Metal dome array, generally, is double layer structure, but there is also single-layered.
For the double layer dome array, there are two layers, including Mylar, spacer and metal dome. The uppermost is the Mylar with the thickness of 0.05 mm, which is very thin. Then the thickness of the spacer is 0.075 mm with the tolerance of ±0.01 mm. And the underneath is the metal dome.
For this structure, the metal domes are connected by ventilation slots in the fabricated dome array. In this way, when you press the metal dome to conduct, the air can run along the ventilation slots. The purpose of it is to have a good click feeling and conduction ability.
For the single layer dome array, the uppermost is Mylar. And its thickness is generally 0.05 mm or 0.075 mm. Besides, some of the Mylars in the single layer dome array will not have the ventilation slots, while some will make a small hole on it according to the customer’s requirements.
Either the single layer dome array or the double layer dome array, there are release paper and protective film under the metal dome, aiming to protect the dome array. When the dome array has been torn down, the release paper and protective film will be the waste.
Therefore, the effect caused by the specifications of the release paper and protective film is not particularly large.