TW202147648A - Method for manufacturing porous pressure sensor and device thereof by proceeding porosity processing on the piezoelectric film, for example, proceeding wet etching process or heat treatment process - Google Patents

Abstract

The present invention provides a method for manufacturing a porous pressure sensor. The steps include: providing a substrate; forming a piezoelectric film on the upper surface of the substrate; proceeding porosity processing on the piezoelectric film, for example, proceeding wet etching process or heat treatment process to form a porous pressure sensing layer; and forming a first electrode and a second electrode on the two opposite sides of the upper surface of the porous pressure sensing layer respectively. The present invention is also directed to a pressure sensor manufactured by the manufacturing method of the porous pressure sensor.

Description

Manufacturing method and device of porous pressure sensor

The invention belongs to the field of pressure sensors, in particular to a method for manufacturing a porous pressure sensor and a device prepared by the method.

A pressure sensor is a sensor used to measure the pressure of liquids and gases, which can convert the pressure applied on it into an electrical signal as a function of pressure. Up to now, pressure sensors have been widely used in automobiles, aircraft, satellites, ships, diving equipment, and weather forecasting equipment to measure atmospheric pressure, liquid flow, diving depth or flight altitude.

However, the current pressure sensors have the disadvantages of narrow sensing range and poor sensing sensitivity. Existing pressure sensors are generally piezoelectric pressure sensors, in which a piezoelectric film is disposed on a substrate as a pressure sensing element. When the substrate is bent by an external force, the piezoelectric film will also deform with the bending of the substrate, and generate a corresponding electrical signal. The inspector can judge the magnitude of the force according to the electrical signal. Since the piezoelectric film is connected to the substrate, the sensitivity of the piezoelectric pressure sensor will decrease if the substrate cannot be deformed arbitrarily after being stressed, or if the bonding surface between the piezoelectric film and the substrate is not properly bonded. And the sensing range is narrow, with the problem of pressure detection inaccuracy.

For this reason, based on overcoming the shortcomings of the conventional technology, the inventor has developed the "manufacturing method and device for a porous pressure sensor" of the present invention after careful experiments and research, and with a spirit of perseverance. To overcome the above disadvantages of the prior art, the following is a brief description of the present invention.

In view of this, the main purpose of the present invention is to provide a manufacturing method of a porous pressure sensor, which can improve the sensitivity of the pressure sensor and increase the sensing range of the pressure sensor.

Another object of the present invention is to provide a porous pressure sensor produced by the method for manufacturing a porous pressure sensor proposed by the present invention.

In a preferred embodiment of the present invention, a method for manufacturing a porous pressure sensor is provided, which includes the following steps: (1) providing a substrate; (2) forming a piezoelectric film on the upper surface of the substrate; (3) Porous treatment of the piezoelectric thin film to form a porous pressure sensing layer; and (4) respectively forming a first electrode and a second electrode on two opposite sides of the upper surface of the porous pressure sensing layer side.

Preferably, the substrate is a solid flexible substrate composed of silicon wafer, soft polymer, metal, glass or mica, and the porous pressure sensing layer is a single-layer or multi-layer structure.

Preferably, the step of forming a piezoelectric film on the upper surface of the substrate is performed by a physical vapor deposition method, such as sputtering or evaporation, or a solution method.

Preferably, the step of porosifying the piezoelectric film to form a porous pressure sensing layer is performed by a wet etching process, wherein the etching solution used in the wet etching process is a diluted Acid/base solution, such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, or sodium hydroxide (KOH) solution, the concentration of the etching solution is 0.1 mM, and the etching time is one minute.

Optionally, the step of porosifying the piezoelectric film to form a porous pressure sensing layer is performed by a heat treatment process, wherein the heat treatment process is performed in a tubular furnace or a box furnace, The heating temperature is 500-600°C, and the heating time is one hour.

Preferably, the material of the piezoelectric film is metal oxide, nitride, polyvinylidene fluoride (PVDF), barium titanate BaTiO3, lead titanate PbTiO3, lead zirconate PbZrO3, lead zirconate titanate PbZrTiO3 (PZT) one of them.

Preferably, the first electrode is composed of one of gold, silver, platinum, and copper, and the second electrode is a transparent metal composed of indium tin oxide (ITO) or aluminum zinc oxide (AZO). conductive film. Alternatively, the first electrode is a transparent conductive film made of indium tin oxide (ITO) or aluminum zinc oxide (AZO), and the second electrode is made of one of gold, silver, platinum, and copper. The first electrode and the second electrode function as anode/cathode or cathode/anode of the porous pressure sensor.

In addition, another embodiment of the present invention is a porous pressure sensor manufactured by the manufacturing method of the present invention.

The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

100: Porous Pressure Sensor

10: Substrate

11: Piezoelectric film

12: Porous pressure sensing layer

121: empty hole

14: The first electrode

15: Second electrode

1(A)-FIG. 1(D) illustrate, in a preferred embodiment of the present invention, a method of fabricating a porous pressure sensor and a pressure sensor fabricated by the method.

FIG. 2 shows the surface morphology of the zinc oxide film after porosification in a preferred embodiment of the present invention.

In order to further understand the composition and other features of the present invention, more specific embodiments of the present invention are given and described in detail with the accompanying drawings as follows.

Please refer to FIG. 1(A) to FIG. 1(D), which show a manufacturing method of a porous pressure sensor and a pressure sensor manufactured by the method in a preferred embodiment of the present invention. As shown in FIG. 1(A), the steps of the manufacturing method of the porous pressure sensor of the present invention include: preparing a substrate 10, which is a solid flexible substrate, and the material can be silicon wafer, soft polymer, metal , glass or mica, etc.

Next, referring to FIG. 1(B) , a piezoelectric film 11 is grown on the substrate 10 . In the step of growing a piezoelectric film 11 on the substrate 10, a physical vapor deposition method (PVD) or a solution synthesis method can be used to grow a piezoelectric film 11 on the substrate 10, wherein the physical vapor deposition method may include, However, it is not limited to sputtering or vapor deposition. The piezoelectric film 11 is composed of a piezoelectric material, which can be metal oxide (eg, zinc oxide), nitride (eg, indium nitride, gallium nitride), polyvinylidene fluoride (PVDF), barium titanate BaTiO3 , Lead titanate PbTiO3, lead zirconate PbZrO3, lead zirconate titanate PbZrTiO3 (PZT), etc.

Next, referring to FIG. 1(C) , the piezoelectric film 11 is subjected to a porous process to form a porous pressure sensing layer 12 including a plurality of holes 121 . In a preferred embodiment of the present invention, the porosification process can be an isotropic wet etching process, for example, using a diluted acid/alkali solution such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, sodium hydroxide (KOH) ) or other acidic solution or alkaline solution is used as the etching solution, and the concentration and etching time of the etching solution are controlled to etch the piezoelectric film 11 , so as to etch a plurality of holes 121 to form the porous pressure sensing layer 12 . In this embodiment, the concentration of the etching solution is 0.1 mM, and the etching time is one minute.

In another preferred embodiment of the present invention, the porosification process may be a heat treatment process. In this embodiment, heating can be used to remove reactive gas (such as oxygen) and crystallize the piezoelectric film 11 , so as to generate holes 121 in the piezoelectric film 11 to form a porous pressure sensor Layer 12. In this embodiment, the heat treatment is performed in a tubular furnace or a box furnace (neither are shown), the heating temperature is 500-600° C., and the heating time is one hour.

Next, referring to FIG. 1(D), a first electrode 14 and a second electrode 15 are respectively plated on two opposite sides of the porous pressure sensing layer 12 to form a porous pressure sensor 100, as shown in Figure 1(D). The porous pressure sensing layer 12 can be a single-layer structure or a multi-layer junction structure. structure. The first electrode 14 and the second electrode 15 may be the anode and the cathode or the cathode and the anode of the porous pressure sensor 100 , respectively. The porous pressure sensor 100 is composed of a substrate 10, a porous pressure sensing layer 12, a first electrode 14 and a second electrode 15, wherein the material of the first electrode 14 is gold, silver, platinum, copper, etc. metal, and the second electrode 15 is a transparent conductive film composed of indium tin oxide (ITO) or aluminum zinc oxide (AZO). However, the selection of the material of the first electrode 14 and the material of the second electrode 15 is not limited to the precise forms disclosed in the embodiments herein. For example, the first electrode 14 may be a transparent conductive film composed of indium tin oxide (ITO) or aluminum zinc oxide (AZO), and the material of the second electrode 15 may be gold, silver, platinum, copper and other metals.

Please refer to FIG. 2 , which shows the surface morphology of the zinc oxide film after porosification in a preferred embodiment of the present invention. Here, the material of the piezoelectric thin film 11 is represented by zinc oxide (ZnO). It can be seen from the scanning electron microscope photograph of FIG. 2 that a plurality of holes 121 can be etched into the piezoelectric film 11 by performing a porosification process such as wet etching or heat treatment on the piezoelectric film 11, thereby forming a porous structure. Porous pressure sensing layer 12 . The comparison results of the pressure sensing output value of the porous pressure sensing layer of the present invention and the pressure sensing output value of the conventional non-porous pressure sensing layer under the condition of applying a force of 0.5 Newton (0.5N) are shown in Table 1 below. shown:

It can be seen from Table 1 that the pressure sensing output value of the porous pressure sensing layer of the present invention is almost twice that of the conventional non-porous pressure sensing layer. Therefore, the pressure sensing of the present invention The layer, because it is a piezoelectric thin film that has undergone porosification, has better sensing properties than the prior art piezoelectric thin film that has not been porosified.

In addition, the porous pressure sensor manufactured by the manufacturing method of the present invention can also have other uses, for example, it can be used to generate electricity. Since the material of the piezoelectric film layer 11 must be a piezoelectric material, when the user applies force to the porous pressure detector of the present invention, the pressure received can be converted into electrical energy for output to achieve the purpose of generating electricity.

To sum up, the method for manufacturing a porous pressure sensor of the present invention can improve the piezoelectric properties of the pressure sensor and the pressure sensing capability due to the porous pressure sensing layer formed by the porous piezoelectric film. effect. The porous pressure sensor obtained by using the method for manufacturing the porous pressure sensor of the present invention can have better sensing sensitivity and a wider sensing range, that is, the pressure sensor can sense an increased range. large, so that even the smallest pressure can be sensed. In addition, the porous pressure sensor obtained by the manufacturing method of the porous pressure sensor of the present invention can be widely used in many technical fields, such as medical treatment, personal wearable device or vehicle device.

To sum up, the structure of the present invention is novel and practical, the function is far superior to the conventional one, it has progress and industrial utilization value, and meets the requirements of an invention patent, and an application for an invention patent can be filed in accordance with the law. The above-mentioned specific embodiments are used to describe the purpose, features and effects of the present invention in detail, and are only part of the embodiments of the present invention. When the scope of implementation of the present invention cannot be limited by this, those who are familiar with the technology should make according to the above-mentioned descriptions, etc. Changes or modifications of the present invention, whose essence does not depart from the scope of the spirit of the present invention, shall be included in the scope of the patent right of the present invention.

100: Porous Pressure Sensor

10: Substrate

12: Porous pressure sensing layer

121: empty hole

14: The first electrode

15: Second electrode

Claims (11)

A method of manufacturing a porous pressure sensor, comprising: providing a substrate; forming a piezoelectric film on an upper surface of the substrate; Porous processing the piezoelectric film to form a porous pressure sensing layer; and A first electrode and a second electrode are respectively formed on two opposite sides of an upper surface of the porous pressure sensing layer. The manufacturing method of a porous pressure sensor according to claim 1, wherein the substrate is a solid flexible substrate composed of silicon wafer, soft polymer, metal, glass or mica. The method for manufacturing a porous pressure sensor according to claim 1, wherein the porous pressure sensing layer is a single-layer or multi-layer structure. The method for manufacturing a porous pressure sensor according to claim 1, wherein the step of forming a piezoelectric film on an upper surface of the substrate is accomplished by a physical vapor deposition method or a solution method. The manufacturing method of the porous pressure sensor according to claim 4, wherein the physical vapor deposition method comprises a sputtering method or an evaporation method. The method for manufacturing a porous pressure sensor according to claim 1, wherein the step of performing a porous treatment on the piezoelectric film to form a porous pressure sensing layer is performed by a wet etching process, wherein An etching solution used in the wet etching process is composed of a diluted hydrochloric acid, nitric acid, acetic acid, sulfuric acid or sodium hydroxide (KOH) solution, wherein the concentration of the etching solution is 0.1 mM, and the etching time is one minute. The method for manufacturing a porous pressure sensor according to claim 1, wherein the step of performing a porous treatment on the piezoelectric film to form a porous pressure sensing layer is performed by a heat treatment process, wherein the heat treatment is performed The procedure is carried out in a tubular furnace or a box furnace with a heating temperature of 500-600°C and a heating time of one hour. The method for manufacturing a porous pressure sensor according to claim 1, wherein the piezoelectric film is made of metal oxide, nitride, polyvinylidene fluoride (PVDF), barium titanate BaTiO3, lead titanate PbTiO3 , one of lead zirconate PbZrO3 and lead zirconate titanate PbZrTiO3 (PZT). The method for manufacturing a porous pressure sensor according to claim 1, wherein the first electrode is made of one of gold, silver, platinum, and copper, and the second electrode is made of indium tin oxide A transparent conductive film composed of (ITO) or aluminum oxide zinc (AZO). The manufacturing method of a porous pressure sensor according to claim 1, wherein the first electrode is a transparent conductive film made of indium tin oxide (ITO) or aluminum zinc oxide (AZO), and the second electrode is made of It is composed of one of the metals of gold, silver, platinum and copper. A porous pressure sensor manufactured according to the manufacturing method of claim 1.

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