JP6569110B2 - Sensor module - Google Patents

Description

  The present invention relates to a sensor module.

  In recent years, a sensor device that easily and accurately measures a very small amount of sample has been demanded. As such a sensor device, for example, as described in Patent Document 1, there is a device that detects a specific substance by fluctuations in the surface stress of a flat member, and other fluid is mixed into the measurement fluid. Is required to improve the reliability of the sensor device.

Japanese Patent No. 5649138

The sensor module of the present disclosure is a sensor module that detects a substance in a fluid, and includes a sensitive part and a housing. The sensitive part changes its characteristics in response to a substance in the fluid. Sensor module has a first flow path for supplying the first fluid to the sensing portion, and a second flow path for supplying the second fluid to the sensitive part. The housing houses the sensitive part and the flow path, and has a first surface and a second surface facing the first surface. The end of the first flow path of the sensor module is positioned through the first surface, and the end of the second flow path is positioned through the second surface. The sensor module detects the substance by a change in the characteristic of the sensitive part.

It is the upper side figure showing the outline of the sensor module concerning one embodiment of the present invention. It is the figure which showed the outline | summary of the one part structure of the sensor module concerning one Embodiment of this invention. It is the figure which showed the outline | summary of the one part structure of the sensor module concerning one Embodiment of this invention.

  A sensor module 1 according to an embodiment of the present invention will be described with reference to the drawings. In the sensor module 1 according to the embodiment of the present invention, any direction may be upward or downward, but in the following description, an orthogonal coordinate system (X, Y, Z) is defined for convenience. The positive side in the Z-axis direction is the upper side.

  As shown in FIG. 1, the sensor module 1 includes a sensitive part 2 that changes characteristics in response to a specific substance in a fluid, a chamber 3 that surrounds the sensitive part 2, and a sensitive part 2 in the chamber 3 (FIG. 2). It has a flow path 4 for supplying or discharging a fluid, and a housing 5 for housing components of the sensor module 1. As a result, the sensor module 1 supplies a fluid such as gas or liquid to the sensitive unit 2 via the flow path 4 and detects a change in characteristics in the sensitive unit 2, thereby detecting a specific substance (specimen) in the fluid. ) Can be detected.

  The sensitive unit 2 according to the present embodiment changes the current value in response to the specimen, and the sensor module 1 according to the present embodiment detects a change in the current value. Further, the characteristic that the sensitive unit 2 according to the present invention changes in response to the specimen is not limited to the current value, but may change the refractive index. In this case, the sensor module 1 may detect a change in light intensity or the like.

  FIG. 1 schematically shows the inside of the housing 5 of the sensor module 1. Specifically, the internal structure of the sensor module 1 when the top surface of the housing 5 is removed is shown from above.

  As shown in FIG. 2, the sensitive portion 2 includes a sensitive film 6 and a piezo element (hereinafter also referred to as “piezoresistive element”) 7. The sensitive film 6 has a function of expanding or contracting in response to a specific substance. The piezoresistive element 7 changes its electrical resistance by receiving stress, for example, when the sensitive film 6 is expanded or contracted. As a result, the sensitive unit 2 can change the electrical resistance depending on a specific substance in the fluid.

  FIG. 2 shows an outline of the main part of the sensitive unit 2. Specifically, FIG. 2 is a cross-sectional view when the sensitive portion 2 is cut in the vertical direction.

  The sensitive film 6 is formed in a film shape. As the material of the sensitive film 6, a different material is selected for each specimen in consideration of reactivity with the specimen. For example, when it is desired to detect acetone, examples of the material of the sensitive film 6 include polyvinyl pyrrolidone, polymethyl methacrylate, and tin oxide. For example, when it is desired to detect hydrogen, the sensitive film 6 material is, for example, a magnesium nickel alloy.

  In addition, the sensitive film | membrane 6 can be formed by conventionally well-known methods, such as a needle type, an inkjet type, and a spray type.

  A specimen is supplied and adsorbed on one surface of the sensitive film 6. Then, the molecules of the specimen adsorbed on the surface of the sensitive film 6 cause steric repulsion, or the specimen and the sensitive film 6 react to generate stress on the surface of the sensitive film 6.

  As shown in FIG. 2, the piezoresistive element 7 has at least a conduction portion 9 and may have a base portion 8. The sensitive film 6 may be in contact with, for example, the conduction part 9 or the base part 8. The base portion 8 according to the present embodiment is an n-type substrate, and the conduction portion 9 is a p-type region formed by doping the base portion 8 with a p-type dopant such as boron. As a result, due to the stress of the sensitive film 6, the conducting part 9 receives the stress and the electrical resistance of the conducting part 9 changes.

  The piezoresistive element 7 can be formed by a conventionally known method such as an ion implantation method.

  As shown in FIG. 1, the sensor module 1 further includes a wiring board 10, and the sensitive unit 2 is installed on the wiring board 10. The wiring substrate 10 is configured to pass a current for driving the constituent members of the sensor module 1 or a current for driving the pump 18.

  The wiring substrate 10 is formed of, for example, a resin substrate and a ceramic substrate. The wiring board 10 can be formed by a conventionally known method.

  The chamber 3 has a function of reducing unintended fluid entry into the sensitive unit 2. As shown in FIG. 3, in the chamber 3, as shown in FIG. 3, a sensitive space 11 for adsorbing the specimen to the sensitive part 2, an introducing part 12 for introducing the specimen into the sensitive space 11, and a derivation part 13 for deriving fluid from the sensitive space 11 have. The chamber 3 according to this embodiment is hermetically sealed except for the introduction part 12 and the lead-out part 13. The introduction unit 12 according to the present embodiment includes a first introduction unit 14 and a second introduction unit 15.

  FIG. 3 is a diagram schematically showing the relationship between the sensitive unit 2 and the chamber 3. A part of the sensor module 1 shown in FIG. 1 is enlarged.

  The chamber 3 is fixed on the wiring substrate 10 by, for example, an adhesive or a fixture. For example, a resin material such as an epoxy resin is used as the adhesive. For example, a screw or the like is used as the fixture, and screw holes are formed in the chamber 3 and the wiring substrate 10 to fix the chamber 3. The chamber 3 is formed by a conventionally known method such as a 3D printer, a molding method, a pressing method, or a cutting method.

  The flow path 4 has openings at both ends. One opening is located outside the housing 5, and the other opening is located inside the housing 5. As a result, the flow path 4 has a function of supplying fluid from the outside of the housing 5 to the sensitive unit 2 inside the housing 5 and discharging fluid from the inside of the housing 5 to the outside of the housing 5. Have. Specifically, one opening of the flow path 4 is inserted into the introduction part 12 and the lead-out part 13 of the chamber 3, and the fluid enters and exits the sensitive space 11.

  The channel 4 has a first channel 16 and a second channel 17. The first fluid flows through the first flow path 16 and the second fluid flows through the second flow path 17. In the flow path 4 according to the present embodiment, a specimen fluid is allowed to flow as the first fluid in the first flow path 16, and atmospheric air or nitrogen gas is allowed to flow as the second fluid in the second flow path 17. . As a result, after measuring the specimen in the first fluid, the second fluid can be flowed in order to release the specimen attached to the sensitive film 5. The first flow path 16 is inserted and connected to the first introduction part 14 of the chamber 3, and the second flow path 17 is inserted and connected to the second introduction part 15 of the chamber 3.

  The flow path 4 is formed in a tubular shape, for example. The material of the flow path 4 is formed of, for example, silicone resin, fluororesin, ABS resin, nylon resin, titanium, aluminum, magnesium alloy, or stainless steel. A pump 18 may be provided in the middle of the flow path 4. By having the pump 18, the amount of fluid supplied from the flow path 4 to the sensitive unit 2 can be controlled. The flow path 4 is formed by a 3D printer, a molding method, a pressing method, a cutting method, or the like. The pump 18 is formed by a conventionally well-known method.

  The housing 5 has a function of housing each component of the sensor module 1 and protecting each component. The outer shape of the housing 5 is, for example, a rectangular parallelepiped. In addition, the shape of the housing | casing 5 is not restricted to a rectangular parallelepiped. The material of the housing 5 is, for example, ABS resin. The material of the housing 5 is not limited to ABS resin. The housing 5 is formed by a conventionally known method such as a 3D printer, a molding method, a pressing method, or a cutting method.

  The housing 5 has a first surface 19 and a second surface 20 facing the first surface 19. The end of the first flow path 16 is positioned through the first surface 19, and the end of the second flow path 17 is positioned through the second surface 20. That is, the direction of the opening of the first flow path 16 and the opening of the second flow path 17 located outside the housing 5 tends to be opposite directions. Therefore, when supplying the first fluid from the first flow path 16, it is possible to reduce the mixing of the second fluid into the first fluid. Therefore, it is possible to reduce the flow of extra fluid other than the first fluid from the first flow path 16 to the sensitive space 11, and to improve the measurement accuracy of the sensor module 1. Therefore, the reliability of the sensor module 1 can be improved.

  The housing 5 has a third surface 21 that is different from the first surface 19 and the second surface 20. The flow path 4 further includes a third flow path 22, and the end of the third flow path 22 is positioned via the third surface 21. Therefore, it is possible to reduce the fluid discharged from the lead-out unit 13 from flowing into the first flow path 16 or the second flow path 17 and improve the measurement accuracy of the sensor module 1.

  In the sensor module 1 according to the present embodiment, each of the first flow path 16, the second flow path 17, and the third flow path 22 penetrates the first surface 20, the second surface 20, and the third surface. Is provided.

  If the first surface 19 and the second surface 20 have a vector component along the same direction when the housing 5 is viewed from the top, the first surface 19 and the second surface 20 face each other. Suppose that The first surface 19 and the second surface 20 may be parallel.

  In the chamber 3, the opening of the first introduction portion 14 may face the first surface 19 of the housing 5, and the opening of the second introduction portion 15 may face the second surface 20 of the housing 5. As a result, the first flow path 16 and the second flow path 17 extending from the first surface 19 and the second surface 20 of the housing 5 can be connected to the chamber 3 without being bent halfway. Therefore, the fluid can be supplied in the flow path 4 without any delay.

  In the chamber 3, each of the first introduction part 14 and the second introduction part 15 includes a first part 23 extending in the same direction from the sensitive space 11 and an end part of the first part 23, as shown in FIG. 3. And a second portion 24 extending in opposite directions. The chamber 3 may have a fixing region 25 that fixes the chamber 3 adjacent to the first part 23 and the second part 24. As a result, for example, when the chamber 3 is fixed with screws, the position close to the chamber 3 with respect to the chamber 3 with a small number of screws compared to the case where the first introduction part 14 and the second introduction part 15 are in a straight line. The chamber 3 and the sensitive part 2 can be fixed tightly symmetrically.

  The chamber 3 may be formed of a light shielding material. Although the piezoresistive element 7 of the sensitive portion 2 according to the present embodiment has a pn junction, the piezoresistive element 7 reacts to light incident on the chamber 3 from the outside because the chamber 3 has the above configuration. This can be reduced. The “light-shielding property” does not completely block light. For example, it is only necessary that the light can be attenuated by coloring the chamber 3 in black. Further, the coloring of the chamber 3 can be realized by a conventionally known method.

  The housing 5 may be formed of a light shielding material. Although the piezoresistive element 7 of the sensitive unit 2 according to the present embodiment has a pn junction, the housing 5 having the above-described configuration allows light entering the chamber 3 through the housing 5 from the outside. It is possible to reduce the reaction of the piezoresistive element 7. The “light-shielding property” does not completely block light. For example, it is only necessary that the light can be attenuated by coloring the chamber 3 in black. Moreover, coloring of the housing | casing 5 is realizable by a conventionally well-known construction method.

  The wiring board 10 may have a notch, and the sensitive part 2 may be arranged in the notch. As a result, for example, when the sensitive unit 2 is replaced, a work space for replacement becomes large, and the replacement work can be performed efficiently. In this case, the chamber 3 may be fitted into the notch, and the sensitive part 2 may be fixed to the notch.

  The sensor module 1 according to the present embodiment further includes an active element 26 that controls the sensitive unit 2 and the like. And the wiring board 10 may have the attachment part of the sensitive part 2 in one main surface, and may have the installation area | region of the active element 26 in the other main surface. As a result, for example, when the sensitive part 2 is heated, the specimen attached to the sensitive part 2 may be detached, or the amount of the specimen attached to the sensitive part 2 may change. 26 can reduce the heating of the sensitive part 2, and can reduce the unexpected detachment of the specimen from the sensitive part 2 and the change in the adhesion amount.

  Further, when the wiring substrate 10 is seen through the top surface, the attachment portion of the sensitive portion 2 located on one main surface of the wiring substrate 10 and the active element 26 located on the other main surface of the wiring substrate 10 do not overlap. Also good. As a result, heating of the sensitive part 2 by the active element 26 can be reduced, and an unexpected detachment of the specimen from the sensitive part 2 and a change in the adhesion amount can be reduced.

  Moreover, the wiring board 10 has a notch. The sensitive part 2 is located in the notch when viewed from above. As a result, the contact area between the sensitive part 2 and the wiring board 10 can be reduced, and the heat conduction from the wiring board 10 to the sensitive part 2 can be reduced. In this case, the sensitive film 6 may be located at the tip of the sensitive part 2.

  The thermal conductivity of the chamber 3 may be smaller than the thermal conductivity of the wiring board 10. As a result, since the chamber 3 surrounds the sensitive part 2, heat conduction from the wiring board 10 to the sensitive part 2 can be reduced. Therefore, it is possible to reduce the heating of the sensitive part 2 by the active element 26 and the like, and it is possible to reduce an unexpected detachment of the specimen from the sensitive part 2 and a change in the adhesion amount.

  The present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Sensor module 2 ... Sensing part 3 ... Chamber 4 ... Flow path 5 ... Case 6 ... Sensing film 7 ... Piezoresistive element 8 ... Base part 9 ... -Conducting part 10 ... Wiring board 11 ... Sensitive space 12 ... Introduction part 13 ... Deriving part 14 ... First introduction part 15 ... Second introduction part 16 ... First flow Path 17 ... 2nd flow path 18 ... Pump 19 ... 1st surface 20 ... 2nd surface 21 ... 3rd surface 22 ... 3rd flow path 23 ... 1st part 24 ・ ・ ・ Second part 25 ・ ・ ・ Fixed region 26 ・ ・ ・ Active element

Claims (7)

A sensor module for detecting a substance in a fluid,
A sensitive part that changes its properties in response to substances in the fluid;
A flow passage and a second flow path for supplying the second fluid to the sensing portion and the first flow path for supplying the first fluid to the sensitive part,
A housing that houses the sensitive portion and the flow path and has a first surface and a second surface facing the first surface;
The end portion of the first flow path is positioned through the first surface, and the end portion of the second flow path is positioned through the second surface. A sensor module for detecting the substance. The flow path further includes a third flow path,
The housing further includes a third surface different from the first surface and the second surface,
The sensor module according to claim 1, wherein an end portion of the third flow path is positioned via the third surface . A chamber surrounding the sensitive part;
The sensor module according to claim 1, wherein at least one of the chamber and the housing is formed of a light-shielding member. The chamber includes a sensitive space in which the sensitive part is disposed, a first introducing part extending from the sensitive space and connected to the first flow path, and a second introducing part connected to the second flow path. In addition,
The opening of the first introduction part faces the first surface,
The sensor module according to claim 3, wherein the opening of the second introduction portion faces the second surface. Each of the first introduction part and the second introduction part has a first part extending in the same direction from the sensitive space and a second part extending in the opposite direction from the first part. ,
5. The sensor module according to claim 4, wherein the chamber has a fixing region for fixing the chamber in a region adjacent to the first part and the second part. An active element for controlling the sensitive part;
Includes a mounting portion of the front Symbol sensitive part on one main surface, and a wiring board having an installation area of the active element to the other major surface, the sensor module according to any one of claims 3-5.   The sensor module according to claim 6, wherein a thermal conductivity of the chamber is smaller than a thermal conductivity of the wiring board.

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