1. The key switch shrapnel (also known as metal dome, snap dome) is made of ultra-thin (0.05mm-0.1mm thickness) and ultra-thick (generally higher hardness) stainless steel 301 or 304 materials. The key shrapnel is an important part of the switch.
2. The key shrapnel is mainly used in membrane switches, dome contact switches, PCB boards, FPC boards, medical equipment and other products. The working principle of the button shrapnel: The button shrapnel on the membrane button is located on the conductive part of the PCB (mostly located above the gold finger on the circuit board). When pressed, the center point of the shrapnel is concave and contacts the circuit on the PCB. , so as to form a loop, the current passes through, and the whole product can work normally.
3. General conventional button shrapnel, according to their different shapes, are divided into: circular metal shrapnel, cross-shaped metal shrapnel, triangular metal shrapnel, and oval metal shrapnel. Diameter from 3mm to 20mm, strength from 100gf to 600gf.
4. The key switch shrapnel can also be divided into: gold-plated, nickel-plated, silver-plated, bright surface, etc. according to the surface electroplating treatment. There are two kinds of single-sided electroplating and double-sided electroplating.
The function of the key switch shrapnel:
Shrapnel is an important part of the key switch. When used to reach the operating force, the pressure switch function is closed and connected to the operating direction of the switch. When the pressure is released, the switch opens and the internal structure is changed by the strength of the metal dome. Perform circuit continuity.
At present, according to the quality, the shrapnel of the key switch can be divided into domestic shrapnel and imported shrapnel. The quality of imported shrapnel is relatively good, but the price is also higher. According to different materials, it can be divided into stainless steel shrapnel and ordinary shrapnel, and can be divided into square shrapnel and round shrapnel according to the shape. However, since the quality of the shrapnel directly affects the normal use of the key switch, the shrapnel must be tested to determine the aging test, salt spray test, etc. to ensure that it is not easily oxidized or aged.
The choice of square and round shrapnel should be considered according to the needs of the key switch. In the case of the same material, the life of the circular shrapnel is generally longer than that of the square shrapnel, but the price of the square shrapnel is relatively cheaper than the round shrapnel, the processing is easy, and the material is saved. Therefore, if you want to have a price advantage, you can consider square shrapnel, and if you have high requirements for quality of life, you are more likely to choose round shrapnel.
The key switch shrapnel is mainly used in membrane switches, dome contact switches, PCB boards, FPC boards, medical equipment and other products. The working principle of the button shrapnel: The button shrapnel on the membrane button is located on the conductive part of the PCB (mostly located above the gold finger on the circuit board). When pressed, the center point of the shrapnel is concave and contacts the circuit on the PCB. , so as to form a loop, the current passes through, and the whole product can work normally.
