Post on 29-May-2022
Dow.com
Protective Materials Over LEDs –and Associated Optical Effects
Presented by Jake Steinbrecher • Dow Performance SiliconesStrategies In Light, February 13, 2018
Why Can’t We Just Have “White” Light?
2
Paul AndreauPhoto: ® 2008 Artists Rights Society (ARS), New York / ADAGP, Paris
Benefits of Protective Materials - Conformal Coatings
3
4000K test part with DOWSIL™ 1-2577 Low VOC Conformal Coating
Silicone, Acrylic, Urethane
• Protect against environmental ingress, corrosion, etc.
• Thin layer provides little impact on light quality
Protective Materials – Conformal Coatings
4
4000K Test Part, No Material4000K Test Part with DOWSIL™ 1-2577
Low VOC Conformal Coating
Benefits of Protective Materials - Encapsulants
5
4000K test part with DOWSIL™ EI-1184 Encapsulant
• Protect against environmental ingress, corrosion, etc.
• Impact protection
Silicone, Acrylic, Urethane
Protective Materials - Encapsulants
6
4000K Test Part, No Material4000K Test Part with DOWSIL™
EI-1184 Optical Encapsulant
Benefits of Protective Materials - Molded Lens
7
4000K test part with DOWSIL™ MS-1002 Moldable Silicone
Silicone, PC, PMMA
• Protect against environmental ingress (when sealed)
• Impact protection• Little impact on light quality
Protective Materials - Molded Lens
8
4000K Test Part, No Material4000K Test Part with DOWSIL™
MS-1002 Moldable Silicone
Lens design courtesy of:
Disadvantages of Protective Materials
9
Effects on Light Quality• Color shift• Lumen depreciation
Cost
Test parts, using DOWSIL™ 1-2577 Low VOC Conformal Coating, DOWSIL™ EI-1184 Encapsulant , and DOWSIL™ MS-1002 Moldable Silicone
4000K3000K
5000K HOK International, Photo: Farid Khayrulin
Protective Materials – Effects on Light QualityTypical LED Package
Blue rays from the LED chip will:1) Go to air through silicone encapsulant material (RI 1.53)2) Hit phosphor particles and emit rays with other spectrum (e.g. yellow, red)
10
Phosphor Silicone Encapsulant(RI 1.53)
Reflector CupLED Chip
1
2
Air (RI 1.00)
Protective Materials – Effects on Light QualityTypical LED Package
Blue rays from the LED chip may:3. Reflect at the interface of silicone encapsulant and air, due to Total Internal
Reflection (TIR). In this example, the critical angle θ1 is equal to sin-1 (1/1.53), which is 40.8 degrees. Any rays that hit this interface with an angle bigger than 40.8 degrees will be reflected, and may interact further with phosphor particles.
11
Phosphor Silicone Encapsulant(RI 1.53)
Reflector CupLED Chip
1
23
Air (RI 1.00)
Protective Materials – Effects on Light QualityTypical LED Package + Protective Material(s)
Blue rays from the LED chip may:4. Have a better chance of escaping at the interface of silicone encapsulant and
protective material due to TIR. In this example, the critical angle θ1 is equal to sin-1
(1.41/1.53), which is 67 degrees. This leads to more blue light rays escaping and less interaction with phosphor, leading to increased color temperature.
12
PhosphorSilicone Encapsulant(RI 1.53)
Reflector CupLED Chip
1
24
Air (RI 1.00) Silicone Protective Material (RI ~1.41)
Protective Materials –DOWSIL™ 1-2577 Low VOC Conformal Coating
133000K, 4000K , and 5000K test parts with
DOWSIL™ 1-2577 Low VOC Conformal Coating
2000
2500
3000
3500
4000
4500
5000
5500
3000K 4000K 5000K
Cor
rela
ted
Col
or T
empe
ratu
re (º
K)
LED Linear Type
DOWSIL™ 1-2577 Low VOC Conformal Coating, Effects on Correlated Color Temperature
BareCoated
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
3000K 4000K 5000K
Lum
inou
s Fl
ux (l
umen
s)
LED Linear Type
DOWSIL™ 1-2577 Low VOC Conformal Coating, Effects on Luminous Flux
BareCoated
Protective Materials –DOWSIL™ EI-1184 Optical Encapsulant
143000K, 4000K, and 5000K test parts with DOWSIL™ EI-1184 Optical Encapsulant
0.0020.0040.0060.0080.00
100.00120.00140.00
3000K 4000K 5000K
Lum
inou
s Fl
ux (l
umen
s)
LED Linear Type
DOWSIL™ EI-1184 EncapsulantEffects on Luminous Flux
Bare
Encapsulant
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
3000K 4000K 5000K
Lum
inou
s Fl
ux (l
umen
s)
LED Linear Type
DOWSIL™ EI-1184 EncapsulantEffects on Luminous Flux
Bare
Encapsulant
2000
3000
4000
5000
6000
7000
8000
9000
3000K 4000K 5000KCor
rela
ted
Col
or T
empe
ratu
re (º
K)
LED Linear Type
DOWSIL™ EI-1184 EncapsulantEffects on Correlated Color Temperature
Bare
Encapsulant
Protective Materials –DOWSIL™ MS-1002 Moldable Silicone
153000K, 4000K, and 5000K test parts with DOWSIL™ MS-1002 Moldable Silicone
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
3000K 4000K 5000K
Lum
inou
s Fl
ux (l
umen
s)
LED Linear Type
DOWSIL™ MS-1002 Moldable SiliconeEffects on Luminous Flux
Bare
Lens
2000250030003500400045005000550060006500
3000K 4000K 5000KCor
rela
ted
Col
or T
empe
ratu
re (º
K)
LED Linear Type
DOWSIL™ MS-1002 Moldable SiliconeEffects on Correlated Color Temperature
Bare
Lens
DOWSIL™ Protective Materials – Effects at 3000K
16
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
Bare DOWSIL™ 1-2577 Low VOC Conformal Coating
DOWSIL™ EI-1184 Encapsulant
DOWSIL™ MS-1002 Moldable Silicone
Lum
inou
s Fl
ux (l
umen
s)
Luminous Flux
DOWSIL™ Protective Materials – Effects at 3000K
17
0.00
500.00
1000.00
1500.00
2000.00
2500.00
3000.00
3500.00
4000.00
4500.00
Bare DOWSIL™ 1-2577 Low VOC Conformal Coating
DOWSIL™ EI-1184 Encapsulant
DOWSIL™ MS-1002 Moldable Silicone
Cor
rela
ted
Col
or T
empe
ratu
re (º
K)
Correlated Color Temperature
DOWSIL™ Protective Materials – Effects at 3000K
18
0.00E+00
5.00E-04
1.00E-03
1.50E-03
2.00E-03
2.50E-03
3.00E-03
350 450 550 650 750 850
Spec
tral
Flux
Wavelength (nm)
Spectral Flux
Bare
DOWSIL™ 1-2577 Low VOC Conformal Coating
DOWSIL™ EI-1184 Encapsulant
DOWSIL™ MS-1002 Moldable Silicone
DOWSIL™ Protective Materials – Effects at 4000K
19
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
Bare DOWSIL™ 1-2577 Low VOC Conformal Coating
DOWSIL™ EI-1184 Encapsulant
DOWSIL™ MS-1002 Moldable Silicone
Lum
inou
s Fl
ux (l
umen
s)
Luminous Flux
DOWSIL™ Protective Materials – Effects at 4000K
20
0.00
1000.00
2000.00
3000.00
4000.00
5000.00
6000.00
Bare DOWSIL™ 1-2577 Low VOC Conformal Coating
DOWSIL™ EI-1184 Encapsulant
DOWSIL™ MS-1002 Moldable Silicone
Cor
rela
ted
Col
or T
empe
ratu
re (º
K)
Correlated Color Temperature
DOWSIL™ Protective Materials – Effects at 4000K
21
0.00E+00
5.00E-04
1.00E-03
1.50E-03
2.00E-03
2.50E-03
3.00E-03
350 450 550 650 750 850
Spec
tral
Flux
Wavelength (nm)
Spectral Flux
Bare
DOWSIL™ 1-2577 Low VOC Conformal Coating
DOWSIL™ EI-1184 Encapsulant
DOWSIL™ MS-1002 Moldable Silicone
DOWSIL™ Protective Materials – Effects at 5000K
22
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
Bare DOWSIL™ 1-2577 Low VOC Conformal Coating
DOWSIL™ EI-1184 Encapsulant
DOWSIL™ MS-1002 Moldable Silicone
Lum
inou
s Fl
ux (l
umen
s)
Luminous Flux
DOWSIL™ Protective Materials – Effects at 5000K
23
0.00
1000.00
2000.00
3000.00
4000.00
5000.00
6000.00
7000.00
8000.00
9000.00
Bare DOWSIL™ 1-2577 Low VOC Conformal Coating
DOWSIL™ EI-1184 Encapsulant
DOWSIL™ MS-1002 Moldable Silicone
Cor
rela
ted
Col
or T
empe
ratu
re (º
K)
Correlated Color Temperature
DOWSIL™ Protective Materials – Effects at 5000K
24
0.00E+00
5.00E-04
1.00E-03
1.50E-03
2.00E-03
2.50E-03
3.00E-03
3.50E-03
4.00E-03
4.50E-03
350 450 550 650 750 850
Spec
tral
Flux
Wavelength (nm)
Spectral Flux
Bare
DOWSIL™ 1-2577 Low VOC Conformal CoatingDOWSIL™ EI-1184 Encapsulant
DOWSIL™ MS-1002 Moldable Silicone
DOWSIL™ Protective Materials
DOWSIL™ 1-2577 Low VOC Conformal Coating• Minimally effects Luminous Flux and CCT
― But, provides the least amount of protection above bare components
DOWSIL™ EI-1184 Optical Encapsulant• Provides significant protection above
bare components ― But, reduces Luminous Flux and increases CCT
DOWSIL™ MS-1002 Moldable Silicone• Slightly increases Luminous Flux and CCT
― And, provides significant protection above bare components
25Ingarden & Ewy Architekci; Arata Isozaki & Associates Photo: Wojciech Wandzel
ThankYou
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Form No. 11-3883-01 26686