The circuit layer is an important part of all membrane switches. Membrane switches, of course, are circuit-controlling devices. Unlike mechanical switches, though, they feature multiple layers that are compressed and joined together using adhesive. While there are many different layers in membrane switches, among the most important is the circuit layer. What is the circuit layer exactly, and why do membrane switches need it?
Overview of the Circuit Layer
The circuit layer is exactly what it sounds like: a thin layer that features the circuitry of a membrane switch. Like all switches, membrane switches control a circuit. Pressing a button on a membrane switch will open or close the respective circuit. The circuit layer is the part of a membrane switch with the conductive traces needed to perform this operation.
Where the Circuit Layer Is Located
In most membrane switches, the circuit layer is found in the middle. Membrane switches are made of multiple layers. They typically feature an overlay layer on top, followed by a spacer layer and then a circuit layer. Underneath the circuit layer is an adhesive layer, and lastly, a tail filler layer.
Different types of membrane switches may feature different layers. Nonetheless, they all have a circuit layer — which is typically found in the middle of the membrane switch. The circuit layer is sandwiched between a spacer layer and an adhesive layer.
Circuit Layer Inks Explained
Membrane switch circuit layers are designed with ink. Ink is essentially what creates the conductive traces on the circuit layer. When designing the circuit layer, manufacturers will print them using conductive ink. The conductive properties of the ink allow electricity to flow through the circuit layer.
Inks commonly used in membrane switch circuit layers include copper, graphite and silver. All three of these materials are electrically conductive. Therefore, electricity can flow through them with ease. This makes copper, graphite and silver popular ink types for membrane switch circuit layers.
How the Circuit Layer Works
The circuit layer works by allowing or prohibiting the flow of electricity. As previously mentioned, switches are circuit-controlling devices. Whether mechanical or membrane, all switches control one or more circuits. Activating a membrane switch will allow electricity to flow through the circuit layer via its conductive ink. The membrane switch will then respond with the appropriate action.
There are many different types of membrane switches, but they all require circuitry. The circuit layer is the thin layer in a membrane switch that features the circuitry.