Customized silicone button rubber keypad with carbon pill

A rubber keypad with carbon pill construction combines molded controls with conductive elements on the working side. The custom layout should align those contacts with the circuit while the visible keys remain centered in the housing. The final spacing is established by the complete enclosure and board support.

Check the relaxed gap and the available movement beneath each key. The carbon pill should reach its intended contact during a press without resting continuously against the board. Clamping near fasteners or the perimeter can change that relationship if the membrane is trapped.

Keep the contact side clean during assembly and avoid unnecessary touching of the working surfaces. Test the keypad after the case is secured, checking successful input, release, and independence of neighboring keys. The complete circuit and keypad determine the required electrical resistance and operating life; those values should not be inferred from the contact type alone. During service, inspect the seating if operation changes after the enclosure is opened, especially where board or case position has shifted.

Material options

Silicone. Custom formulation and color for the intended contact conditions.

Hardness selection

Silicone: 20–80 Shore A. The carbon pill should reach its intended contact during a press without resting continuously against the board.

Custom dimensions

The final spacing is established by the complete enclosure and board support.

Fit & assembly

Clamping near fasteners or the perimeter can change that relationship if the membrane is trapped.

Use & inspection

During service, inspect the seating if operation changes after the enclosure is opened, especially where board or case position has shifted.

Photos illustrate structure or material only. The final spacing is established by the complete enclosure and board support. ETOL directly manufactures custom-shaped silicone and rubber parts to your requirements.