As we all know, the switch plays a role in transmitting instructional information in the electronic machine product. There are many types of switches, and their development is constantly updated with the advancement of electronic machine products. In the 1950s, the toggle switch of the struggling component was used to toggle the switch, and the changeover switch dominated; in the 1960s, a combination switch represented by a key switch was introduced to accomplish a simple function conversion; as the application field expanded and The function of the whole machine increased. In the 1970s, there was a switch of conductive rubber. The switch was a new type of electronic device that was developed in the late 1970s and early 1980s. It was a miniaturization and digitization of products conforming to the electronics industry. Intelligent, multi-functional development needs products.

　　The membrane switch is a switch made by printing a contact circuit with a conductive paste on a flexible polycarbonate or a polyester film, and is a type of contact switch. Membrane switch is a flat type, multi-layer combination, and a sealed structure. It is an assembly of an electronic whole machine operating system that incorporates key switches, panel function marks, readings display transparent windows, indicator window holes and circuits. It has the following features:

(1) Durability
The life of a membrane switch can generally reach more than one million times. The reason why such a switch has such a long life is that the switch action is only achieved by the elastic membrane in the vertical direction. Although the elastic film has been peristalized by millions of times, the creep range is only 0.1 to 0.3 mm (both switching strokes), and the material selection is far from the yield limit of the film. Can withstand more than one million life without deformation. On the other hand, the contact of the switch is vertical and the amount of wear is very small; the screen-printed contacts can form a sufficient thickness, and a layer of conductive carbon is added on the silver paste contacts to achieve high Wear-resistant, self-lubricating purpose, so the life of the membrane switch is more than a dozen times more than the mechanical contact switch.

(2) Good sealing performance
Because the membrane switch is an overall hermetic structure, the contacts of the switch are not eroded by harmful gases and are not easily oxidized. The membrane is waterproof and dustproof, and thus is more suitable for various harsh environments.

(3) Small size, light weight and reliable structure
Membrane switches can be arranged and assembled into a membrane keyboard in a design, and the density of the membrane switch is large. Moreover, it is a sealed sheet structure in which a plurality of layers of thin films are combined. The connecting lines and lead wires between all the switches are screen printed at one time. Completed, the total thickness is 1~3mm, so the volume is reduced, the quality is reduced, and the reliability is improved.

(4) Rich colors and beautiful appearance
Membrane switch can be personalized according to the user's design concept in the design of the color pattern, the decorative effect reflects the material beauty, decorative beauty, craftsmanship and comprehensive characteristics.

(5) Reduce the cost of supporting electromechanical products
Traditional mechanical switches require welding during installation, even with fixed brackets. The membrane switch is installed as a paste type, as long as the adhesive paper is peeled off, it can be firmly stuck on the surface of the whole machine, and the lead outlet of the membrane switch is inserted into the socket of the rear circuit of the complete machine, and the circuit can be connected in an instant. Provincial workers, provincial materials, reduce the overall cost of the machine.

Practical application of membrane switch
Membrane switches are non-trivial switches. Suitable for switching power less than 1W ah, the maximum operating voltage: 42V (DC) or 25V (DC), the maximum operating current is less than 100 mA working. Can be widely used in all microcomputers, CNC. Intelligent instruments, meters, and many areas of electronic circuits that combine discrimination and memory functions.