Application Note

Light Emitting Diode

Assembly and Handling Precautions
for the Nichia 321 Series LEDs

Table of contents
1. Overview ........................................................................ 2
2. Applicable Part Numbers ............................................... 2
3. Storage ............................................................................ 2
4. Design Consideration ..................................................... 4
5. Handling Precautions ..................................................... 6
6. Precautions for Mounting the LEDs............................... 7
7. Examples of Modules assembled with the Nichia 321
Series LEDs .................................................................. 11
8. Thermal Management................................................... 15
9. Electrostatic Discharge (ESD)...................................... 16
10. Cleaning ....................................................................... 17
11. Eye Safety ..................................................................... 17
12. Summary ...................................................................... 17

NCSW321x, NC2W321x, NC3W321x, NC4W321x, and NC5W321x refer to Nichia part numbers.
These Nichia part numbers 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. Overview

Light Emitting Diode

When handling LEDs, care should be taken to ensure that they are handled in a proper manner; if
LEDs are improperly handled, it may cause damage to the LEDs and/or an adverse effect on theirperformance.
The Nichia 321 series LEDs use submounts and are specially designed to be mounted without
soldering. The structure of this LED allows it to be directly attached to a heatsink/housing to achieve
efficient thermal dissipation. These LEDs need to be handled and assembled in a proper manner toobtain excellent heat dissipation.
This application note provides the assembly and handling precautions for the Nichia 321 series
LEDs.

2. Applicable Part Numbers
This application note applies to the LEDs shown in Table 1.
Table 1. Applicable LED Part/Series Numbers
Nichia 321 Series

Category
Part Number

NCSW321x

NC2W321x

NC3W321x

NC4W321x

NC5W321x

3.05×2.8×0.75

3.5×3.2×0.75

3.5×4.0×0.75

3.5×5.1×0.75

3.5×6.1×0.75

Appearance

Package Size(mm)

The x represents a letter that follows the alphanumeric code of the same LED type (e.g.: NC2W321x→ NC2W321B, NC2W321F, etc. NCxW321F → NCSW321F, NC2W321F, NC3W321F etc.).

3. Storage
3.1 Storage Conditions
If the LED absorbs moisture and is exposed to heat during the LED mounting process, it may cause
the moisture to vaporize and the package to expand and the resulting pressure may cause internaldelamination. To minimize moisture absorption in storage/transit, moisture-proof aluminum bags
are used for the LEDs with a silica gel packet to absorb any air moisture in the bag.
Table 2 provides the required storage conditions before and after opening the moisture-proof
aluminum bag.

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Application Note
Table 2. Storage Time and Baking Conditions
Conditions
Before Opening the MoistureStorage

proof Aluminum Bag
After Opening the Moistureproof Aluminum Bag

Light Emitting Diode

BakingTemperature

Humidity

Time

≤30℃

≤90%RHWithin 1 Year from Delivery Date

≤30℃

≤70%RH≤168 hours

65±5℃

-

≥24 hours

Once the moisture-proof aluminum bag is opened, ensure that soldering is completed within thestorage times detailed in the applicable specification. To store any remaining unused LEDs, use ahermetically-sealed container with silica gel desiccants. Nichia recommends placing them back to
the original moisture-proof bag used for shipment and reseal it.
If the “After Opening” storage time has been exceeded or any pink silica gel beads are found, ensurethat the LEDs are baked before use. Baking should only be done once.
These LEDs have aluminum-plated electrodes. If the LEDs are exposed to a corrosive environment,
it may cause the plated surface to tarnish causing issues (i.e. electric connection failures).
3.2 Deformation of the Embossed Carrier Tape
Do not store the LEDs in a manner where excessive external force may be applied to the reel (e.g.
the reel is stored using a vacuum seal, heavy objects are stacked onto the reel, etc.) since it may
cause the embossed carrier tape to deform; see Figure 1. If the embossed carrier tape deforms, theLEDs inside the pockets of the embossed carrier tape may tilt, causing damage to the LEDs and/or
pick-up errors.

Correct

Incorrect
Deformed

Before Opening theSquashed Reel as a Result

Bag with a Reel in it

of Vacuum Sealing

Deformed

Tilted LED in Pocket

Figure 1. Vacuum Storage and Deformation of the Embossed Carrier Tape

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Application Note
3.3 Storage Environment
To avoid condensation, the LEDs must not be stored in areas where temperature and humidity
fluctuate greatly. Also, ensure that the LEDs are not exposed to direct sunlight and/or anenvironment over a long period of time where the temperature is higher than normal room
temperature, and are not stored in a dusty environment.

4. Design Consideration

Light Emitting Diode

4.1 Absolute Maximum Ratings
Absolute maximum ratings of the LEDs are the maximum values that must not be exceeded evenfor a short period of time. It must be ensured that the absolute maximum ratings are taken into
consideration when designing a system/application using the LED and will not be exceeded in theconditions/environments in which the LED will actually be used even for a short period of time.
For the absolute maximum rating values for the LED, refer to the applicable specification.
4.2 Circuit Design Considerations
The circuit must be designed to ensure that the absolute maximum ratings are not exceeded for eachLED. The LEDs should be operated at a constant current per LED. In the case of operating at aconstant voltage, Circuit B is recommended. If Circuit A is used, it may cause the currents flowing
through the LEDs to vary due to the variation in the forward voltage characteristics of the LEDs on
the circuit.

Incorrect

Correct

(A)
(A)
(A)

(B)
(B)

(B)
...
...

...
...

Figure 2. Examples of a Parallel Circuit
4.3 Operating Current
These LEDs are designed to be operated at a forward current. To stabilize the LED characteristics
while in use, Nichia recommends that the LEDs are operated at currents ≥10% of the sorting current.
For the sorting current for the LED, refer to the applicable specification.

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Application Note
4.4 Precautions for when the LED is Off
Ensure that no voltage is applied to the LED in the forward/reverse direction while the LED is off.
If the LEDs are used in an environment where reverse voltages are applied to the LED continuously,
it may cause electrochemical migration to occur causing the LED to be damaged.

Light Emitting Diode

4.5 Volatile Organic Compounds (VOCs)
Materials present around the LEDs (e.g. housing, gasket/seal, adhesive, secondary lens, lens cover,grease, etc.) may contain volatile organic compounds (VOCs); the VOCs that have been released
from them may penetrate the encapsulating resin of the LED. If the LEDs are being used in ahermetically/near-hermetically sealed environment, VOCs can discolor after being exposed to heat
and/or photon energy and it may greatly reduce the LED light output and/or cause color shift (seeFigure 6). Perform a light-up test, sufficient verifications etc. of the chosen application prior to use
to ensure that the expected performance is maintained.
Ventilating the environment may improve the reduction in light output and/or color shift that may
occur due to VOCs.
4.6 Corrosive Gases
To prevent substances/gases from affecting the plated surfaces of the LEDs, ensure that theparts/materials used around the LEDs (e.g. gasket/seal, adhesive, etc.) in the same assembly/system
do not release corrosive gases (i.e. the parts/materials do not contain sulfur, halogens, etc.). If theplating becomes contaminated, it may cause issues (e.g. electrical connection failures). If agasket/seal is used, silicone rubber gaskets/seals are recommended; ensure that this use of silicone
does not result in issues (e.g. electrical connection failures) caused by low molecular weight volatilesiloxane.
Perform a light-up test, sufficient verifications etc. of the chosen application prior to use to ensurethat the expected performance is maintained.
4.7 Precautions for Environmental Conditions
Ensure that transient excessive voltages (e.g. lightning surge) are not applied to the LEDs. If theLEDs are used for outdoor applications, ensure that necessary measures are taken (e.g. protecting
the LEDs from water/salt damage and high humidity).

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Application Note
5. Handling Precautions
5.1 Areas where Contamination Must be Avoided
Avoid contamination of the LEDs, especially the surfaces of the electrodes and the light emittingareas (see Figure 3) and keep them clean. If the LED surfaces are contaminated, the opticalcharacteristics and/or reliability may be affected.

Surface of theLight Emitting
Area

Light Emitting Diode

Surface of theElectrodes
Figure 3. Areas where Contamination Must be Avoided
5.2 Handling with Bare Hands
Do not handle the LEDs with bare hands. This may contaminate the LED surface and have an effecton the optical characteristics and/or reliability.
5.3 Handling with Tweezers
Ensure that when handling the LEDs with tweezers, excessive force is not applied to the LED.
Otherwise, it may cause damage to the light emitting area, the electrodes and/or the silicone resin(e.g. cut, scratch, chip, crack, etc.) and have an effect on the optical characteristics and/or the
reliability.
Table 3. Correct/Incorrect Examples of Handling the LEDs
Correct Examples(A)

Incorrect Examples(B)

Correct(C)

Incorrect(D)

Incorrect

Incorrect

For the LEDs with ceramic substrates, grab/hold the LEDs by the sides of the substrate. See theCorrect Examples in Table 3. Do not apply excessive force to the emitting area, the electrodes and/or
the silicone resin as shown by the Incorrect Examples in Table 3.
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Application Note
5.4 Other Precautions
Do not drop the LEDs; this may cause issues (e.g. crack, chip, and/or deformation of the LED, and/or
cut, scratch, etc. on the emitting area) causing the optical characteristics and/or the reliability to be
adversely affected.

6. Precautions for Mounting the LEDs
6.1 LED Mounting

Light Emitting Diode

The LEDs are designed to be directly attached to a heatsink/housing with an adhesive; no soldering
is required.
Nichia recommends using an adhesive with a high thermal conductivity when mounting the LED.
If an adhesive with a poor thermal conductivity is used, the optical characteristics and/or reliabilityof the LED may decrease due to insufficient heat dissipation while the LED is operated. The
recommended thermal conductivity of an adhesive used with the LEDs is 3W/m・K or higher. As
stated in Sections 4.5 and 4.6, ensure that the adhesives used with the LEDs do not contain
substances that have adverse effects on the LEDs.
When selecting an adhesive, perform a light-up test, sufficient verifications etc. of the chosen
application prior to use to ensure that the expected performance is maintained.
6.2 Pick-and-Place Nozzle
When using a pick-and-place machine, select a pick-and-place nozzle that is appropriate for the 321
series LEDs. The nozzle is placed onto the emitting surface1 and it suctions the surface to pick up
the LED. If the size, shape, or material of the nozzle tip is not appropriate for the LED, this may
damage the LED (i.e. scratch, chip, crack, etc.), affecting the optical characteristics and/or the
reliability.
When setting the LED pick-up position, ensure that the center of the nozzle and the center of theemitting area of the LED are aligned. Do not apply excessive force to the emitting area when picking
up the LED. If the nozzle does not pick up the LED at the center of the emitting area, and/or if
excessive force is applied to the LED, this may damage the LEDs (i.e. scratch, chip, crack, etc.),
affecting the optical characteristics and/or the reliability.
Table 4 shows examples of the pick-and-place nozzles that are appropriate for the 321 series LEDs.

1

The material of the emitting area: Ceramics for the NCxW321F LEDs and hard glass for the NCxW321B LEDs.
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Application Note
Table 4. Examples of the Pick-and-Place Nozzles that are Appropriate for the 321 Series LEDs
Part Number

Appearance(Dimensions of the
Emitting Area: mm)

Cross-sectional view of the
Nozzle when the LED ispicked up

Example of the Shape of the
Nozzle Tip (mm)1.1

Pick-and-Place
NozzleNCSW321x
1.1

Pick-and-Place
Nozzle1.1

NC2W321x2.25(1.15×2.3)

1.1

Pick-and-Place
NozzleNC3W321x3.4(1.15×3.45)

Pick-and-Place
Nozzle1.1

NC4W321x4.55(1.15×4.6)

Pick-and-Place
Nozzle1.1

Light Emitting Diode(1.15×1.15)

NC5W321x5.7(1.15×5.75)

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Application Note
Figure 4 shows examples of LED pick-up positions for the NC3W321 series LEDs.

Correct

Incorrect

Incorrect
Tips ofNozzlesLight Emitting Diode

Correct Nozzle Tip Shape andCorrect LED Pick-up Position

Incorrect LED Pickup Position

Incorrect Nozzle Tip ShapeFigure 4. Examples of LED Pick-up Positions for the NC3W321 Series LEDs
6.3 Electrical Connection
The Nichia 321 series LEDs have aluminum-plated electrodes and are designed to have an electricalconnection by bonding aluminum ribbons including aluminum wires. Materials other thanaluminum such as gold wires are not suitable for these LEDs. To ensure an effective electricalconnection, the surfaces of the electrodes should be free from contamination.
When an aluminum ribbon is bonded to the LED, ensure the loop shape/shadow of the aluminum
ribbon or light reflected from the ribbon does not affect the LED optical design.
An electrical connection created by clamping the LED electrodes with a contact terminal such as aspring plate is not recommended because the input voltage may become unstable.
6.4 Bonding Conditions
A wedge bonding machine is used to bond an aluminum ribbon onto the surface of the LED electrode.
In this bonding method, ultrasonic waves and loads are applied to the aluminum ribbon by using thewedge tool. The ultrasonic output power, the load applied, and the duration will affect the bonding
strength.
The shear test and pull test shown in Figure 5 are used to evaluate the bonding strength. Based on
the resulting strength value and failure mode etc., select the setting conditions that are suitable forthe ribbon bonding.

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Application Note

Shear Direction

Pull Direction

Aluminum
Ribbon(A) Shear Test

Aluminum
Ribbon(B) Pull Test

Light Emitting Diode

Figure 5. Evaluation Methods for the Ribbon Bonding Strength
Note that there is the mutual dependence between the ultrasonic output and load, and the
combination of these setting values has a significant effect on the bonding strength. Figure 6 shows
how the shear strength varies depending on the ultrasonic output and load.

大
High

荷重
大 HighLoad:

Shear Strength
シェア強度

荷重 小

Load: Low

Low
小
小
Small

大
Large
超音波出力
Ultrasonic
OutputFigure 6. An Example of the Mutual Dependence between the Ultrasonic Output and Load
6.5 Precautions after LED Mounting
Do not stack assembled components together. Otherwise, it may cause damage to the emitting area,
the resins, and/or the aluminum ribbons (e.g. scratch, chip, crack, deformation, cut, etc.) and havean effect on the optical characteristics and/or the reliability.

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Application Note
7. Examples of Modules assembled with the Nichia 321 Series LEDs
Nichia prepared the module shown below and performed various evaluations to measure thecharacteristics at the module level.
7.1 Structure/Dimensions of the Module used for the Evaluations

40

34

34

2.5
(1.1)

2.5

(1.1)

9.45

4-φ3.240

9.45

4-φ3.2

LED
21

21

44

Aluminum Plate

31

31 50

44

Alignment Mark (2 Locations)50

High Heat-resistant Glass
Epoxy Substrate (FR-5)

2.95

M2.6 Screw (3 Locations)
2.95

Light Emitting Diode

Figure 7 shows the structure/dimensions of the module used for the evaluations of the Nichia 321
series LEDs. In this module, a high heat-resistant glass epoxy substrate (FR-5: 31mm [L] × 24mm
[W] × 0.5mm [H]) is fixed on an aluminum plate (50mm [L] × 40mm [W] × 2.5mm [H]) at threelocations with M2.6 screws and the LED is mounted on the aluminum plate by using a high thermal
conductivity adhesive. An aluminum ribbon (0.5mm [W] × 0.1mm [H]) is used to create an electricalconnection between the LED and the glass epoxy substrate.

24

4-C1
24

Connector

4-C1
0.5

0.5

[Aluminum Plate]
Surface Finishing: Anodic oxide coating (Black)
Surface Roughness: Ra=0.3μm
Figure 7. Structure/Dimensions of the Module Used for the Evaluations
7.2 Characteristics of the Nichia 321 Series LEDs at the Module Level
Nichia evaluated the optical and thermal characteristics of the LEDs at the module level withheatsinks. The module is fixed to the heatsink at four locations with M3 screws, not with a heatdissipating material such as thermal grease.
Table 5 shows the evaluation results at TJ =25°C when the LED was operated at 1000mA (sorting
current) in pulse mode.
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Application Note
Table 5. Characteristics of the Nichia 321 Series LEDs at the Module Level with Different Heatsinks
LED Part
NumberNCSW321F

NC2W321F

NC3W321F

NC4W321F

NC5W321F

Color Rank

sw57

sw57

sw57

sw57

sw57

Heatsink2

None

Heatsink A

Heatsink A

Heatsink B

Heatsink B

OperatingCurrent
(mA)

1000

1000

1000

1000

1000

(Sorting Current)(Sorting Current)(Sorting Current)(Sorting Current)(Sorting Current)

TJ (℃)

25

25

25

25

25

Voltage (V)3

3.3

6.4

9.6

12.8

16.1

3.3

6.4

9.6

12.8

16.1

(393)

(812)

(1232)(1587)(2033)

Light Emitting Diode

Appearanceof theModuleInput Power(W)3
Luminous
Flux (lm)3,42

Refer to Table 6 for the details of the heatsinks used.

3

The values are the averages of the measured values of three LEDs.

4

The values in parentheses are for reference purposes.

Table 6. Heatsinks Used for the Evaluations
Heatsink A

Heatsink B

NoteW
Appearance

L
W×L×H

60×60×35

80×80×40

t

4

5

1.6

1.6

(3.7)

(2.2)

Material

Aluminum

Aluminum

Surface Finishing

Anodic oxide coating(Black)Anodic oxide coating(Black)Size(mm)

SurfaceRoughness
Ra(μm)
Thermal Resistance(℃/W)55

Surface Roughness: Rat
H

The values in parentheses are for reference purposes.
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Application Note
Figure 8 shows the junction temperatures (TJ) of the Nichia 321 series LEDs at the module level at
different operating currents. The junction temperature (TJ) was measured when the saturation
temperature at the junction was reached under the ambient temperature (TA) of 50°C. Thismeasurement was performed with the LED’s emitting surface upward.
The chosen application must be designed to ensure that the maximum junction temperature (TJ Max)of 150°C is not exceeded.
NCSW321F LED at the Module Level
300
T J Max

Without Heatsink250

TJ (℃)

200

For the details of the TJ calculation, refer to theapplication notes “How to Calculate the Junction
Temperature for the Nichia 321 Series LEDs” and“Thermal Resistance Values of the Nichia 321
Series LEDs”.

150
100
50
0
0

NC2W321F LED at the Module Level

1000

1500

NC3W321F LED at the Module Level
300

T J Max

TJ MaxWithout Heatsink

250

Without Heatsink

250

With Heatsink A

With Heatsink A
200

200

TJ (℃)

TJ (℃)

500
IF (mA)

300

150

150

100

100

50

50

0

0

0

500

1000

0

1500

500

IF (mA)

1000

1500

IF (mA)

NC5W321F LED at the Module Level

NC4W321F LED at the Module Level
300

300

250

250

200

200

TJ (℃)

TJ (℃)

Light Emitting Diode

The TJ estimation of the LED at the module levelcan be calculated by using the temperature of the
LED (TMP) at the measurement point Nichia
specifies, the thermal resistance (RθJMP) from the
LED chip to the TMP measurement point, and the
input power (W).

150

100

150

100
TJ Max50

TJ MaxWithout Heatsink

50

Without Heatsink

With Heatsink B
0With Heatsink B
0

0

500

1000

IF (mA)

1500

0

500

1000

1500

IF (mA)

Figure 8. Relationship between the Operating Current and the Junction Temperature (TA=50°C)
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Application Note
7.3 Placement Accuracy of the Nichia 321 Series LEDs

Light Emitting Diode

When designing the chosen application, the accuracy of the distance between the reference point(the optical component position) and the center of the LED emitting surface is important; however,
the required accuracy varies depending on the application. For reference when designing the chosen
application, Nichia evaluated the placement accuracy of the mounted LEDs based on the alignment
marks on the evaluation module.
Figure 9 shows the evaluation of the LED placement accuracy. In the evaluations, one hundred
NC3W321F LEDs were used and the target LED placement position was defined as the midpoint of
the line connecting the two alignment marks on the aluminum plate. After a high thermal
conductivity adhesive was applied to the aluminum plate, the pick-and-place machine placed the
LED in place where the center of the emitting surface is aligned with the target LED placement
position.
After the LED placement was completed, Nichia evaluated the placement accuracy (the amount of
the deviation between the center of the LED emitting surface and the target LED placement positionin the x and y directions is described as ⊿x and ⊿y, respectively). Nichia also evaluated theplacement accuracy in the angular direction (the amount of the deviation between the center line of
the emitting surface in the x direction and the line connecting the 2 alignment marks is described as⊿θ).
Target LED Placement Position

＋

＋
⊿y

⊿θ

－

－

Alignment Mark (Φ1mm)－ ⊿x ＋
Distance between the Alignment Marks: 21mm

Figure 9. LED Placement Accuracy Evaluation
The evaluation results are shown in Table 7 and Figure 10. At an average value of ±3σ, the deviations
from the target LED placement position in the x and y directions are both within ±15μm and thedeviation in the angular direction is within ±0.1°.

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Application Note
Table 7. Evaluation Results of the LED Placement
Accuracy (For Reference)

Sample Size: 100 LEDs
50

LED Placement Accuracy

Light Emitting Diode

Deviations in x and y
Directions (μm)

Deviation in
the Angular
Direction (°)

30
20

⊿x

⊿y

⊿θ

Average

-0.9

3.5

0.03

σ

3.6

3.9

0.02

Average -3σ

-12

-8

-0.03

-20
-30

Average +3σ

10

15

0.09

Min.

-12

-4

-0.02

Max.

6

15

0.08

Center Pointsof the発光面中心位置
LED Emitting Surfaces40⊿y (μm)10
0-10

Average ±3σ-40-50-50 -40 -30 -20 -10

0

10

20

30

40

50

⊿x (μm)Figure 10. Distribution of the Center Points of
the LED Emitting Surfaces (For Reference)

8. Thermal Management
When designing the chosen application using the LED, it is necessary to consider the heat generated
from the LED during operation. The increase in the junction temperature (TJ) of the LED while inoperation varies depending on the thermal resistances of the heatsink and housing, the thermal
conductivity of the adhesive used, and how the adhesive is applied etc. Ensure that when using the
LED for the chosen application, heat is not concentrated in an area and properly managed in theapplication and the Absolute Maximum Junction Temperature (TJ) is not exceeded under any
circumstances.
The operating current should be determined by considering the temperature conditions surrounding
the LED (i.e. TA). Ensure that when operating the LED, proper measures are taken to dissipate theheat.

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Application Note
9. Electrostatic Discharge (ESD)
9.1 Measures against ESD

Light Emitting DiodeThe Nichia 321 series LEDs are sensitive to transient excessive voltages (e.g. ESD, lightning surge).
If this excessive voltage occurs in the circuit, it may cause the LEDs to be damaged causing issues(e.g. the LEDs to become dimmer or not to illuminate [i.e. catastrophic failure]).
Ensure that when handling the Nichia 321 series LEDs, necessary measures are taken to protect
them from an ESD discharge. The following examples are recommended measures to eliminate thecharge:- Grounded wrist strap, ESD footwear, clothes, and floors- Grounded workstation equipment and tools- ESD table/shelf mat made of conductive materials
Ensure that all necessary measures are taken to prevent the LED modules from being exposed totransient excessive voltages (e.g. ESD, lightning surge):- tools, jigs, and machines that are used are properly grounded- appropriate ESD materials/equipment are used in the work area
- the system/assembly is designed to provide ESD protection for the LED modules
9.2 Measures for when the Tool/Equipment Used is an Insulator
If the tool/equipment used is an insulator (e.g. glass cover, plastic, etc.), ensure that necessary
measures have been taken to protect the LED from transient excessive voltages (e.g. ESD). The
following examples are recommended measures to eliminate the charge:- Dissipating static charge with conductive materials- Preventing charge generation with moisture- Neutralizing the charge with ionizers
9.3 Identifying ESD Damaged LEDs
To detect if an LED was damaged by transient excess voltages (i.e. an ESD event during the system’s
assembly process), perform a characteristics inspection (e.g. forward voltage measurement, light-uptest) at low current (≤1mA). If the LED was damaged by transient excess voltages (e.g. ESD), it
would cause the Forward Voltage (VF) to decrease, the LED not to illuminate at a low current, etc.
For the failure criteria for the LED, refer to the applicable specification; the failure criteria for the
VF at the forward current of 0.5mA is specified.

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Application Note
10. Cleaning
Do not clean and/or wipe the emitting surface of the LED. If an area of the LED other than theemitting surface is contaminated (e.g. dust/dirt), use a cloth, swab, etc. soaked with a small amountof isopropyl alcohol (IPA) and wipe the LED with it in a manner that does not touch the emitting
surface. If another solvent is used, it may cause the LED package/resin to be damaged causing theoptical characteristics and/or the reliability to be affected; ensure that sufficient verification is
performed prior to use.
Do not clean the LED with an ultrasonic cleaner. This may cause the optical characteristics and/or
the reliability to be affected.

Light Emitting Diode

11. Eye Safety
There may be two important international specifications that should be noted for safe use of theLEDs: IEC 62471:2006 Photobiological safety of lamps and lamp systems and IEC 60825-1:2001(i.e. Edition 1.2) Safety of Laser Products - Part 1: Equipment Classification and Requirements.
Ensure that when using the LEDs, there are no issues with the following points:- LEDs have been removed from the scope of IEC 60825-1 since IEC 60825-1:2007 (i.e. Edition
2.0) was published. However, depending on the country/region, there are cases where therequirements of the IEC 60825-1:2001 specifications or equivalent must be adhered to.
- LEDs have been included in the scope of IEC 62471:2006 since the release of the specification in2006.
- Most Nichia LEDs will be classified as the Exempt Group or Risk Group 1 according to IEC
62471:2006. However, in the case of high-power LEDs containing blue wavelengths in theemission spectrum, there are LEDs that will be classified as Risk Group 2 depending on thecharacteristics (e.g. radiation flux, emission spectrum, directivity, etc.)- If the LED is used in a manner that produces an increased output or with an optic to collimate thelight from the LED, it may cause damage to the human eye.
If an LED is operated in a manner that emits a flashing light, it may cause health issues (e.g. visual
stimuli causing eye discomfort). The system should be designed to ensure that there are no harmful
effects on the human body.

12. Summary
The LEDs need to be handled and assembled in a proper manner to obtain the required
characteristics and the reliability. Follow the cautions/suggestions detailed in this application noteand the applicable specification for the LED to ensure that the LED is used properly.
In addition, when selecting the parts/materials to be used with the LED, effects of VOCs andcorrosive gases from the parts/materials (e.g. sulfur, halogens, etc.) must be carefully consideredand sufficient verifications with the conditions/environments in which the chosen application
containing the LED will actually be used must be performed to ensure that the characteristics and/or
the reliability for the LED are not adversely affected.
This document contains tentative information, Nichia may change the contents without notice.
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Application Note
Disclaimer
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within it and Nichia makes no guarantee that customers will see the same results for their chosen
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Light Emitting Diode・ The information/data contained herein are only typical examples of performances and/or
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This document contains tentative information, Nichia may change the contents without notice.
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