The structure of the membrane switch points total of a few layers?
Membrane switch say simple point is above a conductive plate, under a conductive plate, a middle clapboard and set the shrapnel, middle link ends up and down, together is called a membrane switch
A lot of people will say so simple? Of course not.
Zha in that clip figure: membrane switch points total of seven layers
The first layer: panel layer
Panel generally in less than 0.25 MM layer of PET, PC, such as colorless transparent sheet exquisite design and text on screen printing, because of the action of the main panel layer is the logo and key role, so the selection of material must have high transparency, high ink adhesion, high elasticity, high toughness, etc.
Rubber is the role of the main panel layer is closely linked with the circuit layer, to achieve the effect of sealing and connecting, the layer thickness of the general requirements between 0.05-0.15 MM, with high viscosity and the aging; In production, generally choose special membrane switch two-side glue, some can waterproof and high temperature membrane switch, so the surface glue also must according to the need to use different materials.
The third layer: the fixed layer
It is in the second layer surface glue layer between the line and effect of sealing and the connection between, generally used PET double-sided adhesive, its thickness is 0.05-0.2 MM; When choosing this layer material of the product should give full consideration to the overall thickness of insulation, circuit button bag handle and sealing.
The fourth floor: line between layers
Line between layers is also face respectively, are just some place name is different, is the role of the main panel surface glue layer is closely linked with the circuit layer, to achieve the effect of sealing and connecting, thickness of this layer is between 0.05-0.15 MM, with high viscosity and the aging; In production, generally choose special membrane switch two-side glue, some can waterproof and high temperature membrane switch, so the surface glue also must according to the need to use different materials.
Layer 5: shrapnel
Shrapnel classification: bulge, circle, rectangle.
Main materials: stainless steel, nickel plated, gold plated and special shrapnel
Layer 6: circuit layer
This layer adopt good performance of the polyester film (PET) as a carrier of the switching circuit graphics and printing on them in a special process on the conductive silver paste and conductive carbon slurry, has the conductivity, generally within 0.05-0.175 MM, the thickness of the most common is to use 0.125 MM PET
Layer 7: rubber back
Back rubber membrane switch is used to paste is closely related with what kind of material, more commonly used include ordinary double-sided adhesive, 3 m glue, waterproof glue, etc., mainly on the mechanical equipment.