Light emitting diodes (LEDs) incorporating a newly developed passivation LED chip and sealed with an organic ADC monomer have excellent characteristics in weather resistance, heat resistance, and chemical resistance. Various weatherproof tests have proved that the weatherproof LEDs are applicable to outdoor use where conven- tional epoxy LEDs cannot be used.
Shouji Usuda, Shouji Usuda,
"Development of weatherproof LED", Proc. SPIE 1230, International Conference on Optoelectronic Science and Engineering '90, 123005 (1 July 1990); doi: 10.1117/12.2294642; https://doi.org/10.1117/12.2294642