A method for detecting performance in the production of piezoelectric ceramic discs

Abstract

This invention relates to a performance testing method for piezoelectric ceramic discs during production. The method involves performance sampling during piezoelectric ceramic production, employing either air polarization or oil polarization depending on the sample material. The process includes sampling, molding, plasticizing, sintering, and ceramic grinding to prepare the piezoelectric ceramic disc sample, followed by cleaning, silver coating, silver baking, silver infiltration, selection of polarization method, cleaning, measurement, settling, and secondary testing. This invention designs a novel performance sampling and testing scheme, ensuring the stability and rigor of the testing process, improving the production efficiency of piezoelectric ceramics, effectively reducing unnecessary labor, and ensuring timely feedback of ceramic testing data.

Description

Technical Field

[0001] The invention relates to the technical field of piezoelectric ceramic detection and screening, and in particular to a method for detecting performance in the production of piezoelectric ceramic discs. Background Art

[0002] Randomly select a small number of sample units from a batch of products or a process for inspection, and then judge the quality of the product batch according to certain rules based on the number of unqualified products or quality characteristics. This is called sampling inspection. In the production of piezoelectric ceramics, a series of performance tests are required for part of the slurry after spray granulation. If the error of the final test result is within the specified range, the raw materials of this batch meet the production requirements.

[0003] The existing testing process is too complicated and it is impossible to conduct rapid standard testing of the performance quality of the piezoelectric ceramic body during the production process. The testing process using existing manual and operational standards is slow and inefficient, and it is impossible to quickly collect statistics on the data after the ceramic body testing, and the accuracy of the data cannot be guaranteed. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for detecting performance in the production of piezoelectric ceramic wafers. The method for detecting performance is aimed at performance sampling of piezoelectric ceramic production, and air polarization or oil polarization is used according to the material of the sample, and includes the following steps:

[0005] Step S1: clean the processed piezoelectric ceramic disc with an ultrasonic cleaner, apply silver to one side of the piezoelectric ceramic disc with a brush silver coating machine, put it into an oven for 15 minutes, take it out and cool it, apply silver to the other side of the piezoelectric ceramic disc, put it into the oven again for 15 minutes and take it out;

[0006] Step S2: placing the silver-baked piezoelectric ceramic disc in a silver-infiltrating kiln for silver infiltration for 6 hours, then taking it out and cooling it, and at the same time, selecting air polarization in step S3 according to the case where the sample material is p51, or selecting oil polarization in step S4 according to the case where the sample material is p81;

[0007] Step S3: If air polarization is selected, each piezoelectric ceramic disc is clamped with a fixture and confirmed to be fixed. If the fixture is not full, it is clamped with insulating tape. When the oven reaches a predetermined temperature of 160-180 degrees Celsius, the device is placed in the oven; pressurization is set for 20 minutes; after polarization is completed, the oven is opened and cooled with an electric fan; after the temperature is lower than 50 degrees, the disc can be taken out and wait for inspection, and then go to step S6;

[0008] Step S4: If oil polarization is selected, first confirm the positive and negative poles and mark them, clamp each piezoelectric ceramic disc with a fixture, and use a waste small disc to lift the fixture if it is not full, to ensure that the disc is immersed in the insulating medium; after closing the operating table door, set the pressurization time, slowly increase the voltage, and observe and wait for polarization; after polarization is completed, use tweezers to clamp it out, and spread each disc in the cleaning column to cool;

[0009] Step S5: After the oil-polarized piezoelectric ceramic disc has cooled sufficiently, use metal tweezers to conduct the two electrodes of the disc to perform a discharge operation, and ensure that the discharge is completed before starting the cleaning; put the disc together with the cleaning bar into four cleaning basins filled with gasoline in turn, soak and shake them appropriately; after the cleaning is completed, take out the cleaning bar and place it on the operating table, wait for the gasoline on the disc to evaporate and dry, then take out the disc and install it for inspection;

[0010] Step S6: Classify and place each piezoelectric ceramic disc (three discs are sufficient) in a foam box according to the number;

[0011] Step S7: Using quasi-static d 33 The tester checks whether the polarization is complete by randomly measuring the piezoelectric constant of each type of piezoelectric ceramic disc. If there is a disc with a low piezoelectric constant, the disc will be removed;

[0012] Step S8: Use capacitance tester, precision impedance analyzer, automatic component analyzer and other instruments and equipment to test the performance parameters of the wafer according to the process requirements: tanδ (dielectric loss), k p (electromechanical coupling coefficient), ε r T 3 (free relative permittivity), N d (frequency constant) and record;

[0013] Step S9: After standing for three days, all parameters of the wafer are measured again and recorded. If all parameters meet the process standards, the raw materials of the production batch to which the sample belongs meet the production requirements.

[0014] In one embodiment of the present invention, the piezoelectric ceramic disc in step S1 is designed in shape according to the detection requirements and the corresponding detection instrument, and its manufacturing steps are specifically as follows:

[0015] Step a: taking out the slurry obtained after atomization drying with a centrifugal spray granulation desiccant, and pressing it into a piezoelectric ceramic disc with a diameter of 25 mm and a thickness of 1.7 mm using a manual press;

[0016] Step b: number each piezoelectric ceramic disc in turn, stack them up and arrange them in layers on the gasket, heat the disc to 750°C in a Moffitt furnace for 10 hours, keep it warm for 2 hours, cool it to room temperature and then take it out to complete the plastic removal;

[0017] Step c: Take out each disc and spread it on a tray, sprinkle zirconium powder evenly on the disc, then evenly stack them into several rows and cover them with a ceramic cover plate and place them on a gasket; use a type 11 furnace to heat the disc to 1000°C for 5h, then heat it to 1330°C or 1305°C for 3h, keep it warm for 2h, then cool it to room temperature and take it out to complete the sintering;

[0018] Step d: Grind the surface of the disc with a porcelain grinder to make it smooth and flat, and clean the processed disc with an ultrasonic cleaner.

[0019] In one embodiment of the present invention, the insulating medium for polarizing the p81 oil in step S4 refers to an ideal medium for medium-temperature polarization of transformer oil below 120°C, and the polarization temperature of the p81 material is 100-110°C.

[0020] In one embodiment of the present invention, p51 can be air polarized or oil polarized. For thin components p51 with low polarization voltage, the air polarization temperature is 150-200°C, while the insulating medium of p51 in the oil polarization process must be methyl silicone oil, and its polarization temperature is required to be higher than 120°C. During the oil polarization process, the pressurization time of p81 is 6 minutes and the voltage is 185kV; while the pressurization time of p51 is 10 minutes and the voltage is 150kV.

[0021] The above technical solution of the present invention has the following advantages over the prior art: the detection performance method based on the production of piezoelectric ceramic wafers described in the present invention reduces the possibility of low yield in the production process, and greatly ensures the stability of the piezoelectric ceramic production process and the accuracy of the data. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0023] Figure 1 It is a flow chart of the method for detecting performance in the production of piezoelectric ceramic discs according to the present invention. DETAILED DESCRIPTION

[0024] Implementation

[0025] like Figure 1 As shown, this embodiment provides a method for detecting performance in the production of piezoelectric ceramic wafers. The method for detecting performance is for performance sampling of piezoelectric ceramic production, and air polarization is selected according to the situation that the sample material is p51, including the following steps:

[0026] Step S1: clean the processed piezoelectric ceramic disc with an ultrasonic cleaner, apply silver to one side of the piezoelectric ceramic disc with a brush silver coating machine, put it into an oven for 15 minutes, take it out and cool it, apply silver to the other side of the piezoelectric ceramic disc, put it into the oven again for 15 minutes and take it out;

[0027] Step S2: placing the silver-baked piezoelectric ceramic disc in a silver-infiltrating kiln for silver infiltration for 6 hours, then taking it out and cooling it;

[0028] Step S3: If air polarization is selected, each piezoelectric ceramic disc is clamped with a fixture and confirmed to be fixed. If the fixture is not full, it is clamped with insulating tape. When the oven reaches a predetermined temperature of 180 degrees Celsius, the device is placed in the oven; pressurization is set for 20 minutes; after polarization is completed, the oven is opened and cooled with an electric fan; after the temperature is lower than 50 degrees, the disc can be taken out for inspection;

[0029] Step S4: placing each piezoelectric ceramic disc in a foam box according to the number;

[0030] Step S5: Check whether the polarization is complete by randomly measuring the piezoelectric constant of each type of piezoelectric ceramic discs. If there is a disc with a low piezoelectric constant, remove the disc;

[0031] Step S6: Use capacitance tester, precision impedance analyzer, automatic component analyzer and other instruments and equipment to test the performance parameters of the wafer according to the process requirements: tanδ (dielectric loss), k p (electromechanical coupling coefficient), ε r T 3 (free relative permittivity), N d (frequency constant) and record;

[0032] Step S7: Using quasi-static d 33 After the tester has been stationary for three days, all parameters of the wafer are measured again and recorded. If all parameters meet the process standards, the raw materials of the production batch to which the sample belongs meet the production requirements. Example

[0033] This embodiment provides a method for detecting performance in the production of piezoelectric ceramic wafers. The method for detecting performance is for performance sampling of piezoelectric ceramic production, and oil polarization is selected according to the sample material being p81, including the following steps:

[0034] Step S1: clean the processed piezoelectric ceramic disc with an ultrasonic cleaner, apply silver to one side of the piezoelectric ceramic disc with a brush silver coating machine, put it into an oven for 15 minutes, take it out and cool it, apply silver to the other side of the piezoelectric ceramic disc, put it into the oven again for 15 minutes and take it out;

[0035] Step S2: placing the silver-baked piezoelectric ceramic disc in a silver-infiltrating kiln for silver infiltration for 6 hours, then taking it out and cooling it;

[0036] Step S3: If oil polarization is selected, first confirm the positive and negative poles and mark them, clamp each piezoelectric ceramic disc with a fixture, and lift the fixture with a waste small disc if the fixture is not full, to ensure that the disc is immersed in the insulating medium; after closing the operating table door, set the pressurization time, slowly increase the voltage, and observe and wait for polarization; after polarization is completed, use tweezers to clamp out, and spread each disc in the cleaning column to cool;

[0037] Step S4: After the oil-polarized piezoelectric ceramic disc has cooled sufficiently, use metal tweezers to conduct the two electrodes of the disc to perform a discharge operation, and ensure that the discharge is completed before starting the cleaning; put the disc together with the cleaning bar into four cleaning basins filled with gasoline in turn, soak and shake them appropriately; after the cleaning is completed, take out the cleaning bar and place it on the operating table, wait for the gasoline on the disc to evaporate and dry, then take out the disc and install it for inspection;

[0038] Step S5: placing each piezoelectric ceramic disc in a foam box according to the number;

[0039] Step S6: Check whether the polarization is complete by randomly measuring the piezoelectric constant of each type of piezoelectric ceramic discs (three discs are sufficient). If there is a disc with a low piezoelectric constant, remove the disc;

[0040] Step S7: Using quasi-static d 33 The tester is used according to the process requirements. 33 Testers, impedance analyzers, automatic component analyzers and other instruments and equipment test the performance parameters of wafers: tanδ (dielectric loss), k p (electromechanical coupling coefficient), ε r T 3 (free relative permittivity), N d (frequency constant) and record;

[0041] Step S8: After standing for three days, all parameters of the wafer are measured again and recorded. If all parameters meet the process standards, the raw materials of the production batch to which the sample belongs meet the production requirements.

[0042] The p51 in this embodiment 1 can be air polarized or oil polarized. For the thin element p51 with low polarization voltage, the air polarization temperature is 150-200°C, while the insulating medium of p51 in the oil polarization process must be methyl silicone oil, and its polarization temperature is required to be higher than 120°C. During the oil polarization process, the pressurization time of p81 is 6 minutes and the voltage is 185kV; while the pressurization time of p51 is 10 minutes and the voltage is 150kV.

[0043] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for detecting performance in the production of piezoelectric ceramic discs, wherein the method is for performance sampling of piezoelectric ceramic production, and air polarization or oil polarization is used according to the material of the sample, and the method is characterized in that: The steps include: Step S1: clean the processed piezoelectric ceramic disc with an ultrasonic cleaner, apply silver to one side of the piezoelectric ceramic disc with a brush silver coating machine, put it into an oven for 15 minutes, take it out and cool it, apply silver to the other side of the piezoelectric ceramic disc, put it into the oven again for 15 minutes and take it out; Step S2: placing the silver-baked piezoelectric ceramic disc in a silver-infiltrating kiln for silver infiltration for 6 hours, then taking it out and cooling it, and at the same time, selecting air polarization in step S3 according to the case where the sample material is p51, or selecting oil polarization in step S4 according to the case where the sample material is p81; Step S3: If air polarization is selected, each piezoelectric ceramic disc is clamped with a fixture and confirmed to be fixed. If the fixture is not full, it is clamped with insulating tape. When the oven reaches a predetermined temperature of 160-180 degrees Celsius, the device is placed in the oven; pressurization is set for 20 minutes; after polarization is completed, the oven is opened and cooled with an electric fan; after the temperature is lower than 50 degrees, the disc can be taken out and wait for inspection, and then go to step S6; Step S4: If oil polarization is selected, first confirm the positive and negative poles and mark them, clamp each piezoelectric ceramic disc with a fixture, and use a waste small disc to lift the fixture if it is not full, to ensure that the disc is immersed in the insulating medium; after closing the operating table door, set the pressurization time, slowly increase the voltage, and observe and wait for polarization; after polarization is completed, use tweezers to clamp it out, and spread each disc in the cleaning column to cool; Step S5: After the oil-polarized piezoelectric ceramic disc has cooled sufficiently, use metal tweezers to conduct the two electrodes of the disc to perform a discharge operation, and ensure that the discharge is completed before starting the cleaning; put the disc together with the cleaning bar into four cleaning basins filled with gasoline in turn, soak and shake them appropriately; after the cleaning is completed, take out the cleaning bar and place it on the operating table, wait for the gasoline on the disc to evaporate and dry, then take out the disc and install it for inspection; Step S6: placing each piezoelectric ceramic disc in a foam box according to the number; Step S7: Using quasi-static d 33 The tester checks whether the polarization is complete by randomly measuring the piezoelectric constant of each type of piezoelectric ceramic disc. If there is a disc with a low piezoelectric constant, the disc will be removed; Step S8: Use a capacitance tester, precision impedance analyzer, and automatic component analyzer according to the process requirements to test the performance parameters of the wafer: tanδ, k p , ε r T 3. N d and record; Step S9: After standing for three days, all parameters of the wafer are measured again and recorded. If all parameters meet the process standards, the raw materials of the production batch to which the sample belongs meet the production requirements.

2. The performance detection method according to claim 1, characterized in that: The piezoelectric ceramic disc in step S1 is designed in shape according to the detection requirements and the corresponding detection instrument, and its production steps are as follows: Step a: taking out the slurry obtained after atomization drying with a centrifugal spray granulation desiccant, and pressing it into a piezoelectric ceramic disc with a diameter of 25 mm and a thickness of 1.7 mm using a manual press; Step b: number each piezoelectric ceramic disc in turn, stack them up and arrange them in layers on the gasket, heat the disc to 750°C in a Moffitt furnace for 10 hours, keep it warm for 2 hours, cool it to room temperature and then take it out to complete the plastic removal; Step c: Take out each disc and spread it on a tray, sprinkle zirconium powder evenly on the disc, then evenly stack them into several rows and cover them with a ceramic cover plate and place them on a gasket; use a type 11 furnace to heat the disc to 1000°C for 5h, then heat it to 1330°C or 1305°C for 3h, keep it warm for 2h, then cool it to room temperature and take it out to complete the sintering; Step d: Grind the surface of the disc with a porcelain grinder to make it smooth and flat, and clean the processed disc with an ultrasonic cleaner.

3. The performance detection method according to claim 1, characterized in that: The insulating medium of the polarized p81 oil in step S4 refers to the ideal medium of medium-temperature polarization of transformer oil below 120°C, and the polarization temperature of the p81 material is 100-110°C.

4. The performance detection method according to claim 1, characterized in that: P51 can be air polarized or oil polarized. For thin components P51 with low polarization voltage, the air polarization temperature is 150-200℃, while the insulating medium of P51 in the oil polarization process must be methyl silicone oil, and its polarization temperature is required to be higher than 120℃.

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