Preparation of piezoelectric quartz unseeded acoustic surface wafer

Abstract

The invention provides a method for preparing a seed-crystal-free acoustic surface wafer of piezoelectric quartz, which belongs to a method for preparing the material for an acoustic surface wave device, and aims at solving the problems of long production period, low yield, low utilization rate of materials and high cost existing in the prior preparation method at home and abroad. The method comprises the following steps: seed crystal is placed in a high-pressure autoclave to culture crystal by hydrothermal temperature difference method; then, the crystal is cut into crystal wafers, wherein, the seed crystal is a seed crystal wafer in acoustic surface wave propagating angle with the dimension being 2 to 6 inches; sodium hydroxide aqueous alkali and sodium carbonate aqueous alkali are filled in the high-pressure autoclave, the seed crystal is placed on the upper part of the high-pressure autoclave, while raw materials for dissolving is arranged on the lower part of the high-pressure autoclave; the two kinds of solution convectively move upwards, so that the crystal is crystallized along the acoustic surface wave propagating angle to grow a crystal block according to the specification; according to the thicknesses of acoustic surface wafers required by different categories, cutting processing is carried out on the crystal block by wire cutting according to different thicknesses by taking a seed basal lamina as the standard of cutting angle, so as to obtain the seed-crystal-free acoustic surface wafer with the different thicknesses in the acoustic surface wave propagating angle.

Description

technical field [0001] The invention relates to a preparation method of a surface acoustic wave device material, in particular to a preparation method of a seedless acoustic surface wave wafer. Background technique [0002] Piezoelectric crystal acoustic chip is an important material for making surface acoustic wave components, and in the microelectronics process of surface acoustic wave components, it is an important part of making interdigitated electroacoustic transducers, reflectors and couplers. Utilizing the piezoelectric effect of the substrate material, the electrical signal is converted into an acoustic signal through the input interdigital transducer (IDT), which is limited to propagate on the surface of the substrate, and the output IDT restores the acoustic signal to an electrical signal, realizing the electro-acoustic- The conversion process of electricity, complete the electrical signal processing process, and obtain electronic devices for various purposes. Ma...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problems of containing seed crystals, long production cycle, low yield and material utilization rate, and high cost in the existing preparation methods of SAW wafers at home and abroad, and provide a method with significantly shortened production cycle, high yield and high cost. A method for preparing a piezoelectric crystal seedless crystal acoustic surface wafer with improved material utilization and reduced cost. The prepared seedless crystal acoustic surface wafer material can be applied to devices with a bandwidth below 5%, and its electromechanical coupling coefficient is small and temperature-frequency The stability is as high as 0~1.5PPm, especially suitable for low and medium frequency devices with a bandwidth of 3‰~5%.