Organic piezoelectric film built-in sensor

Abstract

To provide an organic piezoelectric film built-in sensor which can be disposed in a high-temperature and high-humidity environment.SOLUTION: An organic piezoelectric film built-in sensor includes an organic piezoelectric element in a flat film shape and a laminate covering a surface area of the organic piezoelectric element in 95% or more. The organic piezoelectric element includes an organic piezoelectric film having a first principal surface and a second principal surface which are opposed, a reference electrode which is disposed on the first principal surface, and a signal electrode which is disposed on the second principal surface. The laminate has a structure in which at least a vapor barrier layer and a sealant layer are laminated. The sealant layer is positioned between the vapor barrier layer and the organic piezoelectric element. A vapor permeability of the vapor barrier layer under the environment of a temperature of 85°C and a relative humidity of 85% is larger than 0 and equal to or less than 1 mg / m2 / day.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sensor incorporating an organic piezoelectric film. [Background technology]

[0002] In recent years, there has been an increasing demand for sensors incorporating organic piezoelectric films. Organic piezoelectric films containing polylactic acid and other materials are hydrolyzable. As hydrolysis of organic piezoelectric films containing polylactic acid and other materials progresses, the organic piezoelectric films lose their piezoelectricity.

[0003] On the other hand, a package described in Patent Document 1 is known as a conventional invention relating to moisture absorption suppression technology. The package described in Patent Document 1 is a laminate in which a resin plate is packaged with a water vapor barrier film. The water vapor barrier film has a base film, a water vapor barrier layer, and a pressure-sensitive adhesive layer. The water vapor barrier film is adhered to both the front and back surfaces of the resin plate and covers the edge faces of the resin plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-109781 Summary of the Invention [Problem to be solved by the invention]

[0005] When exposed to a high-temperature, high-humidity environment, a sensor with an organic piezoelectric film may be unable to output the desired signal due to decomposition of the organic piezoelectric film, which contains polylactic acid or the like. When a sensor with an organic piezoelectric film is to be placed in a high-temperature, high-humidity environment, it is necessary to suppress moisture absorption by the organic piezoelectric film. However, the packaging described in Patent Document 1 is not designed for environments with temperatures higher than 40°C. Therefore, the packaging described in Patent Document 1 cannot be used for a sensor with an organic piezoelectric film that will be exposed to a high-temperature, high-humidity environment.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sensor with a built-in organic piezoelectric film that can be installed in a high-temperature, high-humidity environment. [Means for solving the problem]

[0007] A sensor with a built-in organic piezoelectric film according to one embodiment of the present invention includes: a flat film-shaped organic piezoelectric element; a laminate covering 95% or more of the surface area of ​​the organic piezoelectric element; It is equipped with The organic piezoelectric element is an organic piezoelectric film having a first principal surface and a second principal surface facing each other; a reference electrode provided on the first principal surface; a signal electrode provided on the second main surface; It contains the laminate has a structure in which at least a water vapor barrier layer and a sealing material layer are laminated, the encapsulant layer is located between the water vapor barrier layer and the organic piezoelectric element; The water vapor permeability of the water vapor barrier layer in an environment of a temperature of 85°C and a relative humidity of 85% is greater than 0 and less than 1 mg / m 2 / day or less. [Effects of the Invention]

[0008] According to the present invention, the sensor with a built-in organic piezoelectric film can be installed in a high-temperature and high-humidity environment. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a sensor 1 with a built-in organic piezoelectric film. [Figure 2] FIG. 2 is a plan view of the sensor 1 with a built-in organic piezoelectric film. [Figure 3] FIG. 3 is a cross-sectional view of the organic piezoelectric film built-in sensor 1 taken along the line AA. [Figure 4] FIG. 4 is a cross-sectional view of the organic piezoelectric film built-in sensor 1 according to the first modification taken along the line AA. [Figure 5] FIG. 5 is a cross-sectional view of the organic piezoelectric film built-in sensor 1 according to the second modification taken along the line AA. [Figure 6] FIG. 6 is a cross-sectional view of the organic piezoelectric film built-in sensor 1 according to the third modification taken along the line AA. [Figure 7] FIG. 7 shows the transition of the signal output of the organic piezoelectric element 2 when the organic piezoelectric element 2 is not covered with the laminate 3. In FIG. [Figure 8] FIG. 8 shows the results of an experiment in which the life of the organic piezoelectric element 2 was measured. [Figure 9] FIG. 9 is a cross-sectional view of the water vapor barrier layer 31 in the experiment. [Figure 10] FIG. 10 shows the results of a verification in which the water vapor permeability of the water vapor barrier layer 31 was estimated by multivariate analysis. [Figure 11] FIG. 11 shows the results of estimating the maximum value of the life of the organic piezoelectric element 2 from the water vapor permeability of the water vapor barrier layer 31 and the thickness of the sealing material layer 32. DETAILED DESCRIPTION OF THE INVENTION

[0010] [First embodiment] A sensor 1 with a built-in organic piezoelectric film according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of the sensor 1 with a built-in organic piezoelectric film. FIG. 2 is a plan view of the sensor 1 with a built-in organic piezoelectric film. FIG. 3 is a cross-sectional view of the sensor 1 with a built-in organic piezoelectric film taken along line AA. FIG. 4 is a cross-sectional view of the sensor 1 with a built-in organic piezoelectric film taken along line AA according to Modification 1. FIG. 5 is a cross-sectional view of the sensor 1 with a built-in organic piezoelectric film taken along line AA according to Modification 2. FIG. 6 is a cross-sectional view of the sensor 1 with a built-in organic piezoelectric film taken along line AA according to Modification 3.

[0011] In the organic piezoelectric film-embedded sensor 1, directions are defined as follows, for example. As shown in FIG. 1 , the direction in which the long sides of the organic piezoelectric element 2 extend is defined as the left-right direction. The direction in which the short sides of the organic piezoelectric element 2 extend is defined as the front-rear direction. The direction perpendicular to the left-right and front-rear directions is defined as the up-down direction. However, the left-right, front-rear, and up-down directions in this specification are defined for the convenience of explanation and do not necessarily coincide with the left-right, front-rear, and up-down directions when the organic piezoelectric film-embedded sensor 1 is in use. Furthermore, in each drawing, the left and right directions may be interchanged, the front and rear directions may be interchanged, and the up and down directions may be interchanged.

[0012] The sensor 1 with a built-in organic piezoelectric film is flexible. As shown in Figure 1, the sensor 1 with a built-in organic piezoelectric film is in the form of a flat film. The sensor 1 with a built-in organic piezoelectric film includes an organic piezoelectric element 2, a laminate 3, and a substrate 4.

[0013] The organic piezoelectric element 2 has a flat film shape. As shown in Fig. 2, the organic piezoelectric element 2 has a rectangular shape when viewed in the vertical direction. When viewed in the vertical direction, the organic piezoelectric element 2 has a rectangular shape with two long sides extending in the left-right direction and two short sides extending in the front-rear direction. The shape of the organic piezoelectric element 2 is not limited to the shape shown in this embodiment.

[0014] As shown in FIG. 3, the organic piezoelectric element 2 includes an organic piezoelectric film 21, a reference electrode 22, and a signal electrode .

[0015] The organic piezoelectric film 21 has a first principal surface S211 and a second principal surface S212 that face each other. The organic piezoelectric film 21 also has an organic piezoelectric material. The organic piezoelectric material is polyvinylidene fluoride (PVDF), polylactic acid (PLA), or the like. The organic piezoelectric material is polarized by deformation, generating electric charges on the first principal surface S211 and the second principal surface S212.

[0016] The reference electrode 22 is provided on the first main surface S211. The reference electrode 22 covers the entire first main surface S211. The reference electrode 22 is electrically connected to the ground potential, and thereby functions as a reference electrode and a shield conductor. Note that the reference electrode 22 does not have to cover the entire first main surface S211.

[0017] The signal electrode 23 is provided on the second main surface S212. The signal electrode 23 covers the entire second main surface S212. The signal electrode 23 outputs a signal according to the charge generated on the first main surface S211. Note that the signal electrode 23 does not have to cover the entire second main surface S212.

[0018] The substrate 4 is electrically connected to the signal electrode 23 and the reference electrode 22 at the ends of the organic piezoelectric element 2. In this embodiment, the substrate 4 includes a first conductor film (not shown) and a second conductor film (not shown). The first conductor film and the second conductor film are electrically connected to the reference electrode 22 and the signal electrode 23, respectively, at the left front end of the organic piezoelectric element 2. Note that the positions at which the first conductor film and the second conductor film are electrically connected to the reference electrode 22 and the signal electrode 23, respectively, are not limited to the left front end of the organic piezoelectric element 2.

[0019] The laminate 3 covers 95% or more of the surface area of ​​the organic piezoelectric element 2. As shown in FIGS. 1 and 2, the laminate 3 covers the organic piezoelectric element 2 except for the left end portion of the organic piezoelectric element 2. By covering the organic piezoelectric film 21, the reference electrode 22, and the signal electrode 23 with the laminate 3, the parasitic capacitance generated between the reference electrode 22 and the signal electrode 23 and the organic piezoelectric film 21 can be reduced compared to when the laminate 3 covers only the organic piezoelectric film 21 and the reference electrode 22 and the signal electrode 23 are located outside the laminate 3. The left end portion of the organic piezoelectric element 2 is the location where the substrate 4 and the organic piezoelectric element 2 are electrically connected. Therefore, as long as the location where the substrate 4 and the organic piezoelectric element 2 are electrically connected is a location other than the left end portion of the organic piezoelectric element 2, the laminate 3 only needs to cover the organic piezoelectric element 2 except for that location. In other words, the laminate 3 does not need to cover the entire organic piezoelectric element 2.

[0020] 3, the laminate 3 has a structure in which at least a water vapor barrier layer 31 and a sealing material layer 32 are laminated. The sealing material layer 32 is located between the water vapor barrier layer 31 and the organic piezoelectric element 2. In this embodiment, the water vapor barrier layer 31 is bonded to the surface of the organic piezoelectric element 2 by the sealing material layer 32.

[0021] 4, the laminate 3 may further include a base layer 33 having a third main surface S331 and a fourth main surface S332 facing each other. In this case, the water vapor barrier layer 31 is provided on the third main surface S331. The sealing material layer 32 is provided on the fourth main surface S332.

[0022] 3 and 4, in this embodiment, the laminate 3 includes a first sheet S1 and a second sheet S2. Each of the first sheet S1 and the second sheet S2 has a structure in which at least a water vapor barrier layer 31 and a sealing material layer 32 are laminated. The organic piezoelectric element 2 is sandwiched between the first sheet S1 and the second sheet S2. The second sheet S2 is connected to the first sheet S1 on a side surface of the organic piezoelectric element 2 (hereinafter referred to as a glue tab method). At least one of the first sheet S1 and the second sheet S2 may include a base layer 33.

[0023] 5, the second sheet S2 may be connected to the first sheet S1 by wrapping around the end of the first sheet S1 (hereinafter referred to as a folding method). Alternatively, the second sheet S2 may be provided on one main surface of the organic piezoelectric element 2 and on the other main surface of the organic piezoelectric element 2 via the first sheet S1. The second sheet S2 may be provided not only on both ends of the first sheet S1 but also on either one of the two ends of the first sheet S1. Alternatively, for example, the laminate 3 may not include the first sheet S1, and the second sheet S2 may be provided on both ends of the organic piezoelectric element 2 and in contact with both main surfaces of the organic piezoelectric element 2, thereby covering 95% or more of the surface area of ​​the organic piezoelectric element 2.

[0024] 6, the organic piezoelectric element 2 may be wrapped in a first sheet S1. In this case, the sensor 1 with built-in organic piezoelectric film can be formed using a single sheet, making it easy to manufacture the sensor 1 with built-in organic piezoelectric film. Furthermore, since the sheets are connected at only one location, moisture is less likely to penetrate the organic piezoelectric element 2, and the hydrolysis resistance of the sensor 1 with built-in organic piezoelectric film can be further improved.

[0025] The present inventors conducted experiments and verifications to improve the hydrolysis resistance of the organic piezoelectric film-embedded sensor 1. The experiments and verifications conducted by the present inventors will be described below with reference to the drawings. FIG. 7 shows the transition of the signal output of the organic piezoelectric element 2 when the organic piezoelectric element 2 is not covered with the laminate 3. The horizontal axis in FIG. 7 represents time (hours). The vertical axis in FIG. 7 represents the signal output. FIG. 8 shows the experimental results of measuring the lifetime of the organic piezoelectric element 2. The vertical axis in FIG. 8 represents the lifetime (converted into a common logarithm) (hours). For example, if the lifetime (converted into a common logarithm) of the organic piezoelectric element 2 is 2.0 hours, the lifetime of the organic piezoelectric element 2 is 100 hours. The lifetime was measured from the time when the initial value of the signal output of the organic piezoelectric element 2 was measured to the time when the signal output of the organic piezoelectric element 2 decreased to 75% of the initial value.

[0026] 7, when the organic piezoelectric element 2 is not covered with the laminate 3, the signal output of the organic piezoelectric element 2 in an environment of a temperature of 85°C and a relative humidity of 85% drops rapidly after 100 hours to 0. When the organic piezoelectric element 2 is not covered with the laminate 3, the life of the organic piezoelectric element 2 in an environment of a temperature of 85°C and a relative humidity of 85% is about 100 hours.

[0027] The inventors of the present application conducted an experiment to measure the lifespan of an organic piezoelectric element 2 covered with a laminate 3 under various conditions in an environment with a temperature of 85°C and a relative humidity of 85%. The black circles in FIG. 8 represent the average lifespan of the organic piezoelectric element 2 under each condition. The horizontal lines above the black circles in FIG. 8 represent the maximum lifespan of the organic piezoelectric element 2 under each condition. The horizontal lines below the black circles in FIG. 8 represent the minimum lifespan of the organic piezoelectric element 2 under each condition. FIG. 9 is a cross-sectional view of the water vapor barrier layer 31 used in the experiment.

[0028] First, the lifetime of the organic piezoelectric element 2 was measured when the laminate 3 covered the entire organic piezoelectric element 2 and when the laminate 3 did not cover the entire organic piezoelectric element 2 but covered 95% or more of the surface area of ​​the organic piezoelectric element 2. As shown in FIG. 8 , the average lifetime of the organic piezoelectric element 2 was almost the same whether the laminate 3 covered the entire organic piezoelectric element 2 or not. Therefore, as described above, the laminate 3 does not have to cover the entire organic piezoelectric element 2. However, when the laminate 3 covers the entire organic piezoelectric element 2, the maximum lifetime of the organic piezoelectric element 2 can be improved compared to when the laminate 3 does not cover the entire organic piezoelectric element 2. Therefore, the laminate 3 may cover the entire organic piezoelectric element 2.

[0029] Next, the lifespan of the organic piezoelectric element 2 was measured when the organic piezoelectric film built-in sensor 1 was formed using the adhesive margin method (two methods: L = 1 mm or 2 mm) and the folding method. Note that L is the length of the portion shown in Figure 4. As shown in Figure 8, the average lifespan of the organic piezoelectric element 2 was almost the same whether it was the adhesive margin method (L = 1 mm or 2 mm) or the folding method. Therefore, as mentioned above, the method of forming the organic piezoelectric film built-in sensor 1 is not limited to the adhesive margin method.

[0030] Next, the lifetime of the organic piezoelectric element 2 was measured for the following types of water vapor barrier layer 31: (1) polyethylene terephthalate (PET), (2) cycloolefin copolymer (COC), (3) PET + 10 μm thick aluminum foil, (4) PET + 30 μm thick aluminum foil, and (5) PET + 30 μm thick aluminum foil. In the cases of (3) to (5), as shown in FIG. 9 , an aluminum foil 313 was provided on the upper main surface of the PET layer 311 via an adhesive layer 312. The lower main surface of the PET layer 311 was bonded to the encapsulant layer 32.

[0031] 8, (1) the life of the organic piezoelectric element 2 in the case of PET is slightly longer than (2) the life of the organic piezoelectric element 2 in the case of COC. Furthermore, when aluminum foil 313 is provided on the upper main surface of PET layer 311, the life of the organic piezoelectric element 2 is longer than when aluminum foil 313 is not provided on the upper main surface of PET layer 311. The thicker the aluminum foil 313, the longer the life of the organic piezoelectric element 2.

[0032] Next, the lifespan of the organic piezoelectric element 2 was measured when the thickness of the sealing material layer 32 was 20 μm, 50 μm, and 75 μm. The thicker the sealing material layer 32, the longer the lifespan of the organic piezoelectric element 2.

[0033] Next, the lifespan of the organic piezoelectric element 2 was measured for three different materials for the sealing material layer 32, A to C. The lifespan of the organic piezoelectric element 2 when the sealing material layer 32 was made of material A or C was longer than the lifespan of the organic piezoelectric element 2 when the sealing material layer 32 was made of material B. The water vapor permeability of material A was 0.14 g / m 2 / day. The water vapor permeability of C was 0.4 g / m under an environment of 40°C and 90% relative humidity. 2 It was / day.

[0034] Furthermore, the inventors of the present application conducted multivariate analysis based on the above-mentioned experimental results in order to identify factors that significantly contribute to extending the life of the organic piezoelectric element 2. First, the inventors of the present application examined the type of water vapor barrier layer 31. FIG. 10 shows the results of the examination in which the water vapor permeability of the water vapor barrier layer 31 was estimated by multivariate analysis. The horizontal axis in FIG. 10 represents the thickness (μm) of the aluminum foil. The vertical axis in FIG. 10 represents the estimated value (converted to common logarithm) of the water vapor permeability of the water vapor barrier layer 31 (g / m 2 / day). For example, if the estimated water vapor permeability (converted into a common logarithm) of the water vapor barrier layer 31 is −2 g / m 2 / day, the estimated water vapor transmission rate of the water vapor barrier layer 31 is 10 mg / m 2 / day. In order to confirm the influence of the presence or absence of PET and the thickness of the aluminum foil on the water vapor permeability of the water vapor barrier layer 31, the thickness of the COC and the laminate 3 were excluded from the explanatory variables.

[0035] 10, whether (5) there is a 25 μm thick PET or (6) there is no PET, the thicker the aluminum foil, the lower the water vapor permeability of the water vapor barrier layer 31. Providing a 25 μm thick PET has the same effect on the water vapor permeability of the water vapor barrier layer 31 as reducing the thickness of the aluminum foil by 7.2 μm. Therefore, from the perspective of miniaturizing the organic piezoelectric film-embedded sensor 1, it is more desirable to reduce the thickness of the aluminum foil without providing PET.

[0036] Next, the inventors of the present application performed multivariate analysis based on the above-mentioned experimental results in order to identify factors that significantly contribute to extending the life of the organic piezoelectric element 2. Note that the type of water vapor barrier layer 31 was changed to the water vapor permeability (converted to common logarithm) of the water vapor barrier layer 31 as an explanatory factor. Furthermore, in order to bring the life of the organic piezoelectric element 2, which is the objective variable, closer to a normal distribution, the life of the organic piezoelectric element 2 was converted to the life of the organic piezoelectric element 2 (converted to common logarithm).

[0037] Multivariate analysis confirmed that the correlation between the lifetime (converted into a common logarithm) of the organic piezoelectric element 2 and the water vapor permeability (converted into a common logarithm) of the water vapor barrier layer 31 and the thickness of the encapsulant layer 32 was stronger than the correlation between the lifetime (converted into a common logarithm) of the organic piezoelectric element 2 and other explanatory variables. The correlation coefficient between the lifetime (converted into a common logarithm) of the organic piezoelectric element 2 and the water vapor permeability (converted into a common logarithm) of the water vapor barrier layer 31 was greater than -1 and less than -0.5. The correlation coefficient between the lifetime (converted into a common logarithm) of the organic piezoelectric element 2 and the thickness of the encapsulant layer 32 was greater than 0.5 and less than 1. The correlation coefficient between the lifetime (converted into a common logarithm) of the organic piezoelectric element 2 and other explanatory variables was greater than -0.5 and less than 0.5. Therefore, it was confirmed that the water vapor permeability (converted into a common logarithm) of the water vapor barrier layer 31 and the thickness of the sealing material layer 32 are each significant explanatory variables for the life (converted into a common logarithm) of the organic piezoelectric element 2. It was also confirmed that the smaller the water vapor permeability (converted into a common logarithm) of the water vapor barrier layer 31 or the thicker the sealing material layer 32, the longer the life (converted into a common logarithm) of the organic piezoelectric element 2.

[0038] Furthermore, the inventors of the present application estimated the maximum value of the lifetime of the organic piezoelectric element 2 when the water vapor permeability of the water vapor barrier layer 31 and the thickness of the sealing material layer 32 were changed, based on the regression equation of the lifetime (converted into common logarithm) of the organic piezoelectric element 2 obtained by multivariate analysis. Fig. 11 shows the estimation results of the maximum value of the lifetime of the organic piezoelectric element 2 estimated from the water vapor permeability of the water vapor barrier layer 31 and the thickness of the sealing material layer 32.

[0039] As shown in FIG. 11, the water vapor permeability (common logarithm conversion) of the water vapor barrier layer 31 is −2.04 to −6.00 g / m 2 / day (where the water vapor permeability of the water vapor barrier layer 31 is in the range of 0.001 to 1 mg / m 2 / day), the maximum value of the life of the organic piezoelectric element 2 exceeds 650 hours, which is significantly longer than the life of the organic piezoelectric element 2 of about 100 hours when the organic piezoelectric element 2 is not covered with the laminate 3. Therefore, the water vapor permeability of the water vapor barrier layer 31 in an environment of a temperature of 85°C and a relative humidity of 85% is greater than 0 and is less than 1 mg / m2 / day or less, the hydrolysis resistance of the organic piezoelectric film-embedded sensor 1 can be improved, and the maximum life of the organic piezoelectric element 2 can be extended. Note that the water vapor permeability of the water vapor barrier layer 31 in an environment of a temperature of 85°C and a relative humidity of 85% is greater than 0 and is 1 mg / m 2 / day or less, the maximum life of the organic piezoelectric element 2 can exceed 1000 hours, as in sample 7.

[0040] Furthermore, when the thickness of the sealing material layer 32 is in the range of 30 μm to 75 μm, the maximum lifespan of the organic piezoelectric element 2 exceeds 650 hours, which is significantly longer than the approximately 100 hours of the lifespan of the organic piezoelectric element 2 when the organic piezoelectric element 2 is not covered with the laminate 3. Therefore, if the thickness of the sealing material layer 32 is 30 μm or more, the hydrolysis resistance of the organic piezoelectric film-embedded sensor 1 can be improved, and the maximum lifespan of the organic piezoelectric element 2 can be extended. Note that, although the thicker the sealing material layer 32, the longer the lifespan of the organic piezoelectric element 2 can be, from the perspective of miniaturizing the organic piezoelectric film-embedded sensor 1, the thickness of the sealing material layer 32 is preferably 30 μm or more and 100 μm or less. Note that if the thickness of the sealing material layer 32 is 30 μm or more, the maximum lifespan of the organic piezoelectric element 2 can exceed 1,100 hours, as in sample 8.

[0041] As described above, the maximum water vapor transmission rate of the sealing material layer 32 used in the experiment was 0.4 g / m under an environment of a temperature of 40° C. and a relative humidity of 90%. 2 Therefore, the water vapor transmission rate of the sealing material layer 32 in an environment of a temperature of 40° C. and a relative humidity of 90% was 0.4 g / m 2 It is preferable that it is / day or less.

[0042] [Other embodiments] The sensor with a built-in organic piezoelectric film according to the present invention is not limited to the sensor 1 with a built-in organic piezoelectric film, and can be modified within the scope of the gist thereof.

[0043] The present invention has the following configuration.

[0044] (1) a flat film-shaped organic piezoelectric element; a laminate covering 95% or more of the surface area of ​​the organic piezoelectric element; It is equipped with The organic piezoelectric element is an organic piezoelectric film having a first principal surface and a second principal surface facing each other; a reference electrode provided on the first principal surface; a signal electrode provided on the second main surface; It contains the laminate has a structure in which at least a water vapor barrier layer and a sealing material layer are laminated, the encapsulant layer is located between the water vapor barrier layer and the organic piezoelectric element; The water vapor permeability of the water vapor barrier layer in an environment of a temperature of 85°C and a relative humidity of 85% is greater than 0 and less than 1 mg / m 2 / day or less, Sensor with built-in organic piezoelectric film.

[0045] (2) The thickness of the sealing material layer is 30 μm or more and 100 μm or less. The organic piezoelectric film-embedded sensor according to (1).

[0046] (3) The water vapor transmission rate of the sealing material layer in an environment of a temperature of 40°C and a relative humidity of 90% is greater than 0 and is 0.4 g / m 2 / day, A sensor with an organic piezoelectric film according to (1) or (2).

[0047] (4) the laminate further includes a substrate layer having opposing third and fourth major surfaces; the water vapor barrier layer is provided on the third main surface, the sealing material layer is provided on the fourth main surface; A sensor with a built-in organic piezoelectric film according to any one of (1) to (3).

[0048] (5) the laminate includes a first sheet and a second sheet, the first sheet and the second sheet each have a structure in which at least the water vapor barrier layer and the sealing material layer are laminated, the organic piezoelectric element is sandwiched between the first sheet and the second sheet, the second sheet is connected to the first sheet at a side surface of the organic piezoelectric element; A sensor with a built-in organic piezoelectric film according to any one of (1) to (4).

[0049] (6) the laminate includes a first sheet and a second sheet, the first sheet and the second sheet each have a structure in which at least the water vapor barrier layer and the sealing material layer are laminated, the organic piezoelectric element is sandwiched between the first sheet and the second sheet, The second sheet is connected to the first sheet by wrapping around an end of the first sheet. A sensor with a built-in organic piezoelectric film according to any one of (1) to (4).

[0050] (7) The laminate includes a first sheet, the first sheet has a structure in which at least the water vapor barrier layer and the sealing material layer are laminated, the organic piezoelectric element is wrapped in the first sheet; A sensor with a built-in organic piezoelectric film according to any one of (1) to (4). [Explanation of symbols]

[0051] 1: Sensor with built-in organic piezoelectric film 2: Organic piezoelectric element 3: Laminate 4: Circuit board 21: Organic piezoelectric film 22:Reference electrode 23: Signal electrode 31: Water vapor barrier layer 32: Encapsulant layer 33: Base material layer 311:PET layer 312: Adhesive layer 313: Aluminum foil S1: 1st seat S2: Second seat S211: 1st main surface S212: 2nd main surface S331: Third main surface S332: Fourth main surface

Claims

1. a flat film-shaped organic piezoelectric element; a laminate covering 95% or more of the surface area of ​​the organic piezoelectric element; It is equipped with The organic piezoelectric element is an organic piezoelectric film having a first principal surface and a second principal surface facing each other; a reference electrode provided on the first principal surface; a signal electrode provided on the second main surface; It contains the laminate has a structure in which at least a water vapor barrier layer and a sealing material layer are laminated, the encapsulant layer is located between the water vapor barrier layer and the organic piezoelectric element; The water vapor permeability of the water vapor barrier layer in an environment of a temperature of 85°C and a relative humidity of 85% is greater than 0 and less than 1 mg / m ２ / day or less, Sensor with built-in organic piezoelectric film.

2. The thickness of the sealing material layer is 30 μm or more and 100 μm or less. The organic piezoelectric film-embedded sensor according to claim 1 .

3. The water vapor transmission rate of the sealing material layer in an environment of a temperature of 40°C and a relative humidity of 90% is greater than 0 and is 0.4 g / m ２ / day, The organic piezoelectric film-embedded sensor according to claim 1 or 2.

4. the laminate further includes a substrate layer having opposing third and fourth major surfaces; the water vapor barrier layer is provided on the third major surface, the sealing material layer is provided on the fourth main surface; The organic piezoelectric film-embedded sensor according to claim 1 or 2.

5. the laminate includes a first sheet and a second sheet, the first sheet and the second sheet each have a structure in which at least the water vapor barrier layer and the sealing material layer are laminated, the organic piezoelectric element is sandwiched between the first sheet and the second sheet, the second sheet is connected to the first sheet at a side surface of the organic piezoelectric element; The organic piezoelectric film-embedded sensor according to claim 1 or 2.

6. the laminate includes a first sheet and a second sheet, the first sheet and the second sheet each have a structure in which at least the water vapor barrier layer and the sealing material layer are laminated, the organic piezoelectric element is sandwiched between the first sheet and the second sheet, The second sheet is connected to the first sheet by wrapping around an end of the first sheet. The organic piezoelectric film-embedded sensor according to claim 1 or 2.

7. The laminate includes a first sheet, the first sheet has a structure in which at least the water vapor barrier layer and the sealing material layer are laminated, the organic piezoelectric element is enclosed in the first sheet; The organic piezoelectric film-embedded sensor according to claim 1 or 2.

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