NSSM032A_15 Datasheet, PDF (16/17 Pages) NICHIA CORPORATION – Pb-free Reflow Soldering Application

NICHIA STS-DA1-3916 <Cat.No.150831>
(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.
(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).
● LEDs with ESD-damaged dice (i.e. other than red) may have an increased leakage current, current flow at a low voltage,
or no longer illuminate at a low current.
Failure Criteria: V_F<2.0V at I_F=0.5mA
(6) Thermal Management
● Proper thermal management is an important when designing products with LEDs. LED die temperature is affected
by PCB thermal resistance and LED spacing on the board. Please design products in a way that the LED die temperature
does not exceed the maximum Junction Temperature (T_J).
● Drive current should be determined for the surrounding ambient temperature (T_A) to dissipate the heat from the product.
(7) Cleaning
● The LEDs should not be cleaned with water, benzine, and/or thinner.
● If required, isopropyl alcohol (IPA) should be used. Other solvents may cause premature failure to the LEDs
due to the damage to the resin portion. The effects of such solvents should be verified prior to use.
In addition, the use of CFCs such as Freon is heavily regulated.
● When dust and/or dirt adheres to the LEDs, soak a cloth with Isopropyl alcohol (IPA), then squeeze it before wiping the LEDs.
● Ultrasonic cleaning is not recommended since it may have adverse effects on the LEDs
depending on the ultrasonic power and how LED is assembled.
If ultrasonic cleaning must be used, the customer is advised to make sure the LEDs will not be damaged prior to cleaning.
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