Electronic Cigarette Emitter Technology: Electret is the Current Mainstream, Silicon Mai May Become the Future Trend

Just like the atomization core, which is divided into ceramic core and cotton core, there are also sub types of electronic cigarette microphones, mainly two types: electret and silicon microphone. Among them, electret microphones are currently common, while silicon microphone is considered the future trend.
Let's take a look at the comparison between two types of electronic cigarette capacitive microphones. Generally speaking, a microphone includes two parts: a sensor and an ASIC chip. This article mainly discusses the differences in the sensor part.
1. Basic principle of microphone induction - parallel plate capacitors
Firstly, the principle is that the response of the electret microphone and the silicon microphone is formed by a parallel plate capacitor composed of a diaphragm and a back plate. The differential pressure of the airflow causes the diaphragm to deform, and then the capacitance changes. After being recognized and processed by the ASIC chip, an electrical signal is output, ultimately achieving the start and stop of the electronic cigarette.
The key point is the change in capacitance.
In circuit science, the ability of a capacitor to store charges at a given voltage is called capacitance, labeled C. A parallel plate capacitor is a simple type of capacitor composed of two thin plate conductors that are parallel to each other and isolated by space or dielectric.
Electronic Cigarette Emitter Technology: Electret is the Current Mainstream, Silicon Mai May Become the Future Trend
According to the relevant formula of parallel plate capacitors, it is:
Normal electronic cigarette head: the guide plate area A remains fixed, and the dielectric capacitance ε The default is air, and the airflow causes the diaphragm to deform - the distance d between the diaphragm and the electrode plate changes - causing a change in capacitance;
Electronic cigarette tip with oil leakage: The area A of the guide plate remains fixed, and the area between the electrode plate and the diaphragm is not air, but oil. Therefore, the dielectric permittivity ε Change - cause capacitance change - self start.
2. Electret microphone vs silicon microphone: differences in structure and diaphragm
In terms of structure, most of the electret microphones have an electrode plate on top and a diaphragm on the bottom, with holes in the substrate. This design makes it easy for the electret microphones to enter oil and water, causing changes in dielectric permittivity and capacitance, such as self starting.
If we adopt a structural design with the electrode plate at the bottom and the diaphragm at the top to avoid oil leakage, although it can avoid oil leakage, it will be difficult to assemble and increase production costs.
Electronic Cigarette Emitter Technology: Electret is the Current Mainstream, Silicon Mai May Become the Future Trend
Microscopic structure of the microphone head
And capacitive silicon microphone, according to professionals, can be designed as a structure with a diaphragm on top and a plate on bottom. Meanwhile, unlike the polymer diaphragm of the electret microphone, the diaphragm of silicon wheat is a silicon based membrane.
In terms of manufacturing process, electret microphones are usually manually assembled, and some leading companies use automated assembly, while silicon microphones use MEMS technology.
In terms of performance, the electret microphone is currently the most widely used electronic cigarette microphone, with advantages of stable mass production and low cost. At the same time, there are also some shortcomings, such as lack of oil resistance, poor heat dissipation, and inability to pass SMT.
If we want to pursue better performance and higher production efficiency, the advantages of silicon wheat will gradually become prominent, such as waterproof and oil resistant, small size, high temperature resistance, SMT resistance, consistency and stability, and so on.
The main problem with silicon wheat is its cost, which means "everything is good, but it's expensive". The good news is that with the progress of technology, according to relevant manufacturers, in the case of large-scale production applications, its cost can be comparable to that of electret microphones.
summary
The above is a comparison between two types of electronic cigarette capacitive microphones. In addition to capacitive microphones, there are also resistive microphones. We will have the opportunity to introduce them in another chapter later.
Overall, there are two main types of capacitive microphones: electret and silicon microphone. The two have differences in structure, diaphragm material, manufacturing process, and performance. In the application of electronic cigarettes, electret microphones are the current mainstream, while silicon microphone is considered the future trend.