Surface mountable electret condenser microphone

Abstract

Disclosed is an electret condenser microphone capable of surface mounting which has a structure highly resistant to high temperature. The electret condenser microphone comprises a case, a polar ring, a diaphragm, a spacer, a back-plate, a first base, a second base and a printed circuit board (PCB), wherein the first base surrounds the diaphragm, the spacer and the back-plate, so that the first base prevents characteristics of an electret formed on any one of the diaphragm and the back-plate from being deteriorated in a reflow process for surface mounting. Further, in order to prevent sensitivity of the electret condenser microphone from being lowered due to decrease of an electrical potential value of the electret in the reflow process. High gain IC devices are used. The electret condenser microphone capable of surface mounting can be obtained by, first, using main components made from a high-temperature resistant insulating material, for example, a polymer-, a plastic- or a fluoro resin-based material, second, constructing the fist base to surround acoustic based components, third, using a cream solder for high temperature to bond components to the PCB, fourth, using the high gain IC devices, fifth, providing the connecting terminal with gas discharge grooves and protruding the connecting terminal to be higher than a curled surface of the electret condenser microphone.

Description

technical field [0001] The present invention relates to an electret condenser microphone, and more particularly, to a surface mountable electret condenser microphone, which has a structure that is particularly resistant to high temperatures. Background technique [0002] A typical condenser microphone includes: a biasing element (eg, an electret); a diaphragm / backplate pair forming a capacitor that changes in response to sound pressure; and a JFET (junction field effect transistor) for pairing The output signal is buffered. The electret condenser microphone has an electret formed on either of the diaphragm and the backplate. Specifically, the electret formed on the diaphragm is called the front electret, and the electret formed on the back plate is called the back electret. Typically, the electret is formed by forcibly injecting charges into the organic film. [0003] figure 1 A conventional electret condenser microphone is schematically represented. [0004] like figu...

AI Technical Summary

Problems solved by technology

Therefore, it is not suitable to apply SMT to temperature sensitive components

In addition, the electret condenser microphone has another problem in that, by forcibly injecting electrons into an organic thin film (for example, FEP (fluoroethylene propylene copolymer), PET (polyethylene terephthalate) Diester), PTFE (polytetrafluoroethylene), etc.) to form an electret, so the increase in humidity or temperature makes the injected electrons easy to separate, thereby reducing the performance of the electret

Images