The hole on PET around metal dome or the slot between dome and dome is called the “vent hole” or “vent slot”, which is very important for the normal operation of metal dome. It will result in poor feel and affect the function of the switch if without the vent hole. Although this design may not be used in every applicable product, it is desirable in almost all applications. When you press on metal dome, the air is trapped underneath it. So when we press on snap dome, in order to prevent the air from being compressed underneath, we have to make a vent slot for dome switch.
There are different ways to make vent holes of dome array, for example:
- the vent holes can be designed between metal dome and the spacer;
- A small opening hole can be made on the top layer of dome retainer;
- It can be made a hole through the PCB board.
In a word, the improper design of the vent hole of Dome array will seriously affect the feel of metal dome when pressed. Please pay attention for this issue.
