NSSW004T Datasheet, PDF (5/13 Pages) NICHIA CORPORATION – TYPE WHITE LED

7.CAUTIONS
Nichia STSE-CC7188A-1
<Cat.No.071127>
The LEDs are devices which are materialized by combining Blue LEDs and special phosphors.
Consequently, the color of the LEDs is changed a little by an operating current.
Care should be taken after due consideration when using LEDs.
(1) Moisture Proof Package
· When moisture is absorbed into the SMT package it may vaporize and expand during soldering.
There is a possibility that this can cause exfoliation of the contacts and damage to the optical
characteristics of the LEDs. For this reason, the moisture proof package is used to keep moisture
to a minimum in the package.
· The moisture proof package is made of an aluminum moisture proof bag. A package of
a moisture absorbent material (silica gel) is inserted into the aluminum moisture proof bag.
The silica gel changes its color from blue to pink as it absorbs moisture.
(2) Storage
· Storage Conditions
Before opening the package :
The LEDs should be kept at 30°C or less and 90%RH or less. The LEDs should be used within a
year. When storing the LEDs, moisture proof packaging with absorbent material (silica gel)
is recommended.
After opening the package :
The LEDs should be kept at 30°C or less and 70%RH or less. The LEDs should be soldered
within 168 hours (7days) after opening the package. If unused LEDs remain, they should be
stored in moisture proof packages, such as sealed containers with packages of moisture absorbent
material (silica gel). It is also recommended to return the LEDs to the original moisture proof bag
and to reseal the moisture proof bag again.
· If the moisture absorbent material (silica gel) has faded away or the LEDs have exceeded the storage
time, baking treatment should be performed using the following conditions.
Baking treatment : more than 24 hours at 65 ± 5°C
· This product has silver plated metal parts that are inside and/or outside the package body. The silver
plating becomes tarnished when being exposed to an environment which contains corrosive gases.
Any LED with tarnished leads may lead to poor solderability and deterioration of optical characteristics.
Please do not expose the LEDs to corrosive atmosphere during storage.
· After assembly and during use, silver plating can be affected by the corrosive gases emitted by
components and materials in close proximity of the LEDs within an end product, and the gases entering
into the product from the external atmosphere. The above should be taken into consideration when
designing.
· Please avoid rapid transitions in ambient temperature, especially in high humidity environments where
condensation can occur.
(3) Heat Generation
· Thermal design of the end product is of paramount importance. Please consider the heat generation
of the LED when making the system design. The coefficient of temperature increase per input
electric power is affected by the thermal resistance of the circuit board and density of LED placement
on the board, as well as other components. It is necessary to avoid intense heat generation and operate
within the maximum ratings given in this specification.
· The operating current should be decided after considering the ambient maximum temperature of LEDs.
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