Membrane switch is a set of operating system with key functions, indicating components and instrument panel.
It is composed of panels, surface glue, isolation layer, thread and glue. The membrane switch has a tight structure, beautiful appearance and good airtightness.
It has the characteristics of waterproof, high temperature resistance,dust resistance, radiation resistance, corrosion resistance, stable and reliable performance, light weight, small size and long service life.
It is widely used in electronic communications, electronic measuring instruments, industrial control, medical equipment, automotive industry, smart toys, household appliances and other fields.
The panel layer is usually made of colorless transparent light sheet materials such as PET, PC, which are less than 0.25mm, made of exquisite patterns and text.
Because the main function of the panel layer is the sign and the key function, the selected material must have high transparency, the ink has high adhesion, high elasticity, high toughness, etc.
Surface adhesive layer
The main function of the surface glue is to tightly connect the panel layer and the circuit layer to achieve the effect of a sealed connection.
The thickness between this layer is generally required to be 0.05-0.15mm, which has high viscosity and antiaging;
in production, special membrane switches are generally used Double-sided tape, some membrane switches require waterproof and high temperature resistance,
so the glue must be made of materials with different properties according to needs.
Control circuit upper and lower layers
This layer uses polyester film(PET) with good performance as the carrier of the exchange circuit pattern,
shields conductive silver paste and conductive carbon paste on it, and make it conductive through a special process.
Its thickness is generally 0.05-0.175mm, and the most common is 0.125mm PET.
It is located between the upper circuit layer and the lower circuit layer and plays a role of sealing and connecting.
Generally, double-sided tape is used, with a thickness of 0.05-0.2mm.
When choosing the material, the total thickness of this layer should be fully considered for the product and insulating material, circuit buttons include feel and tightness.
The use of switch glue and film is closely related to the degree of adhesion of the material.
Commonly used are ordinary double-sided, 3M glue, and waterproof glue.