Common Components of Membrane Switches

Common Components of Membrane Switches

Membrane Switches's products widely used in medical, industrial control, automation, rail transit, aviation and shipping, network communication, consumer electronics, instruments and meters, agricultural machinery, equipment manufacturing, and other extensive fields. Below, we will introduce the common components of membrane switches.

1. Panel layer

The panel layer is generally made by silk-screening exquisite graphics and text on colorless transparent film materials such as PET and PC with a thickness of less than 0.25mm. Since the primary function of the panel layer is to serve as an identifier and button, the selected material must have high transparency, strong ink adhesion, high elasticity, and resistance to folding.

2. Cushioning layer

The primary function of the cushioning layer Z is to securely connect the panel layer with the circuit layer, achieving sealing and connection effects. This layer typically requires a thickness between 0.02 and 0.05 mm, offering high-strength adhesion and anti-aging properties. In production, specialized double-sided adhesive film switches are commonly used. Some film switches require waterproofing and heat resistance capabilities, so the cushioning layer must also use materials with different properties according to specific needs.

3. Control circuit upper and lower layers

This layer employs a high-performance polyester film (PET) as the carrier for the switch circuit graphics, on which special processes are used to screen print silver paste, carbon paste, or gold paste to give it conductive properties. Its thickness is generally within 0.05 - 0.175 mm, with the most common being 0.125 mm PET.

4. Laminated layer

It is located between the upper and lower circuit layers, serving as a seal and connection. Generally, PET double-sided adhesive tape is used, with thicknesses ranging from 0.05 to 0.2 mm. When selecting materials for this layer, it is essential to consider the overall thickness of the product, insulation, the feel of the circuit keys when holding them, and sealing properties.

5. Adhesive layer on the back

The adoption of adhesive backing is closely related to the type of Membrane Switch and the material it adheres to. Commonly used adhesives include general double-sided tape, 3M tape, waterproof tape, etc.

The raw materials for membrane switches and panels, in addition to requiring flatness and printability, are primarily characterized by flexibility and high elasticity.