JP2014016272A - Detection sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection sensor 20 which can prevent creeping of liquid, such as sample liquid, on a back surface side of a piezoelectric piece 31 placed inside a recessed part 23 and perform highly reliable measurement in the detection sensor 20 in which a common piezoelectric piece 31 where a first piezoelectric oscillator 3A and a second piezoelectric oscillator 3B are formed is placed so as to close the recessed part 23 on a wiring board 2.SOLUTION: A water-repellent agent 30 is adhered inside a recessed part 23 placed in the detection sensor 20 and provided with a piezoelectric piece 31, liquid which is entering the recessed part 23 is repelled, so that creeping of the liquid on a back surface side of the piezoelectric piece 31 is preventable. Thus, it is possible to prevent defect caused by the liquid being adhered on an electrode on the back surface side of the piezoelectric piece 31. Also, a similar effect can be obtained by sealing up a space between the piezoelectric piece 31 and a circumferential wall surface of the recessed part 23 with a seal material 8.

Description

  The present invention relates to a sensing sensor for sensing a sensing object using a piezoelectric vibrator that changes its natural frequency by adsorbing to the adsorption layer provided on the surface of the sensing object.

  As a method for detecting a detection object in a sample fluid, for example, a trace amount of protein in blood or serum, a detection sensor using QCM (Quartz Crystal Microbalance) as shown in Patent Document 1, for example, is shown. The QCM is provided with an adsorption film on the surface of the excitation electrode of the quartz vibrator provided in the sensing sensor, and adsorbs the sensing object by antigen-antibody reaction. The sensing object is quantified based on the change in the frequency of the crystal unit due to the load.

  Specifically, the frequency when the reference liquid that does not include the sensing object is supplied and the frequency when the sample liquid with the unknown presence or concentration of the sensing object is supplied are detected, and these frequencies are detected. The detection of the sensing object and the measurement of the concentration are performed assuming that the difference in frequency corresponds to the mass of the sensing object adsorbed on the adsorption film. The sample liquid supply flow path side of the crystal unit is grounded, and the electrode not in contact with the sample liquid on the back surface is an electrode for acquiring the frequency for detection and reference.

  When such a sensor is used, for example, in the clinical field or food inspection field, it is often performed using a simple device, and a small, simple device that accurately detects the device is required. ing. However, if the supply flow path is made narrower for downsizing and simplification of the sensor, the flow rate and flow rate will change due to slight unevenness, so by installing a crystal piece in the supply flow path, In some cases, the flow rate and flow velocity are not stable, or the sample solution is not supplied onto the excitation electrode.

  Further, when the sensor is downsized, the space between the electrodes becomes narrower, so that the electrode gets wet by a slight sample liquid or reference liquid that wraps around the back surface of the crystal piece, and is based on the adhering liquid or the first liquid. On the basis of the conduction between the excitation electrode and the second excitation electrode, oscillation may be weakened or accurate oscillation may not be possible.

JP 2009-206792 A

  The present invention has been made under such circumstances, and an object thereof is to close a concave portion on a wiring board with a common piezoelectric piece on which a first piezoelectric vibrator and a second piezoelectric vibrator are formed. An object of the present invention is to provide a sensor that can perform measurement with high reliability by preventing a liquid such as a sample liquid from flowing around a back surface of a piezoelectric piece located in a recess.

The sensing sensor of the present invention comprises a wiring board having a connection terminal portion connected to a measuring instrument for measuring an oscillation frequency and having a recess formed on one surface side,
An excitation electrode is provided on a common piezoelectric piece arranged on the wiring board so as to close the recess so that each vibration region faces the recess, and each excitation electrode is electrically connected to the connection terminal portion. A first piezoelectric vibrator and a second piezoelectric vibrator;
Forming a flow path that is provided so as to cover a region on one surface side of the wiring substrate including the first piezoelectric vibrator and the second piezoelectric vibrator and that supplies a sample liquid to the area. An adsorbing film that is provided on only one of the member and the first piezoelectric vibrator and the second piezoelectric vibrator so as to face the flow path and adsorbs a sensing object in the sample liquid;
A water repellent that is attached to the recess and has a greater water repellency than the material that forms the recess, in order to prevent the liquid from entering the recess.
The water-repellent region prevents the detection electrode and the reference electrode from being electrically connected to each other by the sample liquid.

  In the sensing sensor of the present invention, each of the excitation electrodes of the first piezoelectric vibrator and the second piezoelectric vibrator has a ground electrode on the side facing the flow path, and faces the recess. The excitation electrode on the side may be a detection electrode and a reference electrode, and the water-repellent region may be provided on the bottom surface of the recess.

Alternatively, the sensing sensor of the present invention includes a wiring board having a connection terminal portion connected to a measuring instrument for measuring an oscillation frequency and having a recess formed on one surface side,
An excitation electrode is provided on a common piezoelectric piece arranged on the wiring board so as to close the recess so that each vibration region faces the recess, and each excitation electrode is electrically connected to the connection terminal portion. A first piezoelectric vibrator and a second piezoelectric vibrator;
Forming a flow path that is provided so as to cover a region on one surface side of the wiring substrate including the first piezoelectric vibrator and the second piezoelectric vibrator and that supplies a sample liquid to the area. Members,
An adsorbing film that is provided on only one of the first piezoelectric vibrator and the second piezoelectric vibrator so as to face the flow path and adsorbs a sensing object in a sample liquid;
A non-conductive sealing agent provided so as to close a space between the peripheral wall surface of the recess and the first and second piezoelectric vibrators. In each of the excitation electrodes of the first and second piezoelectric vibrators, the excitation electrode on the side facing the flow path is a ground electrode, and the excitation electrode on the side facing the recess is the detection electrode and the reference It may be a feature electrode.

In the present invention, an adsorption film that adsorbs a sensing object in a sample solution is formed on one of a first piezoelectric vibrator and a second piezoelectric vibrator formed on a common piezoelectric piece, and is formed on a wiring board. In the sensing sensor in which the piezoelectric piece is arranged so as to close the concave portion, the water repellent is adhered in the concave portion, so that the liquid entering the concave portion is repelled. Wraparound can be suppressed. Therefore, it is possible to prevent a problem that the liquid adheres to the electrode on the back surface side of the piezoelectric piece.
The other invention has the same effect because the space between the piezoelectric piece and the peripheral wall surface of the recess is closed by the sealing material.

1 is a perspective view of a sensing device according to the present invention. It is a perspective view of the sensing sensor which comprises the said sensing device. It is the disassembled perspective view which showed the upper surface side of each part of a detection sensor. It is the disassembled perspective view which showed the lower surface side of each part of a detection sensor. It is a vertical side view which shows the structure of the said crystal oscillator and a recessed part. It is a perspective view which shows the structure of the said crystal oscillator and a recessed part. It is a top view which shows the upper surface side of the crystal oscillator which comprises the said sensor. It is a top view which shows the lower surface side of the crystal oscillator which comprises the said sensor. It is a top view which shows the state which installed the said crystal oscillator in the supply flow path. It is a schematic block diagram of the said sensing apparatus. It is explanatory drawing explaining the effect | action of the sensing sensor of this invention. It is a vertical side view of the sensing sensor which concerns on other embodiment. It is a vertical side view which shows the structure of the sensing sensor which concerns on 2nd Embodiment. It is a top view which shows the structure of the sensing sensor which concerns on 2nd Embodiment. It is a top view which shows the structure of the sensing sensor which concerns on other embodiment.

  Hereinafter, a sensing device using the sensing sensor 20 according to the embodiment of the present invention will be described. This sensing device is configured to detect the presence or absence of human influenza virus infection by detecting the presence or absence of an antigen such as influenza virus in a sample liquid obtained from, for example, a human nasal wipe. Yes. As shown in the external perspective view of FIG. 1, the sensing device includes a measuring device 11 including an oscillation circuit unit 12 and a main body 13, and a detection sensor 20 that is detachably connected to the oscillation circuit unit 12 of the measuring device 11. The oscillation circuit unit 12 is connected to the main body 13 via a coaxial cable 14, for example. The display unit 15 provided on the front surface of the main body unit 13 serves to display, for example, the measurement result of the frequency or the change in the frequency, and is configured by a liquid crystal display screen, for example.

  FIG. 2 is a perspective view of the sensing sensor 20, and the wirings and electrodes in the subsequent drawings are hatched to distinguish them from the substrate or the like. The sensing sensor 20 includes a wiring board 2, a crystal resonator 3 that is one of piezoelectric resonators, and a flow path forming member 4, and has a length of about 2.0 cm and a width of about 1.2 cm. Consists of dimensions. FIG. 3 is an exploded perspective view showing the upper surface side of each part of the sensing sensor 20, and FIG. 4 is an exploded perspective view showing the lower surface side of each part of the sensing sensor 20. FIG. 5 is a longitudinal side view showing the configuration of the crystal unit 3 and the wiring board 2, and FIG. 6 is an exploded perspective view showing the configuration of the recess 23 provided in the crystal unit 3 and the wiring board 2. . The sensing sensor 20 will be described with reference to FIGS.

  The wiring board 2 has a connection terminal portion 22 inserted into the oscillation circuit unit 12 on one end side in the length direction. A rectangular recess 23 is formed with a depth of 0.1 mm on the other end side of the wiring board 2 (hereinafter referred to as a tip end portion 21). The recess 23 is provided with a step 24 for supporting the peripheral edge of the crystal unit 3 along the inner wall. A water repellent 30 (specifically, for example, Adesso) having a water repellency greater than the water repellency of the recess 23 is provided on the bottom surface of the recess 23 provided on the wiring board 2. Apply to the entire bottom surface to form a water repellent area.

  Wirings 25, 26, and 27 are provided on the upper surface of the wiring board 2. These wirings 25 to 27 are routed from one end side (connection terminal portion 22 side) of the wiring board 2 to the step 24 of the recess 23 and are formed to extend in parallel along the length direction of the wiring board 2. Has been. Terminals 25a, 26a, and 27a are formed on the connection terminals 22 side of the wirings 25, 26, and 27, respectively. The wires 25, 26, and 27 are routed from the outer edge of the recess 23 to the bottom of the recess 23, and the ends of the wires form terminal portions 25b, 26b, and 27b, respectively.

  Next, the crystal unit 3 will be described with reference to FIGS. 7 and 8 showing the upper and lower surfaces, respectively. The quartz resonator 3 is formed on a rectangular quartz piece 31 that is, for example, AT-cut and has a width of 2.5 mm, a length of 5.0 mm, and a thickness of 0.05 mm. On the crystal piece 31, if the length direction of the crystal piece 31 is the front-rear direction, the left half and the right half are assigned to the first crystal oscillator 3A and the second crystal oscillator 3B, respectively. Hereinafter, the left half region and the right half region of the crystal piece 31 will be referred to as a first vibration region 32a and a second vibration region 32b, respectively.

In FIG. 7 and FIG. 8, the first vibration region 32a and the second vibration region 32b are respectively surrounded by dotted lines. An excitation electrode 33a is formed on the upper surface side of the first vibration region 32a, and an excitation electrode 33b is formed on the upper surface side of the second vibration region 32b. On the other hand, an excitation electrode 34a is formed on the lower surface side of the first vibration region 32a, and an excitation electrode 34b is formed on the lower surface side of the second vibration region 32b. These excitation electrodes 33a, 33b, 34a, 34b are formed by slightly changing the thickness of the quartz piece 31 or the mass of the excitation electrodes 33a, 33b, 34a, 34b provided in the respective vibration regions 32a, 32b. The oscillation frequency of the main mode from the crystal unit 3A and the second crystal unit 3B is made different.
In addition, an adsorption film (not shown) made of an antibody that selectively binds to an antigen as a sensing object is provided on the surface of the excitation electrode 33a provided in the first vibration region 32a. On the other hand, an inhibition film (not shown) that inhibits the binding between the antigen and the excitation electrode 33b is provided on the surface of the excitation electrode 33b in the second vibration region 32b.

  The excitation electrodes 33a and 33b on the upper surface side are connected to each other, and the extraction electrode 35 is extended from the connection portion toward the periphery of the crystal piece 31. The extraction electrode 35 is routed to the peripheral edge of the lower surface of the crystal piece 31 through the side surface of the crystal piece 31. From the excitation electrodes 34 a and 34 b on the lower surface side of the crystal piece 31, extraction electrodes 36 a and 36 b are drawn out in the length direction of the crystal piece 31 toward the outer side.

  When the crystal unit 3 is placed on the step 24 provided in the recess 23, the excitation electrodes 34 a and 34 b provided on the lower surface of the crystal unit 3 are connected to the bottom surface of the recess 23 and the water repellent 30. It arrange | positions so that it may oppose through the clearance gap of about 20 micrometers. The terminal portions 26b and 27b routed to the step 24 of the recess 23 are connected to the extraction electrodes 36a and 36b from the excitation electrodes 34a and 34b on the lower surface side of the crystal piece 31, respectively. Are connected to the terminal portion 25b routed to the lead electrode 35 routed from the excitation electrodes 33a and 33b on the upper surface side of the crystal piece 31.

  When the crystal resonator 3 is placed on the step 24, the height position of the upper surface is located within a range of 0.05 mm vertically from the height position of the upper surface of the wiring board 2. As will be described later, when the detection sensor 20 is connected to the main body 13, the terminal portions 25a, 26a, 27a extended on the wiring board 2 are connected to the main body 13, and each of the terminal portions 26a, 27a is the first one. The oscillation circuit and the second oscillation circuit are connected, and the terminal portion 25a is grounded. The first oscillation circuit outputs a frequency for detecting the mass of the antigen, and the second oscillation circuit is used for outputting a reference frequency. That is, the excitation electrodes 34a and 34b facing the recess 23 become a detection electrode 34a and a reference electrode 34b, respectively, and the excitation electrodes 33a and 33b on the upper surface side of the crystal resonator 3 become ground-side electrodes 33a and 33b, respectively.

  Next, the flow path forming member 4 will be described with reference to FIG. 9 which is a cross-sectional plan view. The flow path forming member 4 is formed in a square plate shape, and is laminated on the surface of the distal end portion 21 of the wiring board 2. When the direction in which the connection terminal portion 22 of the wiring board 2 is provided is the rear side and the tip end portion 21 is the front side, a sample solution injection port 41 is opened in a circle on the front side of the flow path forming member 4. The flow path forming member 4 is penetrated in the thickness direction. A waste liquid port 42 for storing and discharging the sample solution after detection is opened behind the injection port 41 and is configured to penetrate the flow path forming member 4 in the thickness direction in the same manner as the injection port 41. Has been. Both the inlet 41 and the waste liquid port 42 are configured to be out of the projection area of the crystal unit 3, and the waste liquid port 42 is configured to have a larger volume than the injection port 41.

  The configuration of the back surface of the flow path forming member 4 will be described. On this back surface, the enlarged flow path portion 43 is further rearward than the waste liquid port 42 and the wiring is formed when the flow path forming member 4 and the wiring board 2 are laminated. It is formed at a position facing the concave portion 23 provided on the substrate 2 and the crystal unit 3. A first linear channel 44 is formed between the injection port 41 and the enlarged channel part 43 so as to be connected to each other. Similarly, a second linear channel 44 that connects the enlarged channel part 43 and the waste liquid port 42 to each other is formed. The linear flow path 45 is formed.

  The flow path forming member 4 is made of, for example, PDMS (polydimethylsiloxane) having a high self-adsorption property. The flow path forming member 4 is plasma-cleaned to activate its surface and remove organic substances on the surface. Therefore, the affinity with the supply liquid of the first and second linear flow paths 44 and 45 and the supply flow path 43 is enhanced, the flow of the supply liquid is facilitated, and the flow path forming member 4 and the wiring board are provided. Adhesion with 2 is enhanced, and leakage of the supply liquid from these gaps is prevented. The flow path forming member 4 can be made of, for example, acrylic resin or quartz other than PDMS.

  A cylindrical filter 46 is detachably provided at the inlet 41 provided in the flow path forming member 4. The filter 46 is a porous body, and is configured by bundling straw-shaped chemical fibers made of, for example, cellulose, and a plurality of small holes are also formed on the side wall of the straw. The filter 46 has a role of preventing clogging of the flow path by capturing foreign substances contained in the supply liquid in the holes. On the other hand, the size is such that the fine particles are sufficiently passed while holding the supply liquid so as not to prevent the passage of the antigen contained in the supply liquid. The material of the filter 46 is not limited to cellulose, but it is preferable to select a material having a high affinity with the supply liquid in order to allow the supply liquid to pass through quickly.

  The flow path forming member 4 is laminated on the distal end portion 21 of the wiring board 2 in which the filter 46 is inserted into the injection port 41 and the crystal resonator 3 is loaded. When the flow path forming member 4 closely contacts the wiring substrate 2 and the crystal unit 3, the lower side of the first linear flow path 44, the second linear flow path 45, and the enlarged flow path portion 43 is closed. A flow path is formed that connects from the inlet 41 to the waste liquid port 42 via the first linear flow path 44, the supply flow path 40, and the second linear flow path 45.

  When the connection terminal portion 22 of the sensing sensor 20 is inserted into the oscillation circuit unit 12, the terminal portions 25a, 26a, and 27a of the connection terminal portion 22 correspond to the terminal portions 25a, 26a, and 27a in the oscillation circuit unit 12. The sensing device 1 shown in FIG. 1 is configured by being electrically connected to the connection terminal portion formed as described above. FIG. 10 is a schematic configuration diagram of the sensing device 1, and the oscillation circuit unit 12 is provided with a first oscillation circuit 64 and a second oscillation circuit 65. The first oscillation circuit 64 is a first crystal oscillation. The second oscillation circuit 65 causes the second crystal resonator 3B to oscillate the child 3A.

  Next, each unit provided in the main body unit 13 constituting the sensing device will be described. A switch unit 66 is provided following the oscillation circuits 64 and 65, and the frequency signal from the two oscillation circuits 64 and 65 is taken into the data processing unit 67 by the switch unit 66. The data processing unit 67 digitally processes a frequency signal as an input signal, and oscillates by the first oscillation circuit 64. The time series data of the oscillation frequency “F1” and the oscillation frequency “F2” from the second oscillation circuit 64 are obtained. ”Is acquired. Further, the difference “F1−F2” of each time series data is calculated, the time series data of the difference data is acquired, and the graph of “F1−F2” is displayed on the display unit 15.

  The operation of the sensing device 1 using the sensing sensor 20 according to the embodiment of the present invention will be described. In addition, in the supply liquid, a liquid for making the surroundings of the crystal unit 3 into a liquid atmosphere without including the sensing object is referred to as a reference liquid, and the sensing sensor 20 is used to determine whether or not the sensing object is included. The liquid to be supplied is referred to as a sample liquid. In this example, the reference solution is physiological saline, and the sample solution is obtained by diluting a human nasal wiping solution with physiological saline.

  First, when the measuring instrument 11 is activated and the sensing sensor 20 is inserted into the oscillation circuit unit 12, the crystal resonators 3A and 3B oscillate, and the frequency signals F1 and F2 corresponding to the respective frequencies are taken out. These frequency signals are time-divided and taken into the data processing unit 57 and A / D converted, and then each digital value is subjected to signal processing. The frequencies “F1, F2” are extracted from the frequency signals of the two channels and stored in a memory (not shown), and “F1-F2” is calculated based on the stored “F1, F2” and stored in the memory. The stored operation is continued. Further, the above-described graph is displayed on the display unit 15, and the change in the frequency difference “F1-F2” is displayed in real time.

  Next, the user drops a reference solution, for example, physiological saline, into the injection port 41 of the sensing sensor 20 with a dropper. The reference liquid supplied to the inlet 41 is absorbed by the filter 46, descends downward in the filter 43 due to gravity, and is supplied to the first linear channel 44. The supply liquid flows through the first linear channel 44 and is supplied to the supply channel 40 by capillary action. When the reference liquid flows through the supply flow path 40, the environmental atmosphere of the first and second vibration regions 32a and 32b of the crystal unit 3 provided in the supply flow path 40 changes from the gas phase to the liquid phase, and the viscosity of the liquid The output frequency F1, F2 of each channel decreases due to the increase in resistance based on.

Here, when the supply liquid flows through the supply flow path 40, the supply liquid may not spread uniformly due to the undulation of the supply flow path 40. In the detection sensor 20 according to the embodiment of the present invention, the wiring board 2 is provided with a recess 23 and the crystal resonator 3 is inserted, and the height position on the upper surface side of the crystal resonator 3 is It is configured to be in the range of 0.05 mm vertically from the height position of the upper surface. Therefore, the supply liquid can be stably supplied onto the ground electrodes 32a and 32b with less unevenness in the supply flow path 40. Further, when the supply channel 40 is filled with the supply liquid, the supply liquid flows from the periphery of the crystal piece 31, and the detection electrode 34a and the reference electrode 34b provided on the lower surface side of the crystal resonator 3 are mutually connected by the supply liquid. It becomes conductive. In the sensing sensor 20 according to the embodiment of the present invention, the water repellent 30 is applied to the bottom surface of the recess 23 to form a water repellent region. Therefore, as shown in FIG. 11, even when the supply liquid enters from the gap between the crystal resonator 3 and the recess 23, the supply liquid stays at the edge of the crystal piece 31 due to the action of the water repellent 30. Since the detection electrode 34a and the reference electrode 34b are not conducted by the supply liquid, the output frequency is stable.
When the reference liquid expands the supply flow path 40, the reference liquid flows through the second linear flow path 45 and flows through the second linear flow path 45 by capillary action as in the first linear flow path 44. . When the reference liquid passes through the second linear flow channel 45, it flows out to the waste liquid port 42 and is stored in the waste liquid port 42.

Subsequently, the sample solution is dropped into the injection port 41. The sample liquid is absorbed by the filter 46 in the same manner as the reference liquid, and moves downward through the filter 46 due to gravity, whereby the reference liquid remaining on the filter 46 is pushed downstream, and all of the reference liquid is supplied. It flows through the path 40 and heads toward the waste liquid port 42.
Then, the sample solution enters the supply channel 40 by the capillary phenomenon of the filter 46 in the same manner as the reference solution, flows so as to spread along the outer edge of the supply channel 40, and the liquid phase in the supply channel 40 is the reference solution. Is replaced with the sample solution. When the sample object contains a sensing object, the first crystal resonator 3A adsorbs the antigen by the antigen-antibody reaction, so that a mass load is applied and the oscillation frequency changes. On the other hand, in the second crystal unit 3B, no mass load is caused by the adsorption of the antigen. When the sample liquid contains an antigen, in the first crystal resonator 3A, in addition to the frequency changing due to the temperature and viscosity of the sample liquid, the antigen is adsorbed to the adsorption film by the antigen-antibody reaction, and due to the mass load effect The value of the frequency “F1” further decreases. On the other hand, a frequency “F2” that changes in accordance with the temperature and viscosity of the sample solution is output from the channel 2 on the second crystal resonator 3B side. As a result of such a frequency change, the frequency “F1-F2” decreases. The sample liquid flows from the supply channel 40 to the waste liquid port 42 and is stored. When the amount of liquid in the waste liquid port 42 increases and the water pressure increases, the movement of the sample liquid from the injection port 41 stops.

  When the sample solution does not contain the antigen, it flows in the same way as when it contains the antigen. However, the above-described antigen-antibody reaction does not occur in the first crystal unit 3A, and the temperature of the sample solution is increased from channel 1 and channel 2. Since the frequencies “F1” and “F2” that change according to the viscosity are extracted, the frequency difference hardly changes. Then, a difference value a−b between the value “a” of “F1−F2” from a certain time t1 to t2 and the value “b” of “F1−F2” after time t2 is calculated, and this difference value ab is a predetermined allowable value. If it falls within the value, it is determined that there is no antigen in the sample solution, and if the difference value a−b exceeds the allowable value, it is determined that the antigen is present in the sample solution.

  According to the above-described sensing sensor 20, the concave portion 23 is formed on the wiring substrate 2 and the crystal resonator 3 is fitted, whereby the undulation of the supply flow path 40 is reduced, and the upper surface of the crystal resonator 3. The supply liquid is stably supplied to the side. Further, by applying a water repellency to the recess 23, the supply liquid is prevented from flowing into the lower surface side of the crystal unit 3 facing the bottom surface of the recess 23. Since the detection electrode 34a and the reference electrode 34b provided on the lower surface side of the crystal resonator 3 are prevented from being electrically connected to each other by the supply liquid, stable measurement can be performed.

  A recess formed in the wiring board 2 is formed by forming an adsorption film that adsorbs a sensing object in the sample liquid on one of the first piezoelectric vibrator 3A and the second piezoelectric vibrator 3B formed on the common piezoelectric piece. In the sensing sensor 20 in which the piezoelectric piece 31 is arranged so as to close the 23, the water repellent 30 is adhered in the recess 23, so that the liquid that is going to enter the recess 23 is repelled. It is possible to suppress the sneak in of the liquid to the back side. Accordingly, it is possible to prevent a problem that the liquid adheres to the electrode on the back surface side of the piezoelectric piece 31.

  The sensing sensor 1 according to the embodiment of the present invention may have a configuration in which a supply liquid is supplied onto the crystal unit 3 and discharged from the crystal unit 3. As shown in FIG. 12, the upper flow path forming member 61 and the lower flow path forming member 62 are configured to be stacked on the wiring board 2. When the lower flow path forming member 62 and the wiring board 2 are stacked, the enlarged flow path portion 63 is provided at a position facing the concave portion 23 and the crystal vibrator 3 provided in the wiring board 2 and the crystal vibrator 3 is inserted. The supply flow path 64 is configured by stacking on the wiring board 2. A water repellent 30 is applied to the bottom surface of the recess 23 provided on the wiring board 2 so that the supply liquid does not crawl around the excitation electrodes 34 a and 34 b facing the recess 23. An injection port 65 penetrating the lower flow path forming member 62 in the thickness direction is provided at a position above the front end of the crystal piece 31, and the lower flow path forming member 62 is thickened at a position above the front end of the crystal piece 31. A waste liquid port 66 penetrating in the vertical direction is provided. The injection port 65 and the waste liquid port 66 are provided with columnar filters 67 and 68 made of a porous material.

A mortar-shaped injection port 69 is provided on the upper surface side of the upper flow path forming member 61. The bottom of the injection port 69 is connected to the injection port 65 and the upper part of the filter 67 is exposed. A waste liquid reservoir 70 is provided on a lower surface side of the upper flow path forming member 61 at a position lower than the above-described injection port 69, and is connected to the waste liquid port 66. The supply liquid supplied to the injection port 69 is absorbed by the filter 67 of the injection port 65, and is supplied to the supply channel 64 by the capillary phenomenon of the filter 67 and gravity. The supply liquid supplied to the supply flow path 64 flows so as to expand the supply flow path 64 and fills the supply flow path 64. When the supply liquid fills the supply flow path 64, the supply liquid is absorbed by the filter 68 provided at the waste liquid port 66. The waste liquid pool 70 is located at a position lower than the injection port 69. Therefore, the supply liquid is circulated from the supply flow path 64 to the waste liquid pool 70 by the capillary phenomenon caused by the filters 67 and 68 and the siphon effect. Even in the case of the sensing sensor 20 having such a configuration, since the conduction between the detection electrode 34a and the reference electrode 34b due to the wraparound of the supply liquid can be prevented, stable detection can be performed.
Alternatively, the water repellent 30 may be applied to the gap between the wall surface of the recess 23 and the crystal piece 31 to prevent the supply liquid from entering.

[Second Embodiment]
As a second embodiment, the water repellent 30 is applied so that the back surface side detection electrode 34a and the reference electrode 34b are not electrically connected to each other by the supplied liquid, but the crystal piece is formed by the sealing agent 8. It is also possible to configure so that the supply liquid does not turn to the lower surface side by closing the gap around the bottom surface. For the sealing agent 8, for example, a non-conductive material such as silicon resin is used.

  For example, as shown in FIGS. 13 and 14, the step 23 is not provided in the recess 23 formed in the wiring substrate 2, and the wirings 25, 26, 27 routed on the wiring substrate 2 are routed to the side wall of the recess 23, 25b, 26b, 27b. On the other hand, the lead electrodes 35, 36 a, and 36 b led from the ground electrodes 33 a and 33 b, the detection electrode 34 a, and the reference electrode 34 b are routed to the side surface of the crystal piece 31. A conductive adhesive 81 is applied to the terminal portions 25b, 26b, 27b provided on the side wall of the recess 23 of the wiring board 2 and the lead electrodes 35, 36a, 36b drawn around the side surface of the crystal piece 31, and the crystal piece 31 is inserted into the recess 23. The conductive adhesive 81 is applied again to the joint between the terminal portions 25b, 26b, and 27b and the lead electrodes 35, 36a, and 36b, and then cured, so that the height position of the crystal piece 31 is the height of the surface of the wiring board 2. From the position, it is fixed so that it is located between 0.05 mm up and down.

  After the conductive adhesive 81 is cured, sealing is performed from the gaps around the crystal piece 31 caused by the thicknesses of the respective terminal portions 25b, 26b, 27b and the lead electrodes 35, 36a, 36b and the conductive adhesive 81. Agent 8 is filled with a dispenser. In addition, although FIG. 14 is a top view, the sealing agent 8 in the figure was hatched. At this time, in order to prevent the CI value of the crystal resonator 3 from increasing, the sealing agent 8 is filled so as not to contact the detection electrode 34 a and the reference electrode 34 b provided on the crystal piece 31. After leveling the sealing agent 8 on the peripheral edge of the crystal piece 31, the portion connected to the electrode end by the conductive adhesive 81 is closed with the sealing agent 8. Even in such a configuration, it is possible to prevent the detection electrode 34a and the reference electrode 34b from being conducted by the supply liquid, and thus the same effect can be obtained. Further, the crystal unit 3 may not be a rectangular crystal piece but may be configured using a disk-like crystal piece 9 as shown in a plan view in FIG.

DESCRIPTION OF SYMBOLS 1 Sensing apparatus 2 Wiring board 3 Crystal oscillator 4 Channel formation member 11 Measuring device 12 Oscillation circuit unit 20 Sensing sensor 22 Connection terminal part 31 Crystal piece 33a, 33b Ground electrode 34a Detection electrode 34b Reference electrode 40 Supply channel 41 Inlet 42 Waste liquid port

Claims (5)

A wiring board having a connection terminal portion connected to a measuring instrument for measuring an oscillation frequency and having a recess formed on one surface side;
An excitation electrode is provided on a common piezoelectric piece arranged on the wiring board so as to close the recess so that each vibration region faces the recess, and each excitation electrode is electrically connected to the connection terminal portion. A first piezoelectric vibrator and a second piezoelectric vibrator;
Forming a flow path that is provided so as to cover a region on one surface side of the wiring substrate including the first piezoelectric vibrator and the second piezoelectric vibrator and that supplies a sample liquid to the area. An adsorbing film that is provided on only one of the member and the first piezoelectric vibrator and the second piezoelectric vibrator so as to face the flow path and adsorbs a sensing object in the sample liquid;
A water repellent that is attached to the recess and has a greater water repellency than the material that forms the recess, in order to prevent the liquid from entering the recess.
A sensing sensor, wherein the water repellent region prevents the detection electrode and the reference electrode from being electrically connected to each other by a sample solution.   In each excitation electrode of the first piezoelectric vibrator and the second piezoelectric vibrator, the excitation electrode on the side facing the flow path is a ground electrode, and the excitation electrode on the side facing the recess is a detection electrode The sensing sensor according to claim 1, wherein the sensing sensor is a reference electrode.   The sensor according to claim 1, wherein the water repellent region is provided on a bottom surface of the recess. A wiring board having a connection terminal portion connected to a measuring instrument for measuring an oscillation frequency and having a recess formed on one surface side;
An excitation electrode is provided on a common piezoelectric piece arranged on the wiring board so as to close the recess so that each vibration region faces the recess, and each excitation electrode is electrically connected to the connection terminal portion. A first piezoelectric vibrator and a second piezoelectric vibrator;
Forming a flow path that is provided so as to cover a region on one surface side of the wiring substrate including the first piezoelectric vibrator and the second piezoelectric vibrator and that supplies a sample liquid to the area. Members,
An adsorbing film that is provided on only one of the first piezoelectric vibrator and the second piezoelectric vibrator so as to face the flow path and adsorbs a sensing object in a sample liquid;
A sensing sensor comprising: a peripheral wall surface of the recess; and a non-conductive sealing agent provided so as to block between the first piezoelectric vibrator and the second piezoelectric vibrator.   In each excitation electrode of the first piezoelectric vibrator and the second piezoelectric vibrator, the excitation electrode on the side facing the flow path is a ground electrode, and the excitation electrode on the side facing the recess is a detection electrode The sensing sensor according to claim 4, wherein the sensing sensor is a reference electrode.

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