Capacitive pressure sensor

Abstract

A capacitive pressure sensor includes a first conductive layer, a second conductive layer, a first flexible dielectric layer, and a second flexible dielectric layer. The first flexible dielectric layer is disposed on the first conductive layer and includes a material containing silicon, and the first flexible dielectric layer has a plurality of microprotrusions arranged at intervals from each other and deformable. The second flexible dielectric layer is disposed on the second conductive layer and includes a material containing silicon, and the second flexible dielectric layer is bonded to the microprotrusions. The microprotrusions are configured to be compressed and deformed when the first conductive layer and the second conductive layer are brought close to each other.

Description

Technical Field

[0001] This utility model relates to a pressure sensor, and more particularly to a flexible capacitive pressure sensor. Background Technology

[0002] Existing pressure sensors mainly sense deformation and displacement through a single or two sensing elements, thus having the following drawbacks:

[0003] 1. Poor sensing sensitivity, unable to accurately detect subtle pressure changes.

[0004] 2. The sensing area is limited, making it unsuitable for applications requiring large-area sensing.

[0005] 3. Due to the small number of sensing components and their poor uniformity of distribution, inconsistent sensing responses are likely to occur at different locations, resulting in uneven pressure sensing and poor stability. Utility Model Content

[0006] One objective of this invention is to provide a capacitive pressure sensor that overcomes at least one drawback of the prior art.

[0007] The capacitive pressure sensor of this invention comprises a first conductive layer, a second conductive layer, a first flexible dielectric layer, and a second flexible dielectric layer.

[0008] The first flexible dielectric layer is disposed on the first conductive layer and is made of silicon. The first flexible dielectric layer has a plurality of deformable micro-protrusions arranged at intervals between each other. The second flexible dielectric layer is disposed on the second conductive layer and is made of silicon. The second flexible dielectric layer is bonded to the micro-protrusions, which are configured to be compressed and deformed when the first conductive layer and the second conductive layer are brought close together.

[0009] In some embodiments, the first flexible dielectric layer is a single component manufactured in an integral molding manner.

[0010] In some embodiments, the first flexible dielectric layer also has a substrate connected to the first conductive layer, and the micro-protrusions are integrally formed on the side of the substrate opposite to the first conductive layer.

[0011] In some embodiments, each of the micro-protrusions defines the spacing between the substrate of the first flexible dielectric layer and the second flexible dielectric layer.

[0012] In some embodiments, at least one of each of the micro-protrusions and the second flexible dielectric layer has a modified surface, which is bonded to the other of each of the micro-protrusions and the second flexible dielectric layer.

[0013] In some embodiments, the first conductive layer has a first substrate and a first adhesive portion and a first conductive portion formed on opposite sides of the first substrate, the first adhesive portion being adhered to the first flexible dielectric layer; the second conductive layer has a second substrate and a second adhesive portion and a second conductive portion formed on opposite sides of the second substrate, the second adhesive portion being adhered to the second flexible dielectric layer.

[0014] In some embodiments, the first conductive layer has a first substrate and a bonding portion and a first conductive portion formed on opposite sides of the first substrate, the bonding portion comprising silicon and bonded to the first flexible dielectric layer, the second conductive layer has a second substrate and a second conductive portion formed on one side of the second substrate, the second flexible dielectric layer being formed on the side of the second substrate opposite to the second conductive portion.

[0015] In some embodiments, the bonding portion has a modified surface that is bonded to the first flexible dielectric layer.

[0016] In some embodiments, the bonding portion is a film containing silicon or silicon dioxide deposited on the first substrate, and the second flexible dielectric layer is a film containing silicon or silicon dioxide deposited on the second substrate.

[0017] In some embodiments, the bonding portion is a release agent containing silicon or silicon dioxide and coated on the first substrate, and the second flexible dielectric layer is a release agent containing silicon or silicon dioxide and coated on the second substrate.

[0018] This invention has at least the following advantages: By arranging multiple micro-protrusions of the first flexible dielectric layer at intervals, the sensitivity to pressure changes can be improved, thus enabling precise sensing of minute pressure changes. It also allows for a wider sensing range, enabling the capacitive pressure sensor to be used in large-area sensing applications. Furthermore, the multiple micro-protrusions ensure good uniformity in their positional distribution, thereby improving the uniformity and stability of pressure sensing. Attached Figure Description

[0019] Other features and effects of this utility model will be clearly presented in the embodiments with reference to the drawings, wherein:

[0020] Figure 1 This is an incomplete cross-sectional view of a first embodiment of the capacitive pressure sensor of the present invention, illustrating the connection relationship between a first conductive layer, a second conductive layer, a first flexible dielectric layer and a second flexible dielectric layer.

[0021] Figure 2 This is a top view of the first flexible dielectric layer in the first embodiment;

[0022] Figure 3This is an incomplete cross-sectional view of a second embodiment of the capacitive pressure sensor of this utility model; and

[0023] Figure 4 This is an incomplete cross-sectional view of a third embodiment of the capacitive pressure sensor of this utility model. Detailed Implementation

[0024] Before this utility model is described in detail, it should be noted that similar components are represented by the same numbers in the following description.

[0025] See Figure 1 A first embodiment of the capacitive pressure sensor 100 of this utility model includes a first conductive layer 1, a second conductive layer 2, a first flexible dielectric layer 3, and a second flexible dielectric layer 4.

[0026] See Figure 1 and Figure 2 A first conductive layer 1 and a second conductive layer 2 are spaced apart from each other. One of the first conductive layer 1 and the second conductive layer 2 is a transmitting conductive layer for transmitting signals, and the other is a receiving conductive layer for receiving signals. A first flexible dielectric layer 3 is disposed on the first conductive layer 1 and contains silicon. The first flexible dielectric layer 3 has a plurality of deformable micro-protrusions 31 arranged at intervals between each other. A second flexible dielectric layer 4 is disposed on the second conductive layer 2 and contains silicon. The second flexible dielectric layer 4 is bonded to the micro-protrusions 31. The micro-protrusions 31 are configured to be compressed and deformed when the first conductive layer 1 and the second conductive layer 2 are brought close together.

[0027] The first conductive layer 1 has a first substrate 11, and a first adhesive portion 12 and a first conductive portion 13 respectively formed on opposite sides of the first substrate 11. The first substrate 11 is made of, for example but not limited to, an insulating material such as polyethylene terephthalate (PET). The first adhesive portion 12 is formed by, for example but not limited to, an adhesive coating on the first substrate 11. The first adhesive portion 12 is adhered to the first flexible dielectric layer 3 to fix the first flexible dielectric layer 3 to the first substrate 11. In this way, the first conductive layer 1 can be fixed to the non-self-adhesive first flexible dielectric layer 3 by the first adhesive portion 12. The first conductive portion 13 is, for example, a signal transmitting portion for transmitting signals.

[0028] The second conductive layer 2 has a second substrate 21, and a second adhesive portion 22 and a second conductive portion 23 respectively formed on opposite sides of the second substrate 21. The second substrate 21 is made of, for example but not limited to, an insulating material such as polyethylene terephthalate (PET). The second adhesive portion 22 is formed by, for example but not limited to, an adhesive coating on the second substrate 21. The second adhesive portion 22 adheres to the second flexible dielectric layer 4 to fix the second flexible dielectric layer 4 to the second substrate 21. This allows the second conductive layer 2 to adhere and fix the non-self-adhesive second flexible dielectric layer 4 via the second adhesive portion 22. The second conductive portion 23 is, for example, a signal receiving portion for receiving signals.

[0029] The first flexible dielectric layer 3 is made of, for example but not limited to, silicone. In this first embodiment, the first flexible dielectric layer 3 is made of liquid silicone rubber (LSR). The first flexible dielectric layer 3 is a single component manufactured in an integral molding manner. The first flexible dielectric layer 3 also has a substrate 30 connected to a first adhesive portion 12 of the first conductive layer 1. Micro-protrusions 31 are integrally protruding from the substrate 30 on the side opposite to the first adhesive portion 12 of the first conductive layer 1. In this first embodiment, the micro-protrusions 31 are arranged, for example but not limited to, in an array, or in an alternating array. Each micro-protrusion 31 is, for example but not limited to, cylindrical. Each micro-protrusion 31 may also be prismatic, pyramidal, conical, or hemispherical.

[0030] The second flexible dielectric layer 4 is made of, but is not limited to, silicone. In this first embodiment, the second flexible dielectric layer 4 is made of liquid silicone rubber (LSR).

[0031] To ensure a stable bond between the micro-protrusions 31 of the first flexible dielectric layer 3 and the second flexible dielectric layer 4, in this first embodiment, at least one of each micro-protrusion 31 and the second flexible dielectric layer 4 has a modified surface, which is bonded to the other of the two. Specifically, each micro-protrusion 31 has a modified surface 311 bonded to the second flexible dielectric layer 4. The modified surface 311 of each micro-protrusion 31 is formed by surface modification, for example, by irradiating ultraviolet light with an excimer lamp. The modified surface 311 of each micro-protrusion 31 is bonded to the second flexible dielectric layer 4, for example, but not limited to, by thermoforming. Because the ultraviolet light emitted by the excimer lamp has high energy, only surface modification of each micro-protrusion 31 is needed to ensure a stable bond between the micro-protrusion 31 and the second flexible dielectric layer 4. This effectively improves the manufacturing speed and efficiency of the capacitive pressure sensor 100.

[0032] It should be noted that in another embodiment of this first embodiment, for example, the surface of the second flexible dielectric layer 4 is modified by irradiating ultraviolet light with an excimer lamp to form a modified surface, so that the second flexible dielectric layer 4 is bonded to each micro-protrusion 31 through the modified surface.

[0033] Each micro-protrusion 31 defines a gap S between the substrate 30 of the first flexible dielectric layer 3 and the second flexible dielectric layer 4. The gap S provides space for the substrate 30 and the second flexible dielectric layer 4 to move closer together. When either the first conductive layer 1 or the second conductive layer 2 is compressed, they can move closer together, respectively pulling the substrate 30 and the second flexible dielectric layer 4 closer together. This causes the substrate 30 and the second flexible dielectric layer 4 to compress the micro-protrusion 31, causing it to deform and accumulate restoring elasticity. Because the gap S provides space for the substrate 30 and the second flexible dielectric layer 4 to move closer together, applying a small pressure to either the first conductive layer 1 or the second conductive layer 2 can easily move the substrate 30 and the second flexible dielectric layer 4 closer together. This improves the sensitivity to pressure changes and allows for precise sensing of minute pressure variations. When the pressure on the first conductive layer 1 or the second conductive layer 2 is released, the reset elastic force accumulated in the micro-protrusion 31 will bounce back the substrate 30 of the first flexible dielectric layer 3 and the second flexible dielectric layer 4, so that the substrate 30 and the second flexible dielectric layer 4 respectively drive the first conductive layer 1 and the second conductive layer 2 to reset.

[0034] Since both the first flexible dielectric layer 3 and the second flexible dielectric layer 4 are made of silicon-containing materials, they can be directly bonded together without the need for additional adhesive bonding, thus simplifying the manufacturing process. Because the first flexible dielectric layer 3 is a single component manufactured using an integral molding method, the number of components in the capacitive pressure sensor 100 can be reduced, effectively improving manufacturing speed and efficiency. By bonding each micro-protrusion 31 of the first flexible dielectric layer 3 to the second flexible dielectric layer 4 through a modified surface 311, the stability of the bonding between the micro-protrusions 31 of the first flexible dielectric layer 3 and the second flexible dielectric layer 4 can be improved.

[0035] By arranging multiple micro-protrusions 31 of the first flexible dielectric layer 3 at intervals, the first flexible dielectric layer 3 can stably support the second flexible dielectric layer 4 and the second conductive layer 2, ensuring that the first conductive layer 1 and the second conductive layer 2 maintain a predetermined distance when not under pressure. Furthermore, this design enhances sensitivity to pressure changes, enabling precise sensing of minute pressure variations, and also broadens the sensing range, allowing the capacitive pressure sensor 100 to be used in large-area sensing applications. Moreover, the multiple micro-protrusions 31 ensure excellent uniformity in their distribution, thereby improving the uniformity and stability of pressure sensing.

[0036] See Figure 3 The second embodiment of the capacitive pressure sensor 100 of this utility model has a general structure that is similar to that of the first embodiment, except that the first flexible dielectric layer 3 and the second flexible dielectric layer 4 are different.

[0037] In this second embodiment, each micro-protrusion 31 is surface-modified to form a modified surface 311, for example, by plasma or corona treatment. The second flexible dielectric layer 4 is surface-modified to form a modified surface 41, for example, by plasma or corona treatment. The modified surface 311 of each micro-protrusion 31 and the modified surface 41 of the second flexible dielectric layer 4 are bonded together by thermocompression.

[0038] See Figure 4 The third embodiment of the capacitive pressure sensor 100 of this utility model has a general structure that is similar to the first and second embodiments, except that the first conductive layer 1, the second conductive layer 2 and the second flexible dielectric layer 4 are different.

[0039] In this third embodiment, the first conductive layer 1 has a bonding portion 14 formed on the side of the first substrate 11 opposite to the first conductive portion 13. The bonding portion 14 contains silicon and is bonded to the substrate 30 of the first flexible dielectric layer 3. The second flexible dielectric layer 4 is formed on the side of the second substrate 21 opposite to the second conductive portion 23. In one embodiment, the bonding portion 14 is a film containing silicon or silicon dioxide deposited on the first substrate 11, and the second flexible dielectric layer 4 is a film containing silicon or silicon dioxide deposited on the second substrate 21. In another embodiment, the bonding portion 14 is a release agent containing silicon or silicon dioxide coated on the first substrate 11, and the second flexible dielectric layer 4 is a release agent containing silicon or silicon dioxide coated on the second substrate 21. Thus, the self-adhesive bonding portion 14 and the self-adhesive second flexible dielectric layer 4 can be fixed to the first substrate 11 and the second substrate 21 respectively without the need for adhesive.

[0040] To ensure a secure bond between the bonding portion 14 and the first flexible dielectric layer 3, in this third embodiment, the bonding portion 14 has a modified surface 141 bonded to the substrate 30 of the first flexible dielectric layer 3. The modified surface 141 of the bonding portion 14 is formed by surface modification, for example, by irradiating the surface with ultraviolet light using an excimer lamp. Alternatively, the modified surface 141 of the bonding portion 14 can be formed by surface modification using methods such as plasma or corona treatment, and is not limited to the aforementioned methods. The modified surface 141 of the bonding portion 14 is bonded to the substrate 30 of the first flexible dielectric layer 3, for example, but not limited to, thermoforming. In this way, the bonding portion 14 can be securely bonded to the substrate 30 of the first flexible dielectric layer 3 through the modified surface 141.

[0041] The capacitive pressure sensor 100 of this third embodiment has a simple structure, which can improve manufacturing speed and efficiency and reduce manufacturing costs.

[0042] In summary, the capacitive pressure sensor 100 of each embodiment, by means of a plurality of micro-protrusions 31 arranged at intervals on the first flexible dielectric layer 3, can improve the sensitivity to pressure changes and thus accurately sense minute pressure changes, and can also expand the sensing range, enabling the capacitive pressure sensor 100 to be used in large-area sensing applications. Furthermore, the plurality of micro-protrusions 31 can ensure good uniformity of positional distribution, thereby improving the uniformity and stability of pressure sensing, thus effectively achieving the purpose of this utility model.

[0043] The above description is merely an embodiment of the present utility model and should not be construed as limiting the scope of the present utility model. Any simple equivalent changes and modifications made in accordance with the claims and description of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A capacitive pressure sensor, characterized in that: Include: First conductive layer; Second conductive layer; A first flexible dielectric layer, disposed on the first conductive layer and containing a silicon material, The first flexible dielectric layer has multiple deformable micro-protrusions arranged at intervals between each other; and A second flexible dielectric layer is disposed on the second conductive layer and contains a silicon material. The second flexible dielectric layer is bonded to the microbump, which is configured to be compressed and deformed when the first conductive layer and the second conductive layer are brought close to each other.

2. The capacitive pressure sensor according to claim 1, characterized in that: The first flexible dielectric layer is a single component manufactured in one piece.

3. The capacitive pressure sensor according to claim 1, characterized in that: The first flexible dielectric layer also has a substrate connected to the first conductive layer, and the micro-protrusion is integrally protruding on the side of the substrate opposite to the first conductive layer.

4. The capacitive pressure sensor according to claim 3, characterized in that: Each of the micro-protrusions defines the spacing between the substrate of the first flexible dielectric layer and the second flexible dielectric layer.

5. The capacitive pressure sensor according to claim 1, characterized in that: Each of the micro-protrusions and the second flexible dielectric layer has at least one modified surface, which is bonded to the other of each of the micro-protrusions and the second flexible dielectric layer.

6. The capacitive pressure sensor according to any one of claims 1 to 5, characterized in that: The first conductive layer has a first substrate and a first adhesive portion and a first conductive portion formed on opposite sides of the first substrate, the first adhesive portion being adhered to the first flexible dielectric layer. The second conductive layer has a second substrate and a second adhesive portion and a second conductive portion formed on opposite sides of the second substrate, the second adhesive portion being adhered to the second flexible dielectric layer.

7. The capacitive pressure sensor according to any one of claims 1 to 5, characterized in that: The first conductive layer has a first substrate and a bonding portion and a first conductive portion formed on opposite sides of the first substrate, the bonding portion comprising silicon and bonded to the first flexible dielectric layer. The second conductive layer has a second substrate and a second conductive portion formed on one side of the second substrate, the second flexible dielectric layer being formed on the side of the second substrate opposite to the second conductive portion.

8. The capacitive pressure sensor according to claim 7, characterized in that: The bonding portion has a modified surface that is bonded to the first flexible dielectric layer.

9. The capacitive pressure sensor according to claim 7, characterized in that: The bonding portion is a coating containing silicon or silicon dioxide deposited on the first substrate, and the second flexible dielectric layer is a coating containing silicon or silicon dioxide deposited on the second substrate.

10. The capacitive pressure sensor according to claim 7, characterized in that: The bonding portion is a release agent containing silicon or silicon dioxide and coated on the first substrate, and the second flexible dielectric layer is a release agent containing silicon or silicon dioxide and coated on the second substrate.

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