JP2019028005A - Sensor sheet - Google Patents

Abstract

To provide a sensor sheet that can measure a temperature and a moisture at the same time.SOLUTION: The present invention includes: a film base material; a plurality of first linear electrodes 2 on the film base material, the first electrodes extending in parallel to one another; a plurality of second linear electrodes 4 on the film base material, the second electrodes extending in parallel to one another and intersecting with the first electrodes; conductive detection materials located between the first electrodes and the second electrodes at positions where the first electrodes and the second electrodes intersect with one another, the detection materials having electromagnetic characteristics which change according to a level of a temperature or a moisture, and the intersecting positions forming a temperature detection unit 31 or a moisture detection unit 32. The present invention further includes a cover member 5 for sealing the temperature detection unit 31 between the temperature detection unit and the film base material.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sensor sheet.

  In Patent Document 1, there is a sheet-like sensor for temperature detection, which includes a flexible base material, parallel electrode groups formed on the base material, and a heat-sensitive material that covers the electrode group. It is disclosed. According to the technique described in Patent Document 1, it is possible to detect a change in the electrical resistance value of the heat-sensitive material according to the temperature near the intersection of the electrodes.

JP 2000-88670 A

  By the way, in recent years, there is a demand for a sensor that can measure not only temperature but also humidity. However, at present, a sensor in the form of a sheet that can simultaneously measure temperature and humidity has not been realized. Therefore, the present invention has been made to solve the above problems, and an object thereof is to provide a sensor sheet capable of measuring temperature and humidity at the same time.

  The present inventors have intensively studied to solve the above problems. As a result, the following aspects of the invention are provided.

Item 1. A film substrate;
A plurality of linear first electrodes provided on the film substrate and extending in parallel;
A plurality of linear second electrodes provided on the film base material, intersecting the plurality of first electrodes and extending in parallel;
At least at the intersection between the first electrode and the second electrode, it is disposed between the first electrode and the second electrode, and is a conductive detection material whose electromagnetic characteristics change depending on the temperature or humidity. A detecting material that constitutes a temperature detecting unit for detecting the temperature or a humidity detecting unit for detecting the humidity at the intersection, and
At least a cover member that seals the temperature detection unit with the film base,
A sensor sheet.

Item 2. A plurality of openings are formed in the cover member,
Item 2. The sensor sheet according to Item 1, wherein the humidity detection unit is exposed to the outside from each opening.

Item 3. Item 3. The sensor sheet according to Item 1 or 2, wherein the humidity detection unit and the temperature detection unit are disposed adjacent to each other.

Item 4. The sensor sheet according to claim 3, wherein the temperature detection unit and the humidity detection unit are disposed on the adjacent first electrode or the second electrode, respectively.

Item 5. Item 5. The sensor sheet according to Item 3 or 4, wherein the humidity measured by each humidity detection unit is corrected based on a temperature measured by the temperature detection unit adjacent to the humidity detection unit.

Item 6. Item 6. The sensor sheet according to any one of Items 1 to 5, wherein the cover member is formed of a moisture-proof material.

It is a perspective exploded view of a sensor sheet concerning one embodiment of the present invention. It is a top view of the sensor sheet | seat of FIG. FIG. 3 is a partial cross-sectional view of FIG. 2. It is a figure which shows the manufacturing method of the sensor sheet | seat of FIG. It is a block diagram of a sensor system. It is a block diagram of a measuring device. It is a top view which shows the other example of the sensor sheet | seat of FIG.

  Hereinafter, an embodiment of a sensor sheet according to the present invention will be described with reference to the drawings.

<1. Overview of sensor sheet>
In the sensor sheet according to the present embodiment, a plurality of detectors whose electromagnetic characteristics such as a resistance value change according to temperature or humidity are two-dimensionally arranged in a grid. Specifically, the configuration is as follows.

  1 is an exploded perspective view of the sensor sheet, FIG. 2 is a plan view of the sensor sheet, and FIG. 3 is a cross-sectional view taken along line AA of FIG. As shown in FIGS. 1 to 3, the sensor sheet 100 includes a film substrate 1, a plurality of linear first electrodes 2 provided on the film substrate 1, and each of the first electrodes. A plurality of detection members 3 arranged, and a plurality of linear second electrodes 4 arranged on the detection member 3 and arranged to be orthogonal to the first electrode 2 are provided. Further, the sensor sheet 100 includes a cover member 5 that covers both the electrodes 2 and 4 and a part of the detection member 3. Hereinafter, these members will be described in detail.

  The plurality of first electrodes 2 described above are formed in a linear shape, and these are arranged on the film substrate 1 in parallel with the X direction. The plurality of detection members 3 described above are also formed in a linear shape, and these detection members 3 are arranged so as to cover the first electrodes 2. That is, each detection member 3 is arranged in parallel to the X direction, like the first electrode 2. Further, the plurality of second electrodes 4 are also formed in a linear shape, and these are arranged in parallel to the Y direction so as to be orthogonal to the first electrode 2 and the detection member 3.

  And in the some location where the 1st electrode 2 and the 2nd electrode 4 cross | intersect, the detection member 3 arrange | positioned among these comprises the temperature detection part 31 or the humidity detection part 32. FIG. That is, each of the temperature detecting unit 31 and the humidity detecting unit 32 functions as a sensor for detecting temperature or humidity. In the present embodiment, the temperature detection unit 31 and the humidity detection unit 32 are alternately arranged on the first electrode 2 and the second electrode 4. Thereby, the temperature detector 31 and the humidity detector 32 are alternately arranged in the X direction and the Y direction.

  The cover member 5 mentioned above is arrange | positioned so that the film base material 1 whole may be covered. However, a plurality of openings 51 are formed in the cover member 5, and these openings 51 are formed in portions corresponding to the humidity detection unit 32. Therefore, the humidity detector 32 is exposed to the outside from the opening 51 of the cover member 5, and the temperature detector 31 is sealed so as not to be exposed to the outside between the film base 1 and the cover member 5. .

<2. Examples of materials constituting sensor sheet>
Although the material which forms the film base material 1 is not specifically limited, For example, it can form with the transparent or opaque material which has flexibility, such as a polyimide and PET. Furthermore, in order to reduce the influence of humidity, a metal may be deposited on the film substrate 1.

  As a material constituting each electrode 2, 4, for example, metal foil such as silver foil, copper foil, aluminum foil, conductive polymer, and the like can be used. However, the material is not limited to this, and a material having high conductivity is used. It can be adopted as appropriate.

  The detection member 3 includes conductive particles and a resin, and has a characteristic that the electrical resistance value increases as the temperature increases. That is, when the resin expands or contracts according to the temperature, the distance between the conductive particles changes, and the resistance value changes. For example, in the range of at least 30 ° C. to 200 ° C., the electrical resistance value increases as the temperature increases, and the electrical resistance value decreases as the temperature decreases.

  Moreover, this detection member 3 has the specification which an electrical resistance value rises not only with temperature but with the change of humidity. That is, when the resin absorbs water according to humidity and expands or contracts, the distance between the conductive particles changes and the resistance value changes. For example, in the range of approximately 30 to 90%, the electrical resistance value increases as the humidity increases, and the electrical resistance value decreases as the humidity decreases.

  The conductive particles contained in the detection member 3 are not particularly limited as long as the particles have conductivity, and conductive particles contained in a known conductive temperature-sensitive material can be used. Specific examples of conductive particles include carbon-based particles (including fibrous materials) such as carbon black, graphite, carbon nanotubes, carbon nanohorns, carbon nanofibers, and carbon nanocoils; iron, nickel, copper, aluminum, magnesium, Metal particles such as platinum, silver, gold, and alloys containing at least one of these metals; tin oxide, zinc oxide, silver iodide, copper iodide, barium titanate, indium tin oxide, strontium titanate, etc. Examples thereof include conductive inorganic material particles. Among these, conductive carbon black is particularly preferable from the viewpoint of a temperature-sensitive element that can accurately measure the temperature of a subject over a wide temperature range. One type of conductive particles may be used alone, or two or more types may be used in combination. Such conductive particles can also be used for measuring humidity.

  Although it does not restrict | limit especially as a particle diameter of electroconductive particle, Preferably it is 1 micrometer or less, More preferably, it is 100 nm or less, More preferably, it is 50 nm or less.

  The content of the conductive particles contained in the detection member 3 is not particularly limited and may be set so as to have a desired electric resistance value or volume resistance value, but the temperature of the subject over a wide temperature range or humidity range. Or it is preferably less than 15% by mass, more preferably about 2 to 9% by mass so that the humidity can be measured with high accuracy. For example, when conductive carbon black produced by an oil furnace method is used as the conductive particles, from the same viewpoint, it is preferably less than 10% by mass, more preferably about 1 to 8% by mass, and further preferably 2 to 6%. About mass% is mentioned. From the same viewpoint, when using conductive carbon black produced by the acetylene decomposition method, it is preferably less than 15% by mass, more preferably about 4-12% by mass, and further preferably 6-9% by mass. Degree.

  The resin contained in the detection member 3 is not particularly limited, and a resin contained in a known conductive temperature-sensitive material can be used. The glass transition temperature of the resin can be appropriately selected according to the usage mode of the detection member 3. From the viewpoint of providing a temperature sensitive element that can accurately measure the temperature of the subject over a wide temperature range, the glass transition temperature of the resin is preferably equal to or higher than the upper limit of the temperature measurement range of the temperature detector 31. That is, for example, when the upper limit value of the temperature measurement range of the temperature detection unit 31 is 200 ° C., the glass transition temperature of the resin is preferably 200 ° C. or more, and the upper limit of the temperature measurement range of the temperature detection unit 31 When the value is 100 ° C., the glass transition temperature of the resin is preferably 100 ° C. or higher. Examples of the method for adjusting the glass transition temperature of the resin include a method of adjusting the molecular weight, molecular skeleton, and the like of the resin. The glass transition temperature of the resin is preferably about 80 to 400 ° C. When a plurality of types of resins are contained in the conductive temperature sensitive material, the glass transition temperature of the resin means the glass transition temperature of the entire resin contained in the conductive temperature sensitive material. A resin having such a glass transition temperature can be used for detecting humidity in the above-described range, for example.

  Specific examples of the resin include thermosetting resins such as silicone resin, polyimide resin, and epoxy resin; polyamideimide resin, polyetherimide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resin, polyacetal resin, polyphenylene sulfide resin, Thermoplastic resins such as polyetheretherketone resin, fluororesin, and polyester resin are listed. Among these, from the viewpoint of a thermosensitive element capable of measuring the temperature of the specimen with high accuracy over a wide temperature range, a silicone resin, a polyimide resin, an epoxy resin, a polyamideimide resin, a polyethylene terephthalate resin, and a polyetherimide resin are preferable. A polyimide resin and an epoxy resin are particularly preferable. One type of resin having a glass transition temperature of 200 ° C. or higher may be used alone, or two or more types may be used in combination.

  In this embodiment, the glass transition temperature (Tg (° C.)) of the resin is a value measured by differential scanning calorimetry (DSC).

  The content of the resin contained in the detection member 3 can be set according to the type of conductive particles and is not particularly limited, but the temperature or humidity of the subject is measured with high accuracy over a wide temperature range or humidity range. In order to do this, it is preferably 85% by mass or more, more preferably about 91 to 98% by mass. For example, when conductive carbon black produced by an oil furnace method is used as the conductive particles, from the same viewpoint, it is preferably 90% by mass or more, more preferably about 92 to 99% by mass, and still more preferably 94 to 98%. About mass% is mentioned. From the same viewpoint, when conductive carbon black produced by an acetylene decomposition method is used, it is preferably 85% by mass or more, more preferably about 88 to 96% by mass, and still more preferably 91 to 94% by mass. Degree.

  The detection member 3 may further contain an additive in addition to the above-described conductive particles and resin. The additive is not particularly limited, and a known additive contained in a conductive temperature-sensitive material having PTC characteristics such as titanium oxide, alumina, and mica can be used.

  The cover member 5 is not particularly limited as long as the temperature detection unit 31 can be sealed between the film base 1 and, for example, a film can be attached with an adhesive. In addition, the surface can be covered with a moisture-proof material such as fluorine, acrylic or urethane.

<3. Example of sensor sheet manufacturing method>
Next, a method for manufacturing the sensor sheet will be described with reference to FIG. The sensor sheet 100 is manufactured as follows, for example. First, as shown to Fig.4 (a), the some 1st electrode 2 is formed on the film base material 1 by screen printing. Next, as shown in FIG. 4B, the detection member 3 is formed on each first electrode 2 by screen printing.

  Subsequently, as shown in FIG. 4C, a plurality of second electrodes 4 are formed by screen printing so as to be orthogonal to the detection member 3. Then, after masking the part corresponding to the humidity detection part 32, the cover member 5 is formed on the film base material 1 by screen printing. Thereafter, if the mask is removed, the cover member 5 having a plurality of openings 51 is formed. Then, the humidity detector 32 is exposed from each opening 51. Thus, the sensor sheet 100 is completed.

<4. Overview of sensor system>
Next, the sensor system 200 of this embodiment will be described. The sensor system 200 includes the sensor sheet 100, the measurement device 300, the display 400, the connector 500 that connects the sensor sheet 100 and the measurement device 300, and the input device 600.

<4-1. Connector>
The connector 50 is attached to the sensor sheet 100. A plurality of terminals (not shown) are provided in the end region of the sensor sheet 100, and each terminal is electrically connected to one of a plurality of contacts provided on the connector 50. Each of the plurality of temperature detection units 31 and humidity detection units 32 provided on the sensor sheet 100 is connected to a corresponding terminal via the first and second electrodes 2 and 4.

  The connector 50 acquires changes in electromagnetic characteristics in the temperature detection unit 31 and the humidity detection unit 32 as output values. The connector 50 incorporates an electronic element called a multiplexer in order to apply a voltage to the plurality of temperature detection units 31 and the humidity detection unit 32 in order.

  The connector 50 obtains an output in order from each of the plurality of temperature detection units 31 and the humidity detection unit 32 by sequentially applying a voltage to the plurality of temperature detection units 31 and the humidity detection unit 32. Specifically, when one of the first electrode 2 and the second electrode 4 is a drive electrode and the other is a receive electrode, the connector 50 sequentially applies a voltage to the plurality of drive electrodes, By measuring the resistance values of the plurality of receive electrodes in order, the outputs of the temperature detector 31 and the humidity detector 32 are obtained. The resistance value of the receive electrode is inverted and amplified by an operational amplifier and obtained as a voltage value. By setting the applied voltage and the output amplification factor, the output can be arbitrarily amplified.

  The connector 50 converts an analog signal indicating an output value (temperature value or humidity value) output from each temperature detection unit 31 and humidity detection unit 32 of the sensor sheet 100 into a digital signal and outputs the digital signal to the measurement apparatus 300. .

<4-2. Measuring device>
FIG. 6 is a block diagram showing a measuring apparatus according to this embodiment. As illustrated in FIG. 6, the measurement apparatus 300 according to the present embodiment is a computer in which a control unit 301, a storage unit 302, an external interface 303, and a drive 304 are electrically connected. In FIG. 6, each external interface 303 is described as “external I / F”.

  The control unit 301 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and controls each component according to information processing. The storage unit 302 is an auxiliary storage device such as a hard disk drive or a solid state drive, for example, and stores a measurement program 321 executed by the control unit 301, data 322 relating to detected temperature, humidity, and the like.

  The external interface 303 is a USB (Universal Serial Bus) port or the like, and is an interface for connecting to an external device. The connector 500, the input device 600, and the display 400 described above are connected via the external interface 303. The input device 600 is a device for inputting with a mouse, a keyboard, or the like, for example. Note that external devices other than the above, such as a printer and a speaker, can also be connected. In addition, a communication interface for connecting the measuring apparatus 300 to the outside via a network can be provided. This communication interface is, for example, a wired LAN (Local Area Network) module, a wireless LAN module, or the like, and is an interface for performing wired or wireless communication via a network.

  The drive 304 is, for example, a CD (Compact Disk) drive, a DVD (Digital Versatile Disk) drive, or the like, and is a device for reading a program stored in the storage medium 341. The type of the drive 304 may be appropriately selected according to the type of the storage medium 341. The measurement program 321 may be stored in the storage medium 341.

  The storage medium 341 stores information such as a program by an electric, magnetic, optical, mechanical, or chemical action so that information such as a program recorded by a computer or other devices or machines can be read. It is a medium to do.

  Note that the measurement apparatus 300 may be a general-purpose desktop PC (Personal Computer), tablet PC, or the like, in addition to an information processing apparatus designed exclusively for the provided service.

  The sensor system 200 includes a thermocouple (measuring instrument) (not shown) that measures the temperature of the same atmosphere as the sensor sheet 100. Although the thermocouple is installed in the connector 500, it is not limited to this and may be installed in the vicinity of the sensor sheet 100. The measurement signal output from the thermocouple is converted into a digital signal and input to the measurement apparatus 300. The means for measuring the temperature in the same atmosphere as the sensor sheet 100 is not limited to a thermocouple. Moreover, a measuring instrument that measures not only the temperature but also the humidity in the same atmosphere as the sensor sheet 100 can be provided, and this measuring instrument can be integrated with a device that measures the temperature.

  <5. Operation of sensor system>

  Next, the operation of the sensor system configured as described above will be described. First, the measurement apparatus 300 calculates a temperature distribution from output values obtained from each of the plurality of temperature detection units 31, and calculates to calculate a pressure distribution from output values obtained from each of the plurality of humidity detection units 32. It functions as a part. The temperature distribution of the subject can be measured by calculating the temperature distribution from the output values obtained from each of the plurality of temperature detection units 21. In addition, the humidity distribution of the subject can be measured by calculating the humidity distribution from the output values obtained from each of the plurality of humidity detectors 32.

  The measuring apparatus 300 functions as a correction unit that corrects the output value obtained on the other side based on the output value obtained on the other side of the temperature detection unit 31 and the humidity detection unit 32. By correcting the output value obtained by the humidity detection unit 32 based on the output value obtained by the temperature detection unit 31, the temperature dependence of the humidity detection unit 32 can be eliminated. On the other hand, since the temperature detection part 31 is sealed between the film base material 1 and the cover member 5, it can be in the state of 0% humidity, and can prevent the influence by the change of humidity. Therefore, below, correction | amendment of the humidity detection part 32 is demonstrated.

  Specifically, the temperature dependence of the humidity detector 32 can be eliminated by the following method. First, the temperature dependence of the humidity detector 32 is obtained from the output curve when the temperature is changed at a constant humidity. This may be performed at the time of factory shipment of the sensor sheet 100 or may be performed by each user. Further, it may be performed for all the humidity detection units 32, or the representative value may be applied to all the humidity detection units 32. Next, the temperature detector 31 is calibrated by measuring the output at each temperature point using the temperature detector 31. As the temperature at this time, the temperature of the temperature detection unit 31 adjacent to each humidity detection unit 32 is used. This may be performed at the time of factory shipment of the sensor sheet 100 or may be performed by each user. Further, it may be performed for all the temperature detection units 31, or the representative value may be applied to all the temperature detection units 31.

  Then, when measuring the humidity distribution by the humidity detector 32, an accurate temperature value is acquired by the calibrated temperature detector 31, and the humidity distribution is corrected using the temperature dependence curve of the humidity detector 32 previously obtained. . Thereby, the temperature dependence of the humidity detector 32 can be eliminated. In this method, the humidity detector 32 can be corrected even if the rate of change in temperature and the rate of change due to temperature dependency of the humidity detector 32 do not match.

<5. Features>
As described above, according to the present embodiment, the distribution of temperature and humidity can be measured with a single sensor sheet. In particular, since temperature detection and humidity detection are performed by the detection member 3 made of the same material, a sensor sheet capable of measuring both temperature and humidity can be configured at low cost.

  Moreover, since the temperature detection part 31 is sealed between the film base material 1 and the cover member 5, the influence of the humidity at the time of temperature measurement can be suppressed. On the other hand, the humidity detector 32 is exposed to the outside from the opening 51 of the cover member 5 in order to facilitate the detection of humidity. However, since the humidity detection unit 32 is adjacent to the temperature detection unit 31, the temperature dependence of the humidity detection unit 32 can be accurately eliminated using the temperature measured by the adjacent temperature detection unit 31.

<6. Modification>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. Note that the following modifications can be combined as appropriate.

<6-1>
The 1st electrode 2 and the 2nd electrode 4 do not necessarily need to be orthogonal, and should just cross | intersect at least 45 degree | times or more.

<6-2>
The temperature detection unit 31 and the humidity detection unit 32 are alternately arranged on the first and second electrodes 1 and 4, but the temperature detection unit 31 and the humidity detection unit 32 may be arranged adjacent to each other. That's fine. Therefore, for example, as shown in FIG. 7, the temperature detectors 31 and the humidity detectors 32 can be alternately arranged on the adjacent first electrodes 1. An opening 51 is formed in the cover member 5 so that the humidity detector 32 is exposed to the outside.

  Further, the temperature detection unit 31 and the humidity detection unit 32 do not necessarily have to be adjacent to each other, and the temperature detection unit 31 and the humidity detection unit 32 may be arranged at any position on the sensor sheet 100. .

<6-3>
Since the cover member 5 only needs to cover at least the temperature detection unit 31, the opening 51 is formed at a corresponding position of the humidity detection unit 32 after being disposed on the entire film base 1 as in the above embodiment. Instead, it may be arranged so as to cover at least a portion where the temperature detection unit 31 is provided.

DESCRIPTION OF SYMBOLS 1 Film base material 2 1st electrode 3 Detection member 31 Temperature detection part 32 Pressure detection part 4 2nd electrode 5 Cover member

Claims (6)

A film substrate;
A plurality of linear first electrodes provided on the film substrate and extending in parallel;
A plurality of linear second electrodes provided on the film base material, intersecting the plurality of first electrodes and extending in parallel;
At least at the intersection between the first electrode and the second electrode, it is disposed between the first electrode and the second electrode, and is a conductive detection material whose electromagnetic characteristics change depending on the temperature or humidity. A detecting material that constitutes a temperature detecting unit for detecting the temperature or a humidity detecting unit for detecting the humidity at the intersection, and
At least a cover member that seals the temperature detection unit with the film base,
A sensor sheet. A plurality of openings are formed in the cover member,
The sensor sheet according to claim 1, wherein the humidity detection unit is exposed to the outside from each opening.   The sensor sheet according to claim 1, wherein the humidity detection unit and the temperature detection unit are disposed adjacent to each other.   The sensor sheet according to claim 3, wherein the temperature detection unit and the humidity detection unit are disposed on the adjacent first electrode or the second electrode, respectively.   The sensor sheet according to claim 3 or 4, wherein the humidity measured by each of the humidity detection units is corrected based on a temperature measured by the temperature detection unit adjacent to the humidity detection unit.   The sensor sheet according to claim 1, wherein the cover member is made of a moisture-proof material.