LED package with epoxy resin is the main
component of bis-PhenolA type epoxy resin, the basic body because it
contains a UV-absorbing aromatic benzene ring structure, bis-PhenolA
type epoxy resin, after absorption of ultraviolet light will result in
the formation of carbonyl-based oxidation The hair color Wai yellow
discoloration caused by resin, reaction type as shown. In addition,
when the epoxy resin after overheat easily oxidative discoloration,
resulting in lower transmittance decline. But this is like the white
LED light for Blu-ray luminosity Yu a greater impact than the right
side red LED does not pose a problem. 『Packaging materials containing
benzene ring structure of aging will eventually happen. 』Be held in
Japan," 2006 LED Technology Seminar "three piezoelectric oxygen LED
business unit Minister Koji so that as a high-power LED packaging
materials, resin-like material may not be able to avoid the problem of
aging. However, this is only require high power and long life of the
circumstances, if a life of about 2 million hours of product, through
the formation of the interface is not hard resin material, can use the
resin package. So if you want to make a white LED light for general
illumination light sources, which for the LE light-emitting optical
component caused by aging, need to be developed to avoid this problem
of packaging materials. Recent packaging material is gradually aging
from epoxy resin to light and lighter Silicone resin over, but only
contains a benzene ring, it is impossible to avoid the color gradually
partial exchange, the need for further improvements resin packaging
material - Silicone (Silicone) resin encapsulation Materials As the
epoxy resin can not completely remove the UV absorption, for blue,
white and UV LED UV can increase the performance of packaging
materials, the recent development of Silicone resins are considered to
be blue and UV LED package, the best packaging materials, the 405nm
wavelength of light transmittance of about 99%, in white and blue LED
on the near ultraviolet transmittance higher than those of epoxy resin.
As the transmission rate is high and will not absorb ultraviolet light,
so you can Yangchih resin aging. For example, the short wave length 400
~ 450nm light, epoxy resin about 2 ~ 5% absorption, whereas silicone
resin 400 ~ 450nm light absorption of less than 1%, such a gap, making
the anti-short wavelength area, Silicone resin has a relatively good
performance. Silicone resin, hardening the hardness of Yu polycarbonate
PC equivalent to the use of blue LED chips packaged Silicone resin, its
mechanical strength than epoxy resin, the refractive index is 1.4 ~
1.5. Has been developed in 2003, started to sell LED using Silicone
resin, but the relatively large number of LED manufacturers have
already started selling the product was purchased after 2005, because
each LED light output power higher and higher, LED chips issued by the
short-wavelength light epoxy resin due to the faster aging of packaging
materials, resulting in the future market demand for Silicone.
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