JP2010014131A - Micro valve, its manufacturing method, and opening/closing detecting method of micro valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a micro valve reliably detecting an opening/closing trouble when a trouble occurs in opening/closing a valve body owing to a foreign matter, etc. <P>SOLUTION: A diaphragm 12 serves concurrently as a first electrode (movable electrode) comprising an opening/closing detection means 26. A second electrode (fixed electrode) 28 comprising the opening/closing detection means 26 is formed in a position facing the diaphragm 12 in a groove section 22 of a second substrate 20. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a microvalve and a manufacturing method thereof, and a microvalve open / close detection method, and more particularly, a microvalve capable of reliably detecting an open / closed state of a valve body part that opens and closes a fluid inlet and outlet. The present invention relates to a method and a method for detecting opening and closing of a microvalve.

  In recent years, a microvalve having a diaphragm structure in which a micromachining technique is applied to a semiconductor substrate such as silicon has been proposed and put into practical use. For example, in Patent Document 1, a movable electrode is formed on the surface of the valve body portion of the valve body substrate facing the first substrate, and a fixed electrode is formed on the surface of the first substrate facing the movable electrode. A microvalve is described in which a predetermined amount of gap is provided between the movable electrode and the fixed electrode. With such a configuration, the valve hole can be closed by the contact pressure when the valve body portion does not apply a voltage to the movable electrode and the fixed electrode.

Further, for example, in Patent Document 2, one end of a flexible region is connected to a semiconductor substrate that is a frame body via a heat insulating region, and a movable element that is a valve body is connected to the other end of the flexible region. A microvalve is described in which the flexible region is composed of a thin part and a thin film having different thermal expansion coefficients. Thereby, when the diffusion resistance formed on the surface of the thin portion is heated, the flexible region is displaced due to the difference in thermal expansion between the thin portion and the thin film, and the movable element as the valve body can block the valve hole.
JP 2005-180530 A JP 2000-309000 A

  However, in the microvalve shown in Patent Document 1 described above, for example, a foreign substance such as an insulator is sandwiched between the movable electrode and the fixed electrode, and the valve body is sufficiently directed toward the first substrate when a driving voltage is applied. There was a problem that even if the valve hole could not be raised and caused a valve opening / closing failure, the occurrence of such a failure could not be detected.

  Similarly, in the microvalve shown in Patent Document 2, for example, a foreign object is sandwiched between a movable element and a pedestal in which a valve hole is formed, and the operation of the movable element is limited due to the foreign object when a driving voltage is applied. There is a problem that even if an open / close failure is caused, the occurrence of such a failure cannot be detected.

  The present invention has been made to solve the above problems, and provides a microvalve capable of reliably detecting an open / close failure in a valve body portion due to entry of a foreign substance or the like. With the goal.

  It is another object of the present invention to provide a method for manufacturing a microvalve that can detect an opening / closing failure of a valve body portion caused by intrusion of foreign matter.

  It is another object of the present invention to provide a micro-valve open / close detection method capable of reliably detecting an open / close failure in the valve body due to entry of foreign matter or the like.

In order to solve the above problems, the present invention provides the following microvalve.
That is, the microvalve of the present invention includes a first substrate having a valve body portion and a fixing portion on one surface side of the diaphragm portion, and a second substrate having a groove portion formed at a position facing the diaphragm portion. And a third substrate on which at least one or both of an inflow port and an outflow port of fluid are formed at a position facing the valve body portion, and the third substrate, the first substrate, and the first substrate The microvalve is formed by superimposing two substrates and joining and integrating them at the fixed portion, and includes an open / close detection means for detecting deformation of the diaphragm portion.

The open / close detection means may be formed of a first electrode formed on the other surface side of the diaphragm portion and a second electrode formed at a position facing the first electrode in the groove portion. . Further, the open / close detection means may be formed from a piezoresistive element formed in the diaphragm portion. A plurality of the piezoresistive elements may be formed, and the piezoresistive elements may be arranged so that the directions in which stress is applied are different from each other when the diaphragm portion is deformed. It is only necessary that a fluid opening for driving the valve body and the diaphragm is further formed in the groove.

  The microvalve manufacturing method of the present invention includes a first substrate having a valve body portion and a fixing portion on one surface side of a diaphragm portion, and a second substrate in which a groove portion is formed at a position facing the diaphragm portion. And a third substrate on which at least one or both of the fluid inflow port and the outflow port are formed at a position facing the valve body portion, and the third substrate, the first substrate, A method of manufacturing a microvalve, in which a second substrate is overlaid and bonded and integrated at the fixed portion, the step of forming a first electrode on the other surface side of the diaphragm portion, and the groove portion And a step of forming a second electrode at a position facing the first electrode.

  The microvalve manufacturing method of the present invention includes a first substrate having a valve body and a fixing portion on one surface side of the diaphragm portion, and a second portion in which a groove portion is formed at a position facing the diaphragm portion. And a third substrate on which at least one or both of the fluid inlet and outlet are formed at a position opposite to the valve body portion, and the third substrate, the first substrate, A method of manufacturing a microvalve in which a substrate and a second substrate are overlapped and bonded and integrated at the fixed portion, and includes at least a step of forming a piezoresistive element in the diaphragm portion.

  According to the microvalve open / close detection method of the present invention, a first substrate in which a valve body portion and a fixed portion are formed on one surface side of a diaphragm portion, and a first electrode is formed on the other surface side of the diaphragm portion. And a second substrate in which a groove is formed at a position facing the diaphragm, a second electrode is formed at a position facing the first electrode in the groove, and a position facing the valve body. A third substrate on which at least one or both of the fluid inlet and the outlet are formed, the third substrate, the first substrate, and the second substrate are overlapped, and the fixing portion A method for detecting opening / closing of a microvalve that is joined and integrated at the inlet, and by measuring the capacitance between the first electrode and the second electrode, Detecting the open / closed state of the outlet And features.

  An opening for allowing fluid to flow in and out is formed in the groove, and the valve body and the diaphragm may be driven by allowing fluid to flow in and out through the opening. In addition, a direct current for driving the valve body and the diaphragm is applied between the first electrode and the second electrode, and between the first electrode and the second electrode. In addition, the capacitance between the first electrode and the second electrode may be measured by applying an alternating current having a voltage lower than the voltage value of the direct current. Further, a piezoresistive element may be formed in the diaphragm portion, and a voltage value that changes according to the resistance value of the piezoresistive element may be measured.

  According to the microvalve of the present invention, the open / close detection means for detecting the open / closed state of the valve body formed in the diaphragm is provided. Thereby, the open / closed state of the valve body can be confirmed from the outside without adding a pressure sensor, a flow rate sensor or the like to the external flow path. Therefore, even if a foreign substance or the like enters the valve body portion and an opening / closing failure occurs in the valve body portion, a microvalve capable of reliably detecting this can be realized.

  Further, according to the microvalve manufacturing method of the present invention, it is possible to manufacture a microvalve capable of reliably confirming the open / closed state of the valve body portion from the outside by including the step of forming the open / close detection means.

  Furthermore, according to the micro-valve open / close detection method of the present invention, by using the micro-valve provided with the open / close detection means for detecting the open / close state of the valve body formed in the diaphragm, the valve body is opened / closed. The state can be confirmed from the outside. As a result, even if foreign matter or the like enters the valve body and an open / close failure occurs in the valve body, this can be reliably detected.

  Hereinafter, the best mode of a microvalve, a manufacturing method thereof, and a microvalve open / close detection method according to the present invention will be described with reference to the drawings. The present embodiment is specifically described for better understanding of the gist of the invention, and does not limit the invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easier to understand, there is a case where a main part is shown in an enlarged manner for convenience, and the dimensional ratio of each component is the same as the actual one. Not necessarily.

[First embodiment (microvalve)]
FIG. 1 is a cross-sectional view showing an example of the microvalve of the present invention. The microvalve 1 according to the present embodiment is formed, for example, by superimposing the first substrate 10, the second substrate 20, and the third substrate 30 and joining them together.

  In the first substrate 10, for example, a part of an SOI (Silicon on Insulator) substrate 11 is etched from the silicon side to form a diaphragm unit 19. On the lower surface (one surface) side of the diaphragm portion 19, a valve (valve body portion) 13 and a fixing portion 14 are provided via an oxide film 25. Further, the diaphragm 12 is formed on the upper surface (the other surface) of the diaphragm portion 19. The diaphragm portion 19 also serves as a first electrode (movable electrode) that constitutes the open / close detection means 26. Further, an oxide film 27 is provided on the upper surface of the diaphragm 12.

The second substrate 20 has the same size as the first substrate 10 and is etched from the lower side at a position facing the diaphragm 12 of the glass substrate 21 containing a material that can be anodically bonded, for example, movable ions such as Na. Thus, the groove 22 constituting the gap 24 necessary for the diaphragm 12 to bend is formed. Further, an opening 23 serving as an inflow port and an outflow port for fluid for driving the valve 13 and the diaphragm 12 is formed at one end of the groove portion 22.
A second electrode (fixed electrode) 28 constituting the open / close detection means 26 is formed at a position facing the diaphragm 12 in the groove 22. Furthermore, a through electrode 29 for taking out the potential of the diaphragm (first electrode) 12 is formed at one end of the second substrate 20.

  The third substrate 30 is formed of a glass substrate 31, and a fluid inlet 32 and an outlet 33 are formed at positions corresponding to the valve 13.

  The first substrate 10 made of an SOI substrate is made of, for example, a diaphragm 12 that is a single crystal Si (100) with a thickness of about 1 to 100 μm and a single crystal Si (100) with a thickness of about 100 to 600 μm. And the oxide film 25 which is a buried oxide film having a thickness of about 0.1 to 10 μm between the diaphragm 12 and the valve 13 and the fixed part 14. That's fine. The thickness of each of these layers may be optimized as appropriate depending on the flow rate and pressure of the fluid controlled by the microvalve 1. The size of the first substrate 10 may be selected from various sizes such as a 4-inch substrate and a 6-inch substrate according to the specifications of the manufacturing apparatus.

  The glass substrate constituting the second substrate 20 or the third substrate 30 includes, for example, borosilicate glass that contains movable ions such as Na and can be anodically bonded to the first substrate 10, alkali-free glass that can be directly bonded, and the like. It may be constituted by.

  In the microvalve 1 having such a configuration, when the pressure in the gap 24 formed by the diaphragm 12 of the first substrate 10 and the groove portion 22 of the second substrate 20 is high, the valve 13 is connected to the third substrate 30. The inlet 32 and the outlet 33 are closed by the valve 13. Thereby, the flow path from the inflow port 32 to the outflow port 33 is blocked, and the fluid cannot flow. That is, the microvalve 1 is in a “closed” state.

  On the other hand, when the pressure in the gap 24 is lowered, the diaphragm 12 bends upward, that is, so as to enter the groove portion 22 as the pressure decreases. When the diaphragm 12 is curved, the valve 13 that has closed the fluid inlet 32 and outlet 33 moves away from the surface of the third substrate 30, and the inlet 32 and outlet 33 are opened. As a result, the fluid can flow through the flow path from the inlet 32 to the outlet 33. That is, the microvalve 1 is in the “open” state.

  In this way, by increasing or decreasing the pressure in the gap 24, the curvature of the diaphragm 12 can be controlled, and the opening and closing of the microvalve 1 can be controlled. The pressure in the gap 24 can be increased or decreased by introducing a fluid into the gap 24 from the opening 23 or discharging the fluid from the gap 24.

  That is, in the microvalve 1, the fluid is introduced into the gap 24 from the opening 23 and the inside of the gap 24 is set to a predetermined pressure or higher, so that the microvalve 1 is in the “closed” state. In addition, the microvalve 1 is in the “open” state by discharging the fluid in the gap 24 from the opening 23 and reducing the pressure in the gap 24 to a predetermined pressure or lower. In the opening / closing control of the valve 13 by increasing / decreasing the pressure in the gap 24, the valve 13 is closed without applying pressure to the gap 24. There is a normally open type that is open, and an appropriate type may be selected as necessary.

  In the microvalve 1 of the first embodiment, of the first electrode and the second electrode constituting the open / close detection means 26, the configuration in which the first electrode is also used as the diaphragm 12, that is, the diaphragm 12 is Although the function of opening and closing the valve 13 by bending and the function as a movable electrode are combined, the first electrode may be formed at a position facing the second electrode separately from the diaphragm 12.

Further, in the embodiment shown in FIG. 1 described above, both the fluid inlet and outlet are formed at a position opposite to the valve body, but in addition to this, at a position opposite to the valve body. May have a configuration in which either the inflow port or the outflow port is formed.
For example, as shown in FIG. 13, in the third substrate 430, only the inlet 432 through which a fluid flows is formed at a position facing the valve (valve body portion) 413 of the first substrate 410. The structure which formed the outflow port 433 in the position remove | deviated from the valve body part) 413 may be sufficient. In this case, the outlet 433 is always open. Furthermore, it is preferable to provide a check valve or the like at the end of the outlet 433.

[First embodiment (microvalve open / closed detection method)]
The operation of the microvalve shown in the first embodiment, that is, the microvalve open / closed detection method of the present invention will be described. In the microvalve 1 shown in FIG. 1, the open / close detection means 26 detects the open / closed state of the valve 13. That is, the value of the capacitance C formed in the gap d between the diaphragm (first electrode: movable electrode) 12 and the second electrode (fixed electrode) 28 that constitute the open / close detection means 26 and face each other is measured. By doing so, the open / closed state of the valve 13 can be detected.

  For example, when the microvalve 1 shown in FIG. 1 is in the “closed” state, the gap b between the diaphragm 12 and the second electrode 28 is maximized. At this time, the value of the capacitance C takes the minimum value. On the other hand, when the microvalve 1 is in the “open” state, the gap d between the diaphragm 12 and the second electrode 28 is minimized. The value of the capacitance C at this time takes a maximum value. Therefore, when the result of measuring the capacitance value C formed by the gap d between the diaphragm 12 and the second electrode 28 is the minimum value, the microvalve 1 is in the “closed” state and when the value is the maximum value. It is possible to detect that the microvalve 1 is in the “open” state.

In order to measure the capacitance value formed by the gap d between the diaphragm (first electrode) and the second electrode 28, for example, a circuit as shown in FIG. 2 may be used. That is, a fixed capacitance C2 is connected in series with the capacitance C1 formed by the gap d between the diaphragm 12 and the second electrode 28, and a voltage V is applied to these capacitances C1 and C2. To do. The combined capacitance of the capacitance C1 and the capacitance C2 is C, the voltage across the capacitance C1 and the capacitance C2 is the amount of charge accumulated in the V1, V2, capacitance C1, and capacitance C2, respectively. If Q is Q, it becomes as follows.
V = V1 + V2
V = Q / C
C = (C1 × C2) / (C1 + C2): combined capacitance of C1 and C2 V1 = Q / C1
V2 = Q / C2

Therefore,
V1 = {C2 / (C1 + C2)} × V
V2 = {C1 / (C1 + C2)} × V
Here, the capacitance C1 when the microvalve 1 is in the “open” state is C1o, the capacitance C1 when the microvalve 1 is in the “closed” state is C1c, and the capacitance C1 is applied across the capacitance C1 when it is in the “open” state. The voltage applied to both ends of the capacitance C1 in the “closed” state is represented as V1c,
V1o = {C2 / (C1o + C2)} × V
V1c = {C2 / (C1c + C2)} × V
Here, since C1o> C1c,
V1o <V1c
Therefore, the open / closed state of the microvalve 1 can be detected as a change in voltage.

  Since the value of the capacitance C1 formed by the diaphragm 12 and the second electrode 28 and the opening of the microvalve 1, that is, the flow rate of the liquid flowing through the microvalve 1 are correlated, the capacitance C It is also possible to control the flow rate of the fluid flowing through the microvalve 1 by measuring and controlling the pressure in the gap 24 according to the value.

In other words, the capacitance C1 formed between the diaphragm 12 and the second electrode 28 is such that the area of these electrodes is S, the distance between both electrodes is d, and the dielectric constant is ε.
C1 = ε × S / d
That is, d = ε × S / C1
Therefore, the distance between the diaphragm 12 and the second electrode 28 can be calculated by measuring the capacitance C1. The distance between the valve 13 and the surface of the third substrate 30 can be calculated from the distance between the diaphragm 12 and the second electrode 28, and the flow rate of the fluid controlled by the microvalve 1 is determined from the valve 13 and the third substrate 30. Depends on the distance from 30 surfaces. Therefore, by using the value of the capacitance C1 formed by the gap between the diaphragm 12 and the second electrode 28, the opening degree of the microvalve 1, that is, the flow rate of the liquid flowing through the microvalve 1 can be controlled. become.

[First embodiment (manufacturing method of microvalve)]
A method for manufacturing the microvalve shown in the first embodiment will be described. In manufacturing the microvalve 1 shown in FIG. 1, first, as shown in FIG. 3A, an SOI substrate 100 serving as a first substrate is prepared. The SOI substrate 100 includes a thin film layer 101 made of Si (100) single crystal, a support substrate 103, and a buried oxide film 102 formed between the thin film layer 101 and the support substrate 103.

  After the SOI substrate 100 is cleaned using an RCA cleaning method or the like, oxide films 111a and 111b are formed by thermally oxidizing the front surface (thin film layer side) and the back surface (support substrate side) (see FIG. 3B). ). Then, a photoresist 121 is applied to the back side (see FIG. 3C). By exposing and developing this, a fixed portion pattern 121a and a valve (valve body portion) pattern 121b are formed (see FIG. 3D).

Next, the oxide film 111b is etched using a wet etching method or a dry etching method to form a recess 112 (see FIG. 3E). In the wet etching method, diluted hydrofluoric acid, buffered hydrofluoric acid, or the like may be used as an etchant. Further, an etchant containing a surfactant may be used. In the dry etching method, plasma of a gas containing fluorine such as CF ₄ is used. Note that the oxide film 111a on the surface side of the first substrate is preferably protected with a jig or a photoresist so as not to be removed particularly in wet etching.

  Next, the photoresists 121a and 121b are removed by treatment with a heated chemical solution such as concentrated sulfuric acid or a mixed solution (piranha) of concentrated sulfuric acid and hydrogen peroxide (see FIG. 3F). Note that the photoresists 121a and 121b may be ashed using oxygen plasma treatment or the like, and may be treated with the chemical solution after the ashing treatment.

  Next, the support substrate 103 is subjected to crystal anisotropic etching using an alkaline etching solution through the recess 112 formed in the oxide film 111b to form, for example, a trapezoidal recess 104 in the support substrate 103 (FIG. 3 ( g)). Thereby, the valve 106 and the diaphragm (first electrode) 107 are formed (step of forming the first electrode). As the alkaline etching solution, for example, KOH, TMAH, hydrazine or EDP (ethylenediamine + pyrocatechol) can be used.

When KOH is used as an etchant, it is desirable to use a silicon nitride film having a slow etching rate with KOH instead of the oxide film 111b. In this case, it is desirable to have a laminated film structure in which an oxide film is formed between the silicon nitride film and the first substrate to relieve the stress of the silicon nitride film. In this case, it is preferable to use a dry etching method using a gas containing fluorine such as CF ₄ for etching the silicon nitride film for forming the recess 112.

  Next, a photoresist 122 is applied to the surface of the oxide film 111a, exposed, and developed to form an opening pattern 122a for extracting the diaphragm potential in the photoresist 122 (see FIG. 3H).

Next, using the photoresist 122 having the opening pattern 122a as a mask, the oxide film 111a is etched using a wet etching method or a dry etching method to form an opening 113 (see FIG. 4A). ). In the wet etching method, for example, diluted hydrofluoric acid, buffered hydrofluoric acid, or the like may be used as an etching solution. An etchant containing a surfactant may be used. In the dry etching method, a gas containing fluorine such as CF ₄ may be used. At this time, the buried oxide film 102 exposed at the bottom of the opening 104 formed in the support substrate 103 is simultaneously etched to form the opening 105.

  Then, the photoresist 122 is removed by processing with a chemical solution such as heated concentrated sulfuric acid or a mixed solution (piranha) of concentrated sulfuric acid and hydrogen peroxide (see FIG. 4B). Note that the photoresist 122 may be ashed using oxygen plasma treatment or the like, or may be treated with the chemical solution after the ashing treatment. Thus, on the first substrate 100, the valve 106 is formed on the support substrate 103, the diaphragm 107 is formed on the thin film layer 101, and the oxide film 111c is formed on the diaphragm 107.

  Next, as the second substrate 131, a glass substrate, for example, a borosilicate glass substrate that contains movable ions such as sodium and can be anodically bonded to the silicon substrate, an alkali-free glass substrate that can be directly bonded to the silicon substrate, and the like is prepared. . An etching mask film 132 such as a Cr film is formed on the back surface (surface bonded to the first substrate) side of the second substrate 131 using a sputtering method, a vapor deposition method, or the like (see FIG. 4C).

  Next, an opening 133 is formed in the etching mask film 132 by using a photolithography technique (photoresist application, exposure, development) and an etching technique (see FIG. 4D). As an etching technique, for example, a wet etching technique, a dry etching technique, or the like may be used.

  Next, the second substrate 131 is wet-etched with an etchant capable of etching glass such as hydrofluoric acid to form a groove 134 on the back surface side (see FIG. 4E). Note that the groove 134 may be formed using a dry etching technique. After the etching, the photoresist film may be removed by processing with a chemical solution such as heated concentrated sulfuric acid or a mixed solution of concentrated sulfuric acid and hydrogen peroxide (piranha). Note that the photoresist film may be ashed using oxygen plasma treatment or the like, or may be treated with the chemical solution after the ashing treatment. Then, the etching mask film formed of a Cr film or the like is removed using a wet etching technique or the like (see FIG. 4F).

  Next, the dry film resist film 136 is attached to the surface of the second substrate (the surface opposite to the surface bonded to the first substrate by anodic bonding), and the valve 106 is driven by exposing and developing. Each of the opening pattern 137a for introducing the pressure for the purpose and the opening pattern 137b in the shape of the electrode 140b for taking out the potential of the diaphragm 107 is formed (see FIG. 4F). Then, using the dry film resist film 136 as a mask, a blasting method or the like is used to model a through hole 138a for introducing pressure for driving the valve 106 to the second substrate 131, and an electrode to be formed in a subsequent process. A through hole 138b is formed (see FIG. 4G).

  Next, the dry film resist film 136 is removed, and a conductive film 135 such as a Cr film is formed on the back surface (the surface bonded to the first substrate) side of the second substrate (see FIG. 4H). Then, a second electrode (fixed electrode) 135a is formed using a photolithography technique (photoresist application, exposure, development) and an etching technique (step of forming the first electrode). Thereafter, the photoresist film is removed by treatment with a chemical solution such as heated concentrated sulfuric acid or a mixed solution of concentrated sulfuric acid and hydrogen peroxide (piranha) (see FIG. 5A). Note that the photoresist film may be ashed using oxygen plasma treatment or the like, and may be treated with the chemical solution after the ashing treatment.

  Subsequently, the first substrate 100 and the second substrate 131 are bonded using, for example, an anodic bonding method or a direct bonding method (see FIG. 5B). After the bonding, a metal film 139 such as aluminum is formed on the surface of the second substrate 131 (the surface opposite to the surface bonded to the first substrate). The metal film 139 may be formed by a method of forming a film in a vacuum such as a sputtering method or an electron beam evaporation method.

  When the first substrate 100 and the second substrate 131 on which the metal film 139 is formed are taken out into the atmosphere, the gap surrounded by the groove portion 134 opened in the second substrate 131 and the diaphragm portion 107 of the first substrate 100. Since 24 is a vacuum and the outside of these substrates is at atmospheric pressure, the diaphragm 107 formed on the first substrate 100 is deformed by the pressure difference, and the valve 106 is attracted to the second substrate 131. At this time, an oxide film 111c is formed on the diaphragm 107 on the valve 106, and the diaphragm (first electrode) 107 has a second electrode 135a formed on the second substrate 131 with the oxide film 111c interposed therebetween. To touch.

  Next, a borosilicate glass substrate, a non-alkali glass substrate, or the like is prepared as the third substrate 141 (see FIG. 5C). A dry film resist film 142 is affixed to the third substrate 141, and exposure and development are performed to form a pattern 143 to be a fluid inlet / outlet.

Next, using the dry film resist film 142 as a mask, the third substrate 141 is penetrated in the thickness direction by using a blasting technique or the like, and through holes 144 serving as fluid inlets and outlets are formed ( (Refer FIG.5 (d)). Thereafter, the dry film resist film 142 is removed (see FIG. 5E).
One of the two through holes 144 serving as the inlet and outlet is formed at a position facing the valve 106 of the first substrate 100, and the other is formed at a position away from the valve 106. Also good.

  The third substrate 141 is bonded to the first substrate 100 and the second substrate 131 that are bonded and integrated in the previous process by using, for example, a direct bonding method, an anodic bonding method, or the like (see FIG. 5F). ). At this time, since the valve 106 formed on the first substrate is attracted to the second substrate 131, the depth of the groove 134 formed on the second substrate 131 is set appropriately, so that the third substrate 141 and the valve 106 can be sufficiently separated from each other. Accordingly, since the valve 106 is not in close contact with the third substrate 141 during direct bonding, they are not bonded.

  Even in the case of using the anodic bonding method, the electrostatic force generated by the voltage applied to the first substrate 100 and the third substrate 141 by sufficiently separating the valve 106 from the third substrate 141. Thus, the valve 106 can be prevented from being attracted to the third substrate. For this reason, the valve 106 and the third substrate are not anodically bonded.

Next, the metal film 139 formed on the second substrate 131 is etched using, for example, a photolithography technique (photoresist application, exposure, development) and an etching technique, leaving a portion that becomes the electrode 140b. As an etching method, a wet etching method, a dry etching method, or the like can be used. Further, when the metal film 139 is removed from the through hole 138a that introduces pressure for driving the valve 106, the atmosphere flows from the through hole 138a, and the groove part 134 opened in the second substrate 131 and the oxide film 111c. The space 24 surrounded by is at atmospheric pressure. Then, since the pressure difference that deformed the diaphragm 107 disappears, the diaphragm 107 returns to its original shape, the valve 106 contacts the third substrate 141, and closes the fluid inlet 144 and outlet 145 (see FIG. 5 (f)).
Through the steps as described above, the microvalve 1 of the first embodiment shown in FIG. 1 can be manufactured.

[Second Embodiment (Microvalve)]
FIG. 6 is a cross-sectional view showing another example of the microvalve of the present invention. The microvalve 2 according to the present embodiment is formed, for example, by superimposing the first substrate 40, the second substrate 50, and the third substrate 60 and joining them together.

  For example, a part of an SOI (Silicon on Insulator) substrate 11 is etched from the silicon side to form a diaphragm portion 49, and an oxide film is formed on the lower surface (one surface) side of the diaphragm portion 49. A valve (valve body part) 43 and a fixing part 44 are provided via 55. A diaphragm 42 is formed on the upper surface (the other surface) of the diaphragm portion 49. The diaphragm 49 also serves as a first electrode (movable electrode) constituting the open / close detection means 56. Further, an oxide film 57 is provided on the upper surface of the diaphragm 42.

  In the second substrate 50, a groove portion 52 that forms the gap 54 is formed. A second electrode (fixed electrode) 58 that constitutes the open / close detection means 56 is formed at a position facing the diaphragm 42 in the groove 52. At one end of the groove 52, a through electrode 59a for supplying electric power to the second electrode 58 and taking out the potential of the second electrode 58 to the outside is formed. A through electrode 59b for supplying electric power to the diaphragm (first electrode) 42 and taking out the potential of the diaphragm 42 to the outside is formed at one end of the second substrate 50.

  The third substrate 60 is formed of a glass substrate 61, and a fluid inlet 62 and outlet 63 are formed at positions corresponding to the valve 43.

  The microvalve 2 having such a configuration opens and closes the valve 43 by driving (bending) the diaphragm 42 with electrostatic force. That is, when no voltage is applied to the second electrode 58 that forms a capacitance with the diaphragm (first electrode) 42, the microvalve 2 is connected to the diaphragm and the second electrode 58. There is no electrostatic force between them. For this reason, the valve 43 is pressed against the third substrate 60, and the inlet 62 and the outlet 63 are closed by the valve 43. Thereby, the flow path from the inflow port 62 to the outflow port 63 is blocked, and the fluid cannot flow. That is, the microvalve 2 is in a “closed” state.

  On the other hand, when a voltage is applied between the diaphragm (first electrode) 42 and the second electrode 58, an electrostatic force is generated between the diaphragm 42 and the second electrode 58, and the diaphragm 42 It is attracted to the electrode 58 and curved. When the diaphragm 42 is curved, the valve 43 that has closed the fluid inlet 62 and outlet 63 is separated from the surface of the third substrate 60, and the inlet 62 and outlet 63 are opened. As a result, the fluid can flow through the flow path from the inlet 62 to the outlet 63. That is, the microvalve 2 is in the “open” state.

[Second Embodiment (Microvalve Open / Closed Detection Method)]
The operation of the microvalve shown in the second embodiment, that is, the microvalve open / close detection method of the present invention will be described. FIG. 7 is a schematic diagram showing a driving circuit for the diaphragm constituting the microvalve and a capacitance measuring circuit for the twelfth electrode and the second electrode.

  The voltage required to open and close the valve 43 depends on the pressure of the fluid to be controlled, the area and thickness and rigidity of the diaphragm 42, the opening area of the fluid inlet 62 and outlet 63, and the like, and must be designed appropriately. It is. In order to bend the diaphragm 42 toward the second electrode 58 and bring the microvalve 2 into the “open” state, a direct current voltage (between the diaphragm 42 and the second electrode 58 via the through electrodes 59a and 59b). Driving voltage) V is applied.

On the other hand, when detecting the curved state of the diaphragm 42, that is, the open / closed state of the valve 43, an alternating voltage V (t) having a voltage value lower than the driving voltage is applied to be superimposed on the direct driving voltage V. . For example, let Z1 be the impedance of the capacitance C1 formed by the diaphragm (first electrode) 42 and the second electrode 58, and i (t) be the current flowing through the capacitance C1. Further, the capacitance C1 when the microvalve is in the “open” state is C1o, the impedance Z1 is Z1o, the current i (t) flowing through the capacitance C1 is io (t), and the electrostatic capacitance when the microvalve is in the “closed” state. If the capacitance C1 is C1c, the impedance Z1 is Z1c, and the current i (t) flowing through the capacitance C1 is ic (t), then C1o> C1c, Z1o <Z1c, and the current when the AC voltage v (t) is applied. i (t) is
io (t)> ic (t)
Therefore, the open / close state of the microvalve can be detected as a change in current. The minute AC voltage v (t) superimposed on the DC drive voltage V is preferably set to drive voltage V >> minute AC voltage v (t) so as not to affect the opening and closing of the valve 43. .

[Third embodiment (microvalve)]
FIG. 8A is a plan view showing another example of the microvalve of the present invention. FIG. 8B is a cross-sectional view taken along line AA in FIG. The microvalve 3 according to the present embodiment is formed by joining and integrating the first substrate 70, the second substrate 80, and the third substrate 90.

  In the first substrate 70, for example, a part of an SOI (Silicon on Insulator) substrate 71 is etched from the silicon side to form a diaphragm portion 79. A valve (valve body portion) 73 and a fixing portion 74 are provided on the lower surface (one surface) side of the diaphragm portion 79 via an oxide film 85. A diaphragm 72 is formed on the upper surface (the other surface) of the diaphragm portion 79. The diaphragm 72 is formed with a piezoresistive element 88 that constitutes an open / close detection means. Further, an oxide film 87 is provided on the upper surface of the diaphragm 72.

  The piezoresistive element 88 may be, for example, one that is arranged so that the longitudinal directions of the four piezoresistive elements 88a to 88d are orthogonal to each other and connected to form a bridge circuit. Thus, for example, when the diaphragm 79 is bent upward and the valve 73 is opened in a state where current flows in the longitudinal direction of the piezoresistive elements 88a to 88d, the piezoresistive elements 88a and 88c and the piezoresistive elements In 88b and 88d, the directions in which stress is applied to each other are shifted by 90 °. As a result, the balance of the bridge circuit is lost, and the position of the valve 73 can be detected.

  The second substrate 80 is the same size as the first substrate 70 and is necessary for the diaphragm 72 to bend by etching from the lower side at a position opposite to the diaphragm 72 of the glass substrate 81 that can be anodically bonded. A groove portion 82 that constitutes the gap 84 is formed. In addition, an opening 83 serving as an inflow port and an outflow port for driving the valve 73 and the diaphragm 72 is formed at one end of the groove 82. Further, a through electrode 89 for taking out the potential of the piezoresistive element 88 to the outside is formed at one end of the second substrate 80.

  The third substrate 90 is formed of a glass substrate 91, and a fluid inlet 92 and an outlet 93 are formed at positions corresponding to the valves 73.

  In the microvalve 3 having the above configuration, the valve 73 is pressed against the third substrate 90 when the pressure in the gap 84 formed by the diaphragm 72 of the first substrate 70 and the groove portion 82 of the second substrate 80 is high. Then, the inlet port 92 and the outlet port 93 are closed by the valve 73. As a result, the flow path from the inlet 92 to the outlet 93 is blocked, and the microvalve 1 is in the “closed” state.

  On the other hand, when the pressure in the gap 84 is lowered, the diaphragm 72 is curved so as to enter the groove portion 82 upward, that is, as the pressure decreases. When the diaphragm 72 is curved, the valve 73 that has closed the fluid inlet 92 and outlet 93 is separated from the surface of the third substrate 90, the inlet 92 and outlet 93 are opened, and the microvalve 1 is “ Opened state.

[Third embodiment (microvalve open / closed detection method)]
The action of the microvalve shown in the third embodiment, that is, the method for detecting opening / closing of the microvalve of the present invention will be described. The microvalve 3 shown in FIG. 8 detects the open / close state of the valve 73 by a piezoresistive element 88 that is an open / close detection means. That is, the open / close state of the valve 73 can be detected by measuring the voltage values of the piezoresistive elements 88a to 88d whose resistance values change according to the curvature of the diaphragm 72. Such piezoresistive elements 88a to 88d may be connected so as to form a bridge circuit, for example.

  For example, when the microvalve 3 shown in FIG. 8 is in the “closed” state, the diaphragm 72 is flat, and distortion due to the curvature of the diaphragm 72 is not added to the piezoresistive elements 88a to 88d, so that the resistance of the piezoresistive elements 88a to 88d. The value is constant. Thereby, it can be detected that the microvalve 3 is in the “closed” state.

  On the other hand, when the microvalve 3 is in the “open” state, the diaphragm 72 is curved upward. Then, stresses in directions shifted by 90 ° are applied to the piezoresistive elements 88a and 88c and the piezoresistive elements 88b and 88d arranged so that their longitudinal directions are orthogonal to each other. Thereby, for example, the resistance values of the piezoresistive elements 88a and 88c are decreased, and conversely, the resistance values of the piezoresistive elements 88b and 88d are increased. As a result, the resistance value of the piezoresistive elements 88a to 88d, which was constant when the microvalve 3 is in the “closed” state, changes and the bridge circuit is unbalanced. It becomes possible to detect the “open” state of the valve 3.

  In order to measure the voltage value of the piezoresistive element 88 formed on the diaphragm 72, for example, a circuit as shown in FIG. 9 may be used. When the microvalve 3 is in the “closed” state, since the diaphragm 72 is flat, the output voltage V when the current i is applied to the bridge circuit formed by the piezoresistive element 88 becomes zero. On the other hand, when the diaphragm 72 is bent to open the microvalve, the output voltage V of the bridge circuit formed by the piezoresistive element 88 changes and takes a constant value V that is not zero.

  Note that the value of the output voltage V and the sign of the voltage at this time are determined by the design of the piezoresistive element 88. The value of the output voltage V when the microvalve 3 is in the “closed” state or the “open” state is adjusted by adjusting a variable resistor 95 that adjusts the balance of the bridge circuit composed of the piezoresistive elements 88. The voltage can also be set to a non-zero offset voltage.

  Further, since the value of the output voltage V of the bridge circuit composed of the diaphragm 72 and the piezoresistive element 88 and the opening of the microvalve 3, that is, the flow rate of the liquid flowing through the microvalve 3 are correlated, the output voltage V is measured. In addition, the flow rate of the fluid flowing through the microvalve 3 can be controlled by controlling the pressure in the gap 84 according to the value.

[Third Embodiment (Microvalve Manufacturing Method)]
A method for manufacturing the microvalve shown in the third embodiment will be described. In manufacturing the microvalve 3 shown in FIG. 8, first, as shown in FIG. 10A, an SOI substrate is used as the first substrate 300. Both the thin film layer 301 and the support substrate 303 are n-type Si (100) single crystal substrates. A buried oxide film 302 is formed between the thin film layer 301 and the support substrate 303.

  After the SOI substrate 300 is cleaned using an RCA cleaning method or the like, oxide films 311a and 311b are formed by thermally oxidizing the front surface (thin film layer side) and the back surface (support substrate side). Photoresist 351 is applied to the surface side, exposed, and developed to form a piezoresistive element pattern 351a and a diffusion layer wiring portion pattern 351b (see FIG. 10B). Then, phosphorus ions are ion-implanted into the thin film layer 301 using the photoresist pattern as a mask to form an ion-implanted layer 352a serving as a piezoresistive element and an ion-implanted layer 352b serving as a diffusion layer wiring portion.

  Next, the photoresist 351 is removed by treatment with a chemical solution such as heated concentrated sulfuric acid or a mixed solution of concentrated sulfuric acid and hydrogen peroxide (piranha) (see FIG. 10C). Note that the photoresist 351 may be ashed using oxygen plasma treatment or the like, or may be treated with the chemical solution after the ashing treatment. The SOI substrate 300 is heat-treated in an inert gas such as nitrogen or argon gas at a temperature of about 900 ° C. to 1100 ° C. to activate the portion into which phosphorus ions are implanted, and the piezoresistive element 353a which is a p-type semiconductor layer Diffusion layer wiring portion 353b is formed (step of forming a piezoresistive element in the diaphragm portion). Thereafter, a photoresist 321 is applied to the back side.

By exposing and developing the photoresist 321, a fixed portion pattern 321 a and a valve body portion pattern 321 b are formed (see FIG. 10D). Then, using a wet etching method or a dry etching method, the oxide film 311b is etched using the photoresist 321 as a mask to form an opening 312 (see FIG. 10E). In the wet etching method, diluted hydrofluoric acid, buffered hydrofluoric acid, or the like may be used as an etchant. Further, an etchant containing a surfactant may be used. In the dry etching method, plasma of a gas containing fluorine such as CF ₄ is used. Note that the oxide film 311a on the surface side of the first substrate 300 is protected by using a jig or a photoresist so that it is not removed during the etching in this step, particularly in wet etching. preferable.

  Next, the photoresists 321a and 321b are removed by processing with a chemical solution such as heated concentrated sulfuric acid or a mixed solution of concentrated sulfuric acid and hydrogen peroxide (piranha) (see FIG. 10F). Note that the photoresists 321a and 321b may be ashed using oxygen plasma treatment or the like, and may be treated with the chemical solution after the ashing treatment.

Through the opening 312 formed in the oxide film 311b, the support substrate 303 is crystal anisotropically etched using an alkaline etching solution. Thereby, the recessed part 304 is formed in the support substrate 303 (refer FIG.10 (g)). As the alkaline etching solution, KOH, TMAH, hydrazine or EDP (ethylenediamine + pyrocatechol) or the like can be used. When KOH is used as an etchant, it is desirable to use a silicon nitride film having a slow etching rate with KOH instead of the oxide film 311b. In this case, it is desirable to have a laminated film structure in which an oxide film is formed between the silicon nitride film and the first substrate to relieve the stress of the silicon nitride film. In this case, a dry etching method using a gas containing fluorine such as CF ₄ may be used for etching the silicon nitride film for forming the opening 312.

Next, a photoresist 322 is applied to the surface side, exposed, and developed to form an opening pattern 322a for supplying a voltage to the piezoresistor 353a and the diffusion layer wiring portion 353b on the oxide film 311a (FIG. 10 (h)). Then, the oxide film 311a is etched using a wet etching method or a dry etching method to form an opening 313 (see FIG. 11A). In the wet etching method, diluted hydrofluoric acid, buffered hydrofluoric acid, or the like may be used as an etching solution. Further, an etchant containing a surfactant may be used. In the dry etching method, a gas containing fluorine such as CF ₄ is used. At this time, the buried oxide film 302 exposed at the bottom of the recess 304 formed in the support substrate 303 is also etched at the same time to form an opening 305.

  Next, the photoresist 322 is removed by treatment with a chemical solution such as heated concentrated sulfuric acid or a mixed solution of concentrated sulfuric acid and hydrogen peroxide (piranha) (see FIG. 11B). Note that the photoresist 322 may be ashed using oxygen plasma treatment or the like, or may be treated with the chemical solution after the ashing treatment. Through the above steps, the valve 306 is formed on the support substrate 303, the diaphragm portion 307 is formed on the thin film layer 301, the oxide film 311c, and the piezoresistor 353a are formed on the diaphragm portion 307.

  Next, as the second substrate 331, a glass substrate, for example, a borosilicate glass substrate that contains movable ions such as sodium and can be anodic bonded to the silicon substrate, an alkali-free glass substrate that can be directly bonded to the silicon substrate, and the like is prepared. An etching mask film 332 such as a Cr film is formed on the back surface (surface bonded to the first substrate) side of the second substrate 331 by using a sputtering method, a vapor deposition method, or the like (see FIG. 11C).

  An opening 333 is formed in the etching mask film 332 by using a photolithography technique (photoresist application, exposure, development) and an etching technique (see FIG. 11D). As an etching technique, a wet etching technique, a dry etching technique, or the like can be used.

  Next, using the etching mask film 332 as a mask, the second substrate 331 is wet-etched with an etchant that etches glass such as hydrofluoric acid to form a groove 334 on the back surface side (see FIG. 11E). Note that the groove 334 may be formed using a dry etching technique. The photoresist film of the etching mask film 332 is removed by treatment with a chemical solution such as heated concentrated sulfuric acid, a mixed solution of concentrated sulfuric acid and hydrogen peroxide (piranha), or the like. Note that the photoresist film may be ashed using oxygen plasma treatment or the like, or may be treated with the chemical solution after the ashing treatment.

  Next, the etching mask film 332 formed of a Cr film or the like is removed using a wet etching technique or the like (see FIG. 11F). A dry film resist film 336 is attached to the surface of the second substrate (the surface opposite to the surface bonded to the first substrate by anodic bonding), exposed, and developed to drive the valve. An opening pattern 337a for introducing pressure and an opening pattern 337b for taking out an electrode 340b for applying a voltage to the piezoresistor 353a and the diffusion layer wiring portion 353b are formed (see FIG. 11G).

  Next, for example, a through hole 338a for introducing pressure for driving the valve to the second substrate 331 and a through hole 338b for the electrode 340b are formed on the second substrate 331 by using a blasting method or the like (FIG. 11 (h)). reference). Thereafter, the dry film resist film 336 is removed (see FIG. 12A).

  The first substrate 300 and the second substrate 331 are bonded using an anodic bonding method, a direct bonding method, or the like. After bonding, a metal film 339 such as aluminum is formed on the surface of the second substrate 331 (the surface opposite to the surface bonded to the first substrate) (see FIG. 12B). The metal film 339 is formed using a method of forming a film in a vacuum such as a sputtering method or an electron beam evaporation method.

  When the first substrate 300 and the second substrate 331 on which the metal film is formed are taken out into the atmosphere, a gap surrounded by the groove portion 334 opened in the second substrate 331 and the diaphragm portion 307 of the first substrate 300 is formed. Since the outside of these substrates is at atmospheric pressure under vacuum, the diaphragm portion 307 formed on the first substrate 300 is deformed by the pressure difference, and the valve 306 is attracted to the second substrate 331.

  Next, a borosilicate glass substrate, an alkali-free glass substrate, or the like is prepared as the third substrate. A dry film resist film 342 is attached to the third substrate 341, and exposed and developed to form a pattern 343 of opening portions serving as fluid inlets and outlets (see FIG. 12C). Then, using this dry film resist film 342 as a mask, a blast technique or the like is used to penetrate the third substrate 341 in the thickness direction to form through holes 344 that serve as fluid inlets and outlets (FIG. 12 (d)). Thereafter, the dry film resist film 342 is removed (see FIG. 12E).

  The third substrate 341 is bonded to the first substrate 300 and the second substrate 331 that are bonded and integrated in the previous process by using a direct bonding method, an anodic bonding method, or the like (see FIG. 12F). . At this time, the valve 306 formed on the first substrate is attracted to the second substrate 331. Therefore, by appropriately setting the depth of the groove 334 formed on the second substrate 331, the third substrate is set. 341 and valve 306 can be separated sufficiently. Accordingly, since the valve 306 is not in close contact with the third substrate 341 at the time of direct bonding, they are not bonded.

  In the case of using the anodic bonding method, the valve 306 is sufficiently separated from the third substrate 341, so that the electrostatic force generated by the voltage applied to the first substrate 300 and the third substrate 341 can be used. Since the valve 306 can be prevented from being attracted to the third substrate, it is not anodically bonded.

  Next, the metal film 339 formed on the second substrate 331 is etched by using a photolithography technique (photoresist application, exposure, development) and an etching technique, leaving a portion to be the electrode 340b (see FIG. 12G). ). As an etching method, a wet etching method, a dry etching method, or the like can be used.

Further, when the metal film 339 is removed from the through hole 338a for introducing the pressure for driving the valve, the atmosphere flows from the through hole 338a, so that the groove 334 opened in the second substrate 331 and the first substrate The space 84 surrounded by the 300 diaphragm portions 307 is at atmospheric pressure. Then, since the pressure difference that deformed the diaphragm portion 307 disappears, the diaphragm portion 307 returns to its original shape, and the valve 306 comes into contact with the third substrate 341 and closes the fluid inlet and outlet 344.
Through the steps as described above, the microvalve 3 of the third embodiment shown in FIG. 8 can be manufactured.

  In the above-described microvalve manufacturing method, an example in which an SOI substrate is used as the first substrate has been described, but a single crystal silicon substrate can also be used. Further, a dry etching method can be used instead of the crystal anisotropic etching of the support substrate of the first substrate.

  In the etching of the second substrate or the third substrate, the photoresist film used for pattern formation of the etching mask film is removed before etching these substrates, but the photoresist film on the etching mask film is removed. The second substrate or the third substrate may be etched while remaining. In this case, the photoresist film is removed after the substrate is etched. Since the etching mask has a two-layer structure, etching resistance of the etching mask is improved, and generation of defects due to pinholes or the like of the etching mask can be suppressed.

  In addition, in the same way as a general semiconductor device manufacturing method, a plurality of microvalves are formed on a set of substrates at the same time, and finally cut using means such as dicing. It can also be produced.

  Various driving forces such as gas (vacuum, gas pressure) and electrostatic force can be used as microvalve driving means, a unimorph structure consisting of piezoelectric elements on the diaphragm, and magnetism can be used. . Even when these driving means are used, as in the present invention, the change in the capacitance between the movable electrode formed in the diaphragm portion and the fixed electrode formed on the substrate or the change in the piezoresistance formed in the diaphragm portion is observed. It is possible to detect the open / closed state of the microvalve.

It is sectional drawing which shows an example of the microvalve of this invention. It is explanatory drawing which shows the opening / closing detection method of the microvalve of this invention. It is sectional drawing which shows an example of the manufacturing method of the microvalve of this invention. It is sectional drawing which shows an example of the manufacturing method of the microvalve of this invention. It is sectional drawing which shows an example of the manufacturing method of the microvalve of this invention. It is sectional drawing which shows another example of the microvalve of this invention. It is explanatory drawing which shows the opening / closing detection method of the microvalve of this invention. It is the top view and sectional drawing which show another example of the microvalve of this invention. It is explanatory drawing which shows the opening / closing detection method of the microvalve of this invention. It is sectional drawing which shows an example of the manufacturing method of the microvalve of this invention. It is sectional drawing which shows an example of the manufacturing method of the microvalve of this invention. It is sectional drawing which shows an example of the manufacturing method of the microvalve of this invention. It is sectional drawing which shows another example of the microvalve of this invention.

Explanation of symbols

1 Microvalve 10 First substrate 12 Diaphragm 13 Valve (valve element)
19 Diaphragm unit 20 Second substrate 26 Opening / closing detection means 30 Third substrate 32 Inlet 33 Outlet

Claims (11)

A first substrate having a valve body and a fixing portion on one surface side of the diaphragm, a second substrate having a groove formed at a position facing the diaphragm, and a position facing the valve body And a third substrate on which at least one or both of the fluid inlet and outlet are formed, and the third substrate, the first substrate, and the second substrate are overlaid and fixed. It is a micro valve that is joined and integrated at the part,
A microvalve comprising an open / close detection means for detecting deformation of the diaphragm portion.   The open / close detection means includes a first electrode formed on the other surface side of the diaphragm part and a second electrode formed at a position facing the first electrode in the groove part. A micro valve according to claim 1.   2. The microvalve according to claim 1, wherein the open / close detection means comprises a piezoresistive element formed in the diaphragm portion.   4. The microvalve according to claim 3, wherein a plurality of the piezoresistive elements are formed and arranged such that directions of applying stress are different from each other when the diaphragm portion is deformed.   The microvalve according to any one of claims 1 to 4, wherein the groove portion is further formed with a fluid opening portion for driving the valve body portion and the diaphragm portion. A first substrate having a valve body and a fixing portion on one surface side of the diaphragm, a second substrate having a groove formed at a position facing the diaphragm, and a position facing the valve body And a third substrate on which at least one or both of the fluid inlet and outlet are formed, and the third substrate, the first substrate, and the second substrate are overlaid and fixed. A method of manufacturing a microvalve that is integrally joined at a portion,
At least a step of forming a first electrode on the other surface side of the diaphragm portion, and a step of forming a second electrode at a position facing the first electrode in the groove portion. Microvalve manufacturing method. A first substrate having a valve body and a fixing portion on one surface side of the diaphragm, a second substrate having a groove formed at a position facing the diaphragm, and a position facing the valve body And a third substrate on which at least one or both of the fluid inlet and outlet are formed, and the third substrate, the first substrate, and the second substrate are overlaid and fixed. A method of manufacturing a microvalve that is integrally joined at a portion,
A method of manufacturing a microvalve comprising at least a step of forming a piezoresistive element in the diaphragm portion. A first substrate having a valve body and a fixing portion formed on one surface side of the diaphragm portion and a first electrode formed on the other surface side of the diaphragm portion, and a groove portion at a position opposite to the diaphragm portion A second substrate in which the second electrode is formed at a position facing the first electrode in the groove, and a fluid inlet and an outlet at a position facing the valve body, A third substrate on which at least one or both are formed, and opening and closing a microvalve formed by superimposing the third substrate, the first substrate, and the second substrate, and joining and integrating them at the fixing portion A detection method,
Opening and closing of the microvalve characterized by detecting the opening and closing states of the valve body portion with respect to the inlet and outlet by measuring the capacitance between the first electrode and the second electrode Detection method.   9. An opening for allowing fluid to flow in and out is formed in the groove, and the valve body and the diaphragm are driven by allowing fluid to flow in and out through the opening. The opening / closing detection method of the microvalve described.   A direct current that drives the valve body and the diaphragm is applied between the first electrode and the second electrode, and between the first electrode and the second electrode, 9. The microvalve according to claim 8, wherein the capacitance between the first electrode and the second electrode is measured by applying an alternating current having a voltage lower than the voltage value of the direct current. Open / close detection method. 9. The microvalve open / close detection method according to claim 8, wherein a piezoresistive element is formed in the diaphragm, and a voltage value that changes in accordance with a resistance value of the piezoresistive element is measured.

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