There are so many customers to ask this question. I know it is very important for the product design. You should leave the enough space for the metal dome & metal dome array between your PCB & cover layer.
This time follow me to clarify this question, it is very easy for us whom are specializing in this industry for so many years.
For the metal dome, you can see our 6mm diameter, four-leg shape metal dome. The total height is 0.31mm, & the thickness of the material is 0.06mm, so the stroke is 0.31-0.06=0.25mm.
The formula is: Stroke= Height – Thickness of material – Thickness of the dimple (if there is a dimple in center).
For the four-leg metal domes, the life cycles always have the one million times. & they are popular used in the membrane switche products.
For the metal dome array, you can see the follow picture:
You can see the 3# spacer is parallel to the 2# metal dome & the thickness is lower than the domes. So you can ignore the thickness of the spacer. The total height = Mylar + Metal dome=0.05+0.31=0.36mm. For the more detail, you can see my last blog.http://www.metal-domes.com/blog/2009/11/07/the-whole-thickness-of-our-metal-dome-arrays/
How about the stroke? In fact, it is the same as the natural metal domes. It should be ignored the thickness of the Mylar & Spacer. So you can use the above formula to calculate the stroke.
Best Technology Co., Ltd