“The application of CSP technology will inevitably drive the market demand for innovative packaging materials.” Mr. Kazunori Maruyama, global marketing director of Dow Corning Lighting Solutions, said at the LEDforum 2015 China International LED Market Trend Summit Forum hosted by LEDinside, China LED Network and Guangzhou International Lighting Exhibition on June 11.
Due to the particularity of LED packaging, the industry has extremely high requirements for packaging materials. The first is heat resistance. During the eutectic reaction process, the LED junction temperature exceeds 150°C, which requires the packaging material to withstand high temperatures. The second is high light stress. The light output of LED is very demanding, and its heat flux reaches 100 W/cm2, which requires the packaging material to have good heat carrying capacity. The third is stability. During the packaging process, the packaging material may react chemically with the phosphor or be oxidized, which requires it to have high stability.
Dow Corning began researching high-stability, high-refractive-index packaging materials in 2002, and successfully launched the first-generation phenyl silicone OE-66xx series in 2006. Compared with methyl silicone, phenyl silicone has a higher refractive index, air tightness and stress relief, which can help LED products increase the light output by 7%.
Mr. Kazunori Maruyama said that after the advent of phenyl silicone, LED manufacturers hoped that packaging materials would have better mechanical reliability, so the second-generation product OE-7620/30/40 appeared, and its thermal cycle durability and stress relief have been greatly improved. At this year's Guangya Exhibition, Dow Corning brought its third-generation product OE-7651N/7662. Compared with the previous two generations of products, this new product has made great breakthroughs in phosphor compatibility and air tightness, effectively improving color quality and reliability.
Talking about the latest technological trends in LED packaging, Mr. Kazunori Maruyama said that in order to reduce overall costs and improve performance, LED manufacturers have begun to delve into chip-scale packaging CSP. This trend will inevitably drive market demand for innovative packaging materials.
To this end, Dow Corning has launched a new packaging material-fluorescent packaging film made of curable hot-melt silicone. When the temperature is lower than 60°C, it is solid and viscoelastic; when the temperature is 100-140°C, this material will melt and cover the surface of the product; and when the temperature exceeds 150°C, it will thermally solidify to form a fluorescent packaging film. This innovative material can simplify the production process and reduce costs; it gives LED packages greater design flexibility; it can also improve the uniformity of phosphor distribution and provide better light quality.
ANNA