Bicrystal piezoelectric ceramic loudspeaker

Abstract

The invention discloses a bicrystal piezoelectric ceramic loudspeaker capable of prolonging the service life of the loudspeaker and improving the sound quality, which comprises a front cover, a bicrystal piezoelectric ceramic sheet, an elastic vibration film and a metal film side frame, wherein a flexible printed circuit board (FPCB) is electrically connected with the electrode lead-out end of the bicrystal piezoelectric ceramic sheet, a back cover and the front cover are fixedly connected, the bicrystal piezoelectric ceramic sheet, the elastic vibration film and the metal film side frame are positioned in a cavity circulated by the back cover and the front cover, the bicrystal piezoelectric ceramic sheet comprises two monocrystal piezoelectric ceramic sheets with two opposite polarization directions, a middle ceramic film layer is arranged between the two monocrystal piezoelectric ceramic sheets, an upper-layer ceramic film layer is arranged on the outer side surface of the top layer of the monocrystal piezoelectric ceramic sheet, the end part of the upper-layer ceramic film layer is provided with the electrode lead-out end, and a lower-layer ceramic film layer is arranged at the outer side surface of the bottom-layer monocrystal piezoelectric ceramic sheet. The bicrystal piezoelectric ceramic loudspeaker is applicable to portable equipment such as mobile phones, tablet computers, notebook computers, electronic books and the like.

Description

technical field [0001] The invention relates to a piezoelectric ceramic loudspeaker, in particular to an ultra-thin double crystal piezoelectric ceramic loudspeaker used for voice and music playback in a portable device terminal. Background technique [0002] Currently commonly used piezoelectric ceramic speakers include a front cover, a metal film is arranged on the inside of the front cover, and a single crystal piezoelectric ceramic sheet is arranged on the metal film. The metal film and single crystal piezoelectric ceramic sheet constitute the vibration component of the piezoelectric ceramic speaker. , the flexible printed circuit board (referred to as FPCB board) is pressed on the single crystal piezoelectric ceramic sheet and electrically connected to the electrode lead-out end of the single crystal piezoelectric ceramic sheet, and the metal film, single crystal piezoelectric ceramic sheet and flexible printed circuit board A piezoelectric sound-generating device is fo...

AI Technical Summary

Problems solved by technology

[0004] The main disadvantages of the single crystal piezoelectric ceramic loudspeaker with the above structure are: 1. Since the metal film must be used, the frequency of the sound emitted is relatively high, and the lowest resonance frequency F 0 It can only reach 800-850Hz, the bass is insufficient, and the tone is not full; 2. The silver electrode layer on the outer layer of the piezoelectric ceramic sheet is exposed in the air, making the silver electrode layer easily oxidized, which affects the service life of the piezoelectric ceramic speaker

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