The key point to determine the quality of metal dome and snap dome is that whether the metal dome is cleaned or not. If the metal dome switch is not cleaned, it will affect the conduction of circuit board, which causes a functional problem, so the process of cleaning is very important. The cleaning of metal dome is done by Ultrasonic, Steps as below:
1)Put unclean snap domes in box
2)Using a special chemical potion with about an hour of cleaning for tactile dome
3)Clean tactile dome by clean water after medicine cleaned
4)Drying metal dome for an hour
If cleaning is not thorough, there may be laminated, rust and stains will be produced. So we need to check the appearance of metal domes carefully, such no scratch or crush on the surface and no deformation, spots, dirty.