Method for preparing multilayer piezoelectric film, piezoelectric module and electronic equipment

Abstract

The invention discloses a method for preparing a multilayer piezoelectric film, a piezoelectric module and electronic equipment. The method for preparing the multilayer piezoelectric film comprises the step of sequentially preparing electrode layers and piezoelectric film layers which are alternately arranged on a substrate so as to obtain the multilayer piezoelectric film. The step of preparing the nth piezoelectric film layer comprises the steps that: in a crystallization auxiliary solvent atmosphere, the nth piezoelectric film layer is crystallized through heat treatment, so that crystal particles of the nth piezoelectric film layer penetrate through part of the electrode layer to be connected with the (n-1) th piezoelectric film layer, wherein n is larger than or equal to 2. According to the method for preparing the multi-layer piezoelectric film, the piezoelectric module and the electronic equipment, when the multilayer piezoelectric film is prepared, the piezoelectric film layers do not need to be attached through glue, so that the overall thickness of the piezoelectric module can be reduced, and the performance of the piezoelectric module is improved.

Description

technical field [0001] The invention relates to the field of piezoelectric technology, in particular to a method for preparing a multilayer piezoelectric film, a piezoelectric module and electronic equipment. Background technique [0002] At present, the mainstream sound emitting devices under the screen are usually electromagnetic type and piezoelectric ceramic type. For the electromagnetic drive sounding device, due to its large size, high cost and opaque piezoelectric ceramics, it is not easy to be placed between the display screen and the glass cover, so it will occupy a lot of assembly space, and the sound conduction layer is thick, increasing energy consumption. For piezoelectric film materials such as vinylidene fluoride trifluoroethylene copolymer or polyvinylidene fluoride, it has the advantages of high transparency, sound on the screen, saving assembly space, low power consumption, and more user functions, etc. Widely favored. [0003] Since the sound intensity ...

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Problems solved by technology

In the related technology, after printing the electrodes on the piezoelectric film that has been polarized, it is cut into the required shape, and the layers are bonded by glue bonding. However, because the thickness of the single layer of glue > 10um, coupled with the thickness of the film itself and the thickness of the electrodes, the overall thickness of the module increases significantly with the increase in the number of stacked layers, which greatly increases the vibration load of the module, so that the increased thickness will offset the increase in the number of layers. performance improvement for

Although, with the improvement of the piezoelectric film preparation process, its thickness can be controlled below 10um, but the thickness of the interlayer adhesive + electrode will be greater than the thickness of the functional layer, and the performance will reach the bottleneck after 2-3 layers are pasted.

In addition, the reliability of the glue is low, and there is a risk of aging failure, and, due to the difference in the modulus and mechanical properties of the glue and the diaphragm, there will also be a problem of glue cracking when the film vibrates

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