Guozi tablets generally refer to button shrapnel
The button shrapnel (also commonly known as the metal dome, snap dome) is made of ultra-thin (0.05mm-0.1mm thickness) and ultra-thick (generally harder) stainless steel 301 or 304 materials. The button shrapnel is an important part of the switch.
Chinese name : Button shrapnel
Also known as : Pot slices
Material : Stainless steel 301 or 304
Diameter : 3mm to 20mm
Button 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 board (mostly located above the golden fingers on the circuit board). When pressed, the center point of the shrapnel is concave and touches the circuit on the PCB. , Thus forming a loop, the current passes through, and the whole product can work normally.
Generally, conventional button shrapnels can be divided into round metal shrapnel, cross-shaped metal shrapnel, triangular metal shrapnel, and oval metal shrapnel according to their different shapes. The diameter ranges from 3mm to 20mm, and the strength ranges from 100g to 600gf. According to the surface electroplating treatment, it can be divided into: gold plating, nickel plating, silver plating, bright surface and so on. There are two types of single-sided electroplating and double-sided electroplating.
|Membrane switch parametersameters|
|Electronic properties||Working voltage:≤50V（DC）||Working current:≤100mA|
|Contact resistance:0.5~10Ω||Insulation resistance:≥100MΩ（100V/DC）|
|Substrate pressure resistance:2kV（DC）||Rebound time:≤6ms|
|Loop resistance: 50 Ω, 150 Ω, 350 Ω, or determined according to the user's needs.||Insulation ink withstand voltage:100V/DC|
|mechanical propertiesti||Reliability service life:>One million times||Closure displacement: 0.1 ~ 0.4mm (tactile type) 0.4 ~ 1.0mm (tactile type)|
|Working force: 15 ~ 750g||Migration of conductive silver paste: at 55 ℃, temperature 90%, after 56 hours, it is 10m Ω / 50VDC between two wires|
|There is no oxidation and impurity on the silver paste line||The line width of silver paste is greater than or equal to 0.3mm, the minimum interval is 0.3mm, the rough edge of line is less than 1 / 3, and the line gap is less than 1 / 4|
|Pin spacing standard 2.54 2.50 1.27 1.25mm||The bending resistance of outgoing line is 80 times with d = 10 mm steel rod.|
|Environmental parametersme||Operating temperature:－20℃～+70℃||Storage temperature: - 40 ℃ ~ + 85 ℃, 95% ± 5%|
|Printing index index||The printing size deviation is ± 0.10 mm, the outline side line is not clear, and the weaving error is ± 0.1 mm||The chromatic deviation is ± 0.11mm/100mm, and the silver paste line is completely covered by the insulating ink|
|No ink scattered, no incomplete handwriting||The color difference is not more than two levels|
|There shall be no crease or paint peeling||The transparent window shall be transparent and clean, with uniform color, without scratches, pinholes and impurities.|