7. CAUTIONS
White LEDs are devices which are materialized by combining Blue LEDs and special phosphors.
Consequently, the color of White 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 with a zipper.A package of a
moisture absorbent material (silica gel) is inserted into the moisture proof bag. The silica gel changes
its color from blue to pink as it absorbs moisture.
(2) Storage
!
The LEDs should be kept at 30 degrees C or less and 90%RH or less. The LEDs should be used within
a year. When storing LEDs, moisture proof packaging with absorbent material (silica gel) is
recommended.
!
After opening the package, the LEDs should be kept at 30 degrees C or less and 70%RH or less. The
LEDs should be soldered within 168 hours (7 days) 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 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 60 _ 5 C
+
!
Gilway LED electrode sections are comprised of a gold plate. The gold surface, may be affected by
environments which contain corrosive gases and so on. Please avoid conditions which may cause the
LED to corrode, tarnish or discolor. This corrosion or discoloration may cause difficulty during
soldering operations. It is recommended that the User use the LEDs as soon as possible.
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 in this specification.
!
The operating current should be decided after considering the ambient maximum temperature of
LEDs.
GILWAY [ GILWAY TECHNICAL LAMP ]
