bridge circuit 60 formed by the piezoresistive elements 61, 62, 63, 64 changes, and the magnitude of the pressure (absolute pressure) received by the pressure receiving surface 541 can be obtained based on the output. it can.

  In the sensor chip 3, since the cavity 8 and the semiconductor circuit 9 are provided on the same surface side of the substrate 5, the element peripheral structure 7 forming the cavity 8 is different from the semiconductor circuit 9 of the substrate 5. Without overhanging from the opposite side, the height can be reduced. In addition, the element surrounding structure 7 is formed by the same film formation as at least one of the interlayer insulating films 71 and 73 and the wiring layers 72 and 74. Thereby, the element surrounding structure 7 can be formed together with the semiconductor circuit 9 by using the CMOS process. Therefore, the manufacturing process of the sensor chip 3 is simplified, and as a result, the cost of the sensor chip 3 can be reduced. Further, even when the cavity 8 is sealed as in this embodiment, the cavity 8 can be sealed using a film forming method, and a conventional substrate is bonded to seal the cavity. In this respect, the manufacturing process of the sensor chip 3 is simplified, and as a result, the cost of the sensor chip 3 can be reduced.

≪IC chip≫
The IC chip 4 has a function of calculating the magnitude of pressure applied to the sensor chip 3 based on, for example, an electrical signal generated by the sensor chip 3.

  The IC chip 4 is plate-shaped and has a quadrangular shape larger than the sensor chip 3 in plan view. The IC chip 4 is provided below the sensor chip 3 so as to be separated from the sensor chip 3. As described above, the IC chip 4 is arranged so as to overlap the sensor chip 3 in a plan view (arranged vertically), thereby reducing the size in the width direction of the physical quantity sensor 1 and reducing the size of the physical quantity sensor 1. Can be achieved.

As shown in FIG. 5, the IC chip 4 is a multilayer wiring board, and an insulating film 42 made of a silicon oxide film (SiO ₂ film) is laminated on a semiconductor substrate 41 made of a semiconductor such as silicon. Thus, a semiconductor circuit (circuit) 40 for detecting the magnitude of the pressure received based on a signal obtained from the bridge circuit 60, for example, is formed on and above the semiconductor substrate 41. In addition, a surface protective film (passivation film) 43 is laminated on the insulating film 42 in order to protect the semiconductor circuit 40. The surface protective film 43 is not particularly limited, and a film having resistance to protect the element from moisture, dust, scratches, and the like, such as a silicon oxide film, a silicon nitride film, a polyimide film, and an epoxy resin film can be used. . In addition, a part of the surface protective film 43 is removed, and from the removed portion, the four conductive connection terminals (connection portions) 410 included in the semiconductor circuit 40 and the four conductive connection terminals (connection portions). ) 420 is exposed.

  The semiconductor circuit 40 includes, for example, a drive circuit (not shown) for driving the sensor chip 3 and temperature compensation for temperature compensation based on the temperature detected by the temperature sensor with respect to the output from the bridge circuit 60. A circuit (not shown) and the like are formed.

  In the sensor chip 3 and the IC chip 4 as described above, the connection terminal 74 b ′ included in the sensor chip 3 and the connection terminal 420 included in the IC chip 4 are connected to each other via the fixing member 92 having conductivity. Thereby, the sensor chip 3 and the IC chip 4 are electrically connected. By connecting the sensor chip 3 and the IC chip 4 to each other via the fixing member 92 in this way, the relative positional relationship between the sensor chip 3 and the IC chip 4 can be regulated. And the IC chip 4 can be prevented from contacting each other. Further, since the sensor chip 3 and the IC chip 4 can be assembled in advance, the physical quantity sensor 1 can be easily manufactured (assembled). The fixing member 92 is not particularly limited as long as it has 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.

  Further, the connection terminal 410 included in the IC chip 4 is electrically connected to a terminal 85 provided on the package 2 via a bonding wire 81. Thus, the IC chip 4 is electrically connected to the external electrode 86 provided on the lower surface of the package 2 via the bonding wire 81.

  The structure including the sensor chip 3 and the IC chip 4 thus connected to the package 2 is accommodated in the package 2 in a state of being separated from the inner wall of the package 2, that is, in a non-contact state. As described above, the non-contact state with respect to the package 2 can reduce the propagation of the stress due to the distortion generated in the package 2 to the structure. Therefore, it can reduce that the detection performance of sensor chip 3 and IC chip 4 falls because the stress acts on a structure.

  The structure is installed such that the sensor chip 3 faces the opening side of the package 2 and the IC chip 4 faces the base 21 side. Further, the sensor chip 3 is arranged so that the surface on which the diaphragm 54 is formed faces the opening side of the package 2. With this arrangement, the pressure receiving surface 541 can be directed toward the opening of the package 2 and can be brought close to the opening of the package 2, so that the pressure applied to the physical quantity sensor 1 acts on the pressure receiving surface 541 more efficiently. . Thereby, the pressure detection performance (sensitivity) of the sensor chip 3 can be further improved.

  Note that the physical quantity sensor 1 of the present embodiment has four bonding wires 81, and each bonding wire 81 is provided near the four corners of the IC chip 4. Thus, by arranging the bonding wires 81 in contrast to each other, the IC chip 4 and the sensor chip 3 can be supported substantially horizontally with respect to the base 21 in a non-contact state with the inner wall of the package 2. It becomes easy.

  In addition, the thickness of the bonding wire 81 is, for example, preferably 0.1 μm or more and 50 μm or less, and more preferably 1 μm or more and 30 μm or less. Thereby, the bonding wire 81 can have appropriate rigidity and flexibility. Moreover, it does not specifically limit as a constituent material of the bonding wire 81, Various metal materials, such as gold | metal | money, aluminum, copper, can be used.

≪Protection Department≫
As shown in FIG. 1, the protection portion 12 is filled to a depth in the middle of the recess 28. The lower portion of the structure including the IC chip 4 and the sensor chip 3 is buried in the protection unit 12. Here, the protection unit 12 is provided between the package 2 and the IC chip 4, between the package 2 and a part of the sensor chip 3, and between the IC chip 4 and the sensor chip 3. Further, as shown in FIG. 5, the protection portion 12 is in contact with the entire outer peripheral surface of the IC chip 4 and the outer peripheral surface of the element surrounding structure 7 that defines the cavity 8 of the sensor chip 3. The protection unit 12 is also in contact with the bonding wire 81.

  The protection unit 12 provided in this manner functions as a support member that supports (fixes) the structure including the sensor chip 3 and the IC chip 4 to the package 2. Thereby, the structure can be stably supported on the package 2. Therefore, fluctuations in the position of the structure within the recess 28 can be reduced.

  Further, the protection unit 12 is made of a material harder than the pressure propagation unit 11, and the rigidity of the element surrounding structure 7, particularly the sealing layer 76, that defines the cavity (pressure reference chamber) 8 of the sensor chip 3. It has a function to compensate. Due to the presence of the protective part 12, it is possible to reduce the pressure propagated from the pressure propagation part 11 from being propagated to the element surrounding structure 7, particularly the sealing layer 76. Therefore, it can reduce that the sealing layer (wall part) 76 bends toward the cavity part 8 side by receiving pressure, and can reduce that the cavity part 8 which functions as a pressure reference chamber deform | transforms by receiving pressure. . Thereby, it can prevent or reduce that the standard pressure of physical quantity sensor 1 changes.

  As a state of such a protection part 12, it has constituted gel form or solid form, for example. In such a state, it is more reliably reduced that the sealing layer 76 bends toward the cavity 8 side.

  In particular, when the protective part 12 is solid, the protective part 12 has, for example, a Young's modulus (longitudinal elastic modulus) of preferably 0.1 GPa to 50 GPa, more preferably 1 GPa to 10 GPa. preferable. Moreover, when the protection part 12 is gel-like, the protection part 12 should just have a needle penetration smaller than the pressure propagation part 11, For example, it is preferable that the penetration is 1 or more and 200 or less, More preferably, it is 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 protective portion 12 can ensure the necessary rigidity (hardness), and can more effectively exhibit the function of supplementing the rigidity of the sealing layer 76. .

  Moreover, the protection part 12 has insulation. Thereby, even if the protection part 12 is connected to the bonding wire 81 and the fixing member 92, a short circuit between the plurality of bonding wires 81 or between the plurality of fixing members 92 can be prevented more reliably.

  Further, the protection part 12 is in close contact with the pressure propagation part 11. For this reason, generation | occurrence | production of a bubble (void) between the protection part 12 and the pressure propagation part 11 can be reduced, and it suppresses that the propagation of the pressure to the pressure receiving surface 541 is inhibited by generation | occurrence | production of the said bubble. be able to.

  Such a protection part 12 contains resin. Specifically, examples of the constituent material of the protection unit 12 include a silicon-based resin, a fluorine-based resin, an epoxy-based resin, and a polyimide-based resin. One or more of these are used in combination. be able to. Thereby, the protection part 12 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 can reduce that the sealing layer 76 deform | transforms (bends) by the stress resulting from the thermal contraction of the protection part 12. FIG.

  The protection part 12 preferably contains a filler in addition to the 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 protection part 12 can be improved and it can further reduce that the sealing layer 76 bends by pressure receiving. Further, as the filler, among inorganic fillers, those having insulating properties such as ceramic are more preferable. Thereby, even if it connects with the protection part 12 to the bonding wire 81 or the fixing member 92, the short circuit of the bonding wire 81 or the fixing member 92 can be prevented more reliably.

≪Pressure propagation part≫
As shown in FIG. 1, the pressure propagation part 11 is filled in the package 2 above the protection part 12, and the upper part of the sensor chip 3 is buried in the pressure propagation part 11. Here, the pressure propagation part 11 is provided between the package 2 and a part of the sensor chip 3 and is provided so as to close the opening of the package 2. As shown in FIG. 5, the pressure propagation unit 11 is in contact with the pressure receiving surface 541 of the sensor chip 3.

  The pressure propagation unit 11 provided in this way protects the sensor chip 3 and the IC chip 4 (dust and waterproof), and applies pressure applied to the physical quantity sensor 1 through the opening of the package 2 to the pressure receiving surface of the sensor chip 3. 541 is propagated.

  The pressure propagation unit 11 has characteristics (flexibility) that are softer than, for example, the sensor chip 3, the IC chip 4, and the package 2. The state of the pressure propagation part 11 having flexibility is, for example, liquid or gel. In particular, since the gel-like pressure propagation part 11 has low fluidity, fluctuations in the position of the sensor chip 3 in the recess 28 can be reduced. Therefore, the physical quantity sensor 1 can be detected with high accuracy without being affected by the change in the posture. When the pressure propagation part 11 is gel-like, for example, the pressure propagation part 11 preferably has a penetration of 50 or more and 250 or less, and more preferably 150 or more and 250 or less. Thereby, the pressure propagation part 11 can be made sufficiently soft, and the pressure applied to the physical quantity sensor 1 acts on the pressure receiving surface 541 efficiently. Moreover, the fluctuation | variation of the position of the sensor chip 3 in the recessed part 28 can be suppressed more exactly.

  Such a pressure propagation part 11 contains resin which has a softness | flexibility (soft property). By including a resin having flexibility, the gel-like pressure propagation part 11 can be easily obtained.

  Specific examples of the constituent material of the pressure propagation unit 11 include a fluorine-based resin and a silicone resin, and one or more of these can be used in combination. Thereby, the pressure propagation part 11 becomes sufficiently soft, and the pressure applied to the physical quantity sensor 1 can be efficiently propagated to the pressure receiving surface 541.

  As described above, the pressure propagation part 11 and the protection part 12 as described above are provided so that the pressure propagation part 11 contacts the pressure receiving surface 541 so that the protection part 12 contacts the sealing layer 76. Is provided. By providing the pressure propagation part 11 and the protection part 12 in this way, the pressure applied to the physical quantity sensor 1 can be efficiently propagated to the pressure receiving surface 541 and the sealing layer 76 is bent by the pressure reception. It can avoid that the pressure of the cavity part 8 changes by this. For this reason, the accuracy of the physical quantity sensor 1 can be increased.

Second Embodiment
Next, a second embodiment of the physical quantity sensor will be described.

FIG. 6 is a cross-sectional view showing a second embodiment of the physical quantity sensor.
Hereinafter, the second embodiment of the physical quantity sensor will be described, but the description will focus on differences from the above-described embodiment, and the description of the same matters will be omitted.

  In the physical quantity sensor 1 of the second embodiment, the IC chip 4 is omitted, and the configuration of the sensor chip 3 is different, but the same as the first embodiment described above.

  In the physical quantity sensor 1 shown in FIG. 6, the semiconductor element (IC circuit) provided in the sensor chip 3 is also generated by the sensor element 6 in the same manner as the IC chip 4 included in the physical quantity sensor 1 of the first embodiment described above. The magnitude of the pressure applied to the sensor chip 3 can be calculated on the basis of the electrical signal thus obtained. Further, by omitting the IC chip 4 in this way, the physical quantity sensor 1 can be further reduced in size and height.

  In the physical quantity sensor 1 of the present embodiment, the connection terminal 74 b ′ included in the sensor chip 3 is electrically connected to the terminal 85 provided on the package 2 via the bonding wire 81.

  Further, in the present embodiment, the connection terminal 74 b ′ faces the base 21 side because the sensor chip 3 is arranged so that the pressure receiving surface 541 faces the opening side of the package 2. For this reason, the bonding wire 81 is substantially S-shaped when viewed from the side.

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

<Third Embodiment>
Next, it is sectional drawing which shows 3rd Embodiment of a physical quantity sensor.

  FIG. 7 is a cross-sectional view showing a third embodiment of the physical quantity sensor. In the following description, the upper side in FIG. 7 is referred to as “upper” and the lower side is referred to as “lower”.

  Hereinafter, the third embodiment of the physical quantity sensor will be described, but the description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted.

  The physical quantity sensor 1 of the third embodiment is the same as that of the first embodiment described above except that the arrangement of the protection unit 12 and the pressure propagation unit 11 is different.

  As shown in FIG. 7, in the physical quantity sensor 1 of the present embodiment, the protection unit 12 is provided between the sensor chip 3 and the IC chip 4. In addition, a pressure propagation part 11 is provided around the entire structure including the sensor chip 3 and the IC chip 4. Therefore, the pressure propagation part 11 is provided so as to surround the protection part 12 in a cross-sectional view in the direction in which the opening of the package 2 and the sensor chip 3 overlap. The pressure propagation part 11 is provided so as to surround the protection part 12 in a plan view in a direction in which the opening of the package 2 and the sensor chip 3 overlap. Further, the protection unit 12 is connected to the sealing layer 76 and the IC chip 4. Further, the pressure propagation unit 11 is connected to the pressure receiving surface 541 and the IC chip 4.

  Unlike the first embodiment described above, the pressure receiving surface 541 and the IC chip 4 are both connected to the pressure propagation unit 11, so that the pressure receiving surface 541 and the IC chip 4 are covered with the same material. It has become. For this reason, in the physical quantity sensor 1 of the present embodiment, a difference in heat conduction between the pressure receiving surface 541 and the IC chip 4 is less likely to occur, and thus problems such as temperature hysteresis are less likely to occur.

  Further, since the pressure propagation part 11 is provided not only on the upper side of the structure but also on the side and the lower side, the stress due to the distortion of the package 2 can be absorbed. By acting on the body, it is possible to reduce a decrease in the detection performance of the sensor chip 3 and the IC chip 4. The same effect can be obtained when the pressure propagation part 11 is on either the side or the lower side, but the pressure propagation part 11 on the side is stress from the vicinity of the side part of the package 2. The pressure propagation part 11 on the lower side can efficiently absorb the stress from the vicinity of the bottom part of the package 2.

  Further, the structure is not fixed to the package 2 by the protection unit 12 as in the first embodiment, but is fixed so as to be suspended from the package 2 by the bonding wire 81 alone. Since the bonding wire 81 has an appropriate rigidity, the structure can be fixed to the package 2 with the bonding wire 81 alone. In addition, the bonding wire 81 has a relatively thin long shape and has a portion bent in a curved shape, so that it has appropriate elasticity (flexibility). For this reason, since the stress resulting from the distortion which arose in the package 2 can be absorbed with the bonding wire 81, it can further reduce that the said stress acts on a structure.

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

<Fourth embodiment>
Next, a fourth embodiment of the physical quantity sensor will be described.
FIG. 8 is a cross-sectional view showing a fourth embodiment of the physical quantity sensor.

  Hereinafter, the fourth embodiment of the physical quantity sensor will be described, but the description will be focused on differences from the above-described embodiment, and description of similar matters will be omitted.

  4th Embodiment is the same as that of 1st Embodiment mentioned above except the arrangement | positioning of the protection part 12 and the pressure propagation part 11 differing.

  As shown in FIG. 8, the physical quantity sensor 1 of the present embodiment has a sandwich configuration in which the protection unit 12 is sandwiched between two pressure propagation units 11. That is, the pressure propagation part 11 is provided on the opening side of the package 2 with respect to the protection part 12 and on the side opposite to the opening of the package 2 with respect to the protection part 12. Further, the protection unit 12 is connected to the sealing layer 76 and the IC chip 4. On the other hand, the pressure propagation unit 11 is connected to the pressure receiving surface 541 and the IC chip 4.

  In the physical quantity sensor 1 having such a configuration, the structure including the sensor chip 3 and the IC chip 4 is fixed by being suspended from the package 2 by the bonding wire 81, and then the pressure propagation unit 11, the protection unit 12, and the pressure propagation The part 11 can be obtained by filling the package 2 in this order. For this reason, manufacture is comparatively easy compared with the said 3rd Embodiment.

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

<Fifth Embodiment>
Next, a fifth embodiment of the physical quantity sensor will be described.

  FIG. 9 is a cross-sectional view showing a fifth embodiment of the physical quantity sensor. 10 is a plan view showing wiring of a flexible wiring board provided in the physical quantity sensor shown in FIG. In the following description, the upper side in FIG. 9 is referred to as “upper” and the lower side is referred to as “lower”.

  Hereinafter, the fifth embodiment of the physical quantity sensor will be described. The description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted.

  The fifth embodiment is the same as the first embodiment described above except that the package configuration is different.

  As shown in FIG. 9, the package 2 includes a flexible wiring substrate 25 in addition to the base 21 and the wall portion 22.

  The flexible wiring board 25 includes a flexible base material 23 and wiring 24 formed on the lower surface side of the base material 23.

  As shown in FIG. 10, the base material 23 has a square frame shape in plan view, and an opening 233 that opens in the thickness direction is formed at the center. 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 has four wiring portions 241 that take out an electrical signal of the sensor chip 3 to the outside of the package 2. Each of the four wiring portions 241 is provided (routed) on the lower surface side of the base material 23, and one end side thereof is provided so as to protrude into the opening 233. A flying lead (tab tape) 27 is constituted by a portion protruding into the opening 233 of the wiring portion 241. The front end portion of the flying lead 27 (the front end portion of the wiring portion 241) is separated from the base material 23, and the connection terminal 410 of the IC chip 4 is fixed to the front end portion of the flying lead 27 via a fixing member 94. (See FIG. 5). As described above, the tip of the flying lead 27 constitutes a fixing part for fixing the IC chip 4 and also constitutes a terminal for electrically connecting the connection terminal 410 of the IC chip 4.

Examples of the constituent material of the wiring 24 include metals such as Ni, Pt, Li, Mg, Sr, Ag, Cu, Co, and Al, alloys such as MgAg, AlLi, and CuLi, and oxides such as ITO and SnO _2. A thing etc. are mentioned, The 1 type (s) or 2 or more types of these can be used in combination.

  Such wiring 24 is electrically connected to an internal electrode 83 provided on the upper surface of the base 21 through a conductive adhesive layer 82. The internal electrode 83 is electrically connected to the external electrode 86 through a through electrode (not shown) that penetrates the wall portion 22 and the base 21.

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

<Sixth Embodiment>
Next, a sixth embodiment of the physical quantity sensor will be described.

  FIG. 11 is a cross-sectional view showing a sixth embodiment of the physical quantity sensor. In the following description, the upper side in FIG. 11 is referred to as “upper” and the lower side is referred to as “lower”.

  Hereinafter, the sixth embodiment of the physical quantity sensor will be described, but the description will focus on differences from the above-described embodiment, and description of similar matters will be omitted.

  The sixth embodiment is the same as the first and third embodiments described above except that the bonding wire 81 is not provided and the connection terminal 95 is provided instead.

  As shown in FIG. 11, in the physical quantity sensor 1 of the present embodiment, a conductive connection terminal 95 is provided on the bottom surface of the recess 28 of the package 2. A conductive adhesive 96 is provided on the connection terminal 95, and the connection terminal 95 is connected to a connection terminal (not shown) exposed on the back side of the IC chip 4 via the conductive adhesive 96. Yes. In addition, a conductive adhesive 97 is provided below the connection terminal 95, and the connection terminal 95 is electrically connected to the through electrode 98 that penetrates the base 21 through the conductive adhesive 97. Thus, the IC chip 4 is electrically connected to the external electrode 86 via the connection terminal 95 and the through electrode 98.

The constituent materials of the connection terminal 95 and the through electrode 98 are not particularly limited as long as they have conductivity, and examples thereof include Cr, Ni, W, Au, Ag, and Cu. One or more of these can be used in combination. The conductive adhesives 96 and 97 are not particularly limited as long as they have conductivity and adhesiveness. For example, epoxy-based, acrylic-based, silicon-based, bismaleimide-based, polyester-based, and polyurethane-based resins. It is possible to use a conductive adhesive in which a conductive filler such as silver particles is mixed, or a metal bump such as a gold bump, a silver bump or a copper bump. The same effect as the form can be exhibited.

<Seventh embodiment>
Next, a seventh embodiment of the physical quantity sensor will be described.

  FIG. 12 is a cross-sectional view illustrating a physical quantity sensor chip included in the physical quantity sensor of the seventh embodiment. In the following description, the upper side in FIG. 12 is referred to as “upper” and the lower side is referred to as “lower”.

  Hereinafter, the seventh embodiment of the physical quantity sensor will be described, but the description will focus on differences from the above-described embodiment, and description of similar matters will be omitted.

  The seventh embodiment is the same as the first embodiment except that the configuration of the sensor chip is different.

  A sensor chip 3 ′ shown in FIG. 12 includes a substrate 35, a sensor element 6, a structure (element surrounding structure) 37, and a cavity 39.

Hereinafter, each of these units will be sequentially described.
The substrate 35 has a plate shape and is made of, for example, single crystal silicon. A structure 37 is provided on one surface side of the substrate 35.

The structure 37 includes a semiconductor substrate 36 formed of an SOI substrate (a substrate in which the first Si layer 361, the SiO ₂ layer 362, and the second Si layer 363 are stacked in this order), and the semiconductor substrate 36 on the semiconductor substrate 36. It is configured by laminating a provided passivation film 371.

In addition, the structure 37 is formed with a recess 391 that opens downward from a part of the second Si layer 363 being removed. The thinned portion by the concave portion 391 constitutes a diaphragm 38 that is bent and deformed by pressure reception, and the upper surface side of the structure 37 is a pressure receiving surface 381. Further, the cavity 39 formed by closing the opening of the recess 391 of the structure 37 with the substrate 35 functions as a pressure reference chamber.
A sensor element 6 is formed on the first Si layer 361 of the semiconductor substrate 36.

  In the physical quantity sensor 1 having such a configuration, the diaphragm 38 bends and deforms downward in FIG. 12 (substrate 35 side) in accordance with the pressure received by the pressure receiving surface 381. In the physical quantity sensor 1 as well, the pressure receiving surface 381 is based on the fact that the resistance values of the piezoresistive elements 61, 62, 63, and 64 change with the deformation of the diaphragm 38, as in the first embodiment. The magnitude of the pressure received at can be obtained.

  Also according to the seventh embodiment, the same effect as that of the first embodiment described above can be exhibited.

2. Next, an example of an altimeter provided with a physical quantity sensor 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 physical quantity 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.

3. Next, a navigation system to which an electronic device including a physical quantity sensor 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 physical quantity sensor 1, and a display unit 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, altitude information can be acquired by the physical quantity sensor 1, and a change in altitude due to entering from an ordinary road to an elevated road is detected, and navigation information in the traveling state of the elevated road is obtained. Can be provided to the user.

  The display unit 301 is configured to be small and thin, such as a liquid crystal panel display or an organic EL (Organic Electro-Luminescence) display.

  The electronic device provided with the physical quantity 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 diagnostic device , Electronic endoscope), various measuring instruments, instruments (for example, instruments for vehicles, aircraft, ships), flight simulators, and the like.

4). Next, a moving body provided with a physical quantity sensor 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 (physical quantity sensor 1).

  The physical quantity sensor, altimeter, electronic device, and moving body of the present invention have been described based on the illustrated embodiments. However, the present invention is not limited to these, and the configuration of each unit has the same function. Any configuration can be substituted. 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.

  In the above-described embodiment, the configuration in which the sensor chip and the IC chip are overlapped with the sensor chip facing upward has been described, but conversely, the IC chip may be overlapped with the IC chip facing upward. Further, the sensor chip and the IC chip may be arranged side by side in the horizontal direction.

DESCRIPTION OF SYMBOLS 1 ... Physical quantity sensor 11 ... Pressure propagation part 12 ... Protection part 2 ... Package 21 ... Base 22 ... Wall part 23 ... Base material 233 ... Opening part 24 ... Wiring 25 ... Flexible wiring Substrate 26 ... Stepped portion 27 ... Flying lead 28 ... Recessed part (internal space)
3, 3 '…… Sensor chip (physical quantity sensor chip)
35 ...... substrate 36 ...... semiconductor substrate 37 ...... structure 38 ...... diaphragm 39 ...... cavity 361 ...... first Si layer 362 ...... SiO ₂ layer 363 ...... second Si layer 371 ...... passivation film 381...: Pressure receiving surface 391...: Recess 4. IC chip 40... Semiconductor circuit 41... Semiconductor substrate 42 .. Insulating film 43 ... Surface protective films 410 and 420. ... Semiconductor substrate 511 ... First Si layer 512 ... SiO ₂ layer 513 ... Second Si layer 52 ... First insulating film 53 ... Second insulating film 54 ... Diaphragm 541 ... Pressure-receiving surface 55 ... ... Recess 6. Sensor elements 611, 621, 631, 641... Piezoresistive parts 613, 623, 633, 643 .. Wiring 632, 642. ... allocation Layers 72a, 72b ... Wiring layer 73 ... Interlayer insulating film 74 ... Wiring layers 74a, 74b ... Wiring layer 74b '... Connection terminal 741 ... Cover layer 742 ... Pore 75 ... Surface protective film 76 ... ... Sealing layer (wall)
8 …… Cavity (pressure reference chamber)
9 ... Semiconductor circuit 91 ... MOS transistor 60 ... Bridge circuit 61, 62, 63, 64 ... Piezoresistive element 81 ... Bonding wire 82 ... Conductive adhesive layer 83 ... Internal electrode 85 ... Terminal 86 ... External electrodes 92, 94 ... Fixing member 95 ... Connection terminals 96, 97 ... Conductive adhesive 98 ... Penetration electrode 200 ... Altitude meter 201 ... Display part 241 ... Wiring part 300 ... Navigation system 301 ... Display unit 400 ... Moving object 401 ... Car body 402 ... Wheel

Claims (10)

A physical quantity sensor chip having a pressure reference chamber, a pressure-receiving surface, and a flexible deformable diaphragm;
A package having an opening and having an internal space containing the physical quantity sensor chip;
A pressure propagation part connected to the diaphragm in the internal space;
A protective part which is made of a material harder than the pressure propagation part and is arranged outside the pressure reference chamber;
A physical quantity sensor characterized by comprising:   The physical quantity sensor according to claim 1, wherein the physical quantity sensor chip is connected to the package via a wire. Furthermore, it has an IC chip,
The physical quantity sensor according to claim 1, wherein the sensor chip is fixed to the IC chip.   4. The physical quantity sensor according to claim 1, wherein the protection part is surrounded by the pressure propagation part in a plan view in a direction in which the opening and the physical quantity sensor chip overlap. 5.   5. The physical quantity sensor according to claim 1, wherein the protection part is surrounded by the pressure propagation part in a cross-sectional view in a direction in which the opening and the physical quantity sensor chip overlap.   The physical quantity sensor according to claim 1, wherein the protection unit includes at least one of a silicon resin, a fluorine resin, an epoxy resin, and a polyimide resin.   The physical quantity sensor according to claim 1, wherein the physical quantity sensor chip is a pressure sensor chip that generates a signal according to pressure.   An altimeter comprising the physical quantity sensor according to any one of claims 1 to 7.   An electronic apparatus comprising the physical quantity sensor according to claim 1.   A moving body comprising the physical quantity sensor according to claim 1.

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