TWI393279B - High pressure electrical properties of lead zirconate titanate silicon dioxide flexible film and its preparation method - Google Patents

Description

High-voltage characteristic lead zirconate titanate ruthenium dioxide flexible film and preparation method thereof

The invention relates to a flexible film and a preparation method thereof, in particular to a high-voltage electrical characteristic lead zirconate titanate ruthenium dioxide flexible film and a preparation method thereof.

Commonly used piezoelectric materials are mainly polyvinylidene fluoride (PVDF) and lead zirconate Titanate (PZT) blocks. Among them, PVDF is often used in soft substrates due to PVDF. It is a polymer piezoelectric material, so it can be easily bonded to a flexible substrate. Therefore, compared with ceramic piezoelectric materials, PVDF can withstand large stresses and bend deformation, and the impact is not caused by a large impact. rupture. The disadvantage of PVDF is that the piezoelectric properties of the material itself are not good, and the piezoelectric properties are significantly degraded when the operating temperature exceeds 65 °C. PZT blocks have superior piezoelectric properties, but their hardness is much larger than that of flexible substrates, and they are not susceptible to bending deformation and can not withstand too much impact force. Therefore, bonding and driving are not suitable for use on polymer substrates.

PZT with a thickness of less than 10μm is called PZT film. The most common PZT film process has sputtering method and sol-gel method. The sputtering process first melts the target and then uses plasma to bombard the target. The PZT film can be deposited onto the substrate. The advantage of sputtering is that the process is simple and not easily affected by the external environment. However, the PZT film has the best piezoelectric characteristics in the ratio of Pb ₁ (Zr _0.52 , Ti _0.48 )O ₃ , but Pb (327 ° C), Zr (1855) °C), Ti (1668 ° C), the difference in melting point of the metal is too large, resulting in different metal volatilization effects, so in the process of melting the target, before reaching the melting point temperature of zirconium, titanium has reached the vaporization temperature of lead, thus causing lead The volatilization of the metal results in the PZT film not having the best composition ratio. In addition, the ion bombardment of the target with high-energy plasma can also cause the PZT film to be difficult due to the different excitation energies of the Pb, Zr, and Ti metals. The optimum composition, so the proportion of PZT film components deposited by sputtering is more difficult to control.

The sol-gel method firstly prepares a lead zirconate titanate solution, and can effectively and accurately control the ratio of Pb, Zr, and Ti in the solution, and then deposit the PZT onto the substrate by spin coating or immersion to form a film by sintering, thereby The PZT film with better piezoelectric characteristics is obtained, and the sol-gel method does not require expensive equipment compared with the sputtering method and other processes. However, the general flexible substrate is mostly made of a polymer material, and the glass thereof is used. The conversion temperature (Glass Temperature) is mostly lower than 200 ° C, but the sintering temperature of the PZT film is about 650 ° C. Therefore, when the PZT film is deposited on the flexible substrate by the sol-gel method, the flexible substrate is damaged due to the high sintering temperature. In addition, the thermal expansion coefficient of the flexible substrate is much larger than that of metals and other materials, and it is easy to cause instability of the sintering during the heating process. Therefore, how to manufacture a flexible high-voltage electric film on the flexible substrate It is a very important issue to avoid damage to the flexible substrate due to excessive process temperature.

The inventors have in view of the fact that the general lead zirconate titanate film is not easily bent and deformed, and cannot withstand too much impact force, and cannot be deposited on a flexible substrate, and the sol-gel method requires high-temperature sintering to obtain better piezoelectric characteristics. Lead zirconate titanate film, but the structure of the flexible substrate is easily damaged when the lead zirconate titanate film is sintered at high temperature. After long-term research and continuous testing, the high-voltage electrical characteristics of lead zirconate titanate is finally invented.矽Flexible film and its preparation method.

The technical means used in the present invention to achieve the above object is to provide a high-voltage electrical characteristic lead zirconate titanate flexible film comprising: a polymer substrate; a lower electrode conductive layer formed on the polymer On the substrate, a lead zirconate titanate composite film is flexible and formed on the lower electrode conductive layer; an upper electrode conductive layer is formed on the lead zirconate titanate composite film.

In the above flexible film, the lead zirconate titanate composite film has a thickness of 50 nm to 50 μm.

In the above flexible film, the lead zirconate titanate composite film has a thickness of 7 μm.

In the above flexible film, the lead zirconate titanate composite film comprises lead zirconate titanate, cerium oxide and MPS ([3-(Methacryloyloxy)propyl]trimethoxysilane).

In the above flexible film, the polymer substrate is a polyimide substrate, the lower electrode conductive layer is a copper conductive layer, and the upper electrode conductive layer comprises a chromium conductive layer and a gold conductive layer.

In the above flexible film, the polyimide substrate has a thickness of 12 μm, the copper conductive layer has a thickness of 35 μm, the chromium conductive layer has a thickness of 30 nm, and the gold conductive layer has a thickness of 120 nm.

The invention further relates to a method for preparing a high-voltage electrical characteristic lead zirconate titanate flexible film, the method comprising the steps of: forming a lower electrode conductive layer on a polymer substrate, forming a lower electrode conductive layer on a surface of a polymer substrate; The lead zirconate titanate cerium oxide composite sol is coated by uniformly coating a lead zirconate titanate cerium oxide composite gel on the surface of the lower electrode conductive layer; the sintering process is to combine the lead zirconate titanate cerium oxide composite The gel is heated to 90-270 ° C, and the organic substance in the lead zirconate titanate composite gel is completely volatilized to form a lead zirconate titanate composite film on the surface of the lower electrode conductive layer; a conductive layer is formed on the surface of the lead zirconate titanate composite film, the polymer substrate, the lower electrode conductive layer, the lead zirconate titanate composite film, and the upper electrode The conductive layer forms a lead zirconate titanate ruthenium oxide film.

In the above method for producing a flexible film, the lead zirconate titanate composite sol is added with MPS.

In the above method for producing a flexible film, in the sintering process, the lead zirconate titanate composite gel is heated to a temperature of 150 ° C by temperature-changing sintering.

In the above method for producing a flexible film, in the sintering process, the temperature rise rate of the temperature-changing sintering is 3 to 20 ° C / min, and when the temperature reaches 150 ° C, the temperature is maintained for 5 to 120 minutes, and the temperature drop rate is 3~20 °C / min to reach room temperature.

The method for preparing the flexible film comprises: preparing a lower electrode conductive layer in the polymer substrate step and the coating the lead zirconate titanate composite sol step, comprising preparing a lead zirconate titanate cerium oxide In the composite sol step, the prepared lead zirconate titanate cerium oxide composite sol step comprises: preparing a solution A, which is tetra-ethyl-ortho-silicate (TEOS), MPS, ethanol, Ionized water and 1N hydrochloric acid are mixed to form A solution. Prepare B solution by mixing 1N hydrochloric acid and deionized water with the A solution to form B solution. Prepare C solution by dispersing lead zirconate titanate. Ethanol is used as the C solution; and the lead zirconate titanate cerium oxide composite sol is prepared, and the B solution is added to the C solution and mixed to form a lead zirconate titanate composite sol.

The method for preparing a flexible film according to the above, wherein the step of preparing the lead zirconate titanate composite sol step is: in the step of preparing the A solution, the ratio of the molar concentration of the MPS to the TEOS is 0.01 to 0.5 The molar concentration ratio of the ethanol to the TEOS is 1-20, the molar concentration ratio of the deionized water to the TEOS is 1-20, and the molar ratio of the hydrochloric acid to the TEOS is 1×10 ^-3 ～ 0.1; in the step of preparing the B solution, the ratio of the molar concentration of the TEOS in the step of preparing the prepared hydrochloric acid solution is 0.1 to 5; the deionized water and the TEOS in the step of preparing the A solution The molar concentration ratio is 0.1-10; in the preparation of the C solution step, the molar ratio of the lead zirconate titanate to the cerium oxide in the TEOS in the step of preparing the B solution is 0.5:10; The volume ratio of the B solution is 0.5 to 5.

The method for preparing a flexible film according to the above, wherein the step of preparing a lead zirconate titanate composite sol further comprises: in the step of preparing the solution A, the TEOS, the MPS, the ethanol, the After the mixed water and the hydrochloric acid are mixed, the temperature is raised to 40 ° C to 80 ° C for 10 to 180 minutes to become the A solution; in the step of preparing the B solution, the hydrochloric acid and the deionized water are mixed with the A solution. The temperature is maintained at 40 ° C ~ 80 ° C, the time is 10 ~ 150 minutes to become the B solution; in the preparation of the C solution step, the lead zirconate titanate and the ethanol is oscillated by the ultrasonic cleaner for 10 to 600 minutes, The lead zirconate titanate is uniformly dispersed in the ethanol to form the C solution, the lead zirconate titanate is lead zirconate titanate particles; and the lead zirconate titanate cerium oxide composite sol is prepared by adding the B solution to The C solution was stirred and mixed for 30 seconds to 30 minutes to form the lead zirconate titanate composite sol.

The method for preparing the flexible film according to the step of preparing the lead zirconate titanate cerium oxide composite sol and the sintering process step comprises an air drying treatment step of combining the lead zirconate titanate The organic matter in the sol volatilizes to form a lead zirconate titanate composite gel layer on the surface of the lower electrode conductive layer.

The high-voltage electric characteristic lead zirconate titanate ruthenium dioxide flexible film provided by the invention and the preparation method thereof, the advantages and the enhancements obtained by the above technical means include at least:

1. The invention adopts a low-temperature sintering and sintering method to effectively reduce the problem that the sol-gel method requires high-temperature sintering to obtain a lead zirconate titanate film having better piezoelectric characteristics.

2. The MPS is added to the lead zirconate titanate cerium oxide composite sol according to the present invention, so that the lead zirconate titanate composite film itself has better flexibility, so that flexibility and impact resistance can be obtained. Piezoelectric material and can be deposited on a flexible substrate.

In order to understand the technical features and practical effects of the present invention in detail, and in accordance with the contents of the specification, the detailed description of the preferred embodiments as illustrated in the following: As shown in the figure, the present invention is a high-voltage electric characteristic lead zirconate titanate ruthenium oxide flexible film and a preparation method thereof, wherein the high-voltage electric characteristic lead zirconate titanate ruthenium oxide flexible film is produced, and the steps thereof include Forming a lower electrode conductive layer on the polymer substrate (10), preparing a lead zirconate titanate cerium oxide composite sol (20), coating a lead zirconate titanate cerium oxide composite sol (30), air drying treatment (40), Sintering process (50), preparing the upper electrode conductive layer (60): the step of forming the lower electrode conductive layer on the polymer substrate (10), as shown in the second figure, is formed on a polymer substrate (71) The electrode conductive layer (72); the polymer substrate (71) may be polyimide (PI), polyethylene terephathalate (PET), polyethylene naphthalate (polyethylene 2,6-naphthalate, PEN), poly-para-xylylene (parylene), poly Polymer substrate such as poly(methyl methacrylate), PMMA, poly(ether sulfone, PES), polycarbonate (PC), polyester, etc., this preferred embodiment A polyimide substrate having a thickness of 12 μm is used, and a metal such as copper, gold, aluminum, titanium or silver is used for stretching, vapor deposition, sputtering, electrolysis, electrophoresis on the polyimide substrate. The lower electrode conductive layer (72) is formed by spin coating, dip plating, screen printing, and spraying. In the preferred embodiment, the lower electrode conductive layer (72) is a copper conductive layer having a thickness of 35 μm, which is formed by stretching to form the lower electrode conductive layer (72) on the surface of the polyimide substrate.

For the preparation of the lead zirconate titanate cerium oxide composite sol (20), please refer to the third figure, which includes:

1. Prepare solution A: first tetraethyl-ortho-silicate ((C ₂ H ₅ O) 4Si, TEOS) 6.34ml~25.28ml, MPS([3-(Methacryloyloxy)propyl) ]trimethoxysilane, H ₂ C=C(CH ₃ )CO ₂ (CH ₂ )3Si(OCH ₃ ) ₃ )0.27ml~3.37ml, ethanol 6.45ml~32.26ml, deionized water 2ml~10ml and 1N hydrochloric acid 9.8× After mixing 10 ^-3 ml~0.25ml, the temperature is raised to 40 ° C ~ 80 ° C for 10 ~ 180 minutes to become A solution; wherein the ratio of the MPS to the TEOS molar concentration is 0.01 ~ 0.5; the ethanol and the TEOS The Mohr concentration ratio is 1-20; the ratio of the deionized water to the TEOS molar concentration is 1-20; the ratio of the hydrochloric acid to the TEOS molar concentration is 1×10 ^-3 ～0.1, and the MPS system is a coupling agent;

2, preparing B solution: mixing 1N hydrochloric acid 0.98ml ~ 12.25ml and deionized water 0.2ml ~ 5ml mixed in the A solution, the temperature is maintained at 40 ° C ~ 80 ° C for 10 ~ 150 minutes to become a B solution; The molar concentration ratio of the TEOS in the step of preparing the A solution is 0.1 to 5; the ratio of the molar concentration of the TEOS in the step of the deionized water and the preparation of the solution A is 0.1 to 10;

3. Preparation of C solution: Nai micron particles such as lead zirconate titanate, zinc oxide, barium titanate, titanium oxide, vanadium oxide, iron oxide and quartz, and nanometer columns and nanometer tubes, etc., in compatible solvents Disperse in the middle. The preferred embodiment adopts lead zirconate titanate particles of the type TKB, which is purchased from Yuchen Technology, and has an average particle diameter of 0.7 nm to 0.9 μm. The piezoelectric zirconate titanate particles are 17.3 g to 86.5. g and ethanol 3.26 ~ 442ml mixed, oscillated by ultrasonic cleaning for 10 to 600 minutes, physically and uniformly dispersed the lead zirconate titanate particles in the ethanol to become a C solution. The molar ratio of the lead zirconate titanate particles to the preparation of the solution B in the TEOS is 0.5 to 10; the volume ratio of the ethanol to the B solution is 0.5 to 5;

4. Preparing a lead zirconate titanate composite sol: adding the B solution to the C solution, stirring and mixing for 30 seconds to 30 minutes to become a lead zirconate titanate composite sol.

The step of coating the lead zirconate titanate cerium oxide composite sol (30) is a spin coating method, a dip coating method, a spray method, an electrophoresis method, a screen printing method, an inkjet method, a roll coating method, or the like. A lead zirconate titanate composite sol is formed on the surface of the lower electrode conductive layer (72). In the preferred embodiment, a lead zirconate titanate composite sol is applied to the lower electrode by a spin coating method. The surface of the conductive layer (72); wherein, the coating rotation speed and time are as shown in the fourth figure, in order to uniformly disperse the lead zirconate titanate composite sol on the lower electrode conductive layer (72), In the preferred embodiment, the lead zirconate titanate is uniformly distributed in the lead zirconate titanate ceria composite sol which is dropped on the surface of the lower electrode conductive layer (72) at an initial rotation speed (500 rpm and a holding time of 20 seconds). After the surface of the conductive layer, the rotation speed is increased to the final rotation speed (2000 rpm, and the holding time is 20 seconds), so that the lead zirconate titanate composite sol can be uniformly distributed to the surface of the lower electrode conductive layer (72).

In the air drying process (40), the polymer substrate (71) coated with the lead zirconate titanate composite sol is placed in a moisture-proof box and maintained at room temperature for 1 second to 30 minutes to make the zirconium. The organic substance in the lead titanate cerium oxide composite sol volatilizes to form a lead zirconate titanate composite gel layer on the surface of the lower electrode conductive layer (72).

The sintering process (50) step can be carried out by a method such as temperature swing sintering, rapid sintering, or the like. In the preferred embodiment, the polymer substrate (71) after air-drying treatment (40) is placed in a high-temperature furnace to increase the temperature, and the temperature rise rate of the temperature-changing sintering is 3-20 ° C/min, when the temperature reaches After 90~270°C, the temperature is 5~120 minutes, and the temperature drop rate is 3~20°C/min to reach room temperature, so that the organic matter in the lead zirconate titanate composite gel layer is completely volatilized to form a zirconium-titanium. The lead-acid cerium oxide composite film (73) is on the surface of the lower electrode conductive layer (72). In this embodiment, the temperature at the temperature-temperature sintering is 150 ° C; please refer to the fifth and sixth figures, respectively. The scanning electron microscope (SEM) and the X-ray diffraction result of the lead zirconate titanate composite film have a thickness of 50 nm to 50 μm. Preferably, the polymer substrate (71) coated with the lead zirconate titanate composite sol is directly subjected to a sintering process (50) without undergoing the air drying treatment. (40) step; the step of preparing the upper electrode conductive layer (60), as shown in the second figure, is to conduct an upper electrode The layer (74) is formed on the polymer substrate (71) containing the lead zirconate titanate composite film (73); the upper electrode conductive layer (74) is made of copper, gold, aluminum, titanium, silver.. The metal is prepared by the method of pressure rolling, vapor deposition, sputtering, electrolysis, electrophoresis, spin plating, immersion plating, screen printing and spraying, and the lead zirconate titanate is prepared on the polymer substrate (71). The surface of the composite film (73); in the preferred embodiment, the upper electrode conductive layer (74) is a 30 nm chromium conductive layer and a 120 nm gold conductive layer, which is formed by vapor deposition to form the upper electrode. a layer (74) on the surface of the lead zirconate titanate composite film (73); and the polymer substrate (71), the lower electrode conductive layer (72), the lead zirconate titanate composite film (73) And the upper electrode conductive layer (74) forms a lead zirconate titanate flexible film (70); as described above, in the preferred embodiment of the lead zirconate titanate composite sol The MPS is added, and the lead zirconate titanate composite film (73) has excellent flexibility, so the lead zirconate titanate composite film (73) can be formed on a flexible base. On. In addition, the present invention uses a lower temperature (90-270 ° C) sintering process, which can further avoid the problems of deformation, melting and burning of the polymer substrate at a high temperature during the high-temperature sintering process, and can smoothly form titanic acid. The lead cerium oxide composite film is on a polymer substrate and has good piezoelectric characteristics.

Moreover, the present invention can also produce the lead zirconate titanate composite sol according to the foregoing steps, and uniformly apply it on a metal substrate, a polymer substrate or a germanium substrate. In this embodiment, the lead zirconate titanate is oxidized. The ruthenium complex sol is coated on the polymer substrate containing the lower electrode conductive layer, and the lead zirconate titanate cerium oxide composite sol step and the sintering process step are performed to make the lead zirconate titanate cerium oxide The composite sol forms a lead zirconate titanate composite film.

However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and the simple equivalent changes and modifications made by the scope of the present invention and the contents of the specification are all It should remain within the scope of this invention.

(10). . . Forming a lower electrode conductive layer on the polymer substrate

(20). . . Preparing lead zirconate titanate cerium oxide composite sol

(30). . . Coating lead zirconate titanate cerium oxide composite sol

(40). . . Air dry processing

(50). . . Sintering process

(60). . . Preparing the upper electrode conductive layer

(70). . . Lead zirconate titanate ruthenium dioxide flexible film

(71). . . Polymer substrate

(72). . . Lower electrode conductive layer

(73). . . Lead zirconate titanate composite film

(74). . . Upper electrode conductive layer

The first figure is a flow chart of the method of the preferred embodiment of the present invention.

The second figure is a schematic diagram of a stacking process of a zirconium titanate ceria flexible film structure according to a preferred embodiment of the present invention.

The third figure is a schematic diagram of a method for preparing a lead zirconate titanate cerium oxide composite sol according to a preferred embodiment of the present invention.

The fourth figure is a schematic diagram of the rotational speed and time of spin coating in accordance with a preferred embodiment of the present invention.

Fig. 5A is a SEM front view of a lead zirconate titanate composite film according to a preferred embodiment of the present invention.

Fig. 5B is a SEM side view of a lead zirconate titanate composite film of the preferred embodiment of the present invention.

The sixth drawing is an X-ray diffraction pattern of a lead zirconate titanate composite film according to a preferred embodiment of the present invention.

(10). . . Forming a lower electrode conductive layer on the polymer substrate

(20). . . Preparing lead zirconate titanate cerium oxide composite sol

(30). . . Coating lead zirconate titanate cerium oxide composite sol

(40). . . Air dry processing

(50). . . Sintering process

(60). . . Preparing the upper electrode conductive layer

Claims (14)

A high-voltage electrical characteristic lead zirconate titanate ruthenium oxide flexible film comprises: a polymer substrate, the polymer substrate is a polyimide substrate, the lower electrode conductive layer is a copper conductive layer, and the upper electrode The conductive layer comprises a chromium conductive layer and a gold conductive layer; the lower electrode conductive layer is formed on the polymer substrate; and a lead zirconate titanate composite film is flexible and formed on the lower electrode conductive layer The lead zirconate titanate composite film comprises lead zirconate titanate and cerium oxide and MPS ([3-(Methacryloyloxy)propyl]trimethoxysilane); an upper electrode conductive layer formed on the lead zirconate titanate On the yttrium oxide composite film. The flexible film according to claim 1, wherein the lead zirconate titanate composite film has a thickness of 50 nm to 50 μm. The flexible film according to claim 1, wherein the lead zirconate titanate composite film has a thickness of 7 μm. The flexible film according to claim 2, wherein the lead zirconate titanate composite film has a thickness of 7 μm. As described in any one of claims 1 to 4 The flexible film, wherein the polyimide substrate has a thickness of 12 μm, the copper conductive layer has a thickness of 35 μm, the chromium conductive layer has a thickness of 30 nm, and the gold conductive layer has a thickness of 120 nm. The invention relates to a method for preparing a high-voltage electric characteristic lead zirconate titanate ruthenium oxide flexible film, comprising the steps of: forming a lower electrode conductive layer on a polymer substrate, forming a conductive layer on a surface of a polymer substrate; coating zirconium and titanium The lead-acid cerium oxide composite sol is obtained by uniformly coating a lead zirconate titanate composite sol on the surface of the lower electrode conductive layer; in the sintering process, the lead zirconate titanate cerium oxide composite sol is heated to 90 ~270 ° C, the organic material in the lead zirconate titanate composite sol completely volatilized to form a lead zirconate titanate composite film on the surface of the lower electrode conductive layer; preparing the upper electrode conductive layer, the system will be An electrode conductive layer is formed on the surface of the lead zirconate titanate composite film, and the polymer substrate, the lower electrode conductive layer, the lead zirconate titanate composite film, and the upper electrode conductive layer form a zirconium titanate Lead bismuth oxide flexible film. The method for producing a flexible film according to claim 6, wherein the lead zirconate titanate composite sol is added with MPS. The method for producing a flexible film according to claim 6, wherein the sintering process is performed by using temperature-changing sintering The lead zirconate titanate composite sol increases the temperature to 150 ° C. The method for producing a flexible film according to claim 7, wherein in the sintering process, the lead zirconate titanate composite sol is heated to a temperature of 150 ° C by temperature-changing sintering. The method for manufacturing a flexible film according to claim 9, wherein in the sintering process, the temperature rise rate of the temperature-changing sintering is 3-20 ° C/min, and when the temperature reaches 150 ° C, the temperature is maintained 5 ~120 minutes, the temperature drop rate is 3~20 °C / min to reach room temperature. The method for producing a flexible film according to any one of claims 6 to 10, wherein the step of forming a lower electrode conductive layer on the polymer substrate and the step of coating the lead zirconate titanate composite sol The method comprises the steps of: preparing a lead zirconate titanate cerium oxide composite sol step, and preparing the lead zirconate titanate cerium oxide composite sol step comprises: preparing a solution A, which is tetraethyl citrate (tetra- strontium) Ethyl-ortho-silicate, TEOS), MPS, ethanol, deionized water and 1N hydrochloric acid are mixed to form A solution. Prepare B solution by mixing 1N hydrochloric acid, deionized water and the A solution to form B solution. Preparing a C solution by dispersing lead zirconate titanate in ethanol to form a C solution; preparing a lead zirconate titanate cerium oxide composite sol, adding the B solution to the C solution, and mixing to form zirconium titanate Lead cerium oxide composite sol. The method for preparing a flexible film according to claim 11, wherein the parameter of the prepared lead zirconate titanate composite sol step is: in the step of preparing the A solution, the MPS and the TEOS The Mohr concentration ratio is 0.01~0.5, the molar ratio of the ethanol to the TEOS is 1-20, the ratio of the deionized water to the TEOS molar concentration is 1-20, and the hydrochloric acid and the TEOS molar concentration are The ratio of the ratio of 1×10 ^-3 to 0.1; in the step of preparing the B solution, the molar concentration ratio of the TEOS in the step of preparing the prepared solution A is 0.1-5; the deionized water and the prepared A The molar concentration ratio of the TEOS in the solution step is 0.1-10; the molar ratio of the lead zirconate titanate to the cerium oxide in the TEOS in the step of preparing the B solution in the step of preparing the C solution It is 0.5:10; the volume ratio of the ethanol to the B solution is 0.5-5. The method for preparing a flexible film according to claim 12, wherein the preparing the lead zirconate titanate composite sol step further comprises: in the step of preparing the A solution, the TEOS, After mixing the MPS, the ethanol, the deionized water and the hydrochloric acid, the temperature is raised to 40 ° C to 80 ° C for 10 to 180 minutes to become the A solution; in the step of preparing the B solution, the hydrochloric acid and the After the ionized water is mixed with the A solution, the temperature is maintained at 40 ° C to 80 ° C for 10 to 150 minutes to become the B solution; in the step of preparing the C solution, the lead zirconate titanate and the ethanol are used. After being oscillated by an ultrasonic cleaner for 10 to 600 minutes, the lead zirconate titanate is uniformly dispersed in the ethanol to form the C solution, and the lead zirconate titanate is lead zirconate titanate particles; preparing lead zirconate titanate In the ruthenium complex sol, the B solution is added to the C solution, and the mixture is stirred and mixed for 30 seconds to 30 minutes to become the lead zirconate titanate composite sol. The method for preparing a flexible film according to claim 13 is characterized in that the step of preparing the lead zirconate titanate composite sol and the step of sintering the process comprises an air drying step, which is The organic substance in the lead zirconate titanate cerium oxide sol is volatilized to form a lead zirconate titanate composite gel layer on the surface of the lower electrode conductive layer.