Many electronic products are now designed to offer some form of backlit illumination utilising LED’s mounted behind a silicone keypad, this could be a simple indicator to show the device is powered or it could be a complete array of illuminated legends.
The most common method of producing backlit legends on a keypad is to use multiple spray operations followed by a laser etching process. There are two finishing options available that depend on the customer requirement.
The first option is for use where the legends are only clearly visible when the buttons are illuminated by the LED’s, and when LED’s are not powered the legends are not easily seen.
This option would require a suitable silicone that offers good light transmission, we would then spray the keypad in an opaque coloured ink and the legends would be formed by burning the surface of the ink using a laser etching machine to reveal the legends as the base silicone material.
The second option is for where the legends need to be visible at all times but when the LED’s are powered the legends are still illuminated, this means the product can be used in daylight and dark environments.
This option would require a suitable silicone that offers good light transmission; we would then spray the keypad with a lightly coloured (often white) slightly translucent coloured ink. We would then overspray with an opaque coloured ink and the legends would then be formed by burning away the surface of the opaque ink using a laser etching machine to reveal the legends as the lightly coloured translucent ink layer.
This offers clear legends when not backlit but then offers excellent crisp clear legends when the LED’s are powered.
Rubbertech have the facilities to offer this type of keypad in our UK factory and also at our partner in China if required. Our UK spraying facilities and latest etching technology means often our processing costs are similar to the Far East cost but offer much improved delivery times.