Dome Switches

Part of the mechanical make-up of certain styles of membrane switches, a dome switch functions in a simple but effective way. Set-up as the layer in between a circuit board and the surface keys, the domes are part of the switch contact system within a variety of keyboards utilized in a variety of settings.

A dome switch is a common keyboard component because of the tactile and audio signals it sends the user of the keyboard; the obvious discernable response is why a dome switch is also considered to be a tactile switch.

Membrane Keypad with Dome Switches
Dome Switches – Douglas Corporation

When a button is pressed that has a dome switch underneath connecting it to the circuit board, the sound and sensation of the pop when the dome is snapped registers at the same time that the circuit board responds accordingly. This means that the communication of commands from user to electronic device is nearly immediate, allowing the user to be more efficient while using the interface utility.

This style of membrane switch is popular among many industries, since most computer keyboards use dome switch pads and virtually every industry utilizes computers. Although the capacitive touch screen technology adopted by iphones and ipads is also becoming universal, the prevalence and ease of button based systems ensures they aren’t going anywhere.

The dome itself may be made of metal or rubber. The metal material is commonly stainless steel, which is often plated in nickel, silver or gold. Because they are usually reliable for over five million cycles and retain the crisp sound and snap well, metal dome switches are often preferred over rubber domes.

The quieter collapsing rubber dome does not provide as much positive response as metal domes and also has a lower life expectancy. However, rubber domes are cheaper, which means that the polyester domes with the inside bubble coated with graphite, are used often enough.

They are utilized in a popular style of dome switch keyboard called the scissor switch, which adds a scissor-like mechanism in between the dome and circuit board that shortens the traveling distance of the dome, extending the life of the keyboard as a whole.

Because of innovations like the scissor switch keyboard, the dome switch approach to membrane switch boards remains popular. Handheld controllers, electronics in automobiles, medical devices and other varieties of consumer electronics all function through the use of the dome switch.

Dome Switches Informational Video