JP2021001839A - Adhesive strength sensor, multipoint adhesive strength sensor, and manufacturing method of multipoint adhesive strength sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive force sensor capable of detecting not only compressive force but also tensile force, and a multipoint adhesive force sensor capable of measuring distribution of compressive force and tensile force using the adhesive force sensor. And its manufacturing method. SOLUTION: In an adhesive force sensor 30, an adhesive 38a or the like is discharged so as to surround an electrode 36 around an end portion of a base film 39. In this state, the pressure-sensitive body 34 and both electrodes 32 and 36 are covered as a whole, and the ends of both base films 31 and 39 are bonded with an adhesive 38a or the like. That is, the adhesive 38a or the like brings the ends of both base films 31 and 39 into close contact with each other so as to surround the measurement point composed of the electrode 36, the pressure sensitive body 34, and the electrode 32. A multi-point adhesive force sensor 40 in which detection points corresponding to the adhesive force sensor 30 are arranged in a matrix on the base film 39 by a lower electrode forming step, an adhesive application step, a pressure sensitive body mounting step, and a base material pressure welding step. To manufacture. [Selection diagram] Fig. 2

Description

The present invention relates to an adhesive force sensor for detecting a compressive force or a tensile force in which a pressure sensitive body is arranged between an electrode formed on a base material and another electrode formed on another base material. The present invention relates to an adhesive force sensor having a structure in which the end portions of both base materials are joined with a predetermined adhesive so as to cover the pressure sensitive body and both electrodes.

The conventional pressure sensor sheet has a structure in which a pressure sensitive layer and a spacer are laminated between, for example, a pair of electrodes (upper electrode and lower electrode). In such a conventional pressure sensor sheet, in addition to the change in the electric resistance of the pressure-sensitive layer itself, the contact area between the lower electrode separated by the spacer and the pressure-sensitive layer increases according to the pressing pressure, and thereby the contact electricity. By changing the resistance, the detection sensitivity of the pressing pressure is increased. However, with such a structure, when a pressing force is hardly applied or a force in the tensile direction (tensile force) is applied, the electrode pair and the pressure sensitive layer are not in contact with each other, so those forces (pushing) There was a problem that pressure (pressure, tensile force) could not be detected.

Patent Document 1 discloses a sensor sheet in which a thin film transistor, a sensor member, and a common electrode are laminated. One of the uses of this sensor sheet is to measure the pressure applied to human skin by installing it on the back side of clothes. Patent Document 1 describes the pressing force, but there is no description or suggestion about the tensile force.

Patent Document 2 discloses a pressure detecting device in which a pressure-sensitive layer is formed between two band-shaped electrodes. The control method of this pressure detection device is described by taking the case where pressure is applied by the sole of a person's foot as an example. Patent Document 2 describes the case where pressure is applied, but there is no description or suggestion regarding tensile force.

As described above, conventional pressure sensor sheets, pressure detectors, etc. focus on the detection of pressing force or compressive force, but there is a problem that they do not support the detection of tensile force acting in the opposite direction. It was.

Therefore, an object of the present invention has been made to solve the above problems, and an object of the present invention is to provide an adhesive force sensor capable of detecting not only compressive force but also tensile force.

A second object of the present invention is to provide a multi-point adhesive force sensor capable of measuring the distribution of compressive force and tensile force by using the adhesive force sensor of the present invention, and a method for manufacturing the same.

In the adhesive force sensor of the present invention, a pressure sensitive body is arranged between an electrode formed on a base material and another electrode formed on another base material, and the pressure sensitive body and both electrodes are covered with the pressure sensitive body. It is an adhesive force sensor for detecting a compressive force or a tensile force, which has a structure in which the ends of both base materials are joined with a predetermined adhesive.

Here, in the adhesive force sensor of the present invention, an ultraviolet curable type adhesive can be used as the predetermined adhesive.

The multi-point adhesive force sensor of the present invention is characterized by integrating the adhesive force sensor of the present invention.

The method for manufacturing a multi-point adhesive force sensor of the present invention includes a lower electrode forming step of forming a predetermined number of rod-shaped electrodes (lower electrodes) on a base material, and a lower electrode forming step on each lower electrode formed in the lower electrode forming step. Used in the adhesive coating step of applying the adhesive on the base material and the lower electrodes after covering the detection points for detecting the compressive force or the tensile force with a mask, and in the adhesive coating step. A pressure sensitive body mounting step of mounting the pressure sensitive body on the lower electrode in each hole after removing the mask, and another base material on which a predetermined number of rod-shaped electrodes (upper electrodes) of a predetermined shape are formed are used. In the pressure-sensitive body mounting step, each upper electrode faces the base material on the side on which the pressure-sensitive body is mounted so as to be orthogonal to each of the lower electrodes, and then the other base material and the base are opposed to each other. It is characterized by including a base material pressure welding process for pressure welding with a material.

Here, in the method for manufacturing a multi-point adhesive force sensor of the present invention, instead of the adhesive coating step and the pressure sensitive body mounting step, a liquid feeling of a predetermined diameter is placed on the lower electrode after the lower electrode forming step. A printing / coating step can be provided in which a predetermined number of pressure members are printed, each liquid pressure sensitive body is masked, and then an adhesive is applied onto the base material and the lower electrode.

In the adhesive force sensor of the present invention, a pressure sensitive body is arranged between an electrode formed on a base material and another electrode formed on another base material, and the interface between the pressure sensitive body and both electrodes is provided. It is an adhesive force sensor that detects a compressive force or a tensile force having a structure in which the above is bonded with a predetermined conductive adhesive, and the interface is a plane-shaped surface facing between the pressure sensitive body and each electrode. It is an adhesive force sensor that detects a compressive force or a tensile force.

Here, in the adhesive force sensor of the present invention, a silver paste or an anisotropic conductive film can be used as the predetermined conductive adhesive.

In the (one point) adhesive force sensor of the present invention, the adhesive is discharged so as to surround the electrodes around the edges of the base film. In this state, the pressure-sensitive body and both electrodes are covered as a whole, and the ends of both base films are bonded with an adhesive. That is, the adhesive adheres the ends of both base films so as to surround the measurement point composed of the electrode, the pressure sensitive body, and the electrode. As a result, according to the adhesive force sensor of the present invention, there is an effect that a larger tensile force can be measured than when only a part of the base film is adhered. As described above, it is possible to provide an adhesive force sensor capable of not only detecting a compressive force but also detecting a large tensile force.

In the method for manufacturing a multipoint adhesive force sensor of the present invention, first, a predetermined number of lower electrodes are formed on a base film (lower electrode forming step). Subsequently, a predetermined number of detection points (almost synonymous with measurement points in the case of a one-point adhesive force sensor) for detecting compressive force or tensile force are placed on each lower electrode formed in the lower electrode forming step. Cover with a mask. After that, an adhesive is applied onto the base film and each lower electrode (adhesive application step). Next, the pressure-sensitive body is placed on the lower electrode in each hole after the mask used in the adhesive application step is removed (pressure-sensitive body mounting step). The upper electrode is opposed to the base film on the side on which the pressure sensitive body is mounted in the pressure sensitive body mounting step so that each upper electrode intersects each lower electrode. After the above, both base films are pressure-welded (base material pressure-welding step). Based on the above, according to the method for manufacturing a multipoint adhesive force sensor of the present invention, it is possible to measure the distribution of compressive force and tensile force based on the structure of the (single point) adhesive force sensor of the present invention. A sensor and a method for manufacturing the sensor can be provided. In the (one point) adhesive force sensor of the present invention, since the adhesive area ratio of the base film is high, the peel strength is high even when a large tensile force is applied. By utilizing the structure of such a (single point) adhesive force sensor, it is possible to achieve a remarkable effect that a large tensile force can be stably measured even if the measurement points are miniaturized and highly integrated.

It is a figure for demonstrating the difference between the general force (pressure, stress, tactile sense, etc.) sensor and the adhesive force sensor of this invention. It is a figure which shows the adhesive force sensor 30 of this invention and the manufacturing method thereof. It is a figure which shows the manufacturing method of the multipoint adhesive force sensor of this invention. It is a figure which shows the AA'cross-sectional view of the multipoint adhesive force sensor 40 shown in FIG. 3 (E). It is a photograph which took the multipoint adhesive force sensor 40 (state of FIG. 3 (E)). It is a figure which shows another type of adhesive force sensor 50 of this invention and the manufacturing method thereof. It is a figure which shows another conductive path Cp'. It is a figure which shows the pressure distribution sensor 60 of the structure which crossed the comb-shaped electrodes. It is a top view of the sensor 70 which can measure shear stress (shear stress). It is a figure which shows the experimental apparatus 100 which performs an experiment such as an adhesive force sensor 20. It is a figure which shows the enlarged photograph in the dotted circle C of FIG. It is a figure which shows the enlarged photograph of the gripping tool 106. It is a figure which shows the enlarged photograph of the load cell 110. It is an exploded schematic drawing for demonstrating the bonding between a sensor sheet 130-acrylic rubber block 120-load cell 110. It is a graph which shows the result of having performed the experiment of the tensile force / compressive force using the material tester 102. It is a figure which shows the electric circuit used in an experiment.

Hereinafter, examples will be described in detail with reference to the drawings.

First, the difference between a general force (pressure, stress, tactile sensation, etc.) sensor and the adhesive force sensor of the present invention will be described. FIG. 1A shows a general force sensor 10. In FIG. 1 (A), reference numeral 12 is an upper electrode, 16 is a lower electrode, Fp is a compressive force, 14 is a pressure sensitive body which is a substance whose electrical resistance changes when a compressive force Fp is applied, and Cp is a pressure sensitive body 14. It is a conductive path for passing electricity through. In FIG. 1A, an electrode pair composed of two layers (upper electrode 12 and lower electrode 16) is shown, but since the electrode pair is a conductive path Cp for passing electricity through the pressure sensitive body 14, it will be described later. There may be another conductive path. As shown in FIG. 1A, when the compressive force Fp is applied to the upper electrode 12 of the force sensor 10, the pressure sensitive body 14 is deformed in the compressive force Fp direction. As a result, in the force sensor 10, the distance between the upper electrode 12 and the lower electrode 16 in the compressive force Fp direction decreases, so that the electrical resistance in the conductive path Cp decreases. Therefore, if the relationship between the compressive force Fp and the output voltage from the force sensor 10 with respect to the compressive force Fp is obtained in advance by an experiment, then the compressive force Fp can be obtained (detected) from the relationship by measuring the output voltage. it can. The above is the same for the adhesive force sensor of the present invention.

FIG. 1B shows a case where a tensile force Fd is applied to the upper electrode 12 of the force sensor 10. In FIG. 1 (B), the parts having the same reference numerals as those in FIG. 1 (A) indicate the same elements, and thus the description thereof will be omitted. As shown in FIG. 1 (B), when the tensile force Fd is applied, the upper electrode 12 and the pressure sensitive body 14 are separated from each other, and the pressure sensitive body 14 and the lower electrode 16 are separated from each other. -The pressure sensitive body 14-the lower electrode 16 (conductive path Cp) is in an insulated state. As a result, the tensile force Fd cannot be detected. FIG. 1C shows the adhesive force sensor 20 of the present invention. In FIG. 1 (C), the parts having the same reference numerals as those in FIG. 1 (A) indicate the same elements, and thus the description thereof will be omitted. As shown in FIG. 1C, in the adhesive force sensor 20, the upper electrode 12 and the pressure sensitive body 14 and the pressure sensitive body 14 and the lower electrode 16 are in close contact with each other by the adhesive Ad. There is. Therefore, even when a tensile force Fd is applied as shown in FIG. 1C, the layers between the upper electrode 12 and the pressure sensitive body 14 and between the pressure sensitive body 14 and the lower electrode 16 are not separated. Therefore, the conduction state is maintained between the upper electrode 12-the pressure sensitive body 14-the lower electrode 16 (conductive path Cp). As shown in FIG. 1C, when the tensile force Fd is applied to the upper electrode 12 of the adhesive force sensor 20, the pressure sensitive body 14 is deformed in the tensile force Fd direction. As a result, in the adhesive force sensor 20, the distance between the upper electrode 12 and the lower electrode 16 in the tensile force Fd direction increases, so that the electrical resistance in the conductive path Cp increases. Therefore, if the relationship between the tensile force Fd and the output voltage from the adhesive force sensor 20 with respect to the tensile force Fd is obtained in advance by an experiment, then the tensile force Fd can be obtained (detected) from the relationship by measuring the output voltage. Can be done.

The method of manufacturing the adhesive force sensor 20 described above will be described later, and another type of adhesive force sensor will be described first. FIG. 2 shows the adhesive force sensor 30 of the present invention and a method for manufacturing the same. In FIG. 2A, reference numeral 31 is a base film (base material), 32 is an electrode formed on the base film 31 (in FIG. 2A, it can be said that the electrode is formed under the base film 31), 39. Is a base film (a base material different from the base film 31), 36 is an electrode formed on the base film 39 (an electrode different from the electrode 32), and 34 is arranged between the electrode 32 and the electrode 36. The pressure sensitive bodies 38a and 38b are predetermined adhesives discharged to the end portion of the base film 39. In FIG. 2B, the parts having the same reference numerals as those in FIG. 2A indicate the same elements, and thus the description thereof will be omitted. As shown in FIG. 2B, the end portions of both base films 31 and 39 are joined (pasted) with adhesives 38a and 38b so as to cover the pressure sensitive body 34 and both electrodes 32 and 36 as a whole. match). FIG. 2B shows a state in which the adhesives 38a and 38b are discharged to the left and right ends of the base film 39, but this is because it is a cross-sectional view, and the adhesives 38a and 38b (hereinafter, hereinafter) are actually shown. , "Adhesive 38a, etc.") is discharged so as to surround the electrode 36 around the end portion of the base film 39. Subsequently, a force P was appropriately applied to compress the adhesive force sensor 30, and the compressed state was maintained until the adhesive 38a or the like dried and solidified. The portion composed of the electrode 36, the pressure sensitive body 34, and the electrode 32 in FIG. 2B is referred to as a measurement point.

As the base film 31 and the electrode 32 (base film 39 and electrode 36), a copper-polyimide laminated film was used this time. That is, the base films 31 and 39 were made of polyimide, and the electrodes 32 and 36 were made of copper. In addition, indium tin oxide (ITO) may be used as the electrodes 32 and 36, polyethylene terephthalate (PET) may be used as the base films 31 and 39, and transparent electrode films may be used. The electrodes 32 and 36 are not limited to the above materials, and aluminum, silver, gold, platinum, carbon nanotubes (CNT) and the like may be used. The base films 31 and 39 are not limited to the above materials, and polyethylene (PE), glass, and the like may also be used. As described above, various combinations of insulators and conductors can be selected for the base film 31 and the like and the electrodes 32 and the like.

As the pressure sensitive body 34, conductive rubber was used this time. Alternatively, the conductive polymer polythiophene or polypyrrole may be used. It is said that the electrons in the side chains of the polymer are relatively easy to move and exhibit pressure sensitivity. The pressure-sensitive body 34 is not limited to the above-mentioned materials, and a mixture thereof such as a polymer material such as conductive ink / resin and a semiconductor material whose electric resistance is easily changed may be used. For example, there is a type of conductive rubber in which a conductive filler such as conductive powder or carbon nanotube is mixed with an insulator, and the material itself has a complicated structure such as porous or fibrous and is subjected to external force. There is also a type in which the structure changes and the electrical resistance changes accordingly. It is considered that the adhesive force sensor 30 of the present invention can be applied to a wide variety of pressure sensitive bodies.

In the bonding (bonding) of the left and right ends of both base films 31 and 39 shown in FIG. 2B, the adhesives 38a and 38b are first discharged after masking the electrode 39, and then the feeling is felt after the mask is peeled off. The pressure body 34, the other electrode 32, and the base film 31 were placed in this order, and the base film 31 and the base film 39 were bonded to each other, and the compressed state by the force P was maintained until the adhesives 38a and 38b were dried and solidified. As the adhesives 38a and 38b, spray glue was used this time. For example, 3M (registered trademark) spray glue 77 was used. Other common adhesives can be used. For example, Henkel's Loctite® 638 is suitable as an adhesive with high peel strength. Alternatively, as the adhesives 38a and 38b, ultraviolet curable type adhesives (anaerobic sealing agent high-strength type manufactured by ThreeBond Co., Ltd., etc.) in which the curing timing can be arbitrarily specified may be used. As the mask, a sticky note was used this time, and the portion of the sticky note to which the adhesive was attached was punched out according to the shape of the portion to be masked (electrode 36) and attached to the masked portion. Other masks such as masking tape (registered trademark) and drafting tape can be used as long as they are strong enough to be stuck and peeled off. The time required for the above-mentioned adhesives 38a and 38b to dry and solidify depends on the amount of spray glue discharged, but the adhesives were bonded within about 1 minute after discharge, and a weight was placed for about 3-5 minutes. .. However, the solidification time can be freely set by using the above-mentioned ultraviolet curable type adhesive or the like.

Similar to the adhesive force sensor 20 described with reference to FIG. 1, the adhesive force sensor 30 has a compressive force Fp or a tensile force Fd (for compressive force Fp and tensile force Fd, refer to FIG. Once the relationship with the output voltage from the adhesive force sensor 30 is obtained, the compressive force Fp or the tensile force Fd can be detected from the relationship by measuring the output voltage thereafter. Hereinafter, the point that the adhesive force sensor 30 can detect the tensile force Fd will be described in detail. As shown in FIG. 2B, the adhesive 38a or the like is discharged so as to surround the electrode 36 around the end portion of the base film 39. In this state, the end portions of both base films 31 and 39 were bonded with an adhesive 38a or the like so as to cover the pressure sensitive body 34 and both electrodes 32 and 36 as a whole. That is, the adhesive 38a and the like bring the ends of both base films 31 and 39 into close contact with each other so as to surround the measurement point composed of the electrode 36, the pressure sensitive body 34, and the electrode 32. As a result, the adhesive force sensor 30 can measure a larger tensile force Fd than when only a part of the base film 39 or the like is adhered. That is, since the adhesive force sensor 30 has a high adhesive area ratio of the base film 39 and the like, there is an effect that the peel strength is high even when a large tensile force Fd is applied. Since the tensile force Fd = tensile pressure (per unit area) x adhesive area, the same tension can be obtained by increasing the adhesive area of the base film 39 or the like in consideration of the case where the tensile force Fd is applied to the adhesive force sensor 30. It can withstand a larger tensile force Fd than other joining methods that can withstand only pressure. Therefore, the higher the ratio of the adhesive area, the higher the peel strength, and the two are in a proportional relationship as shown in the above equation. Therefore, both base films 31 and 39 do not peel off (separate) even when a large tensile force Fd is applied, so that between the upper electrode 32-the pressure sensitive body 34-the lower electrode 36 (conductive path Cp, see FIG. 1 (C)). Maintains a conductive state. As a result, the adhesive force sensor 30 can detect a large tensile force Fd.

From the above, according to the first embodiment of the present invention, in the adhesive force sensor 30, the adhesive 38a or the like is discharged so as to surround the electrode 36 around the end portion of the base film 39. In this state, the pressure-sensitive body 34 and both electrodes 32 and 36 are covered as a whole, and the ends of both base films 31 and 39 are bonded with an adhesive 38a or the like. That is, the adhesive 38a and the like are in close contact with the ends of both the base films 31 and 39 so as to surround the periphery of the above-mentioned measurement point composed of the electrode 36, the pressure sensitive body 34, and the electrode 32. As a result, the adhesive force sensor 30 has the effect of being able to measure a larger tensile force Fd than when only a part of the base film 39 or the like is adhered. As described above, it is possible to provide the adhesive force sensor 30 capable of not only detecting the compressive force Fp but also detecting a large tensile force Fd.

Both base films 31 and 39 cover the measurement point as a whole, in other words, cover the circumference of the measurement point. Therefore, the pressure sensitive body 34 is less likely to shift even when a force in the sliding direction is applied, and therefore, there is also an effect that the stability when measuring the tensile force Fd and the compressive force Fp is good.

Based on the structure of the adhesive force sensor 30 described in Example 1, the inventors have developed a multi-point adhesive force sensor capable of observing the distribution of tensile force and compressive force (the adhesive force sensor 30 is a one-point adhesive force sensor). It can be said that). Hereinafter, the multipoint adhesive force sensor in which the adhesive force sensor 30 of the first embodiment is integrated will be described.

FIG. 3 shows a method for manufacturing the multipoint adhesive force sensor of the present invention. In FIG. 3, the parts having the same reference numerals as those in FIG. 2 indicate the same elements, and thus the description thereof will be omitted. Below, the materials of the base film, the upper electrode, the lower electrode, the pressure sensitive body, and the adhesive are the same as those in Example 1. As shown in FIG. 3A, first, a predetermined number of lower electrodes (rod-shaped electrodes of a predetermined shape) 36-i (i = 1 to 5) are formed on the base film (base material) 39 (lower electrode formation). Process). In FIG. 3A, the case of a rectangle as a predetermined shape is illustrated, and the case of a predetermined number = 5 is illustrated. However, the predetermined shape is not limited to a rectangle, and the predetermined number is not limited to five.

Subsequently, on each of the lower electrodes 36-i (i = 1 to 5) formed in the lower electrode forming step described above, a detection point for detecting a compressive force or a tensile force (in the case of the one-point adhesive force sensor 30 described above). It is almost synonymous with the measurement point, but it is called a detection point to distinguish one point from multiple points), and is covered with a desired number of masks Mij (j = 1 to 5). After that, an adhesive is applied onto the base film 39 and each lower electrode 36-i (i = 1 to 5) (adhesive application step). FIG. 3B shows the state after the adhesive application step, reference numeral 38 is the applied adhesive, and holes Hij (i = 1 to 5, j = 1 to 5) are masks Mij (i = 1 to 5, It is a hole after removing j = 1-5). The detection point is represented as a detection point D (i, j) using the position (i, j). In FIG. 3B, the number of detected points was set to 5 × 5 = 25. That is, five masks Mij (j = 1 to 5) were used on each lower electrode 36-i (i = 1 to 5), but the number is not limited to five. For example, by placing a thread on the mask Mij (j = 1 to 5) in advance and connecting the mask Mij (j = 1 to 5) together, the mask Mij (j = 1 to 5) can be quickly applied after the adhesive is applied. 5) can be peeled off. The method of connecting is not limited to the j direction, but may be the i direction.

Next, the lower part in each hole Hij (i = 1-5, j = 1-5) after removing the mask Mij (i = 1-5, j = 1-5) used in the adhesive coating step. The pressure sensitive body 34 (i, j) (i = 1 to 5, j = 1 to 5) is placed on the electrodes 36-i (i = 1 to 5) (pressure sensitive body mounting step). FIG. 3C shows the pressure sensitive bodies 34 (i, j) (i = 1 to 5, j = 1 to 5) to be placed in a matrix. The pressure sensitive bodies 34 (i, j) (i = 1 to 5, j = 1 to 5) are placed in the holes Hij (i = 1 to 5, j = 1 to 5) shown in FIG. 3 (B), respectively. I and j are placed in correspondence with each other. The pressure sensitive bodies 34 (i, j) may be placed one by one in the holes Hij, or the pressure sensitive bodies 34 (i, j) (i = 1 to 5, j = 1 to 5) may be placed in advance in the matrix direction. It may be connected with a thread (vertically and horizontally) and placed integrally in the holes Hij (i = 1 to 5, j = 1 to 5).

FIG. 3D shows another base film (base material) 31 on which a predetermined number of rod-shaped electrodes (upper electrodes) 32-j (j = 1 to 5) having a predetermined shape are formed. In FIG. 3D, the case of a rectangle as a predetermined shape is illustrated, and the case of a predetermined number = 5 is illustrated. However, the predetermined shape is not limited to a rectangle, and the predetermined number is not limited to five. As shown in FIG. 3 (E), the base film on the side where the pressure sensitive body 34 (i, j) is placed on the upper electrode 32-j (j = 1 to 5) in the pressure sensitive body mounting step. With respect to 39, each upper electrode 32-i (j = 1 to 5) faces each lower electrode 36-i (i = 1 to 5) so as to be orthogonal to Sosu. That is, when the base film 31 shown in FIG. 3 (D) is turned over and faced with the base film 39 (however, the base film 39 after the pressure sensitive body mounting step) shown in FIG. 3 (A), FIG. As shown in E), each upper electrode 32-j (j = 1-5) faces each lower electrode 36-i (i = 1-5) so as to be orthogonal (or intersecting) with each other. .. To be orthogonal (or intersect) with each other, the upper electrodes 32-j (j = 1 to 5) and the lower electrodes 36-i (i = 1 to 5) overlap each other in a grid shape in a plan view. It means to become. After the above, the base film 31 (another base material) and the base film 39 are pressure-welded (base material pressure-welding step). For pressure welding, a soft cloth was laid and a book or the like was placed as a weight on the base film 31 to apply pressure. FIG. 3 (E) shows the multi-point adhesive force sensor 40, under which the upper electrode 32-j (j = 1 to 5) and the pressure sensitive body (i, j) (i = 1 to 5) are under the base film 31. It shows a state in which j = 1 to 5), the adhesive 38, and the lower electrode 36-i (i = 1 to 5) are laminated (a state in which they can be seen through).

FIG. 4 shows a cross-sectional view taken along the line AA'of the multipoint adhesive force sensor 40 shown in FIG. 3 (E). For AA', the line on the detection point D (2, j) (j = 1 to 5) is used as an example. In FIG. 4, the parts having the same reference numerals as those in FIG. 3 indicate the same elements, and thus the description thereof will be omitted. As shown in FIG. 4, each of the detection points D (2, j) (j = 1 to 5) has the same shape as the measurement point described in FIG. 2 (B).

FIG. 5 is a photograph of the multipoint adhesive force sensor 40 (state of FIG. 3E). In FIG. 5, reference numeral 36C is an electric wire (cord) from the lower electrode 36-i (i = 1 to 5), 32C is a code from the upper electrode 32-j (j = 1 to 5), and detection point D ( 2 and 2) are shown exemplary. In FIG. 5, the parts having the same reference numerals as those in FIG. 3 (E) indicate the same elements, and thus the description thereof will be omitted. As shown in FIG. 5, the pitch between detection points is 1 cm, the number of detection points is 5 × 5 points (size is about 5 × 5 cm), and the thickness is 0.6 mm. In this production, since the conductive rubbers are individually placed as the pressure sensitive bodies 34 (i, j), the pitch between the detection points is preferably about several mm.

From the above, according to the second embodiment (manufacturing method of the multipoint adhesive force sensor 40) of the present invention, first, the lower electrode (a predetermined rod-shaped electrode) 36-i (i =) is placed on the base film (base material) 39. A predetermined number of 1 to 5) are formed (lower electrode forming step). Subsequently, on each lower electrode 36-i (i = 1 to 5) formed in the lower electrode forming step described above, a detection point for detecting a compressive force or a tensile force (in the case of the one-point adhesive force sensor 30 described above). Cover with a predetermined number of masks that match the planar shape (approximately circular shape) of the measurement point (almost synonymous with the measurement point). After that, an adhesive is applied onto the base film 39 and each lower electrode 36-i (i = 1 to 5) (adhesive application step). Next, the lower part in each hole Hij (i = 1-5, j = 1-5) after removing the mask Mij (i = 1-5, j = 1-5) used in the adhesive coating step. The pressure sensitive body 34 (i, j) (i = 1 to 5, j = 1 to 5) is placed on the electrodes 36-i (i = 1 to 5) (pressure sensitive body mounting step). Each upper electrode 32-j (j) was placed on the base film 39 on the side on which the pressure sensitive body 34 (i, j) was placed in the pressure sensitive body mounting step on the upper electrode 32-j (j = 1 to 5). = 1 to 5) are opposed to each lower electrode 36-i (i = 1 to 5) so as to intersect. After the above, the base film 31 (another base material) and the base film 39 are pressure-welded (base material pressure-welding step). Based on the structure of the adhesive force sensor 30 of the present invention described in the first embodiment, it is possible to provide a multipoint adhesive force sensor 40 capable of measuring the distribution of compressive force and tensile force and a method for manufacturing the same. it can. As described above, in the adhesive force sensor 30 of the first embodiment, since the adhesive area ratio of the base film 39 and the like is high, there is an effect that the peel strength is high even when a large tensile force is applied. By utilizing the structure of the adhesive force sensor 30, it is possible to achieve a remarkable effect that a large tensile force can be stably measured even if the measurement points D (i, j) are miniaturized and highly integrated. it can. The point that the multi-point adhesive force sensor 40 can detect the tensile force has been described in detail above. Needless to say, the multipoint adhesive force sensor 40 based on the structure of the adhesive force sensor 30 can detect the compressive force as described in the first embodiment.

Instead of the adhesive application step and the pressure sensitive body mounting step of the second embodiment, there is a method of screen printing the liquid pressure sensitive body as follows. That is, a predetermined number of liquid pressure sensitive bodies having a predetermined diameter are printed on the lower electrodes 36-i (i = 1 to 5) after the lower electrode forming step. The predetermined diameter is each diameter of the pressure sensitive body 34 (i, j) (i = 1 to 5, j = 1 to 5) to be placed as shown in FIG. 3 (C). As a result, the liquid pressure sensitive body is screen-printed on the lower electrode 36-i (i = 1 to 5) in the form of matrix elements. Next, after masking each printed liquid pressure sensitive body, the adhesive 38 is applied onto the base film 39 and the lower electrodes 36-i (i = 1 to 5) (printing / coating step). In Example 2, since the conductive rubbers were individually placed as the pressure sensitive bodies 34 (i, j), the pitch between the detection points was preferably about several mm. However, in the method of screen printing the liquid pressure sensitive body of Example 3, the pitch between detection points can be highly integrated up to about several hundred μm.

From the above, according to the third embodiment of the present invention, a method of screen printing a liquid pressure sensitive body can be used instead of the adhesive coating step and the pressure sensitive body mounting step of the second embodiment. Specifically, a predetermined number of liquid pressure sensitive bodies having a predetermined diameter are printed on the lower electrodes 36-i (i = 1 to 5) after the lower electrode forming step. That is, the liquid pressure sensitive body is screen-printed on the lower electrode 36-i (i = 1 to 5) in the form of matrix elements. Next, after masking each printed liquid pressure sensitive body, the adhesive 38 is applied on the base film 39 and the lower electrodes 36-i (i = 1 to 5). As a result, the pitch between detection points can be highly integrated up to about several hundred μm.

FIG. 6 shows another type of adhesive force sensor 50 of the present invention and a method for manufacturing the same. In FIG. 6, the parts having the same reference numerals as those in FIG. 2 indicate the same elements, and thus the description thereof will be omitted. The difference between FIG. 6A and FIG. 2A is that the adhesive 38a or the like is not discharged to the end portion of the base film 39. That is, between the electrode 32 formed on the base film 31 (in FIG. 6A, it can be said that the electrode is formed under the base film 31) and another electrode 36 formed on another base film 39. The structure is the same as that of the first embodiment in that the pressure sensitive body 34 is arranged on the surface. Next, as shown in FIG. 6B, the interface between the pressure sensitive body 34 and both electrodes 32 and 36 is joined with a predetermined conductive adhesive 55. Here, the interface is a planar surface facing the pressure sensitive body 34 and the electrodes 32 and 36. That is, since the conductive adhesive 55 is applied without gaps to the planar interface between the pressure sensitive body 34 and the electrodes 32 and 36, there are no gaps between the pressure sensitive body 34 and the electrodes 32 and 36. It is joined on a flat surface. As shown in FIG. 6B, the conductive adhesive 55 is also applied to the peripheral portions of both electrodes 32 and 26.

The materials of the base films 31 and 39, the electrodes 32 and 36, and the pressure sensitive body 34 are the same as those in the first embodiment. This time, a silver paste was used as the predetermined conductive adhesive 55. Alternatively, an anisotropic conductive film (ACF) may be used. It is possible to obtain a large peeling strength if the crimping conditions are met by the amount of thermocompression bonding. The method by which the adhesive force sensor 50 detects the compressive force Fp and the tensile force Fd is as described in the first embodiment. The compressive force Fp is the general force sensor 10 of FIG. 1 (A), and the tensile force Fd is the tensile force Fd. Since it is the same as the adhesive force sensor 20 of FIG. 1C, the description thereof will be omitted.

From the above, according to the fourth embodiment of the present invention, as in the first embodiment, the adhesive force sensor 50 has an electrode 32 formed on the base film 31 and another electrode 36 formed on another base film 39. It is a structure in which the pressure sensitive body 34 is arranged between the two. However, the interface between the pressure sensitive body 34 and both electrodes 32 and 36 was joined with a predetermined conductive adhesive 55. Here, the interface is a planar surface facing the pressure sensitive body 34 and the electrodes 32 and 36. As a result, it is possible to provide the adhesive force sensor 50 capable of not only detecting the compressive force but also detecting a large tensile force as in the first embodiment.

In Example 1, FIG. 1 (A) and the like are used to show a pair of electrodes (upper electrode 12 and lower electrode 16) composed of two layers and a conductive path Cp for passing electricity through the pressure sensitive body 14. FIG. 7 shows another conductive path Cp'. In FIG. 7, the parts having the same reference numerals as those in FIGS. 1A to 1C indicate the same elements, and thus the description thereof will be omitted. In the adhesive force sensor 20'shown in FIG. 7, the electrode pair for passing electricity through the pressure sensitive body 14 does not necessarily have to be composed of two upper and lower layers, and the left and right electrodes 12'and 16' are left and right. It may be paired with. Even in this case, the compressive force Fp and the tensile force Fd can be detected as described in the first embodiment. Base films (not shown) can be provided below the electrode pairs 12'and 16'and above the pressure sensitive body 14. That is, the adhesive force sensor 20'is placed on the electrode pairs 12'and 16'formed on the base film, the pressure sensitive body 14 arranged on the electrode pairs 12'and 16', and the pressure sensitive body 14. It is provided with another base film arranged, and the interface between the pressure sensitive body 14 and both electrodes 12'and 16'has a structure joined by a predetermined conductive adhesive Ad. The interface is a planar surface facing the pressure sensitive body 14 and the electrodes 12'and 16'.

The adhesive strength sensors 20, 30 and 50 of the present invention described above can also be applied to various sensors. FIG. 8 shows a pressure distribution sensor 60 having a structure in which comb-shaped electrodes are crossed. As shown in FIG. 8, the electrode layer 2 is formed by processing a copper-clad polyimide film into a comb shape by a wet etching treatment to form comb-shaped copper electrodes 66-1 to 66-5. The materials such as the copper electrode 66-1 are the same as the materials of the upper electrode 12 or 32 and the lower electrode 16 or 36 of the adhesive force sensors 20 and 30 described above. The base film is a polyimide film, which is the same material as the base film 31 or 39 of the adhesive force sensor 20 or the like described above. The pressure-sensitive layer is a conductive film that is a pressure conversion element of the pressure distribution sensor 60, and has a characteristic that the electric resistance value in the thickness direction changes according to the acting pressure. It is the same material as the pressure sensitive body 14 and the like of the adhesive force sensor 20 and the like described above.

In order to apply the adhesive force sensor 20 and the like of the present invention, as in Example 1 (FIG. 1) or Example 4 (FIG. 6), between the electrode layer 2 and the pressure-sensitive layer, and with the pressure-sensitive layer. Adhesive Ad or 55 (not shown) may be applied between the electrode layer 1 and the adhesive layer 1. As a result, the pressure distribution sensor 60 has a comb-shaped copper electrode 66-1 to 66-5 formed on the electrode layer 2 and a comb-shaped copper electrode formed under the electrode layer 1 (only a part in FIG. 8). It has a structure in which the pressure-sensitive layer is sandwiched between the two sheets (shown). The two comb-shaped copper electrodes 66-1 to 66-5 and the copper electrode on the electrode layer 1 side are orthogonal to each other, and the matrix-shaped intersection formed by the orthogonality is the detection point. .. Alternatively, as in the second embodiment (FIG. 2), the adhesive 38a or the like may be discharged to the ends of the two base films of the pressure distribution sensor 60, and the two base films may be pressure-welded.

The adhesive strength sensors 20, 30 and 50 of the present invention described above can also be applied to various sensors. FIG. 9 is a plan view of the sensor 70 capable of measuring shear stress. As illustrated in FIG. 9, the electrode layer 1 is designed so that a part of the area overlaps a part of the area of the electrode layer 2 vertically (in the z-axis direction perpendicular to the xy axis). A pressure sensitive body (not shown) is sandwiched between the electrode layers 1 and 2. Here, when a shear stress acts between the electrode layers 1 and 2, the electrical resistance value between the electrode layers 1 and 2 changes due to shear deformation in the x-axis or y-axis direction of the pressure-sensitive body in the overlapping region. Therefore, the shear stress in the x-axis or y-axis direction can be measured. In the middle of the electrode layer 2, the electrode layer 1 is designed so that the entire area thereof overlaps the area of a part of the electrode layer 2 vertically (in the z-axis direction perpendicular to the xy axis). Here, when a tensile force or a compressive force acts between the electrode layer 1 and the electrode layer 2, the electricity between the electrode layer 1 and the electrode layer 2 due to the deformation of the pressure sensitive body in the z-axis direction in the overlapping region. Since the resistance value changes, the tensile force or compressive force in the z-axis direction can be measured.

In order to apply the adhesive force sensor 20 and the like of the present invention, as in Example 1 (FIG. 1) or Example 4 (FIG. 6), between the electrode layer 2 and the pressure-sensitive layer, and with the pressure-sensitive layer. Adhesive Ad or conductive adhesive 55 (not shown) may be applied between the electrode layer 1 and the adhesive layer 1. As a result, the sensor 70 has a structure in which the electrode layer 2 and the electrode layer 1 sandwich the pressure-sensitive layer with the adhesive Ad or the like. Alternatively, as in the second embodiment (FIG. 2), the sensor 70 may be sandwiched between two base films, and an adhesive 38a or the like may be discharged to the ends thereof to press-contact the two base films.

Experiment.
An experiment was conducted using the following experimental device 100 for detecting the tensile force / compressive force of the adhesive force sensors 20, 30, 40, 50 and 20'of each of the above-described examples. FIG. 10 shows an experimental device 100 for performing an experiment such as an adhesive force sensor 20. In FIG. 10, reference numeral 102 is a material testing machine, and 4464 manufactured by INSTRON (registered trademark) was used. However, since the load range is significantly different, a load cell 110 (USM-5N manufactured by UNIpulse Corporation (registered trademark)) is sandwiched between chucks 104a and 104b (see FIG. 11) of the material testing machine 102 for precision measurement. The load cell 110 pushes (compressive force) and pulls (tensile force) the sensor sheet 130 composed of the adhesive force sensor 20 and the like of the present invention via the acrylic-rubber block 120. In order to test the tensile force, the sensor sheet 130 was fixed to the stage 132 by covering the pressure sensitive bodies 14, 34 and the like with vinyl tape 134. Each interface between the sensor sheet 130-acrylic-rubber block 120-load cell 110 was attached with strong double-sided tape. The material testing machine 102 is driven by the drive circuit 140, and the measurement results and the like are recorded in the data logger 142. The drive and measurement were controlled by PC 144.

FIG. 11 shows an enlarged photograph in the dotted circle C of FIG. In FIG. 11, the parts having the same reference numerals as those in FIG. 10 indicate the same elements, and thus the description thereof will be omitted. As shown in FIG. 11, the load cell 110 is sandwiched by a gripping tool 106 composed of two claws (chuck 104a and 104b) at the tip of the material testing machine 102. FIG. 12 shows an enlarged photograph of the gripping tool 106. In FIG. 12, the parts having the same reference numerals as those in FIG. 11 indicate the same elements, and thus the description thereof will be omitted. As shown in FIG. 12, when the screw portion 108 of the gripping tool 106 is turned in the R direction, the chucks 104a and 104b advance in the direction of the arrow shown in the dotted circle D, and the gripping tool 106 is tightened. FIG. 13 shows an enlarged photograph of the load cell 110. In FIG. 13, the parts having the same reference numerals as those in FIG. 11 indicate the same elements, and thus the description thereof will be omitted. As shown in FIG. 13, both sides (indicated by arrows) of the screw 112 of the load cell 110 are sandwiched between the chucks 104a and 104b via a sponge (not shown). FIG. 14 is an exploded schematic diagram for explaining the bonding between the sensor sheet 130-acrylic-rubber block 120-load cell 110. In FIG. 14, the parts having the same reference numerals as those in FIG. 10 indicate the same elements, and thus the description thereof will be omitted. As shown in FIG. 14, the acrylic-rubber block 120 is composed of an acrylic plate 122 and a rubber plate 124 when disassembled, and the vinyl tape (cover tape) 134 is only the pressure sensitive bodies 14, 34, etc. of the sensor sheet 130. It is exposed without covering. As shown in FIG. 14, the interface Ssa between the sensor sheet 130 and the acrylic-rubber block 120, the interface Sra between the rubber plate 124 and the acrylic plate 122, and the interface Sal between the acrylic plate 122 and the load cell 110 are strong double-sided tapes, respectively. I pasted them together.

FIG. 15 is a graph showing the results of conducting a tensile force / compressive force experiment using the material testing machine 102. In FIG. 15, the horizontal axis is the applied pressure (kPa) applied by the material testing machine 102 to the pressure sensitive bodies 14, 34 and the like of the sensor sheet 130 via the load cell 110, and the vertical axis is the sensor output (V). The sensor output is the output as a result of changing the magnitude of the tensile force / compressive force into a voltage signal using the adhesive force sensor (film sensor) 20 or the like used in the experiment and an electric circuit (described later). The greater the tensile / compressive force, the greater the sensor output. In FIG. 15 (original drawing), the adhesive force sensor 30 (FIG. 2: Example 1) is a red circle (upper distribution), and the adhesive force sensor 50 (FIG. 6: Example 4) is a blue circle (middle distribution). 10 (FIG. 1 (B): Example 1) is indicated by a green circle (lower distribution). As shown in the distribution on the upper side of FIG. 15, the sensor output of the adhesive force sensor 30 changed according to the applied pressure in both the tensile force and the compressive force, and the sensor output was the largest. Especially in the case of tensile force, the sensor output could be measured up to an applied pressure of 23 kPa. This indicates that the peel strength of the adhesive force sensor 30 is at least 23 kPa or more. As shown in the distribution in the middle of FIG. 15, the adhesive force sensor 50 had a sensor output that changed according to the applied pressure in both tensile force and compressive force, and the sensor output was medium in magnitude. In the case of tensile force, the sensor output could be measured up to an applied pressure of 8 kPa. This indicates that the peel strength of the adhesive force sensor 50 is at least 8 kPa or more. As shown in the distribution on the lower side of FIG. 15, in the case of the force sensor 10 (non-contact type sensor), the sensor output changed according to the applied pressure in the case of the compressive force, and the sensor output was the lowest. However, in the case of tensile force, the sensor output could not be measured.

As is clear from the above experimental results, when a tensile force is applied to the force sensor 10, the upper electrode 12 and the pressure sensitive body 14 are separated from each other, and the pressure sensitive body 14 and the lower electrode 16 are separated from each other. The electrode 12-pressure sensitive body 14-lower electrode 16 (conductive path Cp) is in an insulated state. As a result, it was proved that the tensile force could not be detected. On the other hand, in the adhesive force sensor 50, the interface between the pressure sensitive body 34 and both electrodes 32 and 36 is joined with a predetermined conductive adhesive 55. Therefore, it was proved that it is possible to detect not only the compressive force but also the tensile force. In the adhesive force sensor 30, the adhesive 38a and the like are in close contact with the ends of both base films 31 and 39 so as to surround the measurement point composed of the electrode 36, the pressure sensitive body 34, and the electrode 32. As a result, it was proved that the adhesive force sensor 30 can measure a compressive force and a tensile force larger than those of the adhesive force sensor 50. That is, the adhesive force sensor 50 peels off the conductive adhesive 55, and the adhesive force sensor 30 peels off the adhesive 38 or the like around the measurement point or the detection point, so that the electrodes 32 and 36 and the pressure sensitive body 34, respectively. The tensile force can be detected until the and is separated.

FIG. 16 shows an electric circuit used in the above-mentioned experiment. In FIG. 16, V _IN is an input voltage (5 V), R _s is a sensor resistance, R _F is a fixed resistance, and V _OUT is a sensor output voltage. The sensor output voltage V _OUT is obtained by the following equation 1.

When a compressive force / tensile force is applied to the adhesive force sensor 30 or the like, the sensor resistance R _s becomes small / large, and as a result, the sensor output V _OUT becomes large / small as shown in Equation 1. Here, the sensor resistance R _s mainly consists of "the resistance of the sensor itself" and "the contact resistance between the sensor and the electrode". When the compressive force is weak, the “contact resistance between the sensor and the electrode” becomes high because the rubber and the electrode are not sufficiently in contact with each other in the force sensor 10. On the other hand, in the adhesive force sensor 50, since both are fixed by the conductive adhesive 55 from the beginning, the "contact resistance between the sensor and the electrode" is almost zero. Therefore, as shown in FIG. 15, the adhesive force sensor 50 having almost no “contact resistance between the sensor and the electrode” has a larger sensor output V _OUT when a smaller compressive force is applied than the force sensor 10.

As an application example of the present invention, in addition to the pressure distribution sensor 60 having a structure in which comb-shaped electrodes are crossed and the sensor 70 capable of measuring shear stress, it can be used in various fields as a thin and flexible sensor. Is. For example, it can be applied to the evaluation of the peeling strength of a tape or an adhesive, the evaluation of the adhesive strength acting between cells and the substrate by laying a sensor on the substrate during cell culture, and the like.

1 Upper electrode, 3 Lower electrode, 5 Pressure sensitive layer, 7 Spacer, 10 Force sensor, 12, 12'Upper electrode, 14 Pressure sensitive body, 16, 16' Lower electrode, 20, 30, 50 Adhesive force sensor, 31 , 39 Base film, 32, 36 electrodes, 32-1 to 2-32 5 upper electrodes, 34, 34 (1, 1) to 34 (5, 5) pressure sensor, 36-1 to 36-5 lower electrodes, 38 , 38a, 38b adhesive, 40 multi-point adhesive force sensor, 55 conductive adhesive, 60 pressure distribution sensor, 66-1 to 66-5 copper electrodes, 70 sensor capable of measuring shear stress, 100 experiments Equipment, 102 Material Testing Machine, 104a, 104b Chuck, 106 Grip, 108 Screw Part, 110 Load Cell, 112 Screw, 120 Acrylic-Rubber Block, 122 Acrylic Plate, 124 Rubber Plate, 130 Sensor Sheet (Film Sensor), 132 Stage , 134 Vinyl tape (cover tape), 140 data logger, 144 PC.

Japanese Unexamined Patent Publication No. 2018-128266 JP-A-2017-172973

Claims (7)

A pressure-sensitive body is placed between an electrode formed on the base material and another electrode formed on another base material, and the ends of both base materials are placed so as to cover the pressure-sensitive body and both electrodes. An adhesive force sensor for detecting a compressive force or a tensile force, which has a structure bonded with a predetermined adhesive. The adhesive strength sensor according to claim 1, wherein the predetermined adhesive is an ultraviolet curable type adhesive. A multi-point adhesive force sensor, which comprises integrating the adhesive force sensor according to claim 1 or 2. The method for manufacturing a multipoint adhesive force sensor according to claim 3.
A lower electrode forming step of forming a predetermined number of rod-shaped electrodes (lower electrodes) on a base material,
An adhesive that applies an adhesive on the base material and on each of the lower electrodes after covering a detection point for detecting a compressive force or a tensile force with a mask on each of the lower electrodes formed in the lower electrode forming step. The coating process and
A pressure-sensitive body mounting step of mounting the pressure-sensitive body on the lower electrode in each hole after removing the mask used in the adhesive application step,
Another base material on which a predetermined number of rod-shaped electrodes (upper electrodes) of a predetermined shape are formed is placed on the base material on the side on which the pressure sensitive body is mounted in the pressure sensitive body mounting step. A method for manufacturing a multi-point adhesive force sensor, which comprises a base material pressure welding step of pressing the other base material and the base material after facing the electrodes so as to be orthogonal to each other. In the method for manufacturing a multi-point adhesive force sensor according to claim 4, instead of the adhesive coating step and the pressure sensitive body mounting step,
Printing in which a predetermined number of liquid pressure-sensitive bodies having a predetermined diameter are printed on the lower electrode after the lower electrode forming step, each liquid pressure-sensitive body is masked, and then an adhesive is applied on the base material and the lower electrode. -A method for manufacturing a multi-point adhesive force sensor, which is characterized by having a coating process. A pressure-sensitive body is placed between an electrode formed on a base material and another electrode formed on another base material, and the interface between the pressure-sensitive body and both electrodes is provided with a predetermined conductive adhesive. An adhesive force sensor for detecting a compressive force or a tensile force having a bonded structure, wherein the interface is a plane-shaped surface facing between the pressure sensitive body and each electrode. Adhesive force sensor that detects tensile force. The adhesive strength sensor according to claim 6, wherein the predetermined conductive adhesive uses a silver paste or an anisotropic conductive film.