At the recent 2013 IMAPS Device Packaging Conference, I had the opportunity to discuss the thermal design for our LED-based light bulbs, more commonly known as ‘lamps’. Since we introduced our lamp earlier this year, we’ve had a lot of requests to discuss our unique approach, as our lamp is open at both the top and the bottom.
Taking advantage of our MicroLens® edge-lit optics, the Rambus lamp has been architected to create a strong cooling draft with a central chimney, which is achieved by having an open air design. Traditionally, chimneys are effective methods of removing heat and we designed our lamp to achieve higher performance levels. The fully open design also prevents dust from accumulating in the lamp since air (and dust) passes straight through. Additionally, the “Y” shape, known as the chamber, enhances performance regardless of where the lamp is used, but especially if it is used in a horizontal fixture. These two thermal design features – the chimney and the chamber – are unique to the Rambus lamp.
We designed our lamp in this way to take advantage of one of the main challenges experienced by LED lambs: thermal management. With this approach, we are able to see up to a 50% thermal improvement, which not only cools the electronics in the lamp but also extends the life of the lamp, all while fitting within the standard Edison socket and A19 bulb shape. Overall, this development translates to lower operating temperature of the LEDs, which results in improved reliability and longer life.
Unlike other advanced LED-based lamp cooling systems that use active cooling methods or liquid cooling, this design uses just the air around the lamp to keep it cool and also improves reliability since there are fewer parts or seals to fail.
The “Y” chamber is the most unusual part of the design. This design has evolved from earlier lamp designs that had cooling vents. In the final design, not only does the chamber allow air to flow through in the horizontal mounting, but it is designed with a unique curved dome to pull the air into the chimney when used sideways. Our lamp may actually have the first chimney ever developed to operate horizontally!
We’ve seen great interest in this design from the industry and as some audience members at the 2013 IMAPS Device Packaging Conference pointed out, sometimes the simplest design is often the most difficult to invent and perfect.