This application note provides an overview of the performance of the DRAGON product family (in this case, LEDs without plastic lenses) as well as a summary of the most important customer-relevant LED data with respect to its effect on LED lifetime.

Die Applikationsschrift gibt einen Überblick über die Performance der DRAGON Produktfamilie (hier speziell LEDs ohne Kunststofflinse), sowie eine Zusammenfassung der wichtigsten applikationsrelevanten LED-Daten mit Hinblick auf ihre Auswirkungen auf die Lebensdauer.

This application note gives general informa￯﾿ﾽtion on the assembly and design of the solder pad of the DRAGON product family. Suitable PCB materials will also be described.

The Golden DRAGON LED consists of a leadframe with integrated heat spreader and a thermoplastic body. The chip is mounted in a reflector formed by the thermoplastic. In order to dissipate the heat the package has an additional thermal connection. This connection is soldered to a thermal enhanced PCB, on the backside of the housing. Therefore the Golden DRAGON package is suitable for high power dissipations in the range of 1 W. In order to achieve reliability and optimal performance a proper thermal management design is absolutely necessary.

Like all electronic components, the Golden DRAGON LEDs have thermal limitations. The allowed operation temperature for the specific lifetime is limited by the glass-point of the LED resin. This means that the temperature of the die inside, doesn't have to exceed this value when exposed to the expected operation temperature.

This brief will give the design engineer an introduction in the thermal basic of Golden DRAGON LEDs. Furthermore some concepts are shown in order to improve the thermal design.

In recent years, the brightness of LEDs has continually increased, allowing them to be used in completely new application areas. Due to the strong increase in brightness, the bonded system of chip and housing takes on increased significance. Generally, the lifetime of an LED is not due to the actual semiconductor chip itself, but primarily determined by the housing. The “lifetime“ refers to the period of time, whereby the brightness drops to half of its original value at a specific current. In order to achieve a lifetime in the range of 100,000 hours at room temperature for very bright LEDs, Osram has implemented a new sealing compound consisting of silicone.

The following application note represents a general guideline for mounting LEDs of the Golden DRAGON with Lens product family. A basic overview of the construction of LEDs and important design rules for the development of LED systems are provided.

In addition, the principal processing steps are illustrated for the Golden DRAGON ARGUS LED, and general information about mounting is summarized.

In the following, a recommended selective soldering method by means of laser diodes is also introduced, because it is not possible to process these LED type with a conventional standard soldering process. Thereby the important process parameters and steps for processing of the Golden DRAGON ARGUS LED are described.In a final manner alternative solder techniques are presented.

The Golden DRAGON LED is OSRAM Opto Semiconductors’ high performance LED requiring special considerations in thermal management and electrical implementation.

This application note is intended to help the design engineer with the special electrical considerations of the Golden DRAGON LED. With a higher current there is higher power, and therefore more heat to dissipate. The Golden DRAGON LED package is optimized for removing this heat efficiently. With an integrated heat slug (also known as a heat spreader) the thermal performance is far superior to standard LEDs.