Membrane keyboard manufacturers. Kingley Tech has rich experience on Membrane Keyboard industry over 20 years.
Membrane keyboards work with electrical contact between the keyboard surface and the underlying circuits when key-top areas are pressed.
A membrane keyboard is a computer keyboard whose "keys" are not separate, moving parts, as with the majority of other keyboards, but rather are pressure pads that have only outlines and symbols printed on a flat, flexible surface. Very little, if any, tactile feedback is felt when using such a keyboard and error-free blind typing is difficult.
For the Modern PC keyboards, they re essentially a membrane keyboard mechanism covered with an array of dome switches which give positive tactile feedback.