JP4766932B2 - Manufacturing method of sensor using capacitive element - Google Patents

Description

  The present invention relates to a method for manufacturing a sensor using a capacitive element, and more particularly to an efficient wiring method in a sensor of a type that detects acceleration and angular velocity using a capacitive element.

  A sensor using a capacitive element has been put into practical use as an acceleration sensor or an angular velocity sensor having a small and simple structure. In these types of sensors, normally, a weight body supported so as to be displaceable with a predetermined degree of freedom is prepared, and acceleration and angular velocity acting on the weight body are defined as displacement of the weight body. It has a function to detect. The displacement is detected based on the capacitance value of the capacitive element.

  For example, in Patent Documents 1 to 3 below, a capacitive element is constituted by a displacement electrode formed on the weight body side and a fixed electrode formed on the apparatus housing side, and the capacitance value of this capacitive element changes. An acceleration sensor that can detect the displacement of the weight body and electrically detect the applied acceleration is disclosed. By disposing a plurality of capacitive elements, displacement in each coordinate axis direction in the XYZ three-dimensional coordinate system can be detected independently, thus realizing a multidimensional acceleration sensor despite a relatively simple configuration. It becomes possible to do.

Patent Document 4 below discloses a sensor that detects an angular velocity using a substantially similar structure. The angular velocity is detected by supplying an AC signal to a predetermined capacitive element, moving the weight body by the Coulomb force, and generating a Coriolis force generated by the angular velocity acting on the moving weight body. This is performed by detecting the change in the capacitance of the capacitive element. Also by devising and arranging a plurality of capacitive elements, it is possible to cause the weight body to perform repeated movements along a predetermined trajectory such as simple vibration, circular movement, precession movement, etc., and XYZ three-dimensional Since the displacement in the desired coordinate axis direction in the coordinate system can be detected independently, it is possible to realize a multidimensional angular velocity sensor capable of detecting angular velocities around a plurality of coordinate axes in spite of a relatively simple configuration. Become.
JP-A-4-299227 Japanese Patent Laid-Open No. 5-26754 JP-A-5-215627 JP-A-10-227644

  As described above, an acceleration sensor and an angular velocity sensor using a capacitive element have a feature that can detect acceleration and angular velocity of a multidimensional component in spite of a relatively simple configuration. Mass production is performed by using a substrate or the like as a material. However, since the detection of force and the driving of the weight body are performed using the capacitive element, wiring to the outside for the individual electrodes constituting the capacitive element is indispensable.

  If the weight body is made of a conductive material, the weight body itself can be used as a common displacement electrode for a plurality of capacitive elements, and physical wiring can be reduced. Depending on the number of elements, it is still necessary to secure physical wiring to the outside. In particular, in a multidimensional acceleration sensor and angular velocity sensor, the number of capacitive elements to be used increases, and it is inevitable that physical wiring to the outside becomes complicated. In addition, the angular velocity sensor requires a driving capacitive element for driving the weight body and a displacement detecting capacitive element for detecting the displacement of the weight body, which increases the number of wirings to the outside. become.

  Therefore, the present invention provides a sensor having a three-layer structure in which a conductive substrate is sandwiched between two insulating substrates and having a function of detecting displacement of a weight body by a capacitive element. It is an object of the present invention to provide a manufacturing method capable of performing wiring.

The sensor manufacturing method using the capacitive element according to the present invention has a unique structure in which an intermediate member mainly made of a conductive material is sandwiched between an upper substrate made of an insulating material and a lower substrate made of an insulating material. It is premised on manufacturing a sensor. Here, the intermediate member is flexible between the pedestal and the weight body, the pedestal whose upper end is joined to the upper substrate and the lower end is joined to the lower substrate to support the weight body, and the pedestal and the weight body. The sensor body structure is composed of a connecting portion that is connected to the weight body, and when a force due to acceleration or angular velocity is applied to the weight body, the weight is displaced to the weight body due to the bending of the connection section. Is configured to occur. An upper electrode is formed on a portion of the lower surface of the upper substrate facing the weight body, and a lower electrode is formed on a portion of the upper surface of the lower substrate facing the weight body. The upper capacitive element is formed by the lower electrode and the lower capacitive element is formed by the opposing surface of the weight body, and the displacement generated in the weight body is based on the capacitance of the upper capacitive element and the lower capacitive element. The detected acceleration or angular velocity can be detected. On the premise of manufacturing such a sensor, the present invention has several aspects as follows.
The correspondence relationship between the invention described in each of claims 1 to 21 in the “Claims” of the present application and each of the following modes is as follows.
Invention of Claim 1: It respond | corresponds to the following 3rd aspect.
Invention of Claim 2: It respond | corresponds to the following 4th aspect.
Invention of Claim 3: It respond | corresponds to the following 7th aspect.
Invention of Claim 4: It respond | corresponds to the following 8th aspect.
Invention of Claim 5: It respond | corresponds to a part of following 9th aspect.
Invention of Claim 6: It respond | corresponds to a part of following 10th aspect.
Invention of Claim 7: It respond | corresponds to a part of the following 11th aspect.
Invention of Claim 8: It corresponds to a part of the following 12th aspect.
Invention of Claim 9: It respond | corresponds to a part of following 13th aspect.
Invention of Claim 10: It respond | corresponds to the combination of the following 1st and 11th aspect.
Invention of Claim 11: It respond | corresponds to a part of following 2nd aspect.
Invention of Claim 12: It corresponds to a part of the following twelfth aspect.
Invention of Claim 13: It respond | corresponds to the combination of the following 5th and 11th aspect.
Invention of Claim 14: It respond | corresponds to a part of following 6th aspect.
The invention described in claim 15 corresponds to a part of the following twelfth aspect.
The invention described in claim 16 corresponds to a part of the following thirteenth aspect.
The invention described in claim 17 corresponds to a part of the following fourteenth aspect.
The invention described in claim 18 corresponds to a part of the fifteenth aspect described below.
Invention of Claim 19: It respond | corresponds to a part of following 16th aspect.
The invention described in claim 20 corresponds to a part of the following seventeenth aspect.
The invention described in claim 21 corresponds to a part of the following eighteenth aspect.

(1) A first aspect of the present invention is a method for manufacturing a sensor using a capacitive element shown as the first embodiment in FIG.
A preparation stage for preparing an upper glass substrate for use as an upper substrate, a lower glass substrate for use as a lower substrate, and a silicon substrate for use as an intermediate member, respectively;
An intermediate member forming step of forming an intermediate member having a sensor body structure and a columnar body for connecting the upper substrate and the lower substrate by processing the silicon substrate;
A lower substrate forming step in which a lower electrode and a lower wiring layer for connecting the lower electrode and the lower end of the columnar body are formed on the upper surface of the lower glass substrate to form a lower substrate;
For the upper glass substrate, the first through hole is formed at the first position, the second through hole is formed at the second position where the upper end of the columnar body comes into contact, and the first through hole and A through-wiring part forming step of forming a first through-wiring part and a second through-wiring part, respectively, by filling the second through-hole with a conductive material;
Forming an upper substrate on the lower surface of the upper glass substrate by forming an upper electrode and an upper wiring layer for connecting the upper electrode and the first through-wiring portion;
A lower substrate bonding stage in which the intermediate member or an intermediate member in the middle of forming the intermediate member and the lower substrate are subjected to anodic bonding while applying an electric field between the lower substrate,
An intermediate substrate or an intermediate substrate forming step and an upper substrate bonding step for anodic bonding them while applying an electric field between the upper substrate and the intermediate member,
Forming an external terminal on the upper surface of the upper substrate, forming a first external terminal connected to the first through wiring portion and a second external terminal connected to the second through wiring portion;
Is to do.

(2) According to a second aspect of the present invention, in the method for manufacturing a sensor according to the first aspect described above,
A position where the center of the second through hole is a predetermined distance away from the center of the region where the upper end of the columnar body is in contact so that the upper end of the columnar body is anodically bonded to the upper substrate with sufficient strength Is set.

(3) A third aspect of the present invention is a method for manufacturing a sensor using a capacitive element shown in FIG. 15 as the second embodiment.
A preparation stage for preparing an upper glass substrate for use as an upper substrate, a lower glass substrate for use as a lower substrate, and a silicon substrate for use as an intermediate member, respectively;
An intermediate member forming step of forming an intermediate member having a sensor body structure and a columnar body for connecting the upper substrate and the lower substrate by processing the silicon substrate;
A lower substrate forming step in which a lower electrode and a lower wiring layer for connecting the lower electrode and the lower end of the columnar body are formed on the upper surface of the lower glass substrate to form a lower substrate;
With respect to the upper glass substrate, a first through hole and a second through hole are formed at a first position and a second position, respectively, and a conductive material is placed in the first through hole and the second through hole. A through-wiring portion forming stage for forming a first through-wiring portion and a second through-wiring portion, respectively, by filling;
The upper electrode, the upper electrode upper wiring layer for connecting the upper electrode and the first through wiring portion, the upper end of the columnar body, and the second through wiring portion are connected to the lower surface of the upper glass substrate. Forming an upper wiring layer for a lower electrode for forming an upper substrate, and forming an upper substrate;
A lower substrate bonding stage in which the intermediate member or an intermediate member in the middle of forming the intermediate member and the lower substrate are subjected to anodic bonding while applying an electric field between the lower substrate,
An intermediate substrate or an intermediate substrate forming step and an upper substrate bonding step for anodic bonding them while applying an electric field between the upper substrate and the intermediate member,
Forming an external terminal on the upper surface of the upper substrate, forming a first external terminal connected to the first through wiring portion and a second external terminal connected to the second through wiring portion;
Is to do.

(4) According to a fourth aspect of the present invention, in the method for manufacturing a sensor according to the third aspect described above,
The upper wiring layer for the lower electrode is positioned at a predetermined distance from the center of the region where the upper end of the columnar body is in contact so that the upper end of the columnar body is anodically bonded to the upper substrate with sufficient strength. It is set to terminate.

(5) According to a fifth aspect of the present invention, in the method for manufacturing a sensor using the capacitive element shown as the third embodiment in FIG.
A preparation stage for preparing an upper glass substrate for use as an upper substrate, a lower glass substrate for use as a lower substrate, and a silicon substrate for use as an intermediate member, respectively;
An intermediate member forming step of forming an intermediate member having a sensor body structure and a columnar body for connecting the upper substrate and the lower substrate by processing the silicon substrate;
A lower substrate forming step in which a lower electrode and a lower wiring layer for connecting the lower electrode and the lower end of the columnar body are formed on the upper surface of the lower glass substrate to form a lower substrate;
For the upper glass substrate, the first through hole is formed at the first position included in the region where the upper electrode is to be formed, and the second through hole is formed at the second position where the upper end of the columnar body comes into contact. Forming a first through-hole portion and a second through-hole portion by filling the first through-hole and the second through-hole with a conductive material, respectively,
Forming an upper electrode on the lower surface of the upper glass substrate to form an upper substrate;
A lower substrate bonding stage in which the intermediate member or an intermediate member in the middle of forming the intermediate member and the lower substrate are subjected to anodic bonding while applying an electric field between the lower substrate,
An intermediate substrate or an intermediate substrate forming step and an upper substrate bonding step for anodic bonding them while applying an electric field between the upper substrate and the intermediate member,
Forming an external terminal on the upper surface of the upper substrate, forming a first external terminal connected to the first through wiring portion and a second external terminal connected to the second through wiring portion;
Is to do.

(6) According to a sixth aspect of the present invention, in the method for manufacturing a sensor according to the fifth aspect described above,
A position where the center of the second through hole is a predetermined distance away from the center of the region where the upper end of the columnar body is in contact so that the upper end of the columnar body is anodically bonded to the upper substrate with sufficient strength Is set.

(7) According to a seventh aspect of the present invention, in the method for manufacturing a sensor using the capacitive element shown as the fourth embodiment in FIG.
A preparation stage for preparing an upper glass substrate for use as an upper substrate, a lower glass substrate for use as a lower substrate, and a silicon substrate for use as an intermediate member, respectively;
An intermediate member forming step of forming an intermediate member having a sensor body structure and a columnar body for connecting the upper substrate and the lower substrate by processing the silicon substrate;
A lower substrate forming step in which a lower electrode and a lower wiring layer for connecting the lower electrode and the lower end of the columnar body are formed on the upper surface of the lower glass substrate to form a lower substrate;
For the upper glass substrate, a first through hole is formed at a first position included in a region where an upper electrode is to be formed, and a second through hole is formed at a second position different from the first position. A through-wiring portion forming step for forming the first through-wiring portion and the second through-wiring portion, respectively, by filling the first through-hole and the second through-hole with a conductive material;
Forming an upper substrate on the lower surface of the upper glass substrate by forming an upper electrode and an upper wiring layer for the lower electrode for connecting the upper end of the columnar body and the second through wiring portion; ,
A lower substrate bonding stage in which the intermediate member or an intermediate member in the middle of forming the intermediate member and the lower substrate are subjected to anodic bonding while applying an electric field between the lower substrate,
An intermediate substrate or an intermediate substrate forming step and an upper substrate bonding step for anodic bonding them while applying an electric field between the upper substrate and the intermediate member,
Forming an external terminal on the upper surface of the upper substrate, forming a first external terminal connected to the first through wiring portion and a second external terminal connected to the second through wiring portion;
Is to do.

(8) According to an eighth aspect of the present invention, in the method for manufacturing a sensor according to the seventh aspect described above,
The upper wiring layer for the lower electrode is positioned at a predetermined distance from the center of the region where the upper end of the columnar body is in contact so that the upper end of the columnar body is anodically bonded to the upper substrate with sufficient strength. It is set to terminate.

(9) According to a ninth aspect of the present invention, in the method for manufacturing a sensor according to the first to eighth aspects described above,
In the through wiring portion formation stage, a third through hole is formed at a third position where the upper end of the “base or a portion having the same potential as the pedestal” in the upper glass substrate comes into contact, and this third through hole is formed. Adding a step of forming a third through wiring portion by filling the hole with a conductive material;
In the external terminal formation stage, a step of forming a third external terminal connected to the third through wiring portion on the upper surface of the upper substrate is added.

(10) According to a tenth aspect of the present invention, in the method for manufacturing a sensor according to the ninth aspect described above,
The center of the third through-hole is set to “the portion having the same potential as the pedestal or the pedestal” so that the upper end of “the pedestal or the portion having the same potential as the pedestal” is anodically bonded to the upper substrate with sufficient strength. Is set at a position that is a predetermined distance away from the center of the region that is to be contacted by the upper end.

(11) According to an eleventh aspect of the present invention, in the method for manufacturing a sensor according to the first to eighth aspects described above,
In the through wiring portion forming stage, a third through hole is formed at a third position on the upper glass substrate, and the third through wiring portion is formed by filling the third through hole with a conductive material. Add a process to
In the upper substrate formation stage, a step of forming a pedestal upper wiring layer for connecting the upper end of the pedestal or the portion having the same potential as the pedestal and the third through wiring portion is added. .

(12) According to a twelfth aspect of the present invention, in the method for manufacturing a sensor according to the eleventh aspect described above,
The upper wiring layer for the pedestal is connected to the upper part of the pedestal or the part having the same potential as the pedestal so that the upper edge of the pedestal or the part having the same potential as the pedestal is anodically bonded to the upper substrate with sufficient strength. Is set so as to end at a position a short distance from the center of the region that will contact.

(13) According to a thirteenth aspect of the present invention, in the method for manufacturing a sensor according to the second, fourth, sixth, eighth, tenth, and twelfth aspects described above,
The width of the through-hole wiring part, the lower electrode upper wiring layer end position, or the pedestal upper wiring layer end position is the width of the columnar body or the contact portion of the “base or the part that is equipotential to the pedestal” Is set to be within D / 3 from the contour position of the contact portion of the columnar body or the “part that is equipotential to the pedestal or the pedestal” toward the inner side.

(14) In a fourteenth aspect of the present invention, in the method for manufacturing a sensor according to the first to thirteenth aspects described above,
An intermediate member forming step is performed on the silicon substrate from its lower surface side to form an intermediate member, and an intermediate member is formed from the upper surface side to form an intermediate member. And divided into
After performing the first half step, perform the lower substrate bonding step, then perform the second half step, and then perform the upper substrate bonding step,
In the lower substrate bonding step, a processing intermediate body is placed on the upper surface of the lower substrate, the first anodic bonding electrode is brought into contact with the upper surface of the processing intermediate body, and the second anodic bonding electrode is brought into contact with the lower surface of the lower substrate, Performing anodic bonding while applying an electric field between the first anodic bonding electrode and the second anodic bonding electrode,
In the upper substrate bonding stage, the upper substrate is placed on the upper surface of the intermediate member, the first anodic bonding electrode is brought into contact with the upper surface of the upper substrate, the second anodic bonding electrode is brought into contact with the lower surface of the lower substrate, The anodic bonding is performed while applying an electric field between the first anodic bonding electrode and the second anodic bonding electrode.

(15) According to a fifteenth aspect of the present invention, in the method for manufacturing a sensor according to the first to thirteenth aspects described above,
An intermediate member forming step is performed on the silicon substrate from its upper surface side to form an intermediate member, and an intermediate member is formed from the lower surface side of the intermediate member to be processed from its lower surface side. And divided into
After performing the first half stage, perform the upper substrate bonding stage, then perform the second half stage, and then perform the lower substrate bonding stage,
In the upper substrate bonding stage, the upper substrate is placed on the upper surface of the intermediate workpiece, the first anodic bonding electrode is brought into contact with the upper surface of the upper substrate, and the second anodic bonding electrode is brought into contact with the lower surface of the intermediate workpiece. Performing anodic bonding while applying an electric field between the first anodic bonding electrode and the second anodic bonding electrode,
In the lower substrate bonding step, the lower substrate is disposed on the lower surface of the intermediate member, the first anodic bonding electrode is brought into contact with the upper surface of the upper substrate, the second anodic bonding electrode is brought into contact with the lower surface of the lower substrate, The anodic bonding is performed while applying an electric field between the first anodic bonding electrode and the second anodic bonding electrode.

(16) According to a sixteenth aspect of the present invention, in the method for manufacturing a sensor according to the first to fifteenth aspects described above,
In the intermediate member forming stage, the pedestal and the outer wall are formed so that the weight body and the columnar body can be sealed in a sealed space,
In the through wiring part formation stage, a through wiring part having a function of sealing the through hole is formed,
In the upper substrate bonding step and the lower substrate bonding step, the upper surface and the lower surface of the base and the outer wall portion are bonded to the upper substrate and the lower substrate so that the weight body is sealed in a sealed space. .

(17) According to a seventeenth aspect of the present invention, in the method for manufacturing a sensor according to the sixteenth aspect described above,
Of the upper substrate bonding step and the lower substrate bonding step, at least one of the bonding steps performed later is performed in a vacuum so that the weight body is sealed in the vacuum.

(18) According to an eighteenth aspect of the present invention, in the method for manufacturing a sensor according to the first to seventeenth aspects described above,
An SOI substrate sandwiching an insulating layer is used as a silicon substrate for use as an intermediate member, and a conductive portion that penetrates the insulating layer is formed for a portion that needs to be conducted across the insulating layer. It is a thing.

  According to the method for manufacturing a sensor using the capacitive element according to the present invention, two glass substrates and one silicon substrate are prepared, and a through hole is formed in advance in the glass substrate disposed above. Since the wiring portion is formed and the three layers are joined so that the through wiring portion is in contact with the silicon substrate, efficient wiring to the outside can be performed.

  Hereinafter, the present invention will be described based on the illustrated embodiments.

<<< §0. Basic structure of applicable sensor >>>
The sensor manufacturing method using the capacitive element according to the present invention has a unique structure in which an intermediate member mainly made of a conductive material is sandwiched between an upper substrate made of an insulating material and a lower substrate made of an insulating material. It is premised on manufacturing a sensor. Therefore, here, the basic structure and basic operation of the sensor to which the present invention is applied will be described.

  FIG. 1 is a longitudinal sectional view showing a basic form of a one-dimensional acceleration sensor having a three-layer structure to which a manufacturing method according to the present invention is applied. As illustrated, this sensor has a three-layer structure of an upper substrate 10, an intermediate member 20, and a lower substrate 30. The upper substrate 10 and the lower substrate 30 are substrates made of an insulating material. In this example, glass substrates are used. The intermediate member 20 is made of a conductive material, and in this example, a silicon substrate processed is used. As illustrated, the intermediate member 20 includes a weight body 21, a pedestal 23 having an upper end bonded to the upper substrate 10 and a lower end bonded to the lower substrate 30 to support the weight body 21, It is comprised by the connection part 22 which connects between the weight bodies 21 with flexibility.

  The weight body 21 is a mass having a mass necessary for acceleration detection, and the pedestal 23 is a cylindrical structure surrounding the weight body 21. Although the connection part 22 is a component which connects the weight body 21 and the base 23, since the thickness is thin as shown in the figure, it has flexibility. After all, the weight body 21 is supported in a suspended state by the connection portion 22 in the internal space formed by the upper substrate 10, the pedestal 23, and the lower substrate 30. Gaps SP1 and SP2 are formed between the wall surface of the internal space and the weight body 21, and the weight body 21 can be displaced within the range of the gaps SP1 and SP2. . When acceleration acts on the entire sensor, a force corresponding to the applied acceleration is applied to the weight body 21, the connecting portion 22 is bent, and the weight body 21 is displaced. By detecting this displacement, the applied acceleration can be obtained.

  In order to detect the displacement of the weight body 21, an upper electrode E <b> 1 is provided on the lower surface of the upper substrate 10, and a lower electrode E <b> 2 is provided on the upper surface of the lower substrate 30. The upper electrode E1 is an electrode facing the upper surface of the weight body 21, and the upper capacitor element C1 is formed by the upper surface of the weight body 21 and the upper electrode E1. On the other hand, the lower electrode E2 is an electrode facing the lower surface of the weight body 21, and the lower capacitor C2 is formed by the lower surface of the weight body 21 and the lower electrode E2.

  When acceleration is applied in the vertical direction in FIG. 1, a force in the vertical direction is applied to the weight body 21, and the electrode interval between the capacitive elements C1 and C2 changes, and the capacitance value changes. For example, when the weight body 21 is displaced upward in the figure, the distance between the upper electrode E1 and the upper surface of the weight body 21 is reduced, and the capacitance value of the upper capacitive element C1 is increased. The distance from the lower surface of the weight body 21 increases, and the capacitance value of the lower capacitive element C2 decreases. When the weight body 21 is displaced downward in the figure, a reverse phenomenon occurs. Eventually, the acceleration acting in the vertical direction in the figure can be obtained by detecting the difference between the capacitance value of the upper capacitive element C1 and the capacitance value of the lower capacitive element C2.

  FIG. 2 is an equivalent circuit of a capacitive element included in the sensor shown in FIG. As described above, the upper capacitive element C1 is configured by the upper electrode E1 and the upper surface of the weight body 21, and the lower capacitive element C2 is configured by the lower electrode E2 and the lower surface of the weight body 21. Here, since the weight body 21 is a single lump mainly made of a conductive material, as shown in this equivalent circuit, the lower electrode of the upper capacitor element C1 (the upper surface of the weight body 21) and the lower capacitor element It is equipotential with the upper electrode of C2 (the lower surface of the weight body 21). Therefore, in order to wire this sensor to the outside, it is only necessary to provide three external terminals T1, T2, T3 as shown in the figure.

  Accordingly, in the structure shown in FIG. 1, it is necessary to wire the upper electrode E1 to the external terminal T1, wire the lower electrode E2 to the external terminal T2, and wire the weight body 21 to the external terminal T3. In consideration of convenience in use, these three external terminals T1 to T3 are preferably arranged on the same surface such as the upper surface of the upper substrate 10, for example. The present invention provides a manufacturing method for efficiently performing wiring to such external terminals.

  In the following embodiments, for convenience of explanation, an example in which the present invention is applied to a process for manufacturing a one-dimensional acceleration sensor as shown in FIG. 1 will be described. However, the present invention is not necessarily applied to a one-dimensional acceleration sensor. The present invention is not limited and can be similarly applied to a multidimensional acceleration sensor. In order to detect multidimensional acceleration, a larger number of electrodes may be provided so that the displacement form of the weight body 21 can be detected in more detail. Since the electrode arrangement for such a multidimensional acceleration sensor is disclosed in the above-mentioned patent documents and the like, detailed description thereof is omitted here.

  The present invention is also applicable to a process for manufacturing a one-dimensional or multi-dimensional angular velocity sensor. For example, in order to detect the angular velocity around the X axis on the XYZ three-dimensional coordinate system, it is only necessary to detect the Coriolis force acting in the Z axis direction when the weight body 21 is vibrated in the Y axis direction. . In this case, an excitation electrode is arranged to vibrate the weight body 21, and a detection electrode is arranged to detect the Coriolis force as a displacement of the weight body 21. A large number of electrodes need to be formed. Since the electrode arrangement for such a multidimensional angular velocity sensor is also disclosed in the above-mentioned patent documents and the like, detailed description thereof is omitted here.

  As described above, the present invention is mainly performed between an upper substrate made of an insulating material and a lower substrate made of an insulating material regardless of one-dimensional or multi-dimensional, or an acceleration sensor or an angular velocity sensor. It has a three-layer structure sandwiching an intermediate member made of a conductive material. One or more upper electrodes are formed on the lower surface of the upper substrate, and one or more lower electrodes are formed on the upper surface of the lower substrate. This is a technology that can be applied in common to other sensors.

  As described above, the manufacturing method according to the present invention is aimed at increasing the efficiency of wiring, and has the following three important features. The first feature is that a glass substrate is used as the upper substrate 10 and the lower substrate 30, and a silicon substrate is processed as the intermediate member 20, and these three layers are bonded to each other by anodic bonding. Anodic bonding is a technique widely used in the manufacture of semiconductor devices, and is a bonding method particularly suitable for bonding between a glass substrate and a silicon substrate. The second feature is that a columnar body formed from a part of a silicon substrate is used for wiring to the lower electrode E2 formed on the lower substrate 30 side. By doing so, the columnar body which is one component of the intermediate member 20 can be used for wiring as it is. The third feature is that a through hole is formed in the upper substrate 10 in advance and a conductive material is filled in the through hole to form a through wiring portion. It exists in the point made to join to the intermediate member 20. FIG. Before the bonding to the intermediate member 20 is performed, the through wiring portion is formed on the upper substrate 10 side, so that it is possible to form a favorable wiring without causing disconnection or the like.

  Hereinafter, some specific embodiments of the present invention will be described with reference to the drawings. In addition, although each embodiment described below shows the procedure of the manufacturing process of a sensor, since the wiring method is different for each embodiment, the structure of the sensor as a finished product is also different. It will be a thing. However, the difference in these structures is the difference regarding the portion related to the wiring, not the difference regarding the portion related to the essential function as the sensor.

<<< §1. First Embodiment >>>
First, a basic form of a sensor manufactured by the method according to the first embodiment described here will be described with reference to a longitudinal sectional view of FIG. The sensor shown in FIG. 3 is a one-dimensional acceleration sensor, and its basic principle is exactly the same as that of the sensor shown in FIG. That is, basically, it has a three-layer structure in which an intermediate member 200 made of a conductive material is sandwiched between an upper substrate 100 made of an insulating material and a lower substrate 300 made of an insulating material. Here, the upper substrate 100 and the lower substrate 300 are glass substrates, and the intermediate member 200 is formed by processing a silicon substrate.

  Of the intermediate member 200, the portion shown in the right half of the figure is the portion that forms the sensor body structure (the portion corresponding to the intermediate member 20 in FIG. 1). That is, in the case of the sensor shown in FIG. 3, the sensor body structure includes a weight body 210 and a pedestal whose upper end is joined to the upper substrate 100 and lower end is joined to the lower substrate 300 to support the weight body 210. 230, and the connection part 220 which connects the base 230 and the weight body 210 with flexibility. The function of this sensor main body structure is exactly the same as the function of the intermediate member 20 in the sensor shown in FIG. 1, and when a force due to acceleration or angular velocity acts on the weight body 210, the connection portion 220 bends. Thus, the weight body 210 is configured to be displaced.

  Further, an upper electrode E1 is formed on a portion of the lower surface of the upper substrate 100 facing the weight body 210, and a lower electrode E2 is formed on a portion of the upper surface of the lower substrate 300 facing the weight body 210. The upper capacitive element C1 is formed by the facing surface (upper surface) of the weight body 210, and the lower capacitive element C2 is formed by the lower electrode E2 and the facing surface (lower surface) of the weight body 210. This is exactly the same as the sensor shown in FIG. Of course, the detected acceleration or angular velocity is detected by detecting the displacement generated in the weight body 210 based on the capacitance of the upper capacitive element C1 and the lower capacitive element C2. It is exactly the same.

  Here, for the convenience of describing the manufacturing process of the sensor shown in FIG. 3, the structure will be described in more detail. FIG. 4 is a cross-sectional view of the sensor shown in FIG. 3 cut along cutting line 4-4. As described above, the sensor main body structure including the weight body 210, the connection portion 220, and the base 230 occupies the right half of FIG. In this example, the weight body 210 is constituted by a prism having a square cross section, and the pedestal 230 is formed of a “B” -shaped structure surrounding the periphery thereof. The connecting portion 220 is a thin portion formed between the weight body 210 and the pedestal 230, and the gap portion SP1 is formed in the space above the connecting portion 220. As shown in FIG. 3, a gap SP <b> 2 is formed below the weight body 210.

  On the other hand, the left half of FIG. 4 is provided with a columnar body 240 for playing the role of wiring and an outer wall portion 235 surrounding the columnar body 240. The columnar body 240 is for wiring to the lower electrode E2. That is, as shown in FIG. 3, the lower wiring layer L <b> 2 is connected to the lower electrode E <b> 2, and the lower wiring layer L <b> 2 is in contact with the lower end of the columnar body 240. Eventually, the lower electrode E2 is in a state of being electrically connected to the columnar body 240, and a wiring path for arranging the external terminal T2 for the lower electrode E2 on the upper substrate 100 side is formed.

  Similarly to the weight body 210, the columnar body 240 is also configured by a rectangular column having a square cross section. However, as shown in FIG. 3, the upper end of the columnar body 240 is bonded to the lower surface of the upper substrate 100, and the lower end is bonded to the upper surface of the lower substrate 300, and is in a completely fixed state. Yes. The weight body 210 needs to have a mass sufficient to detect acceleration and angular velocity, but the columnar body 240 has a thickness sufficient to function as a wiring. It's enough.

  A space SP3 is formed between the columnar body 240 and the outer wall portion 235, which is a consideration for preventing the columnar body 240 from being in electrical contact with the outer wall portion 235. The outer wall portion 235 is connected to the pedestal 230 in structure, and is electrically equipotential with the weight body 210. By providing the gap portion SP3 so that the columnar body 240 is isolated from the outer wall portion 235, the columnar body 240 can be electrically insulated from the weight body 210. In FIG. 4, the lower wiring layer L2 passes under the pedestal 230 (a portion functioning as a partition between the right half and the left half in the drawing). As shown in FIG. Since a tunnel for forming the gap SP4 is provided on the lower surface side of the pedestal 230 corresponding to the lower wiring layer L2, the lower wiring layer L2 and the pedestal 230 are electrically isolated.

  As shown in FIG. 3, the upper substrate 100 has through holes formed at three locations, and through wiring portions H1, H2, and H3 are formed in these through holes, respectively. The external terminals T1, T2, and T3 are formed so as to be joined to the through wiring portions H1, H2, and H3. An upper wiring layer L1 for connecting the upper electrode E1 and the through wiring portion H1 is formed on the lower surface of the upper substrate 100.

  Eventually, the upper electrode E1 is wired to the external terminal T1 via the upper wiring layer L1 and the through wiring portion H1, and the lower electrode E2 is connected to the external terminal via the lower wiring layer L2, the columnar body 240, and the through wiring portion H2. The weight body 210 is wired to T2, and the weight body 210 is wired to the external terminal T3 via the connection portion 220, the base 230, and the through wiring portion H3. As a result, the three external terminals T1, T2, T3 necessary for the equivalent circuit shown in FIG. 2 are all arranged on the upper surface of the upper substrate 100.

  Then, the manufacturing process of the sensor which has a structure shown in this FIG. 3 is demonstrated in order. First, as a preparation stage, an upper glass substrate for use as the upper substrate 100, a lower glass substrate for use as the lower substrate 300, and a silicon substrate for use as the intermediate member 200 are prepared. . Both the upper glass substrate and the lower glass substrate are substrates using glass (glass containing movable ions) suitable for anodic bonding to a silicon substrate for use as the intermediate member 200.

  Next, a lower substrate forming step is performed in which the lower electrode E2 and the lower wiring layer L2 are formed on the upper surface of the prepared lower glass substrate to form the lower substrate 300. FIG. 5 is a top view of the lower substrate 300 formed as described above. The lower electrode E2 is formed at a position facing the lower surface of the weight body 210, and the lower wiring layer L2 is formed at a position suitable for connecting the lower electrode E2 and the lower end of the columnar body 240. The lower electrode E2 and the lower wiring layer L2 may be formed of any material, but in practice, a metal layer such as aluminum or chromium is formed on the entire upper surface of the lower glass substrate and then patterned. It is preferable to form by doing.

  Subsequently, an intermediate member forming step of forming the intermediate member 200 having the sensor body structure and the columnar body is performed by processing the prepared silicon substrate. As described above, the sensor main body structure includes the weight body 210, the connection portion 220, and the pedestal 230, and the columnar body 240 includes the structure that connects the upper substrate 100 and the lower substrate 300. However, as shown in FIG. 3, the intermediate member 200 has a slightly complicated structure. In particular, in order to construct the sensor body structure, the processing from the upper surface side of the prepared silicon substrate and the lower surface side are performed. Processing from is required.

  Therefore, in the embodiment described here, this intermediate member forming step is performed on the prepared silicon substrate from the lower surface side to form a processing intermediate body 200 ', and the intermediate processing member is processed with respect to the intermediate processing member. Processing is performed from the upper surface side, and the latter half of forming the intermediate member 200 is performed separately. FIG. 6 is a vertical cross-sectional view of the processing intermediate body 200 ′ formed by this first half stage. As shown in the figure, this processed intermediate body 200 'is formed by forming voids SP2 and SP4' on the lower surface of the silicon substrate. Here, the gap portion SP2 is the gap portion SP2 shown in FIG. 3, and is for securing a necessary space between the lower electrode E2 and the weight body 210. On the other hand, the gap portion SP4 ′ is obtained by adding a portion to be the gap portion SP3 to the gap portion SP4 shown in FIG. 3 to secure a space for arranging the lower wiring layer L2 shown in FIG.

  In order to form such voids SP2 and SP4 'on the lower surface of the silicon substrate, for example, an etching process from the lower surface side may be performed. Since various methods are known for the etching process for such a silicon substrate, detailed description thereof is omitted here.

  6 is prepared, a lower substrate bonding step for bonding the lower substrate 300 shown in FIG. 5 to the lower surface is performed. This bonding is performed by anodic bonding. FIG. 7 is a longitudinal cross-sectional view showing a state in which the workpiece 200 ′ is placed on the lower substrate 300 and the two are anodically bonded. Since the gap portions SP2 and SP4 'are already formed on the lower surface of the processing intermediate body 200', the lower electrode E2 and the lower wiring layer L2 formed on the upper surface of the lower substrate 300 are accommodated in the gap portion. It will be in the state. However, the terminal position of the lower wiring layer L2 (left end in FIG. 7) protrudes further leftward from the gap SP4 ′. For this reason, the terminal portion of the lower wiring layer L2 is stepped on by the lower surface of the workpiece 200 ′ and is slightly crushed.

  Anodic bonding is a bonding method used for bonding a glass substrate and a silicon substrate in a semiconductor manufacturing process or the like. Both substrates to be bonded are brought into physical contact with each other under a predetermined temperature condition. This is done by applying an electric field between the two substrates. In the embodiment shown here, as shown in FIG. 7, a processing intermediate body 200 ′ is placed on the upper surface of the lower substrate 300, and the first anodic bonding electrode EE <b> 1 is brought into contact with the upper surface of the processing intermediate body 200 ′. The second anodic bonding electrode EE2 is brought into contact with the lower surface of 300, and anodic bonding is performed while an electric field is applied between the first anodic bonding electrode EE1 and the second anodic bonding electrode EE2. Specifically, in the case of the embodiment described here, an electric field of about 1000 V is applied between the two electrodes so that the first anodic bonding electrode EE1 side is positive and the second anodic bonding electrode EE2 side is negative. The intermediate body 200 'side made of is made the anode. At this time, when the glass substrate is Pyrex (registered trademark) glass, if the glass side is softened by placing it in a heating environment at a temperature of about 400 ° C., both are bonded in a solid phase. The terminal portion of the lower wiring layer L2 is sandwiched between the lower surface of the columnar bodies 240 (currently part of the processing intermediate body 200 ') and the upper surface of the lower substrate 300 which are anodically bonded to each other. A good conduction state for 240 is ensured.

  Thus, when the lower substrate bonding step is completed, the anode bonding electrodes EE1 and EE2 are removed, and the latter half of the intermediate member forming step is performed. That is, the intermediate member 200 is formed by processing the intermediate body 200 ′ from the upper surface side. FIG. 8 is a longitudinal sectional view showing a state in which the intermediate member 200 is formed by executing the latter half of the processing on the processing intermediate body 200 ′. By processing from the upper surface side, grooves serving as the gap portions SP1 and SP3 are dug, and as shown in the figure, the intermediate member 200 having the weight body 210, the connection portion 220, the pedestal 230, the outer wall portion 235, and the columnar body 240 is formed. Is done. In order to form such voids SP1 and SP3 on the upper surface of the intermediate body 200 ′, an etching process from the upper surface side may be performed using a known method.

  Subsequently, through-hole portions are formed at three locations on the prepared upper glass substrate, and through-hole portions are formed by filling each through-hole with a conductive material. FIG. 9 is a top view of the upper substrate 100 and shows a state in which three through wiring portions H1, H2, and H3 are formed. Here, as shown in FIG. 3, the first through wiring portion H1 may be formed at any position as long as it is suitable for wiring with respect to the upper electrode E1 via the upper wiring layer L1. it can. On the other hand, the second penetrating wiring portion H2 is formed at a position where the upper end of the columnar body 240 comes into contact, and the third penetrating wiring portion H3 is located at a position where the upper end of the base 230 comes into contact. To form. As shown in FIG. 4, the outer wall portion 235 is a portion having the same potential as the pedestal 230, and therefore the third through wiring portion H <b> 3 is not necessarily formed at a position where the upper end of the pedestal 230 comes into contact. There is no need, and it is possible to form the outer wall 235 at a position where the upper end of the portion having the same potential as the pedestal 230 comes into contact.

  In order to form the through hole in the glass substrate, a general method such as a blast method, an ultrasonic method, or mechanical processing using a drill may be used. The conductive material filling the through hole may be any material, but generally, a metal such as aluminum or copper may be filled to form a through wiring portion made of metal. However, when filling the metal into the through-hole, if a general method of pouring molten metal or depositing evaporated metal in the through-hole is used, filling unevenness occurs, and the formed through-wiring part is disconnected. Since this may occur, it is preferable to adopt a method that does not cause uneven filling as much as possible. For example, it is effective to create a melt with relatively low viscosity by dissolving metal in a resin, fill the melt by pouring the melt evenly, and then evaporate the resin to remove it. It is.

  Next, an upper substrate forming step is performed in which the upper electrode E1 and the upper wiring layer L1 are formed on the lower surface of the upper glass substrate to form the upper substrate. FIG. 10 is a bottom view of the upper substrate 100 and clearly shows the planar shapes and positions of the upper electrode E1 and the upper wiring layer L1. The upper electrode E1 is formed at a position facing the upper surface of the weight body 210, and the upper wiring layer L1 is formed at a position suitable for connecting the upper electrode E1 and the first through wiring portion H1. . In the illustrated example, the right end of the upper wiring layer L1 extends just below the first through wiring portion H1. The upper electrode E1 and the upper wiring layer L1 may be formed of any material, but in practice, a metal layer such as aluminum or copper is formed on the entire lower surface of the upper glass substrate and then patterned. It is preferable to form by doing.

  The important point here is that the upper electrode E1 and the upper wiring layer L1 shown in FIG. 10 are formed after the through wiring portions H1, H2, and H3 shown in FIG. 9 are formed. If this order is reversed, the step of filling the through hole with the conductive material cannot be sufficiently performed, and there is a possibility that the through wiring portion may be disconnected. Of course, theoretically, the upper substrate 100 in which the through hole is formed and the upper electrode E1 and the upper wiring layer L1 are further formed on the lower surface is joined to the intermediate member 200, and then each of the through wiring portions H1, H2, and so on. Although it is possible to form H3, in a state where the upper electrode E1 and the upper wiring layer L1 are already formed, or in a state where the upper member is further joined to the intermediate member 200, the conductive material is uniformly filled in the through hole. Processing is relatively difficult, and there is a high possibility that disconnection will occur in the formed through wiring portion. Therefore, as described above, the through wiring portions H1, H2, and H3 are first formed on the glass substrate in which nothing is formed on both surfaces, and then the upper electrode E1 is formed on the lower surface of the glass substrate. If the upper wiring layer L1 is formed, it is easy to form a through wiring portion in which no disconnection occurs.

  When the upper substrate 100 is thus formed, an upper substrate bonding step is performed in which the upper substrate 100 is anodically bonded to the upper surface of the intermediate member 200 shown in FIG. FIG. 11 is a longitudinal sectional view showing a state where the anodic bonding is performed. As shown in the figure, in this upper substrate bonding stage, the upper substrate 100 is placed on the upper surface of the intermediate member 200, the first anodic bonding electrode EE1 is brought into contact with the upper surface of the upper substrate 100, and the second substrate is placed on the lower surface of the lower substrate 300. The anodic bonding electrode EE2 is brought into contact, and anodic bonding is performed while applying an electric field between the first anodic bonding electrode EE1 and the second anodic bonding electrode EE2. Specifically, in the case of this embodiment, an electric field of about 1000 V is applied between the two electrodes so that the first anodic bonding electrode EE1 side is negative and the second anodic bonding electrode EE2 side is positive, and the temperature is 400 ° Bonding is performed in a heating environment of about C.

  Note that an electric field from the second anodic bonding electrode EE2 is indirectly applied to the intermediate member 200 with the lower substrate 300 interposed therebetween, but the intermediate member 200 side is positive and the upper substrate 100 side is negative. Such an electric field is applied, and the upper surface of the intermediate member 200 and the lower surface of the upper substrate 100 are bonded in a solid phase. At this time, the lower end of the second through wiring portion H2 is joined to the upper surface of the columnar body 240, and good electrical contact is ensured between the two. Similarly, the lower end of the third through wiring portion H3 is joined to the upper surface of the pedestal 230, and good electrical contact is ensured between them.

  Thus, when the upper substrate bonding step is completed, the anode bonding electrodes EE1 and EE2 are removed, and external terminals T1, T2, and T3 connected to the through wiring portions H1, H2, and H3 are formed on the upper surface of the upper substrate 100. The external terminal formation stage is performed. FIG. 12 is a top view showing the state of the upper substrate 100 after the external terminals T1, T2, T3 are formed in this way. In this figure, for convenience of explanation, the positions of the through wiring portions H1, H2, and H3 are also shown, but actually, the through wiring portions H1, H2, and H3 are connected to the external terminals T1, T2, respectively. , Hidden behind T3 and not visible from above. In the illustrated example, each of the external terminals T1, T2, and T3 is a circular terminal and is disposed at a position in contact with each of the through wiring portions H1, H2, and H3 in the vicinity of the outer peripheral portion. As long as they are electrically connected to the respective through wiring portions H1, H2, and H3, their shapes and positions may be arbitrary.

  Thus, a one-dimensional acceleration sensor having a three-layer structure as shown in FIG. 3 is obtained. Practically, each external terminal T1, T2, T3 shown in FIG. 12 is wired to a predetermined electric circuit for detection, and as shown in the equivalent circuit of FIG. 2, between the external terminals T1, T3. The capacitance may be detected as the capacitance of the upper capacitance element C1, and the capacitance between the external terminals T2 and T3 may be detected as the capacitance of the lower capacitance element C2.

  By the way, in FIG. 3, the 2nd penetration wiring part H2 is arrange | positioned not in the center position of the columnar body 240 but in the position shifted | deviated slightly from the center. Similarly, the third through wiring portion H3 is also arranged at a position slightly deviated from the center, not the center position of the contact portion of the base 230. As described above, the through wiring portion is arranged so as to be shifted from the center position of the contact portion of the columnar body 240 or the pedestal 230 which is an electrical bonding partner so as not to prevent anodic bonding in the upper substrate bonding stage. It is consideration to make.

  For example, in the upper substrate bonding stage, it is considered that the upper surface of the columnar body 240 and the lower surface of the upper substrate 100 are anodically bonded as shown in FIG. At this time, the second through wiring portion H2 formed on the upper substrate 100 side needs to ensure good electrical contact with the columnar body 240. It is preferable that the center position of the second through wiring portion H2 is aligned with the center position of the columnar body 240 as in the example shown in FIG. Thus, if the center positions of the two are aligned, even if a slight alignment error occurs, there is a high possibility that good electrical contact is ensured between the two.

  However, when it is assumed that the upper substrate 100 and the intermediate member 200 are anodically bonded as in the present invention, if the center position of the second through wiring portion H2 and the center position of the columnar body 240 are aligned, the anode There is a possibility that an adverse effect inherent in bonding may occur. As described above, in order to perform anodic bonding, it is necessary to apply an electric field between two substrates to be bonded. In the example shown in FIG. 13A, the first anodic bonding electrode EE <b> 1 is placed on the upper surface of the upper substrate 100, and a predetermined electric field is applied between the upper substrate 100 and the columnar body 240. However, since the second through wiring portion H2 has conductivity, even the lower end thereof becomes equipotential with the first anodic bonding electrode EE1.

  In the first place, anodic bonding is a bonding method that uses an electric field applied in the thickness direction of a glass substrate containing movable ions to move ions in the glass substrate. An electric field must be applied. However, due to the presence of the second through wiring portion H2, an effective electric field in the thickness direction of the upper substrate 100 is not applied in the vicinity thereof. As a result, as indicated by a cross in FIG. 13A, the strength of anodic bonding between the columnar body 240 and the upper substrate 100 may be insufficient in the vicinity of the through wiring portion H2. . As a result, the electrical contact between the columnar body 240 and the second through wiring portion H2 may be incomplete.

  Therefore, in the embodiment described here, as shown in FIG. 13B, the center position of the second through wiring portion H2 is set to be slightly shifted from the center position of the columnar body 240. In this case, as indicated by x in FIG. 13 (b), the strength of anodic bonding between the columnar body 240 and the upper substrate 100 is low in the vicinity of the through wiring portion H2 (right side portion in the figure). Although it may be sufficient, an effective electric field is applied in the thickness direction of the upper substrate 100 in a portion away from the through wiring portion H2 (left portion in the figure), and sufficient bonding strength is obtained. Thus, as a whole, the upper end of the columnar body 240 is anodically bonded to the upper substrate 100 with sufficient strength.

  Thus, in order to slightly shift the arrangement of the second through wiring portion H2 from the center position of the columnar body 240, the second through wiring is formed when the through hole is formed in the glass substrate in the through wiring portion forming stage. What is necessary is just to set the center of the through-hole for part H2 in the position away from the center of the area | region where the upper end of the columnar body 240 contacts only a predetermined distance. It is considered that the distance from the center of the columnar body 240 depends on the thickness of the upper substrate 100, the width of the columnar body 240, the width of the through wiring portion H2, the applied voltage value, etc. As shown in FIG. 13 (b), when the width of the contact portion of the columnar body 240 with respect to the upper substrate 100 is D, the direction from the contour position of the columnar body 240 toward the inner side is shown in FIG. It was confirmed that sufficient bonding strength could be secured between the columnar body 240 and the upper substrate 100 by anodic bonding when setting was made such that the through wiring portion H2 was included in the range within / 3.

  In FIG. 13, the preferred arrangement of the second through wiring portion H2 has been described in order to perform good anodic bonding between the columnar body 240 and the upper substrate 100. However, the arrangement of the third through wiring portion H3 is described. The same can be said about. That is, as shown in FIG. 3, the third penetrating wiring portion H3 is not located at the center position of the contact portion of the pedestal 230 but at a position slightly shifted to the left side from the center. This is a consideration for making anodic bonding with sufficient strength between the upper surface and the lower surface of the upper substrate 100.

  Further, as described above, the third through wiring portion H3 does not necessarily need to be connected to the pedestal 230, and may be connected to a portion (for example, the outer wall portion 235) that has the same potential as the pedestal 230. Also in this case, the third through wiring portion H3 may be arranged at a position slightly deviated from the center, not the center position of the contact portion having the same potential as the base 230.

  The standard of the shift amount for the third through-wiring portion H3 is the same as the standard of the shift amount for the second through-wiring portion H2, such as “the base 230 or a portion having the same potential as the base (for example, the outer wall portion 235). When the width of the contact portion of D is “D”, it comes within D / 3 from the contour position of the contact portion of “pedestal 230 or a portion having the same potential as the pedestal (for example, outer wall portion 235)” toward the inside. It should be set as follows.

<<< §2. Second Embodiment >>>
Subsequently, a second embodiment of the present invention will be described. In the second embodiment, the connection method between the columnar body 240 and the second through wiring portion H2 in the first embodiment described above is slightly changed. FIG. 14 is a longitudinal sectional view showing the changed connection method. In the first embodiment shown in FIGS. 13 (a) and 13 (b), the lower end of the second through wiring portion H2 is directly connected to the upper end of the columnar body 240. In the second embodiment shown in FIG. 14, the second through wiring portion H2 ′ is indirectly connected to the columnar body 240 through the lower electrode upper wiring layer L2 ′. In the example shown in the drawing, the right end of the lower electrode upper wiring layer L2 ′ is located immediately below the second through wiring portion H2 ′, and the left end is sandwiched between the columnar body 240 and the upper substrate 100. Yes. Thus, even if the columnar body 240 and the second through wiring portion H2 ′ are connected via the lower electrode upper wiring layer L2 ′, the efficiency is substantially the same as in the first embodiment described above. Wiring becomes possible.

  In the structure shown in FIG. 14, in order to perform anodic bonding between the upper surface of the columnar body 240 and the lower surface of the upper substrate 100, the first anodic bonding electrode EE <b> 1 is placed on the upper surface of the upper substrate 100. A predetermined electric field needs to be applied to the body 240. Therefore, the second through wiring portion H2 'is also conductive here, so that even the left end of the lower electrode upper wiring layer L2' is equipotential with the first anodic bonding electrode EE1. Will occur. For this reason, if the left end of the lower electrode upper wiring layer L2 ′ extends too far to the left, the electric field applied in the thickness direction of the upper substrate 100 is insufficient at the contact portion between the columnar body 240 and the upper substrate 100. Therefore, anodic bonding with sufficient strength may not be performed.

  Therefore, in the case of the second embodiment, the lower electrode upper wiring layer L <b> 2 ′ is connected to the upper end of the columnar body 240 so that the upper end of the columnar body 240 is anodically bonded to the upper substrate 100 with sufficient strength. What is necessary is just to set so that it may terminate in the position in front by a predetermined distance from the center of the area | region which will contact. In the case of the example shown in FIG. 14, as indicated by a cross in the figure, in the vicinity of the terminal portion of the lower electrode upper wiring layer L2 ′, a sufficient electric field is not applied in the thickness direction of the upper substrate 100. The strength of anodic bonding with the upper substrate 100 may be insufficient. However, an effective electric field is applied in the thickness direction of the upper substrate 100 at a portion away from the terminal portion of the lower electrode upper wiring layer L2 '(the left portion in the figure), and sufficient bonding strength is obtained. Thus, as a whole, the upper end of the columnar body 240 is anodically bonded to the upper substrate 100 with sufficient strength.

  The distance from the center of the region where the upper end of the columnar body 240 is in contact with the end of the upper electrode layer L2 ′ for the lower electrode depends on the thickness of the upper substrate 100, the width of the columnar body 240, and the lower electrode layer. Although it is considered that the value depends on the width of the upper wiring layer L2 ′, the voltage value to be applied, and the like, according to the experiment conducted by the inventor of the present application, as shown in FIG. If the width is D, the end of the lower electrode upper wiring layer L2 ′ is within the range of D / 3 from the contour position of the columnar body 240 toward the inner side (in other words, If the upper electrode layer L2 ′ for the lower electrode does not enter the region exceeding D / 3 from the contour position of the columnar body 240 in the inward direction), the columnar body 240 and the upper substrate 100 are bonded by anodic bonding. Enough joint strength between There can be secured.

  FIG. 15 is a longitudinal sectional view showing a basic form of a one-dimensional acceleration sensor obtained by applying the manufacturing method according to the second embodiment. The only difference from the sensor shown in FIG. 3 is the second through wiring portion H2 ′, the external terminal T2 ′, and the lower electrode upper wiring layer L2 ′. Other structures are the same as those in the first embodiment shown in FIG. This is exactly the same as the sensor according to the embodiment. In the case of the sensor shown in FIG. 15, the wiring to the outside with respect to the lower electrode E2 is the lower wiring layer L2, the columnar body 240, the lower wiring upper wiring layer L2 ', the second through wiring portion H2', and the external terminal T2 '. It will go through the path.

  The manufacturing method according to the second embodiment described here is as follows. First, in the preparation stage, the upper glass substrate, the lower glass substrate, and the silicon substrate are prepared, which is exactly the same as in the first embodiment. Then, a lower substrate forming step is performed in which the lower electrode E2 and the lower wiring layer L2 are formed on the upper surface of the lower glass substrate to form the lower substrate 300, the silicon substrate is processed from below, and FIG. The intermediate part 200 ′ shown in the drawing is produced, and the lower substrate bonding step is performed to obtain the structure shown in FIG. 8, which is exactly the same as in the first embodiment.

  Subsequently, the through-wiring portion forming step of forming three through-wiring portions by forming three through-holes in the upper glass substrate and filling each through-hole with a conductive material is also performed in the first described above. This is almost the same as the embodiment. However, the three through wiring portions formed here are H1, H2 ′, and H3. The through wiring portion H2 ′ has a wiring function for the lower electrode E2 like the through wiring portion H2 in the first embodiment, but the upper end of the columnar body 240 is in contact with the formation position. Any position can be used as long as the wiring by the upper electrode layer L2 ′ for the lower electrode is possible instead of the position.

  Next, on the lower surface of the upper glass substrate, the upper electrode E1, the upper wiring layer L1 (in this embodiment, referred to as upper wiring layer L1 for upper electrode in order to distinguish from L2 '), the upper wiring layer for lower electrode L2 'is formed. Here, the lower electrode upper wiring layer L2 ′ may be formed at a position suitable for connecting the second through wiring portion H2 ′ and the columnar body 240. However, as described above, the lower electrode upper wiring layer L2 ′ is in contact with the upper end of the columnar body 240 so that the upper end of the columnar body 240 is anodically bonded to the upper substrate 100 with sufficient strength. It is preferable to set it to terminate at a position away from the center of the region by a predetermined distance. More specifically, when the width of the contact portion of the columnar body 240 with respect to the upper substrate 100 is D, this columnar body It is preferable that the upper electrode layer L2 ′ for the lower electrode is set so that the terminal end comes within a range of D / 3 from the contour position of 240 toward the inside.

  Thus, when the upper substrate 100 is ready, an upper substrate bonding step of bonding the upper substrate 100 to the upper surface of the intermediate member 200 is performed. This upper substrate bonding step is also performed by a process substantially similar to that of the first embodiment described above. That is, the upper substrate 100 is placed on the intermediate member 200, an electric field is applied in the vertical direction by the first anodic bonding electrode EE1 and the second anodic bonding electrode EE2, and heated to a predetermined temperature. The upper surface of the member 200 and the lower surface of the upper substrate 100 are anodically bonded. At this time, the terminal portion of the lower electrode upper wiring layer L <b> 2 ′ is sandwiched between the columnar body 240 and the upper substrate 100 and is slightly crushed. As shown in FIG. 14, there is a possibility that the right side portion marked with “x” in the drawing may be insufficiently bonded, but in the left side portion, the columnar body 240 and the upper substrate 100 are bonded with sufficient strength. Thus, the terminal portion of the lower electrode upper wiring layer L2 ′ sandwiched between the two ensures good electrical contact with the columnar body 240.

  Finally, external terminals T1, T2 ′, T3 are formed on the upper surface of the upper substrate 100, and are connected to the through wiring portions H1, H2 ′, H3. With the above, a sensor having the structure shown in FIG. 15 can be manufactured.

<<< §3. Third embodiment >>>
Next, a third embodiment of the present invention will be described. In the third embodiment, the connection method between the upper electrode E1 and the first through wiring portion H1 in the first embodiment is slightly changed. In the structure according to the first embodiment shown in FIG. 3, the first through wiring portion H1 is disposed in the vicinity of the upper electrode E1, and the two are connected by the upper wiring layer L1. On the other hand, in the third embodiment described here, the first through wiring portion H1 is arranged immediately above the upper electrode E1, so that the upper wiring layer L1 can be omitted.

  FIG. 16 is a longitudinal sectional view showing a basic form of a one-dimensional acceleration sensor obtained by applying the manufacturing method according to the third embodiment. The only difference from the sensor structure obtained by the manufacturing method according to the first embodiment is that the position of the first through wiring portion H1 shown in FIG. 3 is changed to the first through wiring portion H1 ′ shown in FIG. This is only the point that the upper wiring layer L1 is omitted. As can be seen from FIG. 16, the through wiring portions H1 ′, H2, and H3 are disposed right above the upper electrode E1, the columnar body 240, and the pedestal 230, respectively. It is sufficient to form only the upper electrode E1, and no wiring layer is required. In this respect, it can be said that the third embodiment described here is an embodiment constituted by very simple wiring among the embodiments of the present application.

  The manufacturing method according to the third embodiment is exactly the same as the manufacturing method according to the first embodiment described above except for the following two differences. The first difference is the position of the three through holes formed in the upper glass substrate in the through wiring portion forming stage. That is, the formation positions of the second through wiring portion H2 and the third through wiring portion H3 are exactly the same as those in the first embodiment, but the first through wiring portion H1 ′ is formed in the upper electrode E1. The difference is that it is formed at a position included in the planned area. As a result, as shown in FIG. 16, the first through wiring portion H1 ′ is formed immediately above the upper electrode E1. On the other hand, the second difference is that the upper electrode E1 is the only conductive layer formed on the lower surface of the upper glass substrate in the upper substrate formation stage. As described above, it is not necessary to form the upper wiring layer L1.

<<< §4. Fourth Embodiment >>>
Subsequently, a fourth embodiment of the present invention will be described. In the fourth embodiment, the connection method between the upper electrode E1 and the first through wiring portion H1 in the second embodiment is slightly changed. That is, in the structure according to the second embodiment shown in FIG. 15, the first through wiring portion H1 is disposed in the vicinity of the upper electrode E1, and the two are connected by the upper wiring layer L1. On the other hand, in the fourth embodiment described here, the first through wiring portion H1 is disposed immediately above the upper electrode E1, so that the upper wiring layer L1 can be omitted.

  FIG. 17 is a longitudinal sectional view showing a basic form of a one-dimensional acceleration sensor obtained by applying the manufacturing method according to the fourth embodiment. The only difference from the structure of the sensor obtained by the manufacturing method according to the second embodiment is that the position of the first through wiring portion H1 shown in FIG. 15 is changed to the first through wiring portion H1 ′ shown in FIG. This is only the point that the upper wiring layer L1 is omitted. As is apparent from FIG. 17, the through wiring portion H2 ′ is connected to the columnar body 240 via the lower electrode upper wiring layer L2 ′, but the through wiring portions H1 ′ and H3 are respectively connected to the upper electrode. E1 is arranged right above the pedestal 230. Therefore, it is sufficient to form the upper electrode E1 and the lower electrode upper wiring layer L2 ′ on the lower surface of the upper substrate 100, and the upper electrode upper wiring layer L1 becomes unnecessary.

  The manufacturing method according to the third embodiment is exactly the same as the manufacturing method according to the second embodiment described above except for the following two differences. The first difference is the position of the three through holes formed in the upper glass substrate in the through wiring portion forming stage. That is, the formation positions of the second through wiring portion H2 ′ and the third through wiring portion H3 are exactly the same as those in the second embodiment, but the first through wiring portion H1 ′ is formed in the upper electrode E1. The difference is that it is formed at a position included in a region to be planned. As a result, as shown in FIG. 17, the first through wiring portion H1 ′ is formed immediately above the upper electrode E1. On the other hand, the second difference is that, in the upper substrate formation stage, the conductive layer formed on the lower surface of the upper glass substrate becomes the upper electrode E1 and the lower electrode upper wiring layer L2 ′. As described above, it is not necessary to form the upper electrode upper wiring layer L1.

<<< §5. Other variations >>
So far, the manufacturing method of the sensor using the capacitive element according to the present invention has been described based on the four embodiments. Here, further modifications to these four embodiments will be described.

  (1) In the four embodiments described so far, the third through wiring portion H3 is provided directly above the pedestal 230, and the bottom of the third through wiring portion H3 is directly bonded to the upper surface of the pedestal 230. However, it is not always necessary to directly join the two, and they may be indirectly joined via a pedestal upper wiring layer formed on the lower surface of the upper substrate 100. In this case, the third through wiring portion H3 may be formed at an arbitrary position in the vicinity thereof, not directly above the pedestal 230, and the third through wiring is formed on the lower surface of the upper substrate 100 in the upper substrate formation stage. A pedestal upper wiring layer for connecting the portion H3 and the pedestal 230 may be formed.

  As already described, the third through wiring portion H3 does not necessarily need to be electrically connected to the pedestal 230, but is connected to a “portion that is equipotential to the pedestal 230” (for example, the outer wall portion 235). It doesn't matter. In this case as well, the third through wiring portion H3 is formed immediately above the “portion having the same potential as the pedestal 230”, and the third through wiring portion H3 is formed into the “portion having the same potential as the pedestal 230”. May be directly joined to each other, or the third through-wiring portion H3 may be formed at an arbitrary position between the third through-wiring portion H3 and “the portion having the same potential as the base 230”. Alternatively, it may be indirectly bonded via a pedestal upper wiring layer formed on the lower surface of the upper substrate 100.

  Further, as described above, in order to ensure good anodic bonding between the pedestal 230 or the “part having the same potential as the pedestal 230” and the upper substrate 100, the thickness of the upper substrate 100 during anodic bonding. It is necessary to apply the necessary electric field in the direction. Therefore, practically, the upper wiring layer for the pedestal is “the pedestal or the pedestal and the pedestal so that the upper end of the“ pedestal 230 or the portion having the same potential as the pedestal ”is anodically bonded to the upper substrate 100 with sufficient strength. It is preferable to set so that the upper end of the “potential part” is terminated at a position a predetermined distance from the center of the region to be contacted. More specifically, the end position of the upper wiring layer for the pedestal is “a portion that is equipotential to the pedestal or pedestal” when the width of the contact portion of the “pedestal or portion that is equipotential to the pedestal” is D. It is preferable to set so as to be within D / 3 from the contour position of the contact portion toward the inside.

  (2) In the four embodiments described so far, the third through wiring portion H3 is provided in order to form the external terminal T3 on the upper substrate 100. However, the external terminal T3 is not necessarily provided on the upper substrate. It is not necessary to form on the upper surface of 100. In the first place, the external terminal T3 is a wiring to the weight body 210, but in the case of the above-described embodiment, the weight body 210, the connection portion 220, the pedestal 230, the outer wall, as is apparent from the cross-sectional view of FIG. Since the parts 235 are members that are electrically equipotential, any of these members can perform the same function as the external terminal T3. Therefore, even if the external terminal T3 is not necessarily provided on the upper surface of the upper substrate 100, no major trouble occurs.

  FIG. 18 is a longitudinal sectional view showing a modified example in which the through wiring portion H3 and the external terminal T3 are removed from the sensor structure according to the third embodiment shown in FIG. By removing these, the wiring form shown in FIG. 18 is the simplest wiring form in the present application. Since only the external terminal T1 for the upper electrode E1 and the external terminal T2 for the lower electrode E2 are formed on the upper surface of the upper substrate 100, it is necessary to separately secure wiring for the weight body 210. Since the outer wall portion 235 is equipotential with the weight body 210, the outer surface of the pedestal 230 and the outer wall portion 235 can be used as an external terminal T3 for the weight body 210.

  For example, in the equivalent circuit shown in FIG. 2, if the external terminal T3 is used as a ground terminal, the outer peripheral surface of the intermediate member 200 in the sensor shown in FIG. Of course, as in the example shown in FIG. 18, when the third through wiring portion H3 and the external terminal T3 are omitted, the formation process of the third through wiring portion H3 may be omitted in the through wiring portion forming stage. In addition, in the external terminal formation stage, the formation process of the external terminal T3 can be omitted.

  (3) In the four embodiments described so far, the intermediate member forming step of forming the intermediate member 200 from the silicon substrate is processed from the lower surface side of the silicon substrate, and the first half of forming the intermediate body 200 ′. The anodic bonding process as shown in FIG. 7 is performed after the first half stage and the second half stage where the intermediate member is formed by processing the intermediate body 200 ′ from the upper surface side. The lower substrate bonding step is performed, followed by the second half step, and then the upper substrate bonding step by the anodic bonding process as shown in FIG. 11 is performed. You can replace them.

  Specifically, the intermediate member forming step is performed on the silicon substrate from the upper surface side to form an intermediate workpiece, and the intermediate member is processed from the lower surface side to the intermediate workpiece. After the first half stage is performed, the upper substrate bonding stage (the stage where the upper substrate is bonded onto the intermediate body that has been processed from the upper surface side) is performed, and then, The second half step may be performed, and then the lower substrate bonding step (the step of bonding the lower substrate under the intermediate member formed after finishing the processing from the lower surface side) may be performed.

  In this case, in the upper substrate bonding stage, the upper substrate is placed on the upper surface of the intermediate workpiece, the first anodic bonding electrode is brought into contact with the upper surface of the upper substrate, and the second anodic bonding electrode is formed on the lower surface of the intermediate workpiece. And anodic bonding is performed while applying an electric field between the first anodic bonding electrode and the second anodic bonding electrode. In the lower substrate bonding stage, a lower substrate is disposed on the lower surface of the intermediate member. The first anodic bonding electrode is brought into contact with the upper surface of the upper substrate, the second anodic bonding electrode is brought into contact with the lower surface of the lower substrate, and the gap between the first anodic bonding electrode and the second anodic bonding electrode An anodic bonding may be carried out while applying an electric field.

  Of course, in the intermediate member forming step, by processing the silicon substrate, the sensor main body structure (the weight body 210, the connecting portion 220, the pedestal 230), and the columnar body 240 for connecting the upper substrate and the lower substrate, As long as the intermediate member 200 having the above can be formed, it may be performed in any form. Therefore, as in the above-described example, it is not necessarily performed in the first half stage and the second half stage. However, when the processing to the form of the intermediate member 200 is completed, the columnar body 240 is physically separated from the sensor main body structure, which is not preferable in mass production. Therefore, in practice, as in the example described so far, the first half of the processing is performed on the silicon substrate from the lower surface side or the upper surface side, and after the shape of the intermediate body is processed, the lower substrate is formed. Alternatively, it is preferable that the latter half of the process is performed by bonding to any one of the upper substrates and then performing processing from the opposite surface side with respect to the intermediate body.

  (4) In the four embodiments described so far, in the intermediate member forming stage, as shown in the cross-sectional view of FIG. 4, the pedestal 230 is formed so as to surround the weight body 210. An outer wall portion 235 that surrounds the periphery is formed. The lower surface of the intermediate member 200 and the lower substrate 300 are anodically bonded, and the upper surface of the intermediate member 200 and the upper substrate 100 are also anodically bonded. Since this anodic bonding is a highly hermetic bonding, if the through wiring portion having a function of sealing the through hole is formed in the through wiring portion forming stage, the weight body 210 and the columnar body 240 are formed. Is completely sealed in a space surrounded by the upper substrate 100 and the lower substrate 300 and the outer peripheral portion of the intermediate member 200.

  As described above, in the present invention, before forming the upper electrode, the upper wiring layer, etc., or performing the anodic bonding, a step of forming the through wiring portion in the upper glass substrate is performed in advance. Yes. Therefore, the process of forming a through hole in the glass substrate and filling it with a conductive material can be performed without any limitation. Therefore, the through wiring portion having a function of completely sealing the through hole can be formed relatively easily, and the inside of the sensor can be maintained in a sealed state. For example, in the example shown in FIG. 3, the gap portion SP2 and the gap portion SP3 are connected via the tunnel-like gap portion SP4, but are completely blocked from the outside. Similarly, the gap SP1 is also completely blocked from the outside.

  As described above, when the upper surface and the lower surface of the pedestal 230 and the outer wall portion 235 are joined to the upper substrate 100 and the lower substrate 300 so that the weight body is sealed in the sealed space, the inside of the sensor is external. Therefore, it is preferable to improve the reliability and durability of the sensor. Also, when mass-producing this sensor, a large number of sensor chips are formed on the wafer, and finally a dicing process is performed to separate each sensor chip. In this dicing process, water is usually used. Since it is used, if the inside of the sensor is in a sealed state, an effect of preventing water from entering during the dicing process can be obtained.

  If such a sealing property is used, the inside of the sensor can be evacuated and the weight body 210 can be sealed in the vacuum. Specifically, at least one of the upper substrate bonding step and the lower substrate bonding step, which is performed later, may be performed in a vacuum. For example, in the case of the first embodiment described above, if the upper substrate bonding step shown in FIG. 11 is performed in a vacuum chamber, the weight body 210 can be sealed in a vacuum. Maintaining the displacement space of the weight body 210 in a vacuum has an advantage in increasing the detection accuracy of the sensor. In particular, in the case of an angular velocity sensor, it is necessary to vibrate the weight body 210. However, if air exists in the displacement space, a damper effect due to air is added to the weight body 210, which is not preferable. Therefore, in practical use, when manufacturing an angular velocity sensor, it is highly preferable that at least one of the upper substrate bonding step and the lower substrate bonding step is performed in a vacuum chamber.

  (5) In the examples described so far, the silicon substrate for use as the intermediate member 200 is an example using a silicon-only substrate as a whole, but in the present invention, the intermediate member 200 is used. The “silicon substrate” used as the material of the above does not necessarily need to be a substrate entirely made of silicon. For example, an SOI (Silicon On Insulator) substrate having a three-layer structure of silicon layer / silicon oxide layer / silicon layer is a substrate that is frequently used in the manufacture of semiconductor devices. In addition, the intermediate member 200 can be configured by processing a silicon substrate with an insulating layer such as a silicon oxide layer interposed therebetween.

  In other words, the intermediate member 200 in the sensor according to the present invention only needs to be formed by processing a substrate mainly made of a conductive material, and does not need to be entirely made of a conductive material. . The “silicon substrate” in the present invention broadly means a substrate mainly composed of a silicon layer, and includes the above-described SOI substrate and the like.

  However, when a silicon substrate including an insulating layer is used as the material of the intermediate member 200, such as an SOI substrate, the portion that needs to be connected across the insulating layer is electrically connected through the insulating layer. The step of forming the part is performed. For example, since the columnar body 240 is a component that functions as a wiring for the lower electrode E2, the columnar body 240 needs to be electrically connected from the upper end to the lower end. Therefore, in the case where the intermediate member 200 is configured using an SOI substrate, it is necessary to form a conducting portion that penetrates the insulating layer and to conduct from the upper end to the lower end for the portion that constitutes the columnar body 240. is there.

  (6) The steps constituting the individual embodiments described so far do not necessarily have to be performed in the order as described above, and the order may be changed within a range not impairing the essence of the invention. For example, in the above-described first embodiment, the lower substrate forming step for forming the lower substrate 300 has been described before the upper substrate forming step for forming the upper substrate 100. Even if the order is reversed, the essence of the invention is not changed, and the order of performing both steps may be arbitrary.

  (7) In this specification, for convenience of explanation, an example in which the present invention is applied to a process for manufacturing a one-dimensional acceleration sensor has been described. However, as described above, the present invention is limited to application to a one-dimensional acceleration sensor. However, the present invention can be similarly applied to a multidimensional acceleration sensor, and can also be similarly applied to a one-dimensional or multidimensional angular velocity sensor. That is, when the number of upper electrodes increases, the number of first through wiring portions H1 may be increased accordingly. When the number of lower electrodes increases, the columnar body 240 and the second electrode What is necessary is just to increase the number of the penetration wiring parts H2 according to it.

It is a longitudinal cross-sectional view which shows the basic form of the one-dimensional acceleration sensor with the three-layer structure used as the application object of the manufacturing method which concerns on this invention. It is an equivalent circuit of the capacitive element contained in the sensor shown in FIG. It is a longitudinal cross-sectional view which shows the basic form of the one-dimensional acceleration sensor obtained by applying the manufacturing method which concerns on the 1st Embodiment of this invention. FIG. 4 is a cross-sectional view of the sensor shown in FIG. 3 cut along a cutting line 4-4. FIG. 4 is a top view of a lower substrate 300 of the sensor shown in FIG. 3. FIG. 4 is a longitudinal sectional view of a processing intermediate body 200 ′ obtained in the first half of the process of forming the intermediate member 200 in the sensor shown in FIG. 3. FIG. 6 is a longitudinal sectional view showing a state where the processing intermediate body 200 ′ shown in FIG. 6 is placed on the lower substrate 300 shown in FIG. It is a longitudinal cross-sectional view which shows the state which formed the intermediate member 200 by performing the latter half stage of a process with respect to the process intermediate body 200 'shown in FIG. FIG. 4 is a top view of the upper substrate 100 of the sensor shown in FIG. 3. FIG. 4 is a bottom view of the upper substrate 100 of the sensor shown in FIG. 3. It is a longitudinal cross-sectional view which shows the state which mounted the upper board | substrate 100 shown in FIG. 9 and FIG. 10 on the intermediate member 200 shown in FIG. 8, and anodic-bonded both. FIG. 10 is a top view showing a state in which terminals for external wiring are formed on the upper substrate 100 shown in FIG. 9. It is a longitudinal cross-sectional view for showing the preferable arrangement | positioning of the penetration wiring part in this invention. It is a longitudinal cross-sectional view for showing another preferable arrangement | positioning of the penetration wiring part in this invention. It is a longitudinal cross-sectional view which shows the basic form of the one-dimensional acceleration sensor obtained by applying the manufacturing method which concerns on the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the basic form of the one-dimensional acceleration sensor obtained by applying the manufacturing method which concerns on the 3rd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the basic form of the one-dimensional acceleration sensor obtained by applying the manufacturing method which concerns on the 4th Embodiment of this invention. It is a longitudinal cross-sectional view which shows the basic form of the one-dimensional acceleration sensor obtained by applying the manufacturing method which concerns on the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Upper substrate 20 ... Intermediate member 21 ... Weight body 22 ... Connection part 23 ... Base 30 ... Lower substrate 100 ... Upper substrate (glass substrate)
200: Intermediate member (processed silicon substrate with conductivity)
200 '... intermediate body 210 ... weight (conductor)
220 ... Connection part (conductor)
230: Pedestal (conductor)
235 ... Outer wall portion (conductor)
240 ... Columnar body (conductor)
300 ... Lower substrate (glass substrate)
C1 ... upper capacitive element C2 ... lower capacitive element D ... width E1 of columnar body 240 ... upper electrode E2 ... lower electrode EE1 ... first anodic bonding electrode EE2 ... second anodic bonding electrodes H1, H1 '... first Through-wiring portions H2, H2 '... second through-wiring portion H3 ... third through-wiring portion L1 ... upper wiring layer (upper electrode upper wiring layer) L2 ... lower wiring layer L2' ... lower electrode upper wiring Layer L3 ... Upper wiring layers SP1 to SP4, SP4 'for pedestal ... Gaps T1, T2, T2', T3 ... External terminals

Claims (21)

It has a structure in which an intermediate member mainly made of a conductive material is sandwiched between an upper substrate made of an insulating material and a lower substrate made of an insulating material,
The intermediate member includes a weight body, a pedestal having an upper end bonded to the upper substrate and a lower end bonded to the lower substrate to support the weight body, and a space between the pedestal and the weight body. A sensor main body structure configured to be connected with flexibility, and when a force due to acceleration or angular velocity is applied to the weight body, the weight is caused by bending of the connection section. Configured to cause displacement in the body,
An upper electrode is formed on a portion of the lower surface of the upper substrate facing the weight body, and a lower electrode is formed on a portion of the upper surface of the lower substrate facing the weight body. The upper electrode and the weight body An upper capacitive element is formed by the facing surface of the lower electrode, and a lower capacitive element is formed by the facing surface of the lower electrode and the weight body,
A sensor capable of detecting the applied acceleration or angular velocity by detecting the displacement generated in the weight body based on the capacitance of the upper capacitive element and the lower capacitive element is manufactured. A method,
Preparation steps for preparing an upper glass substrate for use as the upper substrate, a lower glass substrate for use as the lower substrate, and a silicon substrate for use as the intermediate member,
An intermediate member forming step of forming an intermediate member having the sensor body structure and a columnar body for connecting the upper substrate and the lower substrate by processing the silicon substrate;
Forming a lower substrate on the upper surface of the lower glass substrate by forming the lower electrode and a lower wiring layer for connecting the lower electrode and a lower end of the columnar body;
The upper glass substrate is formed with a first through hole and a second through hole at a first position and a second position, respectively, and conductive in the first through hole and the second through hole. A through-wiring portion forming step of forming a first through-wiring portion and a second through-wiring portion, respectively, by filling the conductive material;
On the lower surface of the upper glass substrate, the upper electrode, the upper electrode upper wiring layer for connecting the upper electrode and the first through wiring portion, the upper end of the columnar body and the second through hole Forming an upper wiring layer for a lower electrode for connecting the wiring portion, and forming an upper substrate as an upper substrate;
A lower substrate bonding step for anodic bonding the intermediate member or the intermediate member in the middle of forming the intermediate member, while applying an electric field between the lower substrate,
An upper substrate bonding step of anodic bonding the intermediate member or the intermediate member forming the intermediate member while applying an electric field between the upper substrate and the intermediate member;
Forming an external terminal on the upper surface of the upper substrate; forming a first external terminal connected to the first through wiring portion and a second external terminal connected to the second through wiring portion;
A method for manufacturing a sensor using a capacitive element. The manufacturing method according to claim 1,
The upper wiring layer for the lower electrode is positioned at a predetermined distance from the center of the region where the upper end of the columnar body is in contact so that the upper end of the columnar body is anodically bonded to the upper substrate with sufficient strength. A method for manufacturing a sensor using a capacitive element, wherein the sensor element is set to be terminated. It has a structure in which an intermediate member mainly made of a conductive material is sandwiched between an upper substrate made of an insulating material and a lower substrate made of an insulating material,
The intermediate member includes a weight body, a pedestal having an upper end bonded to the upper substrate and a lower end bonded to the lower substrate to support the weight body, and a space between the pedestal and the weight body. A sensor main body structure configured to be connected with flexibility, and when a force due to acceleration or angular velocity is applied to the weight body, the weight is caused by bending of the connection section. Configured to cause displacement in the body,
An upper electrode is formed on a portion of the lower surface of the upper substrate facing the weight body, and a lower electrode is formed on a portion of the upper surface of the lower substrate facing the weight body. The upper electrode and the weight body An upper capacitive element is formed by the facing surface of the lower electrode, and a lower capacitive element is formed by the facing surface of the lower electrode and the weight body,
A sensor capable of detecting the applied acceleration or angular velocity by detecting the displacement generated in the weight body based on the capacitance of the upper capacitive element and the lower capacitive element is manufactured. A method,
Preparation steps for preparing an upper glass substrate for use as the upper substrate, a lower glass substrate for use as the lower substrate, and a silicon substrate for use as the intermediate member,
An intermediate member forming step of forming an intermediate member having the sensor body structure and a columnar body for connecting the upper substrate and the lower substrate by processing the silicon substrate;
Forming a lower substrate on the upper surface of the lower glass substrate by forming the lower electrode and a lower wiring layer for connecting the lower electrode and a lower end of the columnar body;
In the upper glass substrate, a first through hole is formed at a first position included in a region where the upper electrode is to be formed, and a second through hole is formed at a second position different from the first position. Forming a through-wiring portion that forms a first through-wiring portion and a second through-wiring portion by forming a hole and filling the first through-hole and the second through-hole with a conductive material, respectively Stages,
An upper substrate formed by forming, on the lower surface of the upper glass substrate, the upper electrode and a lower electrode upper wiring layer for connecting the upper end of the columnar body and the second through wiring portion. A substrate formation stage;
A lower substrate bonding step for anodic bonding the intermediate member or the intermediate member in the middle of forming the intermediate member, while applying an electric field between the lower substrate,
An upper substrate bonding step of anodic bonding the intermediate member or the intermediate member forming the intermediate member while applying an electric field between the upper substrate and the intermediate member;
Forming an external terminal on the upper surface of the upper substrate; forming a first external terminal connected to the first through wiring portion and a second external terminal connected to the second through wiring portion;
A method for manufacturing a sensor using a capacitive element. In the manufacturing method of Claim 3,
The upper wiring layer for the lower electrode is positioned at a predetermined distance from the center of the region where the upper end of the columnar body is in contact so that the upper end of the columnar body is anodically bonded to the upper substrate with sufficient strength. A method for manufacturing a sensor using a capacitive element, wherein the sensor element is set to be terminated. In the manufacturing method in any one of Claims 1-4,
In the through wiring portion formation stage, a third through hole is formed at a third position where the upper end of the “base or a portion having the same potential as the pedestal” in the upper glass substrate comes into contact, and this third through hole is formed. Adding a step of forming a third through wiring portion by filling the hole with a conductive material;
A method of manufacturing a sensor using a capacitive element, wherein a step of forming a third external terminal connected to the third through wiring portion on an upper surface of an upper substrate is added to the external terminal forming step. In the manufacturing method of Claim 5,
The center of the third through-hole is set to “the portion having the same potential as the pedestal or the pedestal” so that the upper end of “the pedestal or the portion having the same potential as the pedestal” is anodically bonded to the upper substrate with sufficient strength. A method for manufacturing a sensor using a capacitive element, characterized in that the sensor is set at a position separated by a predetermined distance from the center of a region where the upper end of the electrode contacts. In the manufacturing method in any one of Claims 1-4,
In the through wiring portion forming stage, a third through hole is formed at a third position on the upper glass substrate, and the third through wiring portion is formed by filling the third through hole with a conductive material. Add a process to
A step of forming an upper wiring layer for a pedestal for connecting the upper end of the pedestal or a portion having the same potential as the pedestal and the third through wiring portion is added to the upper substrate forming stage. A method for manufacturing a sensor using a capacitive element. In the manufacturing method of Claim 7,
The upper wiring layer for the pedestal is connected to the upper part of the pedestal or the part having the same potential as the pedestal so that the upper edge of the pedestal or the part having the same potential as the pedestal is anodically bonded to the upper substrate with sufficient strength. A method for manufacturing a sensor using a capacitive element, characterized in that it is set so as to terminate at a position a short distance from the center of a region where a contact is made. In the manufacturing method in any one of Claim 2,4,6,8,
The width of the through-hole wiring part, the lower electrode upper wiring layer end position, or the pedestal upper wiring layer end position is the width of the columnar body or the contact portion of the “base or the part that is equipotential to the pedestal” Is set so as to be within D / 3 from the contour position of the contact portion of the columnar body or the “pedestal or a portion having the same potential as the pedestal” toward the inner side when D is Manufacturing method of sensor using It has a structure in which an intermediate member mainly made of a conductive material is sandwiched between an upper substrate made of an insulating material and a lower substrate made of an insulating material,
The intermediate member includes a weight body, a pedestal having an upper end bonded to the upper substrate and a lower end bonded to the lower substrate to support the weight body, and a space between the pedestal and the weight body. A sensor main body structure configured to be connected with flexibility, and when a force due to acceleration or angular velocity is applied to the weight body, the weight is caused by bending of the connection section. Configured to cause displacement in the body,
An upper electrode is formed on a portion of the lower surface of the upper substrate facing the weight body, and a lower electrode is formed on a portion of the upper surface of the lower substrate facing the weight body. The upper electrode and the weight body An upper capacitive element is formed by the facing surface of the lower electrode, and a lower capacitive element is formed by the facing surface of the lower electrode and the weight body,
A sensor capable of detecting the applied acceleration or angular velocity by detecting the displacement generated in the weight body based on the capacitance of the upper capacitive element and the lower capacitive element is manufactured. A method,
Preparation steps for preparing an upper glass substrate for use as the upper substrate, a lower glass substrate for use as the lower substrate, and a silicon substrate for use as the intermediate member,
An intermediate member forming step of forming an intermediate member having the sensor body structure and a columnar body for connecting the upper substrate and the lower substrate by processing the silicon substrate;
Forming a lower substrate on the upper surface of the lower glass substrate by forming the lower electrode and a lower wiring layer for connecting the lower electrode and a lower end of the columnar body;
For the upper glass substrate, a first through hole is formed at a first position, a second through hole is formed at a second position where the upper end of the columnar body comes into contact, and the first through hole is formed. A through-wiring part forming step of forming a first through-wiring part and a second through-wiring part by filling a conductive material in the through-hole and the second through-hole, respectively;
Forming an upper substrate by forming the upper electrode and an upper wiring layer for connecting the upper electrode and the first through wiring portion on the lower surface of the upper glass substrate;
A lower substrate bonding step for anodic bonding the intermediate member or the intermediate member in the middle of forming the intermediate member, while applying an electric field between the lower substrate,
An upper substrate bonding step of anodic bonding the intermediate member or the intermediate member forming the intermediate member while applying an electric field between the upper substrate and the intermediate member;
Forming an external terminal on the upper surface of the upper substrate; forming a first external terminal connected to the first through wiring portion and a second external terminal connected to the second through wiring portion;
Have
In the through wiring portion forming stage, a third through hole is formed at a third position on the upper glass substrate, and a conductive material is filled in the third through hole, whereby a third through wiring portion is formed. Adding the process of forming
The step of forming an upper wiring layer for a pedestal for connecting the upper end of “a pedestal or a portion having the same potential as the pedestal” and the third through wiring portion is added to the upper substrate forming step. Of manufacturing a sensor using a capacitive element. In the manufacturing method of Claim 10,
A position where the center of the second through hole is a predetermined distance away from the center of the region where the upper end of the columnar body is in contact so that the upper end of the columnar body is anodically bonded to the upper substrate with sufficient strength A method for manufacturing a sensor using a capacitive element, characterized in that: In the manufacturing method of Claim 10 or 11,
The upper wiring layer for the pedestal is connected to the upper part of the pedestal or the part having the same potential as the pedestal so that the upper edge of the pedestal or the part having the same potential as the pedestal is anodically bonded to the upper substrate with sufficient strength. A method for manufacturing a sensor using a capacitive element, characterized in that it is set so as to terminate at a position a short distance from the center of a region where a contact is made. It has a structure in which an intermediate member mainly made of a conductive material is sandwiched between an upper substrate made of an insulating material and a lower substrate made of an insulating material,
The intermediate member includes a weight body, a pedestal having an upper end bonded to the upper substrate and a lower end bonded to the lower substrate to support the weight body, and a space between the pedestal and the weight body. A sensor main body structure configured to be connected with flexibility, and when a force due to acceleration or angular velocity is applied to the weight body, the weight is caused by bending of the connection section. Configured to cause displacement in the body,
An upper electrode is formed on a portion of the lower surface of the upper substrate facing the weight body, and a lower electrode is formed on a portion of the upper surface of the lower substrate facing the weight body. The upper electrode and the weight body An upper capacitive element is formed by the facing surface of the lower electrode, and a lower capacitive element is formed by the facing surface of the lower electrode and the weight body,
A sensor capable of detecting the applied acceleration or angular velocity by detecting the displacement generated in the weight body based on the capacitance of the upper capacitive element and the lower capacitive element is manufactured. A method,
Preparation steps for preparing an upper glass substrate for use as the upper substrate, a lower glass substrate for use as the lower substrate, and a silicon substrate for use as the intermediate member,
An intermediate member forming step of forming an intermediate member having the sensor body structure and a columnar body for connecting the upper substrate and the lower substrate by processing the silicon substrate;
Forming a lower substrate on the upper surface of the lower glass substrate by forming the lower electrode and a lower wiring layer for connecting the lower electrode and a lower end of the columnar body;
In the upper glass substrate, a first through hole is formed at a first position included in a region where the upper electrode is to be formed, and a second position at which the upper end of the columnar body comes into contact is formed. Through-holes, and the first through-hole portion and the second through-hole portion are filled with a conductive material, thereby forming the first through-wire portion and the second through-wire portion, respectively. Part formation stage,
Forming an upper substrate on the lower surface of the upper glass substrate to form an upper substrate;
A lower substrate bonding step for anodic bonding the intermediate member or the intermediate member in the middle of forming the intermediate member, while applying an electric field between the lower substrate,
An upper substrate bonding step of anodic bonding the intermediate member or the intermediate member forming the intermediate member while applying an electric field between the upper substrate and the intermediate member;
Forming an external terminal on the upper surface of the upper substrate; forming a first external terminal connected to the first through wiring portion and a second external terminal connected to the second through wiring portion;
Have
In the through wiring portion forming stage, a third through hole is formed at a third position on the upper glass substrate, and a conductive material is filled in the third through hole, whereby a third through wiring portion is formed. Adding the process of forming
The step of forming an upper wiring layer for a pedestal for connecting the upper end of “a pedestal or a portion having the same potential as the pedestal” and the third through wiring portion is added to the upper substrate forming step. Of manufacturing a sensor using a capacitive element. In the manufacturing method of Claim 13,
A position where the center of the second through hole is a predetermined distance away from the center of the region where the upper end of the columnar body is in contact so that the upper end of the columnar body is anodically bonded to the upper substrate with sufficient strength A method for manufacturing a sensor using a capacitive element, characterized in that: The manufacturing method according to claim 13 or 14,
The upper wiring layer for the pedestal is connected to the upper part of the pedestal or the part having the same potential as the pedestal so that the upper edge of the pedestal or the part having the same potential as the pedestal is anodically bonded to the upper substrate with sufficient strength. A method for manufacturing a sensor using a capacitive element, characterized in that it is set so as to terminate at a position a short distance from the center of a region where a contact is made. In the manufacturing method in any one of Claims 11, 12, 14, and 15,
The width of the through-hole wiring part, the lower electrode upper wiring layer end position, or the pedestal upper wiring layer end position is the width of the columnar body or the contact portion of the “base or the part that is equipotential to the pedestal” Is set so as to be within D / 3 from the contour position of the contact portion of the columnar body or the “pedestal or a portion having the same potential as the pedestal” toward the inner side when D is Manufacturing method of sensor using In the manufacturing method in any one of Claims 1-16,
An intermediate member forming step is performed on the silicon substrate from its lower surface side to form an intermediate member, and an intermediate member is formed from the upper surface side of the intermediate member to be processed from the upper surface side. Divided into stages,
The lower substrate bonding step is performed after the first half step is performed, and then the second half step is performed, and then the upper substrate bonding step is performed.
In the lower substrate bonding step, the processing intermediate body is placed on the upper surface of the lower substrate, the first anodic bonding electrode is brought into contact with the upper surface of the processing intermediate body, and the second anodic bonding electrode is mounted on the lower surface of the lower substrate. Contacting and performing anodic bonding while applying an electric field between the first anodic bonding electrode and the second anodic bonding electrode,
In the upper substrate bonding step, the upper substrate is placed on the upper surface of the intermediate member, the first anodic bonding electrode is brought into contact with the upper surface of the upper substrate, and the second anodic bonding electrode is brought into contact with the lower surface of the lower substrate. A method for producing a sensor using a capacitive element, wherein anodic bonding is performed while applying an electric field between the first anodic bonding electrode and the second anodic bonding electrode. In the manufacturing method in any one of Claims 1-16,
An intermediate member forming step is performed on the silicon substrate from its upper surface side to form an intermediate member, and an intermediate member is formed from the lower surface side of the intermediate member to be processed from its lower surface side. Divided into stages,
Performing the upper substrate bonding step after performing the first half step, then performing the second half step, and further performing the lower substrate bonding step thereafter,
In the upper substrate bonding stage, an upper substrate is placed on the upper surface of the intermediate workpiece, a first anodic bonding electrode is brought into contact with the upper surface of the upper substrate, and a second anodic bonding electrode is formed on the lower surface of the intermediate workpiece. Contacting and performing anodic bonding while applying an electric field between the first anodic bonding electrode and the second anodic bonding electrode,
In the lower substrate bonding step, the lower substrate is disposed on the lower surface of the intermediate member, the first anodic bonding electrode is brought into contact with the upper surface of the upper substrate, and the second anodic bonding electrode is brought into contact with the lower surface of the lower substrate. A method of manufacturing a sensor using a capacitive element, wherein anodic bonding is performed while applying an electric field between the first anodic bonding electrode and the second anodic bonding electrode. In the manufacturing method in any one of Claims 1-18,
In the intermediate member forming stage, the pedestal and the outer wall are formed so that the weight body and the columnar body can be sealed in a sealed space,
In the through wiring part formation stage, a through wiring part having a function of sealing the through hole is formed,
The upper and lower surfaces of the pedestal and outer wall are bonded to the upper and lower substrates so that the weight body is sealed in a sealed space in the upper substrate bonding step and the lower substrate bonding step. A method for manufacturing a sensor using the capacitive element. The manufacturing method according to claim 19, wherein
A capacitive element characterized in that a weight body is hermetically sealed in a vacuum by performing at least one of the upper substrate bonding step and the lower substrate bonding step performed in a vacuum in a vacuum. The manufacturing method of the sensor used. In the manufacturing method in any one of Claims 1-20,
An SOI substrate sandwiching an insulating layer is used as a silicon substrate to be used as an intermediate member, and a conductive portion that penetrates the insulating layer is formed for a portion that needs to be conducted across the insulating layer. A method of manufacturing a sensor using a capacitive element.