Here is the abstract you requested from the DPC_2009_LED technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Addressing Thermal Issues During Device Packaging and Assembly using Dispense Processes|
|Keywords: Dispensing, Thermal management, Packaging|
|High brightness LED’s may be more rugged and efficient than light bulbs, but they still generate a lot of heat.It may be a surprise to most people that typical incandescent light bulbs only produce approximately 5-6% efficiency. The rest of the energy consumed is heat that is radiated away by the bulb surface. LEDs are typically 3-4 times as efficient, converting 15-20% of the electrical energy into light. However, very little of the heat is radiated and must be conducted away though the backside of the device. Most experts agree the most important consideration in designing LED luminaires is thermal management and package design. To stress the relationship, the IMAP Society has in the past co-located the technology workshops for Thermal Management and High Power LED Packaging. According to the US DDOE web site on Solid State Lighting, there are 6 keys to bringing SSL to the forefront in the quest to replace conventional lighting: quantum efficiency, longevity, stability and control, packaging, infrastructure, and cost reduction. Most experts agree the really important improvements in device fabrication have already been realized. Further improvements will be gradual, although green LEDs are still a fertile opportunity. That leaves the rest of the work to the manufacturer’s packaging efforts. Central to packaging is the effort to extract both heat and light from the device. When temperature is held constant and low it serves longevity, stability and control. The trick is to take advantage of existing infrastructure and keep the package cost low. We know that microprocessor reliability is enhanced through good thermal management practices. By coupling the chip to its package, the package to the circuit board, and the circuit board to a heatsink, a considerable amount of heat is conducted away. However, the remaining heat has to be actively cooled using moving air, or convection. The same considerations should be applied by lighting system designers. The paper will provide an overview of the device packaging process with attention to thermal management materials and overall performance and reliability.|
|Robert H. Hoffman, Business Development Manager