First, the origin and classification of Membrane Switch:
1.Origin:
The graphics are produced on the film substrate, the entire component is a Switch function, which is called the membrane switch, English name Membrane Switches.
By several layers of different materials, the film is bonded into a finished product, the thickness is about 1,2 ~ 2,5 MM, the appearance of such as a plate, both the panel and switch the dual role, it is also known as the panel switch, English name PANEL SWITCHES, or called sheet switch.
Because this kind of switch action stroke is short, only about 0.25~0.5MM, the switch pressing pressure is 0.5~1N, more sensitive, the touch of the hand completes the switch action, it is also called touch switch, or touch the Keyboard.
2.Classification:
Divided into flexible board and rigid board according to circuit substrate
According to the panel shape is divided into flat or stereo
According to operating experience, it is divided into non-inductive and inductive
Divided into transparent and finger touch Screen type according to special purpose
According to the combination of panels and discrete parts and keycaps and keyboards
Here, we only discuss the use of flexible sheet membrane switch (R) sheets and printed materials.
Second, the membrane switch structure and the current R structure
1. Structure: Flexible board (R) and rigid board (Y)
R structure: membrane switch panel layer, isolation layer, circuit layer all from a variety of different properties of the soft film such as: PET, PC, PVC composition.
Y-structure: The pattern and circuit of the switch are made on both sides of the double-sided copper foil on the common double-sided printed circuit board. Through the metallized hole, the two sides are communicated with each other, and the components are welded on the back side, and the metal guide is used as a conductive labyrinth. The contacts of the disk, the wipes are wound with flat cable leads.
Panel materials: AUTOTEX products from Coulter UK and Sanha International have different thicknesses and (thickness 0.12~0.25um) panel materials.
Sand surface PET includes F series (fine sand surface), V series (grit surface). It has good polar sheet material that can be made convex and has undergone special chemical treatment on both sides. Sand surface can be printed with transparent window liquid. Glossy surface can be printed with PVC or PC ink.
Hardcoat chemically treated PET: EBG (glossy) series EBA (matt) series
Hard-coated PC sheets come in different sizes: AUTOFLEX PCG (glossy) AUTOFLEX PCA (matt)
Circuit layer sheet: Yes: AUTOTEX products special PET.
The heat-stable and anti-shrinkage treatment and adhesion treatment of smooth PET sheet, AUTOSTATCT3, CT4, CT5, CT7, thickness was 25,100,125 UM.
The heat-stabilized and anti-shrinkage treatment and adhesion treatment of the misted PET sheet is HT5 with a thickness of 125 um.