-4-

Nichia

STSE-CW7093A

<Cat.No.070615>

7.CAUTIONS

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) 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 85°C

· Nichia LED leadframes are silver plated copper alloy.

The silver surface may be affected by

environments which contain corrosive substances. 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 LEDs be used as soon as possible.

· Please avoid rapid transitions in ambient temperature, especially, in high humidity environments where

condensation can occur.

(2) Circuit Design

· The LEDs should not be constantly subjected to reverse voltage.

(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.

· Please determine the operating current with consideration of the ambient temperature local to the LED

and refer to the plot of Ambient temperature vs. Allowable Forward Current on CHARACTERISTICS

in this specifications.

Please also take measures to remove heat from the area near the LED to improve

the operational characteristics of the LED.

· The equation 1 indicates correlation between Tj and Ta, and the equation 2 indicates correlation

between Tj and Ts.

Tj=Ta + Rja W

1

Tj=Ts + Rjs W

2

Tj = Dice Temperature : °C,

Ta = Ambient Temperature : °C,

Ts = Solder Temperature (Cathode Side) : °C,

Rja = Heat resistance from Dice to Ambient temperature : °C /W,

Rjs = Heat resistance from Dice to Ts measuring point : °C /W,