TECHNICAL DOCUMENT NICHIA BP-CS14256
<1>
NICHIA CORPORATION
Ever Researching for a Brighter World
EXCLUSIVE NICHIA MID-POWER LED PACKAGE DESIGN
ADVANCES LUMEN AND COLOR MAINTENANCE
Proprietary thermoset composite outperforms plastic and ceramic packages
A continuous-improvement mindset among
Nichia researchers and scientists and the
company’s drive to optimize LED
performance through materials science
have produced an exclusive light-emitting
diode (LED) package innovation expected to
speed and deepen LED system adoption
across a range of general and specialty
applications. These include directional,
general, linear, B/L, auto and video—
approximately 80 percent of LED solutions
in place today, based on Nichia estimates.
Nichia re-invents LED package design with
proprietary thermoset composite
Nichia’s 757 series mid-power, small-die
LED package with proprietary thermoset
composite material delivers efficacy and
value beyond current high-power LED
capabilities and performance above other
commercially available mid-power LEDs,
which regularly demonstrate rapid lumen
depreciation and big color shifts over short
periods of time.
Primary mid-power vs. high-power design
advantages consist of:
• Economies of scale that improve the
total cost of solutions;
• Manufacturing yields as multiple
small dies drive higher yields and
lower costs;
• Design flexibility enabled by more
reliable color consistency and a
larger variety of electrical
configurations; and
• Cutting-edge performance featuring
a significant, up to 50 percent lower
cost of light.
Thermoset composite packaging holds great
promise as a next-generation solution
because predecessor LEDs broke application
barriers. Mid-power LEDs have been used in
virtually every retrofit and new SSL
application of the last decade (see Figure 1).
Figure 1 — Performance improvements in widely
used mid-power LEDs enable higher quality, longer
lasting lamp and fixture solutions.
Unique design attributes in Nichia’s 757
series LEDs ensure greater reliability while
delivering visual comfort with low
luminance, uniform light distribution and
tighter color control. Its differentiation rests
with the proprietary thermoset composite
packaging materials that Nichia has paired
with high-efficiency LED chips and specially
blended phosphors.
LM-80 and TM-21 reports from Nichia
certify reliability over a 50,000-hour rated
life.
TECHNICAL DOCUMENT NICHIA BP-CS14256
<2>
NICHIA CORPORATION
Ever Researching for a Brighter World
Nichia adheres to the lumen maintenance
and color maintenance standards set forth
by the Illuminating Engineering Society of
North America (IESNA) LM-80 standard (see
Figure 2) for US EPA Energy Star
qualification at 55
o
C and 85
o
C. Nichia goes
one step further by testing its LED up to
105
o
C.
(a)
(b)
Figure 2 — Nichia 757 series LED LM-80 report on
(a) lumen maintenance and (b) color maintenance.
The fundamental difference between
previous LED package designs and Nichia’s
757 series LED design emerges in an
examination of lumen maintenance and
color maintenance data. Nichia 757 series
LEDs are free from plastics containing
benzene ring structures (see Figure 3).
Benzene ring, a common chemistry in many
plastic LED packages, tends to degrade
under photon energy.
When thermoplastic LED package materials
such as Polyphthalamide (PPA) contain a
benzene ring in a molecular structure,
discoloration builds up through oxidation
and photoexcitation.
Figure 3 — Photoexcitation decomposition in a
benzene ring molecular structure.
Moreover, an amide bond contained in PPA
can decompose with exposure to the heat
produced by operating LEDs. This results in
a string of problems starting with a
discolored LED package (yellowing),
followed by a reduction of reflectivity, and
eventually, significant lumen degradation
and color shift (see Figure 4).
Figure 4 — Decomposition in an amide bond
molecular structure.
Nichia’s proprietary package design—a new
alternative to lower cost pure plastic or
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Relative Optical Power (%)
Lifetime (H)
NF2L757AR
LM-80 Test(φv)
Test conditions: Ts =8 5
o
C, I
F
=150mA
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0 5000 10000 15000 20000
⊿u'v'
Lifetime [H]
NF2L757AR
LM-80 Test (⊿u'v')
Test condition
s: Ts =8 5
o
C, I
F
=150mA