Electrical Characteristics Test and Analysis of Piezoelectric Ceramics

Through the impedance test of the piezoelectric ceramic device, the model parameters and resonant frequency of the piezoelectric oscillator equivalent circuit can be obtained. Through the measurement and analysis of the electrical parameters such as capacitance value, temperature stability, insulation resistance and dielectric withstand voltage of piezoelectric ceramic devices, it can be known that the electrical characteristics of piezoelectric ceramic devices conform to the characteristics of general capacitors, and the connecting wires used are parasitic at the lower frequencies. The capacitor is not obvious, it works stably at the normal temperature, and the insulation and reliability index of the thicker product is better.

When piezo sphere vibration transducer is subjected to a small external force, it can turn mechanical energy into electrical energy. When a voltage is applied, electrical energy is converted into mechanical energy. It is usually formed by solid phase reaction of several oxides or carbonates during sintering, and its manufacturing process is similar to that of ordinary electronic piezo ceramics. Compared with other piezoelectric materials, it has the characteristics of chemical stability,it is easy to dope the convenient shaping. It has been widely used in many fields related to people's lives, including industrial, military, medical and health, and daily life. High capacity piezo ceramic capacitors can be fabricated by using the high dielectric constant of ferroelectric ceramics;various piezoelectric devices can be fabricated by using piezoelectricity; human body infrared detectors can be fabricated by using pyroelectricity;which is transparent by appropriate processes Ferroelectric piezo ceramics have electronically controlled optical properties, which can be used to make electronically controlled optical components for storage, display or switching. Ferroelectric thin films such as PZT and PLZT prepared by physical or chemical methods have important applications in the electro-optical devices and non-volatile ferroelectric memory devices.

The piezo ceramic element will be used as an example to measure and analyze the electrical properties such as impedance test, capacitance value, insulation resistance and dielectric withstand voltage.Measurement parameters and experimental methods. At present, the existing test standards for piezoelectric ceramic materials in China mainly include the piezoelectric ceramic material performance test method, piezoelectric ceramic vibrator frequency temperature stability test method, electric field strain characteristics of piezoelectric ceramic.Test method has static bending strength test method of piezoelectric ceramic material and piezoelectric ceramic material performance method (test of low mechanical quality factor piezoelectric ceramic material performance).

The inverse piezoelectric effect will be applied to the piezoceramic sphere sensor by applying an alternating voltage between the two poles of the piezoelectric ceramic buzzer to generate vibration and enter the working state. Then, the piezoelectric ceramic buzzer is subjected to impedance, capacitance value, insulation resistance.The dielectric withstand voltage,other electrical performance parameters are measured. The main work is to find the maximum and minimum impedance frequency points by measuring the impedance of the piezoelectric ceramic buzzer, and then use the criteria to determine the equivalent circuit model parameters, and observe the change of the capacitance value by changing the frequency. Then, by using different wires and different connection methods, the influence on the capacitance measurement of the piezoelectric ceramics is observed. Finally, the reliability of the parameters has temperature characteristics, insulation resistance and dielectric withstand voltage is studied.

The piezoelectric vibrator is a polarized piezoelectric body which is an elastic body and has a natural vibration frequency. When the frequency of the electrical signal applied to the piezoelectric vibrator is equal to its natural vibration frequency fr, the elastic energy of the PZT material piezoelectric sphere is the largest and resonance occurs. In addition, it also has important critical frequencies such as anti-resonant frequency fa, series resonant frequency fs, parallel resonant frequency fp, minimum impedance frequency fm, maximum impedance frequency fn. L1 is the piezoelectric vibrator dynamic inductance, C0 and C1 are static capacitance and dynamic capacitance, respectively, and R1 is dynamic resistance. L1, R1, and C1 are related to the mass, internal friction coefficient, and elastic constant of the piezoelectric vibrator, respectively, and are not electrical quantities, but are simulated to be electrical quantities for convenience of handling. Only C0 in the model is the electrical quantity. The elastic, piezoelectric and dielectric constants of the piezoelectric vibrator material can be determined by measuring the set size of the piezoelectric vibrator, the series resonant frequency, the material density and the capacitance.