The Choice Of Tact Switch
The key factor of the light touch switch is the protection of the light touch switch, solderability, conduction reliability, life, touch, production process and installation dimensions.
First for pin base material, touch switch pin base is brass or phosphor copper (low grade for iron), in order to reduce contact resistance, pins are basically silver-plated, for silver in the air in the SO2 gas will oxidize, directly affect the switch solderability and contact resistance, so the high quality of the light touch switch first in the base of the pin silver plating thickness and silver plating process Control in place, the market on the merits of silver plating sequence as follows:
Silver plated Thickness: 0.3um above (after silver), 0.2um (silver), 0.1um (White)
Silver Plating process: Pre-ni-plating of substrates, pre-plating copper, silver plated, and direct silver plating on substrates.
Whether there is a protective agent treatment or whether the switch has dustproof and waterproof function is very critical, or even the best silver plating treatment, the switch will be oxidized.
Secondly, the key influencing factor of conduction reliability is the structure of contact point, because the function of touch switch is contact point and shrapnel, so the contact surface of contact point is bigger, the contact surface is decided by structure, there are three kinds of structure in the market, the good and bad order is as follows:
Large bubble (crater type) "O-Contact", slotted "2-point Contact", flat-type "1-point Contact"