The light-emitting diode of an LED package radiates light and heat according to the input power. However, the surface area of an LED package is quite small,and the package itself is expected to release little heat into the atmosphere.An external radiator such as a heat sink is thus required.The heat dissipation structure up to the connection portion of the external radiator uses mainly heat conduction.
The document explains that because LED packages have small surface areas, an external radiator like a heat sink is required to dissipate heat generated by input power. It emphasizes controlling the junction temperature (Tj) to prevent it from exceeding absolute maximum ratings.
The text details the package structure which uses through-holes and conductive copper foil patterns to transfer heat efficiently to the soldering point on an external circuit board acting as a heat sink. It provides formulas and charts relating ambient temperature, driving current, and thermal resistance to ensure Tj remains within safe limits.
An external radiator such as a heat sink is required because the surface area of an LED package is quite small and it cannot release much heat into the atmosphere on its own.
The package structure minimizes thermal resistance by using through-holes and conductive copper foil patterns to conduct heat from the die to the external circuit board via solder.
The absolute maximum rating value for the junction temperature (Tj) in the specifications for the CL-824-U1 package is 120°C.