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, a toggle switch of a struggling element was used to toggle the switch and the switch was dominant; in the 1960s, a combination switch represented by a key switch was used to complete 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 digitalization of products that conformed 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:
The life of the membrane switch can generally reach more than one million times. The reason for this long life is that the switch action is only achieved by the elastic membrane in the vertical direction. Although the elastic film has been subjected to a million perturbations, the creep range is only 0.1 to 0.3 mm (both switching strokes), and the rationality of material selection is far from the yield limit of the film. Therefore, the film material Can withstand more than one million life without deformation. On the other hand, the contacts of the switch
It is the vertical contact, the amount of wear is very small; and 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 resistance and self-lubricating purposes, so the film The life of the 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 formed by a combination of multi-layer films. The connection lines and lead wires between all 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, process beauty features.
(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 attached to 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.
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.