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Application Note
This sheet contains tentative information; we may change the contents without notice.
Light Emitting Diode
SE-AP00012C
Dec.2, 2015
Evaluation of Coating Materials
Contents
1 Introduction
2 Evaluation Items for Coating Materials
3 Evaluation Test with 5 Coating Materials
4 Evaluation Test with 7 Coating Materials
5 Evaluation Test with 9 Coating Materials
6 Summary
7 Request
2/17
Application Note
This sheet contains tentative information; we may change the contents without notice.
Light Emitting Diode
SE-AP00012C
Dec.2, 2015
a
A
b
B
c
COlefin Resin
D
E
Synthetic resin obtained by
polymerizing Olefin containing
Fluorine
Resin made by finely dispersing
Ethylene-Propylene rubber in
Polypropylene
Supplier
d
Fluorine Resin
Silicone Resin
Coating Material No. Main Ingredient
Organic silicone compound mainly
consisting of siloxane bond
Details
Concerns Evaluation Method
- Impact on the optical characteristics such
as decrease in the luminous flux and color
shift
- Impact on the shape of an assembled
product/LED and coating thickness
- Optical characteristics measurement before and after
coating the material
- Optical characteristics measurement with various amounts
of the material
Migration between the leads and on the
circuit, and deterioration of each
component material
- Water proof test
- Moisture permeability test
- Water submersion test
'- Salt spray test
Coating
Method
Uneven coating and space between the
material and the package, which can affect
the optical characteristics and the
properties such as moisture proof, water
repellency, and gas barrier
- External observation for space
- External observation for the coating thickness
Others Impact of corrosive gas Sulfuration test
- Degradation under the influence of the
circumstances such as ultraviolet rays and
high temperatures or the light and the heat
generated from the LEDs
Degradation
Coating
Performance
Evaluation Item
- Weatherability test
'- Aging test
'- Confirm the glass-transition temperature of the coating
material
Moisture Proof / Water Repellency
Coating Property
Gas Barrier Property
Permeability Characteristics
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.
2. Evaluati o n It e m s fo r Co at in g Mate ri a ls
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 the permeability
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
3. Evalu at i o n Test wi t h 5 Co ating Materials
We’ll provide the evaluation methods/results of the 5 items below.
Table 2 shows the description of the coating materials used herein.
- Light Transmission Characteristics
- Degradation
- Moisture Proof / Water Repellency
- Coating Property
- Gas Barrier Property
Table 2 Coating Material Information