A high temperature resistant thin film pressure sensor
By introducing a heat insulation layer design with multiple rows of heat insulation holes and hollow alumina spheres into the pressure sensor, combined with polyimide material, the problem of pressure sensor being easily damaged in high-temperature environments is solved, and the accuracy and stability of the sensor under high temperature conditions are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGZHOU PUHUI TECH CO LTD
- Filing Date
- 2025-09-02
- Publication Date
- 2026-06-26
AI Technical Summary
Existing pressure sensors are easily damaged in high-temperature environments and cannot work stably in industrial equipment such as turbochargers and compressors.
A high-temperature resistant thin-film pressure sensor is designed by using a heat insulation layer composed of multiple rows of heat insulation holes and hollow alumina spheres, combined with the high-temperature resistance of polyimide material. The heat insulation layer is equipped with multiple rows of heat insulation holes and hollow alumina spheres to improve heat insulation performance and reduce temperature rise and sensitivity drift.
It significantly reduces the temperature rise and sensitivity drift of sensing elements, improves the accuracy and stability of sensors in high-temperature environments, and ensures normal operation at high temperatures.
Smart Images
Figure CN224416286U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of pressure sensor technology, and in particular to a high-temperature resistant thin-film pressure sensor. Background Technology
[0002] Most existing pressure sensors are only suitable for working at room temperature. In typical mobile machinery and industrial hydraulic systems such as turbochargers and compressors, the sensors are easily damaged due to the simultaneous effects of high temperature and pressure. Therefore, there is an urgent need for a high-temperature resistant pressure sensor. Utility Model Content
[0003] The purpose of this invention is to provide a high-temperature resistant thin-film pressure sensor that can improve the heat insulation performance of the heat insulation layer, significantly reduce the temperature rise of the sensing element, and reduce thermal zero-point drift and sensitivity drift.
[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0005] A high-temperature resistant thin-film pressure sensor includes a base layer, a heat insulation layer, a pressure-sensitive layer, and an electrode layer arranged sequentially. The heat insulation layer contains a plurality of hollow alumina spheres and multiple rows of heat insulation holes are formed within the heat insulation layer. The multiple rows of heat insulation holes are arranged at intervals along the vertical direction of the heat insulation layer. Each row of heat insulation holes has multiple heat insulation holes, and the multiple heat insulation holes are arranged at intervals along the horizontal direction of the heat insulation layer.
[0006] As a preferred embodiment of this utility model, the diameter of the heat insulation holes in each row of heat insulation hole groups is arranged in a gradient along the vertical direction of the heat insulation layer.
[0007] As a preferred embodiment of this utility model, the closer the heat insulation hole group is to the substrate layer, the larger the diameter of its heat insulation holes.
[0008] As a preferred embodiment of this utility model, the closer the heat insulation hole group is to the pressure-sensitive layer, the greater the number of heat insulation holes.
[0009] As a preferred embodiment of this utility model, the thickness of the substrate layer is 50-150 μm.
[0010] As a preferred embodiment of this utility model, the thickness of the heat insulation layer is 100μm.
[0011] As a preferred embodiment of this utility model, the thickness of the pressure-sensitive layer is 5 to 15 μm.
[0012] As a preferred embodiment of this utility model, the electrode layer is an FPC flexible circuit board.
[0013] As a preferred embodiment of this utility model, the thickness of the electrode layer is 100-150 μm.
[0014] The advantages of implementing the high-temperature resistant thin-film pressure sensor provided by this utility model compared with the prior art are as follows:
[0015] The high-temperature resistant thin-film pressure sensor of this utility model has multiple hollow alumina spheres with high reflectivity to high-temperature infrared radiation inside the heat insulation layer. At the same time, multiple rows of heat insulation holes are formed inside the heat insulation layer to interrupt the solid phase heat conduction path. Thus, the arrangement of the hollow alumina spheres and the heat insulation hole group can synergistically improve the heat insulation performance of the heat insulation layer, significantly reduce the temperature rise of the sensing element, reduce thermal zero-point drift and sensitivity drift, and improve the accuracy and stability of the sensor in high-temperature environments. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings of the embodiments will be briefly described below.
[0017] Figure 1 This is a schematic diagram of the structure of a high-temperature resistant thin-film pressure sensor provided in an embodiment of this utility model;
[0018] Figure 2 This is an embodiment of the present invention providing the operating curves of a high-temperature resistant thin-film pressure sensor at different temperatures;
[0019] Figure 3 This is the working curve of a high-temperature resistant thin-film pressure sensor provided in this embodiment of the utility model before and after 1 million half-load compressions at 150°C;
[0020] Figure 4 This is the stress-strain curve of a high-temperature resistant thin-film pressure sensor provided in this embodiment of the utility model at 150°C.
[0021] Marked in the image:
[0022] Base layer 1; heat insulation layer 2; heat insulation hole group 21; heat insulation hole 211; pressure-sensitive layer 3; electrode layer 4. Detailed Implementation
[0023] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0024] In the description of this utility model, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. It should also be understood that the terms "first," "second," etc., are used in this utility model to describe various information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this utility model, "first" information can also be referred to as "second" information, and similarly, "second" information can also be referred to as "first" information.
[0025] Please see Figure 1 A preferred embodiment of this utility model provides a high-temperature resistant thin-film pressure sensor, which includes a base layer 1, a heat insulation layer 2, a pressure-sensitive layer 3, and an electrode layer 4 arranged sequentially. The heat insulation layer 2 has a plurality of hollow alumina spheres inside, and multiple rows of heat insulation hole groups 21 are formed inside the heat insulation layer 2. The multiple rows of heat insulation hole groups 21 are arranged at intervals along the vertical direction of the heat insulation layer 2 (i.e., the thickness direction of the heat insulation layer). Each row of heat insulation hole groups 21 has a plurality of heat insulation holes 211, and the plurality of heat insulation holes 211 are arranged at intervals along the horizontal direction of the heat insulation layer 2.
[0026] According to the high-temperature resistant thin-film pressure sensor of this utility model embodiment, the heat insulation layer 2 is provided with a plurality of alumina hollow spheres that have high reflectivity to high-temperature infrared radiation. At the same time, the heat insulation layer 2 is formed with multiple rows of heat insulation hole groups 21 that can interrupt the solid phase heat conduction path. Thus, the arrangement of alumina hollow spheres and heat insulation hole groups 21 can synergistically improve the heat insulation performance of the heat insulation layer 2, significantly reduce the temperature rise of the sensing element, and reduce thermal zero-point drift and sensitivity drift.
[0027] For example, the diameters of the heat insulation holes 211 in each row of heat insulation hole groups 21 are arranged in a gradient along the vertical direction of the heat insulation layer 2. Specifically, the closer the heat insulation hole group 21 is to the base layer 1, the larger the diameter of its heat insulation holes 211; the closer the heat insulation hole group 21 is to the pressure-sensitive layer 3, the more heat insulation holes 211 it has. This design can optimize stress distribution, improve resilience and heat insulation efficiency, form a heat insulation barrier with increasing thermal resistance, and achieve better heat insulation effect.
[0028] For example, the base layer 1, heat insulation layer 2, pressure-sensitive layer 3 and electrode layer 4 are all made of polyimide (PI) material. Polyimide itself has the characteristics of high temperature resistance (long-term operating temperature can reach 200-300℃), chemical corrosion resistance and excellent mechanical properties, so that each layer can work normally at high temperature and improve the high temperature stability of the sensor.
[0029] In this embodiment, the substrate layer 1 is a polyimide (PI) film, and its thickness is preferably 50-150 μm.
[0030] In this embodiment, the thickness of the heat insulation layer 2 is preferably 100 μm. It is mainly made by heating and curing commercially available polyamic acid solution, foaming agent azodicarbonamide, hollow alumina spheres, and solvent NMP (N-methylpyrrolidone) on the base layer 1, with the weight ratio of each component being 20 parts: 8 parts: 10 parts: 50 parts. It should be noted that, because the heat insulation layer 2 has multiple rows of heat insulation pores 21 inside, compared with traditional dense polyimide (PI) films or other heat insulation materials (such as ceramics, glass fibers), it avoids the problem of reduced sensor flexibility caused by rigid heat insulation materials, and achieves compatibility between "heat insulation" and "flexibility".
[0031] In this embodiment, the thickness of the pressure-sensitive layer 3 is preferably 5-15 μm, and it is mainly composed of conductive fillers, dispersants, binders, and solvents, with a sheet resistivity of 100-5000 KΩ / square. It is fixed to the surface of the heat insulation layer 2 by spraying or printing. The conductive fillers are preferably one or more carbon-based conductive fillers such as graphene, carbon nanotubes, and carbon black, with a concentration of 2-20 mg / ml; the dispersants are preferably one or more aromatic polyimides, aliphatic polyimides, and semi-aromatic polyimides, with a concentration of 2-20 mg / ml; the binders are preferably epoxy resin crosslinking agents, accounting for 1%-5% of the dispersant; and the solvent is preferably the polar solvent N-methylpyrrolidone (NMP). It is understood that the pressure-sensitive layer 3 uses polyimide (PI) as the dispersing component, relying on the heat resistance of polyimide itself to improve the high-temperature stability of the pressure-sensitive layer 3.
[0032] In this embodiment, the electrode layer 4 is an FPC flexible circuit board, and the thickness of the electrode layer 4 is preferably 100-150μm. The electrode layer 4 is connected and fixed to the pressure-sensitive layer 3 by edge dispensing.
[0033] like Figure 2 As shown, the high-temperature resistant thin-film pressure sensor obtained in this embodiment exhibits high overlap of operating curves at different temperatures, especially maintaining high linearity at 150℃ and within a pressure range of 0-10MPa; Figure 3As shown, the high-temperature resistant thin-film pressure sensor obtained in this embodiment exhibits a signal change of less than 30% after 500,000 cycles at half-range. The stress-strain curve of the high-temperature resistant thin-film pressure sensor obtained in this embodiment at 150℃ is shown below. Figure 4 As shown, the stress-strain curve exhibits a linear change at this temperature, with no obvious yielding. This indicates that under the high temperature and high pressure of the test range, the sensor is in the linear elasticity region, and the deformation is reversible.
[0034] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0035] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.
Claims
1. A high-temperature resistant thin-film pressure sensor, characterized in that, It includes a base layer, a heat insulation layer, a pressure-sensitive layer and an electrode layer arranged sequentially; the heat insulation layer has a plurality of hollow alumina spheres inside, and multiple rows of heat insulation holes are formed inside the heat insulation layer, the multiple rows of heat insulation holes are arranged at intervals along the vertical direction of the heat insulation layer; each row of heat insulation holes has a plurality of heat insulation holes, the plurality of heat insulation holes are arranged at intervals along the horizontal direction of the heat insulation layer.
2. The high-temperature resistant thin-film pressure sensor according to claim 1, characterized in that, The diameter of the heat insulation holes in each row of heat insulation hole groups is arranged in a gradient along the vertical direction of the heat insulation layer.
3. The high-temperature resistant thin-film pressure sensor according to claim 2, characterized in that, The closer the heat insulation hole group is to the base layer, the larger the diameter of its heat insulation holes.
4. The high-temperature resistant thin-film pressure sensor according to claim 3, characterized in that, The closer the heat insulation hole group is to the pressure-sensitive layer, the more heat insulation holes it has.
5. The high-temperature resistant thin-film pressure sensor according to claim 1, characterized in that, The thickness of the substrate layer is 50–150 μm.
6. The high-temperature resistant thin-film pressure sensor according to claim 1, characterized in that, The thickness of the insulation layer is 100 μm.
7. The high-temperature resistant thin-film pressure sensor according to claim 1, characterized in that, The thickness of the pressure-sensitive layer is 5–15 μm.
8. The high-temperature resistant thin-film pressure sensor according to claim 1, characterized in that, The electrode layer is an FPC flexible circuit board.
9. The high-temperature resistant thin-film pressure sensor according to claim 8, characterized in that, The thickness of the electrode layer is 100–150 μm.