membrane switches on curved surface?

anyone know if it is possible to mount a LED backlit membrane switch on a concave surface? Perhaps by playing with where the graphic overlay end and the actual snap button is located?

Anyone done this before? I’m trying to replace a concave button (similiar to power button on the new XBox 360) that is sucking up too much internal volume.

THX.

J

while i think it can be done in specific (limited) circumstances i do know that we have gotten push back from our switch supplier about membrane keypads on curved surfaces. apparently the biggest issue is once the membrane is on a curved surface is flexes the layers together and causes false activation. I think there is also an issue of durability.

how drastic of a curve are you talking about? another solution may be touch-capacitance.

I recently got some samples of switches that were created using in-mold decorating. historically this is a process just for visual effects, but they’re starting to use it to creates switches and interface on complex surfaces.
Something to look into.

Other problems would be:

-keeping the membrane attached to the plastic (delamination)
-correct positioning during assembly
-poor feel (though that kinda goes with membrane switches)

all good points. perhaps I can “simulate” a curved surface by changing where the overlay begins and ends? Say the button and backlit area is on a flat surface while the adhesive overlay continues on the curved area around the button…

Thanks,

J