TW201935658A - Thin-film sensor - Google Patents

Abstract

Present invention relates to a thin film sensor, comprising: two film substrates; at least two conductive layers respectively disposed on the inner surfaces of the two film substrates; a plurality of piezoelectric films, wherein the plurality of piezoelectric films are disposed on the two film substrates, two sides of the piezoelectric film are respectively pasted with the conductive layer on one side of the conductive layer opposite to the film substrate through a conductive glue; wherein, when the thin film sensor of the present invention is bent, the piezoelectric film can be bending with the film substrate, and producing a sensing signal.

Description

Thin film sensor

The invention relates to a thin film sensor, and particularly to a thin film sensor used for motion detection or for detecting strain and stress.

At present, the sensors used to detect motion or deformation on the market are mostly made of mechanical switches or micro-electromechanical components, so their structures are quite complicated and expensive, and they cannot be widely used.

In addition, most of the existing sensors are relatively large in size, and it is not easy to install them on objects with limited space. Moreover, a fixing frame or a base for installing the sensors must be provided, which causes considerable inconvenience in use.

In addition, although some thin-film sensors appear on the market, the process technology used in this type of thin-film sensor is quite complicated, which also makes it impossible to reduce the price and limits its use.

Due to the above reasons, there are various inconveniences in the use of existing sensors. Therefore, how to solve the aforementioned problems through structural improvement has become one of the important issues to be solved in this business.

The main object of the present invention is to provide a thin film sensor with simple structure, low cost, and easy thinning, which can be mounted on various objects.

An embodiment of the present invention provides a thin film sensor, which includes: two thin film substrates, the two thin film substrates have an inner side and an outer side, respectively, and the two thin film substrates face each other in such a manner that the inner sides face each other. Superimposed; at least two conductive layers, at least two of the conductive layers are respectively disposed on the inner sides of the two film substrates; at least one piezoelectric film, and at least one of the piezoelectric films is provided on two of the film substrates Inside surface In the meantime, two sides of at least one piezoelectric film are respectively adhered to one side of the two conductive layers opposite to the two film substrates through a conductive adhesive, so that both sides of the piezoelectric film and the two conductive layers The two surfaces of the film substrate are respectively provided with at least one circuit contact, and at least one of the circuit contacts of each of the film substrates is electrically connected to the conductive layer respectively; When the thin film sensor is bent, at least one of the piezoelectric thin films can be deformed along with the two thin film substrates, and at least one of the piezoelectric thin films can generate a sensing signal due to a piezoelectric effect. The sensing signal generated by at least one of the piezoelectric films is conducted to the circuit contacts on the two film substrates through the two conductive layers.

In a preferred embodiment of the present invention, the piezoelectric thin film is a polymer polymer material having piezoelectric characteristics.

In a preferred embodiment of the present invention, the piezoelectric film is a polyvinylidene fluoride (PVDF) film.

In a preferred embodiment of the present invention, the piezoelectric film is one of polyvinyl chloride, polyvinylidene fluoride, and nylon film.

In a preferred embodiment of the present invention, two of the film substrates are flexible polymer film substrates, and the two conductive layers are metal layers or metal oxide layers disposed on the surface of the film substrates.

In a preferred embodiment of the present invention, each of the conductive layers includes at least one contact electrode portion and at least one lead portion, and at least one of the contact electrode portions is disposed on an inner side surface of the thin film substrate and A position corresponding to at least one of the piezoelectric films, and an area of each of the contact electrode portions is larger than an area of at least one of the piezoelectric films, so that the surface of the at least one piezoelectric film is adhered to the contact At least one of the lead portions is connected to at least one of the contact electrode portion and at least one of the circuit contacts, so that at least one of the contact electrode portion and at least one of the circuit contacts are electrically connected to each other.

In a preferred embodiment of the present invention, two of the thin film substrates are elongated, and a plurality of the piezoelectric thin films are disposed between the two thin film substrates. They are spaced apart from each other, and the two conductive layers each have a plurality of contact electrode portions, the positions of the plurality of contact electrode portions respectively correspond to the plurality of piezoelectric films, and the plurality of contact electrode portions are in contact with a plurality of locations. The two sides of the piezoelectric film are described.

In a preferred embodiment of the present invention, each of the contact electrode portions is connected to one of the lead portions, and the lead portion connected to each of the contact electrode portions is connected to another of the contact electrode portions. The lead portions are not connected to each other.

In a preferred embodiment of the present invention, at least one thin film piezoresistive element is further disposed between the two thin film substrates, and both sides of at least one thin film piezoresistive element are bonded to the two conductive layers through a conductive adhesive, And reach an electrical connection.

In a preferred embodiment of the present invention, the thin film substrate is a flexible printed circuit board, and the conductive layer is a conductive circuit disposed on the flexible printed circuit board.

The beneficial effects of the present invention are that its structure is simple and easy to manufacture, so that it is inexpensive, and the thin film sensor of the present invention can be widely used in various sensing applications, and its structure can be easily adhered to various articles. This makes it versatile and extremely flexible.

In order to further understand the features and technical contents of the present invention, please refer to the following detailed description of the present invention and the accompanying drawings, but the drawings are provided for reference and explanation only, and are not intended to limit the present invention.

1‧‧‧ thin film sensor

10‧‧‧ film substrate

20‧‧‧ conductive layer

21‧‧‧contact electrode

22‧‧‧Wire Department

23‧‧‧Circuit Contact

30‧‧‧ Piezo film

31‧‧‧Conductive Adhesive

40‧‧‧ thin film piezoresistive element

41‧‧‧Conductive Adhesive

FIG. 1 is a schematic cross-sectional structure diagram of a first embodiment of a thin film sensor of the present invention.

FIG. 2 is a schematic partial enlarged plan structure diagram of the first embodiment of the thin film sensor of the present invention.

FIG. 3 is a schematic diagram of the first embodiment of the thin-film sensor of the present invention in a state of being subjected to bending.

FIG. 4 is a schematic plan view of a first embodiment of a thin film sensor according to the present invention.

FIG. 5 is a schematic diagram of a partially enlarged planar structure of a second embodiment of the thin film sensor of the present invention.

FIG. 6 is a schematic cross-sectional structure diagram of a third embodiment of the thin film sensor of the present invention.

[First embodiment]

As shown in FIG. 1 and FIG. 2, the present invention provides a thin film sensor 1 having flexibility to detect bending, displacement, or changes in stress and strain of an object. As shown in FIG. 1, the thin film sensor 1 of the present invention includes two thin film substrates 10, at least two conductive layers 20 disposed on a surface of the thin film substrate 10, and a plurality of piezoelectric thin films 30.

Wherein, the two film substrates 10 are made of a flexible polymer material. In this embodiment, the film substrate 10 is a flexible printed circuit board, and the conductive layer 20 is disposed on a flexible printed circuit. Conductive circuit on the board. In particular, the film substrate 10 and the conductive layer 20 can also be made by other methods. For example, the film substrate 10 can be made of various types of plastic or polymer materials, such as PET, PP, nylon and other plastic films. The conductive layer 20 can be a metal layer or a conductive material disposed on the surface of the film substrate 10 by electroplating or printing.

The film substrate 10 has an inner surface and an outer surface, respectively. The two film substrates 10 are overlapped with each other with the inner surfaces facing each other. The two conductive layers are respectively disposed on the inner surfaces of the two film substrates. The plurality of piezoelectric films 30 are respectively disposed between the two conductive layers 20, so a sandwich-like structure is formed by combining the film substrate 10, the conductive layer 20, and the piezoelectric film 30.

As shown in FIG. 2, the conductive layer 20 is made of a patterned conductive material disposed on the inner surface of the film substrate 10. In this embodiment, the conductive layer 20 includes a contact electrode portion 21 and a lead portion 22. The positions where the contact electrode portions 21 are provided on the film substrate 10 and the positions of the piezoelectric films 30 correspond to each other, and the area of each contact electrode portion 21 is larger than the area of each piezoelectric film 30 so that the Both side surfaces can be completely bonded to the surface of each contact electrode portion 21.

In this embodiment, both sides of the piezoelectric thin film 30 are adhered to the side of the contact electrode portion 21 of the conductive layer 20 opposite to the side of the film substrate 10 through the conductive adhesive 31, so that the piezoelectric thin film 30 and the conductive layer 20 are fixedly adhered, and Achieve electrical connection.

The piezoelectric film 30 is made of a polymer material with piezoelectric characteristics, for example, it can be selected from polyvinyl chloride, polyvinylidene fluoride, polyvinylidene fluoride (PVDF), nylon, etc. When the force is deformed, it can be applied to two volumes of the piezoelectric film 30 Positive and negative charges are generated on the surface, so a sensing signal is generated, and the sensing signal generated when the piezoelectric thin film 30 is deformed is transmitted to the conductive layers 20 attached to both sides of the piezoelectric thin film 30 via a conductive adhesive.

Among various polymer materials with piezoelectric properties, polyvinylidene fluoride (PVDF) is preferred. Therefore, in the preferred implementation of the piezoelectric film 30, polyvinylidene fluoride (PVDF) film material is used. .

As shown in FIG. 4, in this embodiment, the film substrate 10 is made into a strip-like structure, and one end of the film substrate 10 is provided with at least one circuit contact 23, and one end of the conductive layer 20 is connected through a wire portion 22.所述 电路 接点 23。 The circuit contact 23. The circuit contact 23 can be used to connect a signal processing chip or a sensing circuit. After a plurality of the piezoelectric films 30 are deformed by force to generate a sensing signal, the sensing signal can be transmitted through the lead portion 22 of the conductive layer 20. To the circuit contact 23 and the sensing circuit or signal processing chip connected to the circuit contact 23.

As shown in FIG. 3, when the thin film sensor 1 of the present invention is bent by force, the two thin film substrates 10 are bent, and the piezoelectric thin film 30 disposed between the two substrates is also bent along with it, so The material inside the piezoelectric film 30 is subjected to compressive stress or tensile stress. Since the piezoelectric film 30 can generate a sensing signal when the strain is generated, and both sides of the piezoelectric film 30 are adhered to the surfaces of the two conductive layers 20 through the conductive adhesive 31, the sensing signal generated by the piezoelectric film 30 can pass through the conductive adhesive. 31 is transmitted to the conductive layer 20, and is transmitted to the circuit contact 23 provided on the film substrate 10 via the conductive layer 20, and the sensing signal is further transmitted to the signal processing chip or circuit through the circuit contact 23, thereby making the film sense The signal to which the tester 1 is subjected to bending strain can be detected by a signal processing chip or a sensing circuit.

Of course, in addition to bending deformation, the thin-film sensor 1 of the present invention can also be used to detect pressure or gravity load. When both sides of the thin-film sensor 1 are pressed, the piezoelectric device is placed between the two substrates. The film 30 also generates a compressive strain, and can generate a sensing signal, so that the signal of the film sensor 1 under pressure is detected. Therefore, the thin film sensor 1 of the present invention has the following characteristics. First, the present invention The thin-film sensor 1 has a simple structure, so the manufacturing cost is relatively low. Moreover, the thin-film sensor 1 of the present invention is flexible, so it can be attached or set on the surface of various shapes of objects, so it is easy to install and use. In addition, the thin-film sensor 1 of the present invention is made of a thin-film material, so it can be reduced in size, and therefore can be manufactured into sensors of various sizes, and used in various occasions.

The following examples illustrate various practical embodiments of the thin film sensor 1 of the present invention. For example, the thin film sensor 1 of the present invention can be used as a motion sensor for detecting bending motion, or as a bending strain or Stress sensor. When the thin film sensor 1 of the present invention is used as a bending motion sensor, the thin film sensor 1 of the present invention can be adhered to a place where a bending action of an object to be detected occurs (for example, a hinge of a cover body or a door panel, Or the pivot joint of the connecting rod device), when it is desired to detect that the object has a bending action, a sensing signal can be generated by the thin film sensor 1 so that the bending action is detected.

The thin-film sensor 1 of the present invention can also be used to detect changes in compressive stress or weight load. For example, the thin-film sensor of the present invention can be made as a pressure-sensitive gasket, and the pressure-sensitive gasket is set on an overhead frame. At the joint between the floor support and the raised floor, when the floor is carrying a heavy object, the film sensor 1 of the present invention can detect the change in weight load.

In addition, the thin-film sensor 1 of the present invention can also be used as an anti-counterfeit or tamper-resistant label. In this embodiment, the thin-film sensor 1 of the present invention is designed as an attachable label, and is attached to a packaging container or a On the surface of the disassembled object, when the packaging container or object is disassembled, the film sensor 1 of the present invention will be pulled to generate a sensing signal, so that the disassembly message of the container or object is detected.

[Second Embodiment]

As shown in FIG. 5, it is a second embodiment of the thin film sensor 1 of the present invention. The thin film sensor 1 of the second embodiment of the present invention has a plurality of piezoelectric films 30, and each piezoelectric film 30 is arranged at a distance from each other. It is disposed between the two thin film substrates 10. The conductive layers 20 on the surfaces of the two thin film substrates 10 each have a plurality of contact electrode portions 21, and each contact electrode The positions of the portions 21 correspond to the plurality of piezoelectric films 30 and are respectively adhered to both sides of the plurality of piezoelectric films 30 through the conductive adhesive 31.

The second embodiment of the present invention is characterized in that a plurality of contact electrode portions 21 on each conductive layer 20 are respectively connected to a lead portion 22, and the lead portions 22 connected to each contact electrode portion 21 are not connected to each other, thus making each different. The contact electrode portions 21 are independent of each other. That is, when a piezoelectric film 30 in the thin film sensor 1 of the present invention generates a sensing signal, the sensing signal generated by the piezoelectric film 30 is only transmitted to and The contacting electrode portion 21 of the piezoelectric thin film 30 that generates a signal is not conducted to other contacting electrode portions 21.

Therefore, when the thin-film sensor 1 in the second embodiment is used, only the piezoelectric film 30 where the thin-film sensor 1 generates a deformed position will generate a sensing signal, and because of the contact electrode corresponding to each thin-film sensor 1 The part 21 transmits the sensing signal through the mutually independent lead part 22, so that the signal processing circuit can easily recognize the position of the piezoelectric film 30 that sends out the sensing signal, and then detect the position where the film sensor 1 is deformed. .

[Third embodiment]

As shown in FIG. 6, it is a third embodiment of the thin film sensor 1 of the present invention. The thin film sensor 1 of the third embodiment of the present invention is further provided with a thin film piezoresistive element 40 between two thin film substrates 10. The thin film piezoresistive element 40 has a thickness and an appearance similar to that of the piezoelectric thin film 30, and is adhered to the surfaces of the two conductive layers 20 through a conductive adhesive 41.

The thin film piezoresistive element 40 is made of a piezoresistive material, so it has the property of changing the impedance when deformed. In this embodiment, at least one thin film piezoresistive element 40 is provided between a plurality of piezoelectric thin films 30. When the thin film sensor 1 is deformed, the impedance is changed through the thin film piezoresistive element 40 so as to achieve the purpose of changing the sensing signal generated by the piezoelectric thin film 30 due to the impedance change.

[Possible effects of the embodiments]

In summary, the beneficial effects of the present invention are that its structure is simple and its manufacturing is easy, so that the thin-film sensor 1 of the present invention is inexpensive and can be widely used. In addition, the thin film sensor 1 of the present invention can be widely used in various sensing applications, and its structure can be easily adhered and mounted on various articles, so that it is versatile and extremely flexible.

The above are only the preferred and feasible embodiments of the present invention, and therefore do not limit the patent scope of the present invention. Therefore, any equivalent technical changes made using the description and drawings of the present invention are included in the protection scope of the present invention. .

Claims (10)

A thin-film sensor includes: two thin-film substrates, each of which has an inner side and an outer side, and the two thin-film substrates are superimposed on each other with the inner sides facing each other; at least two A conductive layer, at least two of the conductive layers are respectively disposed on the inner surfaces of the two film substrates; at least one piezoelectric film, and at least one of the piezoelectric films is disposed on an inner side surface of the two film substrates In the meantime, two sides of at least one piezoelectric film are respectively adhered to one side of the two conductive layers opposite to the two film substrates through a conductive adhesive, so that both sides of the piezoelectric film and the two conductive layers The two surfaces of the film substrate are respectively provided with at least one circuit contact, and at least one of the circuit contacts of each of the film substrates is electrically connected to the conductive layer respectively; When the thin film sensor is bent, at least one of the piezoelectric thin films can be deformed along with the two thin film substrates, and at least one of the piezoelectric thin films can generate a sensing signal due to a piezoelectric effect. , At least one of The sensing signal generated by the thin film circuit is transferred to the two contacts on the base film via said at least two conductive layers. The thin film sensor according to claim 1, wherein the piezoelectric thin film is made of a polymer polymer material having piezoelectric characteristics. The thin film sensor according to claim 2, wherein the piezoelectric thin film is a polyvinylidene fluoride (PVDF) thin film. The thin film sensor according to claim 2, wherein the piezoelectric thin film is selected from one of a polyvinyl chloride, a polyvinylidene fluoride, and a nylon thin film. The thin film sensor according to any one of claims 1 to 4, wherein the two thin film substrates are flexible polymer thin film substrates, and the two conductive layers are provided on the thin film substrates. A metal or oxide layer on the surface. The thin-film sensor according to claim 5, wherein each of the conductive layers is separately covered Including: at least one contact electrode portion and at least one lead portion, wherein at least one of the contact electrode portions is disposed on an inner side surface of the film substrate and at least one corresponding position of the piezoelectric thin film, and each of the contacts The area of the electrode portion is larger than the area of the at least one piezoelectric film, and the surface of the at least one piezoelectric film is attached to the surface of the contact portion; at least one of the lead portions is connected to at least one of the contacts The electrode portion and at least one of the circuit contacts are used to make at least one of the contact electrode portions and at least one of the circuit contacts conductive with each other. The thin film sensor according to claim 6, wherein the two thin film substrates are elongated, a plurality of the piezoelectric thin films are disposed between the two thin film substrates, and the plurality of piezoelectric thin films are Spaced apart from each other, and at least two of the conductive layers each have a plurality of contact electrode portions, the positions of the plurality of contact electrode portions respectively correspond to the plurality of piezoelectric films, and the plurality of contact electrode portions respectively contact a plurality of The two sides of the piezoelectric film are described. The thin-film sensor according to claim 7, wherein each of the conductive layers has a plurality of the contact electrode portions and a plurality of the lead portions, and each of the contact electrode portions is connected to one of the lead portions, respectively. And the lead wire portion connected to each of the contact electrode portions and the lead wire portion connected to the other contact electrode portion are not connected to each other. The thin-film sensor according to claim 8, wherein at least one thin-film piezoresistive element is further disposed between the two thin-film substrates, and both sides of the at least one thin-film piezoresistive element pass through the conductive adhesive and the two conductive layers. The layers are glued and electrically connected. The thin film sensor according to claim 9, wherein the thin film substrate is a flexible printed circuit board, and the conductive layer is a conductive circuit disposed on the flexible printed circuit board.