The key switch consists of an insert, a base, an elastic sheet, a button and a cover plate. As shown in the figure, a polyimide film is added to the elastic sheet for waterproof touch switch.
Mbth: Touch switch has the advantages of small contact resistance, accurate operating force error and diversified specifications. It is widely used in electronic equipment and white goods, such as audio-visual products, digital products, remote controllers, communication products, household appliances, security products, toys, computer products, fitness equipment, medical equipment, money detectors, laser pen buttons and so on. Because of the environmental conditions (elasticity/environmental temperature and humidity conditions and electrical performance) of key switches, large equipment and high-load keys are directly replaced by conductive rubber or pot switch hardware shrapnel, such as medical equipment and TV remote controllers. About the pin position of five-pin key switch: two pins are a group. When the switch body is pressed correctly, four pins are connected and the fifth pin is grounded. Key switch is the fourth generation switch product developed with the development of electronic technology. The earliest volumes were 12mm* 12mm and 8mm*8mm, and now it is 6 mm * 6 mm. There are three kinds of product structures: vertical, horizontal and horizontal with grounding terminals. Now there are two kinds of combined (3M, 4M, SM, 6M, SM) and potentiometer key switch combinations, which meet the requirements of various domestic electronic products. Installation dimensions are 6.5 mm *4.5 mm, 5.5 mm * 4 mm and 6 mm * 4 mm. There are 4.5mm*4.5mm small key switches and chip key switches abroad, which are suitable for surface assembly. Now there is the fifth generation switch-membrane switch, which has the same function as key switch and is mainly used in electronic instruments and CNC machine tools, but it has high resistance and poor hand feeling. In order to overcome the phenomenon of poor hand feeling, there are also two kinds of key switches that use contact reed instead of silver layer in membrane switches: metal reed is used as the key switch of switch contact piece, which has low contact resistance, good hand feeling and "tick" sound. Switches that use conductive rubber as the contact path are customarily called conductive rubber switches. The switch feels good, but the contact resistance is relatively high, generally at100-300 n. The structure of the key switch is to make the contact reed or conductive rubber block contact with the pad to form a channel by moving the key down. The operating force of the key switch is related to the state of the reed. The initial force is proportional to the compression distance of the reed. When the reed is compressed to 5%-70%, the operating force suddenly decreases, accompanied by "tick" sound. Turtle rubber switch generally has two structures. The operating force curve varies greatly with the geometry of the rubber block. Relative humidity: