A kind of MEMS microphone packaging structure and packaging method

Abstract

The invention discloses a package structure of a MEMS microphone, which comprises a base plate and a metal shell, and the base plate and the metal shell are combined to form an inner space. The metal housing includes a top plate with a sound hole, a side wall, and a partition extending downward from the top plate; a metal support frame is provided in the internal space, which includes a mounting part and a supporting mounting for mounting the MEMS microphone assembly. The supporting part of the part, the carrying part has an opening corresponding to the microphone diaphragm of the MEMS microphone assembly; the supporting part is fixedly connected to the substrate, and the carrying part is fixedly connected to the partition. The partition board and the metal support frame divide the internal space into a first sound cavity and a second sound cavity. A sound transmission channel passing through the sound holes and openings is formed in the first sound cavity, and the sound transmission channel is closed relative to the second sound cavity. The invention also provides a packaging method for the MEMS microphone, which can reduce the occupied area of ​​the substrate and improve the sound collection effect.

Description

technical field [0001] The invention relates to the technical field of MEMS microphone packaging, in particular to a MEMS microphone packaging structure and packaging method. Background technique [0002] With the progress of society and the development of technology, in recent years, the volume of smart mobile devices has been continuously reduced and the performance and consistency have been improved, and the packaging requirements for microphones have become more and more stringent. MEMS microphones integrated with MEMS (micro-electromechanical systems) technology have begun to be applied in batches to mobile phones, notebooks and other idea products. Compared with traditional EMC (resident collective) microphones, this MEMS microphone package has smaller volume, good sealing performance, high reliability, and high temperature resistance, and can withstand the high temperature test of SMT (surface mount technology) process. [0003] The general structure of MEMS micropho...

AI Technical Summary

Problems solved by technology

[0004] This traditional MEMS microphone packaging structure has the following disadvantages: First, both the MEMS microphone assembly 3 and the integrated circuit ASIC chip 2 need to be mounted on the substrate 1 (PCB board). larger area

Secondly, there is only one cavity inside this packaging structure and the MEMS microphone component is mounted on the substrate, so the transmission route of the sound transmission channel in the cavity is not clear

The sound collection effect of the MEMS microphone chip is directly related to the volume of the cavity and the sound transmission line. Obviously, such a package structure affects the sound collection effect of the MEMS microphone.

In addition, because the working principle of the silicon microphone requires that its packaging structure must have a sound hole connecting the internal and external spaces, this causes external dust and light to easily enter the cavity from the outside and directly contact the MEMS chip. It will bring some interference to the work of the MEMS chip, that is, the noise generally understood

At the same time, light shining on the ASIC chip will also affect the electrical performance of the microphone

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