Application Note

Light Emitting Diode

Evaluations of Using Coating
Materials with LEDs

Table of contents
1. Introduction ........................................................................... 2
2. Evaluation Items for Coating Materials ................................ 2
3. Evaluation Test with 5 Coating Materials ............................. 3
4. Evaluation Test with 7 Coating Materials ............................. 8
5. Evaluation Test with 9 Coating Materials ........................... 12
6. Summary.............................................................................. 17
7. Request ................................................................................ 17

The Nichia part numbers NSSW157A, NS6W183A, NS6W183B, NF2W757DR-V1, andNS2W757A-V1 within this document are merely Nichia's part numbers for those Nichia products
and are not related nor bear resemblance to any other company's product that might bear a trademark.

This document contains tentative information, Nichia may change the contents without notice.
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Application Note
1. Introduction
This application note provides evaluation items/methods for coating materials to support customers
when they select the best coating materials for their product with Nichia’s LEDs. For reference,
we’ll show the resin coating materials’ evaluation results in each section.

Light Emitting Diode2. Evaluation Items for Coating Materials
We use coating materials for insulation, dust prevention, water/moisture proofing, water repellent
finish, and to enhance the gas barrier property, etc.
Inappropriate coating materials can affect the optical characteristics of the LEDs due to thepermeability characteristics and deterioration of the materials.
It is important to select coating materials after evaluating the compatibility with assembled products
and the environment. Even when the coating thickness is increased, allowing for insulation, dust
prevention, water/moisture proofing, water repellency, and better weatherability and the gas barrier
property, the optical characteristics of LEDs are impaired.
Table 1 summarizes the evaluation items/methods for coating materials.
Table 1. Evaluation Items/Methods of Coating Materials
Evaluation Item

Permeability
Characteristics

Coating
Performance

Concerns

Evaluation Method- Impact on the optical characteristics
such as decrease in the luminous fluxand color shift- optical characteristics measurementwith various amounts of the material- Impact on the shape of an assembled
product/LED and coating thickness- Optical characteristics
measurement before and after
coating the material- Weatherability test

Degradation- Degradation under the influence ofthe circumstances such as ultraviolet
rays and high temperatures or the lightand the heat generated from the LEDs

Moisture Proof /Water Repellency

Migration between the leads and on
the circuit, and deterioration of eachcomponent material- Moisture permeability test

- Aging test
- Confirm the glass-transition
temperature of the coating material- Water proof test
- Water submersion test
- Salt spray test

Coating Method Coating Property

OthersGas Barrier
Property

Uneven coating and space between the- External observation for spacematerial and the package, which canaffect the optical characteristics and- External observation for the coating
the properties such as moisture proof, thickness
water repellency, and gas barrier
Impact of corrosive gas

Sulfuration test

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Application Note
3. Evaluation Test with 5 Coating Materials
We’ll provide the evaluation methods/results of the 5 items below.
Table 2 shows the description of the coating materials used herein.
Table 2. Coating Material Information
Supplier

Coating Material No.

a

A

b

B

c

C
D
E

Details

Fluorine Resin

Synthetic resin obtained by polymerizing Olefin
containing Fluorine

Olefin Resin

Resin made by finely dispersing EthylenePropylene rubber in Polypropylene

Silicone Resin

Organic silicone compound mainly consisting ofsiloxane bond

3.1 Light Transmission Characteristics
The light transmission characteristics of the coating materials affect the optical characteristics suchas the decrease in the LEDs’ luminous flux and color shift. The degree of the adverse effects varies
depending on the shape/kind of the assembled products/LEDs and the coating thickness. Therefore,
it is necessary to evaluate the impact of the light transmission characteristics on a finished product.
For reference, Table 3 shows the evaluation results of the luminous flux and the chromaticity of
NSSW157A and NS6W183A, according to the 5 coating materials.
Table 3. Evaluation Results of Optical Characteristics of NSSW157A and NS6W183ANSSW157A

Appearance

Size:

Size:

3.0mm×1.4mm×0.52mm

6.0mm×5.0mm×1.35mm

Relative Luminous Flux (%)

110

Luminous
Flux

110

A
B
C

100

D
E

90

A
B
C

100

D

E
90

80

80
Befor coating

Befor coating

After coating

0.10

After coating

0.10

A

A

B
0.05

B
0.05

C

C

D
-0.10

-0.05

D

E

0.00
0.00

-0.05

0.05

0.10

⊿y

Chromaticity

TA=25°C

NS6W183A

Relative Luminous Flux (%)

Part Number⊿yLight Emitting Dioded

Main Ingredient

E

0.00
-0.10

-0.05

0.00

0.05

0.10

-0.05

-0.10

-0.10

⊿x

⊿x

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Application Note
* Brush coating (1 time)* Coating thickness: Silicone Resin (D and E) > Olefin Resin (C) > Fluorine Resin (A and B)
As shown in the data, the characteristics change increased in the following order:
Silicone Resin (D and E) > Olefin Resin (C) > Fluorine Resin (A and B)
This might be related to the coating thickness; the thicker the film is, the larger the change.
There were some differences in the characteristics change between NSSW157A and NS6W183A.
This might be because of the size/shape of the emitting surface.

Light Emitting Diode3.2 Degradation (Weatherability)
Coating materials may be deteriorated by some factors surrounding them such as ultraviolet raysand high temperatures or under the influence of the light and the heat generated from assembled
products.
Therefore, it is important to evaluate coating materials, considering the estimated operating time,
the usage environments, and the construction of the assembled product.
Table 4 shows the accelerated weather resistance test results of LEDs with the 5 coating materials.
Test Method
Light Source:
Illuminance:
Board Surface Temperature:
Operating Time:

Metal halide lamp
500 W/m2 (300 – 400 nm)
63°C
200 hrs.

Test Result
The LED with Material C was significantly deteriorated.
Table 4. Accelerated Weather Resistance Test Result
A

B

C

D

E

No

No

Major
Discoloration

No

Minor
Discoloration

Before Test

After Test

Discoloration* Brush coating (1 time)
As shown in the test results, the LEDs with the individual materials are unsusceptible to degradationin the following order:
Fluorine Resin (A and B) > Silicone Resin (D and E) > Olefin Resin (C)Thus, fluorine resins are more resistant to climate conditions; chemically more stable to the lightsuch as ultraviolet, etc.

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Application Note
3.3 Water Repellency
It is important to evaluate the water repellency of coating materials, considering the usage
environments of the assembled product. For example, we should evaluate the moisture proof
property and the water repellency; “water repellency” refers to the ability to resist wetting and“moisture proof” refers to the ability to create a barrier that blocks moisture from passing throughthe barrier.
Coating materials have different properties. Therefore, the coating material which is fullycompatible with the assembled product should be selected to achieve the desired performance.

Light Emitting Diode3.3.1 Water Repellency Test
Test Method:(1) Coat the board with each coating material with a brush once.
(2) Cure the coating material and place several droplets of water on the board.
(3) Measure the contact angle of the droplets on the board.
The larger the contact angle, the more highly hydrophobic and water repellent the material is.
Table 5. Contact Angle of Water Droplet on the Board
No Coating Material

Coating Material B

77°

Table 6. Water Repellency Test Result
Coating Material

Contact Angle

No Coating

77°

A

117°

B

110°

C

77°

D

104°

E

104°

110°

Test Result
The water repellency of the 5 materials is as follows:
Fluorine Resin (A and B) > Silicone Resin (D and E) > Olefin Resin (C)The more repellent to water, the smaller the surface tension and the more resistant to water.
3.3.2 Moisture Proof Test
Test Method:
In accordance with JIS-Z-0208; “Testing methods for the determination of the water vapor
transmission rate of moisture-proof packaging materials (cup method)” or JIS-Z-7129; “themoisture sensor method, the infrared sensor method, and the gas chromatography method”
The specimen with lower transmission rate has a better moisture proof property.
Table 7. Moisture Proof Test Result
Material

Test Conditions

In accordance with

Film Thickness

Moisture Permeability

Coating Material A

Ta=25°C, RH90%

JIS-Z-0208

30µm

220 g/m2/24h

Coating Material B

Ta=40°C, RH90%

JIS-Z-7129

20µm

200 g/m2/24h

Coating Material C

Ta=40°C, RH90%

JIS-Z-0208

41.7µm13.3 g/m2/24h

Silicone Elastomer *Ta=25°C, RH90%

JIS-Z-7129

25µm

820 g/m2/24h* The moisture permeability of the silicone elastomer is from the database literature.
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Application Note
Test Result
The order of the moisture proof property of the 5 materials is as follows:
Olefin Resin (C) > Fluorine Resin (A and B) > Silicone Resin (D and E)
Olefin resin is superior to any other material. We suspect that the low density/film thickness after
the resin curing process results in low moisture permeability.

Light Emitting Diode

3.4 Coating Property
Depending on the coating property of the coating material, it cannot be uniformly applied on theassembled product, or space is left between the material and the LED/board. In such cases, theassembled product cannot achieve the properties desired for water repellency and gas barrier,affecting the optical characteristics.
Please be advised that the coating property of a coating material depends on some factors such as
the coating object/method. As examples, we’ll show the evaluation results of these properties inTables 8 and 9, using the Coating Material B.
Table 8. External Observation for the Emitting Surface
Coating Material A

Coating Material B

More uniformly coated* Brush coating (1 time)
Table 9. External Observation for the Side Surface
From an Angle

Close upSpace between the
LED and the board

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Application Note
3.5 Gas Barrier Property
Nichia uses silver plating for the lead frames of some of our LEDs. The property of the silver plating
is changed, resulting in degradation of the optical characteristics, when exposed to corrosive gas
containing sulfur and halogen substances.
We conducted a sulfuration test for LEDs coated with each material to evaluate the gas barrier
property.
Please refer to Table 10 and Figure 1 for the sulfuration test results.
Hydrogen Sulfide (H2S)
15 [ppm]
TA=40°C, RH90%
96 hrs. & 192 hrs.

Table 10. NS6W183B Sulfuration Test Result(External Observation)
Coating
Material

120

Appearance
Before Test

After Test

None
DiscoloredB
Minor Discoloration

100

Flux (%)
Luminous
Relative(%)
Optical Power
Relative

Light Emitting Diode

Test Conditions
Corrosive Gas:
Gas Density:
Temperature & Humidity:
Storage Period:

80

60

40

A
B
C
D
D
E
Non-Coated
なし

A
B

20

0

D

0h
0H

Discolored* Brush coating (1 time)

96h
96H
StorageTime (H)
Storage Time(h)

192h
192H

Figure 1. Sulfuration Test Result(Optical Characteristics Change)* We didn’t use Material C during the sulfuration test; however, we confirmed during another test
that the gas barrier property of the LEDs with Material C was similar as that of the LEDs without
any coating material.
Test Result
The gas barrier property decreases in the following order:
Fluorine Resin (A and B) > Silicone Resin (D and E)
Silicone resin is less dense and it has larger spaces throughout its molecular structure, resulting
in the worse gas barrier property.

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Application Note
4. Evaluation Test with 7 Coating Materials(Added in Mar.’14)

There is a large variety of coating materials to apply to the board with electrical components
mounted on.
As stated in Section 2, the permeability characteristics and deterioration of the coating materials
can affect the LEDs’ optical characteristics.
Nichia evaluated the coating materials to select the compatible one with the boards. For example,
here are the verification results of the following aspects, demonstrating the outdoor application:- Deterioration- Water repellency

Light Emitting DiodeWe used NS6W183B for the verification tests. Please refer to Table 11 for the appearance of
NS6W183B and Table 12 for the main ingredients of each coating material .
Table 11. NS6W183B Mounted on Boards
Board

FR-4

AlluminumAppearance

Table 12. Description of Coating Materials
Supplier

Coating Material

a

A（*1）

b

B（*1）
D（*1）

d

E（*1）

Main Ingredient

Details

Fluorine

Thermoplastic resin containing fluorine

Silicone

Organic silicone compound mainly consisting ofsiloxane bondeFAcrylicf

G

Vinyl Butyralg

H

Glass Coating

Amorphous resin obtained by polymerizing acrylic
ester
Amorphous resin obtained by polymerizing polyvinyl
butyral and butylaldehyde
Inorganic coating material containing glass fiber*1 Coating Materials A, B, D, and E are the same ones as in Table 2.
*2 Brush coating (1 time), 1 spray for Material G
4.1 Degradation
We performed the aging test and the weatherability test for the LEDs using each coating material.
4.1.1 Aging Test
We sprayed the LEDs (NS6W183B) mounted on the aluminum board with each coating material
and operated them at 25°C for 100 hours. We evaluated how the LEDs would be deteriorated under
the influence of the light and the heat for a short time.
Figures 2 and 3 show how much the optical characteristics were changed during the aging test.
Table 13 shows the external observation results of the LEDs coated with Materials B, F, G, and H.
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Application Note
Test Condition
Board:
Aluminum (t=1.6mm)
Ambient Temperature: TA=25°C
Duration:
100 hours
Input Current:
350 mA
110

0.050

0.025
90
80
⊿y

Relative Luminous Flux (%)

Light Emitting Diode

100

A
B
D
E
F
G
H
Non-coated

70
60
50

-0.050-0.025

0.000
0.000

-0.0250-0.050

100

0.025
0.050
A
B
D
E
F
G
H
Non-coated⊿x

Test time(h)Figure 2. Aging Test Result(Relative Luminous Flux)

Figure 3. Aging Test Result (Chromaticity)

Table 13. External Observation Result
Fluorine Resin B

Acrylic Resin F

Vinylbutyral Resin G

Glass Coating H

Before Test
CrackedDiscolored
After Test
Aggregated

The luminous flux of the LED coated with Material G (Vinyl Butyral Resin) was reduced due tothe discoloration. We suspect that the material was deteriorated and discolored under the influenceof the light and the heat generated from the LED die. The LED coated with Material H was cracked
and the coating material was aggregated on the emitting surface. This must have been caused by
the same symptom as seen in Material G.
4.1.2 Weatherability Test
We sprayed the LEDs (NS6W183B) mounted on the aluminum board with each coating material
and operated them at the following conditions. Please refer to Section 3.2 for Materials A, B, D,
and E.

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Application Note
Test Conditions
Light Source:
Illuminance:
Board Surface Temperature:
Duration:

Metal halide lamp
500 W/m2 (300 to 400 nm)
63°C/50%RH
200 hrs.

Table 14. Weatherability Test Result
Acrylic Resin F

Vinylbutyral Resin G

Glass Coating H

Before Test

Light Emitting Diode

Discolored

Discolored

After Test
CrackedDiscoloration

Discolored

DiscoloredNo

All the coating materials were significantly deteriorated probably due to the disconnection of themolecular bonds under the influence of the ultraviolet rays
4.2 Water Repellency Test (Water Immersion Test and Salt Spray Test)
We sprayed the LEDs (NS6W183B) mounted on the FR-4 with each coating material and operated
them during the following tests:- Water Immersion Test
- Salt Spray Test
Please refer to Figures 4 and 5 for the test methods and Tables 15 and 16 for the external observation
results before/after the tests. We skipped the tests for Materials A and E.

Fig.4. Water Immersion Test

Fig.5. Salt Spray Test

Test Conditions
Board:
FR-4 (t=1.6mm)
perature:
TA=25°C
Duration:
8 hrs.
Input Current:
100 mA
Water Immersion Test: The LED mounted on the FR-4 is immersed in water and operated.
Salt Spray Test:
Salt water (3% density) is sprayed on the LED mounted on the FR-4
every 30 minutes.
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Application Note
Table 15. Water Immersion Test Result
Coating Material

Before Test

After Test

B
(Fluorine Resin)Lighting Inspection
No Abnormality

CorrodedD(Silicone Resin)

No Abnormality

F(Acrylic Resin)

No Abnormality

Light Emitting Diode

CorrodedG(Vinylbutyral Resin)

Current Leakage

H(Glass Coating)

No Abnormality
Corroded
Current Leakage

None

Table 16. Salt Spray Test Results
Coating Material

Before Test

After Test

Lighting Inspection

B(Fluorine Resin)

No Abnormality

D(Silicone Resin)

No Abnormality
CorrodedF(Acrylic Resin)

No Abnormality
CorrodedG(Vinylbutyral Resin)

No Abnormality
CrackedH(Glass Coating)

No Abnormality
Corroded

None

Current Leakage

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Application Note
Table 17. Water Immersion / Salt Spray Test Results
Coating Material

Main Ingredient

Water Immersion Test

Salt Spray Test

B

Fluorine Resin

○

○

D

Silicone Resin

△

○

F

Acrylic Resin

○

△

G

Vinylbutyral Resin

×

△

H

Glass Coating○×○: No significant corrosion△: Minor Corrosion, compared with the LED without any coating
×: Little difference, compared with the LED without any coating

Light Emitting Diode5. Evaluation Test with 9 Coating Materials(Added in Nov.’15)

Nichia evaluated 9 coating materials: refer to Table 18 for the description of the 9 materials.
Table 18. Description of Coating Materials
Supplier

Coating Material

b

I
J

h

K

Main Ingredient

Details

Fluorine Resin

Synthetic resin obtained by polymerizing Olefin
containing Fluorine

Silicone Resin

Organic silicone compound mainly consisting ofsiloxane bond

L
d

E（*）

i

M

c

N

Polyurethane ResinC（*）

Olefin Resin

Synthetic resin obtained from polymerized olefin

O

Acrylic Resin

Amorphous resin obtained by polymerizing
acrylic ester

Resin containing urethane bond

* C, E: The same materials as described in Table 2 in Section 3
5.1 Applying Method of Coating Materials
Nichia used an automatic dip coating method for Section 5 to evaluate these materials. It’s a highly
reproducible method; the LED-mounted board was dipped into each coating material, and the layer
thickness was adjusted by changing the removing speed. Refer to Table 19 for the sample LED and
Table 20 for the conditions for each material.
Table 19. External Appearance
Part Number

NF2W757DR-V1

Appearance
Size:3.0mm×3.0mm×0.52mm

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Application Note
Table 20. Conditions for each material
Material.

Main Ingredient

I
J

Fluorine Resin

K
L
E

Silicone Resin

Pulling Speed(mm/sec)

Layer Thickness(*) (μm)

Middle

50

10

Low

10

1～2

Low

10

＜1

Low

10

＜1

High

300

160

High

300

160

N

Polyurethane Resin

Middle50

30

C

Olefin Resin

Middle50

20

O

Acrylic Resin

Middle50

30* The above layer thickness is the average of the thickness values at some given points on the layerof each material.
5.2 Light Transmission Characteristics
Each coating material was applied to the LED-mounted (NF2W757DR-V1) aluminum board as
described in Table 20. Refer to Figure 6 for the luminous flux change and Figure 7 for thechromaticity change.
I
J
K
L
E
M
N
C
O

100

90

80

0.05

⊿y

110

Relative Luminous Flux (%)

Light Emitting Diode

M

Viscosity

0.00
-0.05

0.00

-0.05

I
J
K
L
E
M
0.05 NCO

Befor coating After coating⊿x

Figure 6. Optical Characteristics(Relative Luminous Flux)

Figure 7. Optical Characteristics(Chromaticity)

There was little difference in the luminous flux after the sample was coated with each material; on
the other hand, we found a significant color shift in the LED coated with E and M. This is because
their coating layers were much thicker than the others’.

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Application Note
5.3 Degradation
We performed the weatherability test and the aging test for the LEDs using each coating material.
5.3.1 Weatherability Test

Test Conditions
Light Source:
Illuminance:
Board Surface Temperature:
Duration:

Metal halide lamp
500 W/m2 (300 to 400 nm)
63°C/50%RH
500, 1.000 hrs. (*Longer than 3.2 and 4.1.2)

Table 21. Weatherability Test Result
Material
Main
Ingredient

I

J

K

L

E

Fluorine

M
Silicone

N
Polyure
thane

C

D

OlefinAcrylic

Before Test
After Test;
500hrs later
Discolored Discolored

After Test;
1.000hrs later
Discoloration

No

No

No

No

No

No

Discolored DiscoloredNo
Aggregation

120
Relative Luminous Flux (%)

Light Emitting DiodeWe sprayed the LEDs (NF2W757DR-V1) mounted on the aluminum board with each coating
material and operated them at the following conditions, assuming that they were operated outdoors.
Refer to Table 21 for the external observation results and Figure 8 for the relative luminous fluxchange.

I

J

100

K

80

L
E

60

M
N

40

C

20

O

0

Non-coated0500
Test time(h)1000

Figure 8. Relative Optical PowerThe LEDs coated with polyurethane (N) and olefin (C) discolored and their luminous flux decreased
500 hours later.
The acrylic coating material (O) aggregated in the points described in Table 21, and the luminous
flux of the LED coated with O decreased 1.000 hours later.
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Application Note
5.3.2 Aging Test

Relative Luminous Flux (%)

Light Emitting Diode

120

I

100

J

80

K
L

60

E

40

M
Non-coated

20
0
0

500
Test time(h)Relative Luminous Flux (%)

We sprayed the LEDs (NF2W757DR-V1) mounted on the FR-4 board with each coating material
and operated them at 25°C for 1.000 hours. We evaluated how the LEDs would be deteriorated
under the influence of the light and the heat for a short time.
Figures 9 and 10 show how much luminous flux was reduced during the aging test. We skipped thetest for the coating materials N, C, and O which had been significantly deteriorated during theweatherability test in 5.3.1.
Test Conditions
Ambient Temperature: TA=25°C
Duration:
1.000 hrs. (*Longer than 4.1.1)
Input Current:
150mA (Rated Current), 200mA (Maximum Rated Current)
120

I

100

J
K

80

L

60

E

40

M
Non-coated

20
0
0

1000

Figure 9. Relative Optical Power (150mA)

500
Test time(h)1000

Figure 10. Relative Optical Power (200mA)

There was little difference in the relative optical power among the LEDs coated with the fluorine(I, J, K, L) / silicone (E, M) materials and the non-coated LED at either of the input current values(150 and 200mA). None of the LEDs coated with the materials was deteriorated during the aging
test.
5.4 Gas Barrier Property
We mounted a different type of LEDs (NF2W757A-V1*) on an aluminum board and coated themwith each material to conduct a sulfuration test. (* NF2W757A-V1 (Table 22) is more susceptible
to sulfur than NF2W757DR-V1.)
Please refer to Table 23 for the external observation results and Figures 11 and 12 for the opticalcharacteristics measurement results. We skipped the test for the coating materials N, C, and O.
Test Conditions
Corrosive Gas:
Temperature & Humidity:
Storage Period:

Hydrogen Sulfide (H2S): 2ppm + Nitrogen Oxide (NOX): 4ppm
TA=40°C, RH75%
42 hrs. & 84 hrs.

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Application Note
Table 22. Appearance of NS2W757A-V1
Part Number

NS2W757A-V1

Appearance
Size:3.0mm×3.0mm×0.52mm

Table 23. External Observation Result
Material

I

J

K

E

Fluorine

M

Non-Coated

Silicone-

Before Test

After Test
42 hours later
After Test
84 hours later
Discoloration

No

Minor
Discoloration

Major Discoloration

120

I

100

J

J

80

K

K

60

L

40
20

I

0.00

-0.05

0.00

0.05

L

E

E

M

M

0
0

0.05

⊿y

Relative Luminous Flux (%)

Light Emitting Diode

Resin

L

20 40 60 80 100
Test time(h)Figure 11. Optical Characteristics
Measurement Result(Relative Optical Power)

-0.05

⊿x

Figure 12. Optical Characteristics
Measurement Result(Chromaticity)

As described in 3.5, the fluorine resin was superior to the silicone resin in the gas barrier property.
As shown in Table 23, Figures 11 and 12, the fluorine coating materials I and J were less susceptible
to sulfur. The other fluorine coating materials K and L were found to be more susceptible to sulfur
than the silicone ones; this is because of their thinner layers, resulting in the worse gas barrier
property.
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Application Note
6. Summary
Judging from the evaluation results so far, the fluorine coating materials have the least impact on
the LED-mounted board and achieve sufficient coating performance. The silicone resin doesn’t
have significant adverse effects on the coating performances, although its gas barrier property is
inferior to the fluorine resin. The silicone resin features its easy coating and its inexpensive price;
it is effective depending on the purposes. Table 24 summarizes the evaluation results of each coating
material.
Table 24. Summary of Evaluation Results of Coating Materials
CoatingLight Emitting Diode

Coating Performance

Supplier

a
b

h

c

d

Coating Material

Light(Main Ingredient)Transmission

Degradation

MethodWater Repellency

OthersCoating

Gas Barrier

Property

property

Water
Moisture
Water
Salt Spray External Sulfuration
Repellency
Proof
Immersion
Test
Observation
Test

Weatherability

Aging

3.1
5.2

3.2
4.1.2
5.3.1

4.1.1
5.3.2

3.3.1

3.3.2

A

○

○

○

○

○

B

○

○

○

○

○

○

○

○

○

J

○

○

○

△

K

○

○

○

×

L

○

○

○

×

I

FluorineC

Olefin○×N

Polyurethane

○

×

O

Acrylic

○

×

△

○

△
△

D
E

Silicone

×

○

○

○

△

○

○

○

△

○

○

4.2

○

△

○

○

3.4

3.5
5.4

○

○

○

○

×
×

i

M

e

F

Acrylic

×

○

○

△

f

G

Vinylbutyral

×

×

×

△

g

H

Glass Coating

×

×

○

×

×

7. Request
Coating materials can help to achieve insulation and to improve the properties for moisture proof,
water repellency, and gas barrier; however, the incompatibility between a coating material and an
LED-assembled product impairs the performance, or even worse, it shortens the operating life.
Please evaluate coating materials according to the usage purpose and environment, considering theimpact on/from the LED-assembled product.
Please use the evaluation results of some of these coating materials only as reference.

This document contains tentative information, Nichia may change the contents without notice.
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Application Note

Light Emitting Diode

Disclaimer
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to the following: This application note has been prepared solely for reference on the subject matters incorporated
within it and Nichia makes no guarantee that customers will see the same results for their chosen
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This document contains tentative information, Nichia may change the contents without notice.
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