Mechanical structure of silicon membrane switch
Time of issue：
The panel layer of silicon membrane switch is usually made of pet, PC and other colorless transparent sheets with less than 0.25 mm by screen printing with exquisite patterns and characters. Because the main function of the panel layer of silicon membrane switch is to play the role of identification and key, the selected materials must have the characteristics of high transparency, high ink adhesion, high elasticity and high toughness.
Surface adhesive layer
The main function of silicone membrane switch is to connect the panel layer and the circuit layer closely, so as to achieve the effect of sealing and connection. The thickness of this layer is generally required to be between 0.05-0.15mm, with high viscosity and anti-aging property; In production, the special double-sided adhesive for membrane switch is generally selected. Some membrane switches are required to be waterproof and high temperature resistant, so the surface adhesive must also use different materials according to the needs.
Control circuit upper and lower
This layer of silicon membrane switch uses polyester film (PET) with good performance as the carrier of switch circuit graphics, and uses special process to screen conductive silver paste and conductive carbon paste on it, so that it has conductive performance. Its thickness is generally within 0.05-0.175mm, and the most common is 0.125mm pet.
The adhesive layer of silicon membrane switch is located between the upper circuit layer and the lower circuit layer, and plays the role of sealing and connecting. Generally, pet double-sided adhesive is used, and its thickness varies from 0.05 to 0.2mm; When selecting the material of this layer, we should fully consider the overall thickness, insulation, handle and sealing of the circuit key package.
Back adhesive layer
The back glue of silicon membrane switch is closely related to the material of membrane switch, such as ordinary double-sided adhesive, 3M adhesive, waterproof adhesive, etc.