NT2W757GR Datasheet, PDF (22/23 Pages) NICHIA CORPORATION – Built-in ESD Protection Device

NICHIA STS-DA1-3938 <Cat.No.150819>
(3) Handling Precautions
● Do not handle the LEDs with bare hands as it will contaminate the LED surface and may affect the optical characteristics:
it might cause the LED to be deformed and/or the wire to break, which will cause the LED not to illuminate.
● When handling the product with tweezers, be careful not to apply excessive force to the resin.
Otherwise, The resin can be cut, chipped, delaminate or deformed, causing wire-bond breaks and catastrophic failures.
● Dropping the product may cause damage.
● Do not stack assembled PCBs together. Failure to comply can cause the resin portion of the product to be cut, chipped,
delaminated and/or deformed. It may cause wire to break, leading to catastrophic failures.
● CRI Rank R9050 LEDs in this specification use materials that contain halogen-based compounds;
the halogen element found in these materials will not affect the LEDs when the LEDs are used under the conditions
specified in this specification. The other CRI ranks in this specification do not use these materials.
● Due to the variation in the amount of the reflective material (white resin) that is coating the protection device,
the area around the protection device may appear to be a black spot; this will not affect the characteristics of the LED.
Do not use the location of the protection device to determine the polarity of the LED; use the cathode mark.
(4) Design Consideration
● PCB warpage after mounting the products onto a PCB can cause the package to break.
The LED should be placed in a way to minimize the stress on the LEDs due to PCB bow and twist.
● The position and orientation of the LEDs affect how much mechanical stress is exerted on the LEDs placed near the score lines.
The LED should be placed in a way to minimize the stress on the LEDs due to board flexing.
● Board separation must be performed using special jigs, not using hands.
● Volatile organic compounds that have been released from materials present around the LEDs (e.g. housing, packing,
adhesive, secondary lens, lens cover, etc.) may penetrate the LED lens and/or encapsulating resin.
If the LEDs are being used in a hermetically sealed environment, these volatile compounds can discolor after being exposed
to heat and/or photon energy and it may greatly reduce the LED light output and/or cause a color shift.
In this case, ventilating the environment may improve the reduction in light output and/or color shift.
Perform a light-up test of the chosen application for optical evaluation to ensure that there are no issues,
especially if the LEDs are planned to be used in a hermetically sealed environment.
(5) Electrostatic Discharge (ESD)
● The products are sensitive to static electricity or surge voltage. ESD can damage a die and its reliability.
When handling the products, the following measures against electrostatic discharge are strongly recommended:
Eliminating the charge
Grounded wrist strap, ESD footwear, clothes, and floors
Grounded workstation equipment and tools
ESD table/shelf mat made of conductive materials
● Ensure that tools (e.g. soldering irons), jigs and machines that are being used are properly grounded and
that proper grounding techniques are used in work areas. For devices/equipment that mount the LEDs,
protection against surge voltages should also be used.
● If tools or equipment contain insulating materials such as glass or plastic,
the following measures against electrostatic discharge are strongly recommended:
Dissipating static charge with conductive materials
Preventing charge generation with moisture
Neutralizing the charge with ionizers
● The customer is advised to check if the LEDs are damaged by ESD
when performing the characteristics inspection of the LEDs in the application.
Damage can be detected with a forward voltage measurement or a light-up test at low current (≤1mA).
● ESD damaged LEDs may have current flow at a low voltage or no longer illuminate at a low current.
Failure Criteria: V_F<4.0V at I_F=0.5mA
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