Neo-Neon Introduces Advantageous LED Lighting Formulas

New COB package cuts cost and achieves faster cooling

Neo-Neon LED Lighting International Ltd., a Taiwanese-invested company headquartered in China's Guangdong Province, has introduced several new LED formulas, including a unique chip-on-board (COB) packaging method and a special kind of LED lighting production.

The company's new COB packaging method makes the most of the flip-chip process and ceramic board as a carrier substrate. Ceramic material has a thermal expansion coefficient comparable to that of sapphire: 8ppm per degree Celsius, vs. 7.5ppm/C. This ideally low thermal expansion, in contrast to copper's 16ppm/C and aluminum's 23ppm/C, does not make LED chips on ceramic boards to crack because of the large difference in coefficient between the two materials. Ceramic material is also noted for excellent insulation and thermal conductivity.

Neo-Neon's COB package is composed of an aluminum oxide (A12O3) layer, a sliver layer, and an aluminum layer, without the horizontal insulating layer and circuit layer common in conventional packages.

Fewer layers mean lower cost and quicker thermal dissipation. With the horizontal insulating layer eliminated, the company fixes the problem of deformation caused by the different thermal expansion coefficients of the aluminum substrate layer and the layer above by inserting the Al2O3 layer.

The Al2O3 layer and the aluminum layer are attached together to make a compound structure upon which a round sink is built. Conducting heat at an efficient rate, the sink helps get out more light than conventional COB packages can manage.

The package as a whole conducts heat at rate of 150-230W/mK, making it ideal for high-power lighting applications.

Flip-chip process
The flip-chip process increases the reliability of the package by reducing the chance of the gold pins breaking and the die attachment adhesive failing. The process also reduces thermal resistance, making it good for high-power applications.

The company bundles multiple LED dies on a single board. To keep the entire package from failing because of a short circuit in a single LED die, all dies are connected in both parallel and series.

Neo-Neon's COB packages generate high light output thanks to their efficient reflective film coating, along with an additional 10% light output from the micro structure built on the surface of the adhesive.

The company has begun volume production of its COB packages at a rate of one million units a month. The packages offer a high price/performance ratio, high light output, uniform lighting, and efficient thermal dissipation. They can be built into light bulbs, downlights, ceiling lights, streetlights, and patio lights.

The new mode of production is based mostly on the modularizing of LED light sources, helping to reduce production cost and defect rate—and, of course, boost competiveness.

The company will begin using the new mode for mass production in the fourth quarter of this year. This is expected to add greatly to the company's potential for the growth of sales and profits over the next few years.

Also, Neo-Neon has succeeded in affixing LED dies to interconnect boards with conductive or non-conductive adhesive, and then using wire bonding to integrate the LED dies with the substrate. The company has applied for a patent and intellectual property registration for its new die-board integration technology.