Lextar, Everlight, and Dow Corning Discuss Breakthroughs in High-Power Packaging Technology Driving LED Lighting Development
By SEMI Taiwan
To improve optical efficiency and product cost performance, the industry is now investing in high-power LED packaging technology to accelerate the development of the LED lighting market. Even with many advances in high-power LED packaging technology and significant breakthroughs, many challenges, such as heat dissipation, materials and structure, have yet to be overcome. These issues must be resolved for LED lighting to be used in more applications.
SEMI Taiwan recently hosted the "High-Power LED Packaging Technology: Current Development and Challenges" seminar to help members keep up-to-date with the latest trends in LED packaging technology. Lextar R&D manager Tien Yun-yi, Dow Corning senior engineer Feng Ya-jing, and Everlight vice-president of R&D Lu Tsung-lin were invited to speak on the latest developments in Chip-on-Board (COB) high-power packaging, solutions of high-power silicone packaging materials, and high-power LED packaging technology development.
Professor Tien Yun-yi of Lextar said that COB is one of the most significant developments in LED packaging recently. COB's advantages include its compact size, ease of assembly, better light quality and temperature management as well as high luminosity.
On the other hand, COB’s compact size means the design must balance high density and temperature management. Color uniformity is also an issue that requires COB to take a different design approach than conventional package-on-board (POB) technology. Spreading thermal resistance is a particularly important issue in COB design. Modeling must be used to find the optimal layout and design.
Prof. Tien noted that Lextar has been working on COB technology for over a year and has made significant improvements in terms of performance. He also introduced several methods for achieving color uniformity including packaging or chip-level coatings, CIE monitoring and dynamic adjustment, and the use of fluorescent strips.
According to Tien, component integration alone is not enough to realize the goal of simplified design and lower lighting cost. Improvements in "Optical, Mechanical, Electrical, Thermal" integration technology are also essential.
Lu Tsung-lin from Everlight looked at the direction of development in high-power LED packaging technology. Lu noted that commercial/industrial and architectural lighting are the two fastest growing applications in the LED lighting market. Apart from ornamental and street lighting, indoor spot lights are now increasingly shifting toward LED as well.
The range of applications has expanded thanks to the rapid development of COB in the last two years. Lu said that the industry must balance cost, convenience and performance when it comes to deciding how much effort and resources to invest in these three LED categories.
Lu also introduced several innovative high-power LED packaging proposals. These included emerging fluorescent layer processes based on substrate material, vertical/flip chip design, glue dot, spray painting, fluorescent strip and static adhesion.
Feng Ya-jing at Dow Corning introduced the various types of silicone materials for LED packaging. Improved crack-resistance and low viscosity makes them suitable for optical fillings, chip coatings, chip adhesive and reflector cups. Feng also covered some of the more common real-world examples of LED failure analysis and LED reliability in the industry.
Embrace Breakthrough LED Technologies at LED Taiwan Exposition 2013
To help LED companies make inroads into a market with huge opportunities, LED Taiwan Exposition — the only LED manufacturing-focused exhibition in Taiwan — will be co-located with SEMICON Taiwan on September 4-6. Related events include LED forum, LED TechXPOT, LED University Research, and LED Friendship Luncheon and other networking events for hearing high-quality presentations given by renowned LED industry pioneers, exploring innovative ideas among academia, and connecting the LED supply chain leaders, all at one show.
April 9, 2013