High performance Ag mirror product L98

SMMT’s high performance Ag mirror product L98 is specially designed to perform stable in CoB-LED high temperature and environmental conditions.

The extreme high reflectance is achieved with the classic substrate/Ag/SiO2/TiO2 structure wherein the substructure SiO2/TiO2 perform as reflectance enhancement and protective layers. Thin adhesive promoting layers need typically to be applied between the metal substrate and the Ag layer and between the Ag layer and the SiO2 layer to overcome a low adhesion of pure Ag to many oxides.


Above 425nm Ag mirror products come with a very stable reflectance over a wide wavelength range. At characteristic wavelengths for CoB-LED applications such as ~450nm for blue LED chip, ~550nm for white LED phosphors and ~625nm for yellow LED phosphors is the reflectance is extreme high.

Reflectance at 450nm remains stable within a margin of +/-0.75%, at 550nm and 625nm the reflectance remains stable within a margin of +/-0.5%, at a 180°C oven test performed at SMMT. Testing time was up to 168h. Requirement is less than a total reflectance drop of ΔY / (D65 2°) <1.0%.