Membrane switch, also known as light touch keyboard, is a multiplane combination and sealed set of graphics, buttons and symbols displayed by using soft materials such as PC, PET,FPC and double-sided tape, and using screen printing technology, conductive and electronic switch functions in one plastic electronic product.
1. Sand surface polyester (PET) -30～120℃ .1～0.2 glossy film
Good chemical resistance, insoluble in general organic solvents, and not alkali resistant.
It has excellent mechanical properties, electrical properties, rigidity, hardness, and the greatest strength among thermoplastics, low water absorption, excellent wear resistance and friction resistance, and high dimensional stability.
The tensile strength is comparable to that of aluminum film, much higher than that of PC and PVC.
Inexpensive Because the surface is difficult to process into a matte type, textured PET is more expensive and is the most ideal substrate for making membrane switch circuits.
Among them, textured PET is suitable for products with higher surface requirements or liquid crystal display windows.
2.The thickness of the material
Plastic substrate thickness of 0.25mm and below is called film, which is mainly used as the panel layer of membrane switch.
Various indication patterns and texts are printed on the back side to indicate the operation area of the corresponding switch key position.
The thickness selection should be based on the panel Depending on the size of the button, the material is thick, the touch force is increased, and the response is slow; the material is too thin, the hand feels bad when touched, the rebound is not obvious, the thickness is more than 0.25mm, it is called the plate, it is not suitable for three-dimensional key forming, and can be used as The indicative sign panel without key operation can also be used as the lining board of the membrane switch to improve its rigidity.
3. Circuit layer printing materials
The base material for the circuit should be polyester (polyethylene phthalate) film (PET).
It has good insulation and heat resistance, high mechanical strength, transparency and air tightness, especially bending resistance and high elasticity.
It is an ideal material for making membrane switch circuits.