If the colour stability of LEDs is of particular importance, the substrate around the illuminants needs a colour-stable coating which improves the radiation characteristics of the LEDs. By using pure white, yellowing resistant lacquers with high covering power, you achieve a high light efficiency whereas a black coated substrate can increase the contrast to the LEDs.
In the field of both solder resists and conformal coatings Lackwerk Peters offers colour-stable lacquers – in the case of the white systems with high remission – for highest optical requirements. From the area of the high-resolution photoimageable solder resists the latest development ELPEMER® SD 2491 SG-TSW-R5 exhibits a high remission factor of 92 % at 460 nm as well as low ΔE values with exceptional yellowing resistance, even at thermal stress. As black extension of this series the colour-stable version SD 2441 SM is available.
Expecially stable under UV radiation are the thermal curing 2-pack solder resists SD 2496 TSW and SD 2446. Consequently they are particularly suited at the exposure to sun light at the subsequent use.
For the protective coating of LED assemblies especially the covering conformal coatings ELPEGUARD® SL 1397, white, and SL 1347, black are suitable. They are applied by selective coating lines, in order to leave out the LEDs. ELPEGUARD® SL 1397 exhibits very high remission values (> 90 % at 460 nm) and at the same time high light and thermal stability. Strong contrast of the LEDs to the non-reflective substrate can be achieved with the black covering, mat ELPEGUARD® conformal coating SL 1347, which is a particular advantage at representing LED applications, such as display boards, traffic lights etc.
Product specification
ELPEMER® SD 2491 SG-TSW-R5, photoimageable solder resist, white ELPEMER® SD 2441 SM, photoimageable solder resist, black SD 2496 TSW, thermal curing solder resist, white SD 2446, thermal curing solder resist, black ELPEGUARD® SL 1397, physically drying conformal coating, white ELPEGUARD® SL 1347, physically drying conformal coating, black
