To Get Good Actuation Force for Your Rubber Keypad

Rubber Keypad - Actuation Force?

When you design your rubber keypad, you must want to receive excellent tactile feedback when press the keypad buttons. Actuation force of keypad is the force that initiate conduction of buttons connecting with PCB, which gives operators tactile feedback when pressing the rubber buttons. 

Larger or Smaller Actuation Force for Rubber Keypads?

For rubber keypads used in different applications, actuation force would be different. Silicone keypad that is pressed in quick succession requires low actuation force, in order to be easily pressed and have good tactile feel. However, small actuation force would make buttons sensitive to conduction and result in accidental input.

For rubber keypads used in heavy machines or important large apparatus, actuation force can be larger to generate a lager tactile feedback for operators, and remind them the button has been pressed. Such as automotive rubber keypad, its actuation force generally over 300 grams. 

For example, piano rubber keyboard contacts should be with small actuation force because rubber contact buttons could have good sensitivity, and they are usually pressed in quick succession.

In designing rubber keypad buttons for consumer applications, we recommend 130-150 grams actuation force, which gives a good tactile feedback and extend keyboard lifetime. This actuation force can not only prevent silicone buttons pressed from getting stuck into to housing case, but also give rubber keypad manufacturer flexibility to vary actuation force without destroying keypad button functions.

Note: Elastomer rubber keypad with small actuation (less than 120 grams) may have the risk of causing stuck buttons, because rebound force is small as well.

What will Affect Rubber Keypad Actuation Force?

Actuation force of keypad is affected by many elements, including thickness of button webbing, angle of button webbing, coating on silicone keypad, hardness of silicone material.

Rubber keypad webbing thickness plays an important role in actuation force. Thin thickness can generate small actuation force. In silicone keypad production, if we think force is too small, we can thicken the button webbing to enlarger actuation force.

Besides button webbing, color coating, oil coating and PU coating will increase keypad actuation force. For most laser etching keypad, color coating and PU coating are necessary. Actuation force increases by about 20 - 30 grams after coating to the rubber keyboard.

Hardness of silicone material also affects rubber buttons actuation force. Common material hardness is 50 Shore A to 70 Shore A. For silicone keypads with same geometry, lower durometer keypad is easier to press than higher durometer rubber keypad.

Xiamen Better Silicone Rubber as a specialized rubber keypad manufacturer, we can offer you free rubber keypad design guide, and design feasibility evaluation.