High-power tolerance temperature compensation type surface acoustic wave filter structure and preparation method

Abstract

The invention discloses a high-power tolerance temperature compensation type surface acoustic wave filter structure and a preparation method, and relates to the technical field of information electronic materials. The structure comprises a piezoelectric substrate, a composite electrode layer, a temperature compensation layer and a heat conduction layer in sequence from bottom to top; wherein the composite electrode layer sequentially comprises a first electrode priming layer, a first electrode main body layer, a second electrode priming layer, a second electrode main body layer and an electrode antioxidant layer from bottom to top; the composite electrode layer provided by the invention has relatively good stress migration resistance and low resistance; the power tolerance performance of the TCSAW filter is improved; therefore, the TCSAW filter has the advantages of small insertion loss, better rectangular coefficient and higher quality factor. The composite electrode layer is subjected to annealing treatment, crystal defects in the electrode can be effectively reduced, the conductivity of the composite electrode layer is improved, and the manufacturing method disclosed by the invention is easy to implement and popularize on a large scale, and has important practical significance for improving the power tolerance of the TCSAW filter.

Description

technical field [0001] The invention relates to the technical field of information electronic materials, in particular to a structure and a preparation method of a temperature-compensated surface acoustic wave filter with high power tolerance. Background technique [0002] Surface Acoustic Wave (SAW) filters have the advantages of small size, low cost, excellent passband selectivity, and good consistency. They play the role of signal transmission and reception in mobile communication systems and are widely used in mobile communication in the device. With the continuous evolution of 4G to 5G networks and people's urgent demand for high data transmission rates, SAW filter technology is developing in several directions such as high frequency, high power tolerance, high temperature stability, and small size. At the same time, SAW filters are also facing new challenges. [0003] Commonly used piezoelectric substrate materials such as LiTaO 3 or LiNbO 3 The temperature stabili...

AI Technical Summary

Problems solved by technology

When the TCSAW filter is working, under high power conditions, the repeated stress of the Cu electrode will cause the atoms to migrate at the grain boundary, which will cause the metal film to bulge or hole, causing the electrode to short circuit or open circuit

Various alloys have been used to improve the electromigration resistance and power tolerance of devices, but the alloy film process is complicated, and the content of alloy elements is not easy to control, which makes the electrode conductivity worse and the insertion loss larger

In addition, under high power conditions, the TCSAW filter, due to the covered temperature compensation layer SiO 2 The thermal conductivity is low, resulting in insufficient heat dissipation of the TCSAW filter chip, and the surface is usually in a high temperature state, which may easily lead to device failure

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