A High Thermal Conductive Solderable Adhesive

With increasing LED development and production, thermal issues are becoming more and more important for LED devices, particularly true for high power LED and also for other high power devices. In order to dissipate the heat from the device efficiently, Au80Sn20 alloy is being used in the industry now. However there are a few drawbacks for Au80Sn20 process: (1) higher soldering temperature, usually higher than 320°C; (2) low process yield; (3) too expensive. In order to overcome the shortcomings of Au80Sn20 process, YINCAE Advanced Materials, LLC has invented a new solderable adhesive – TM 230. Solderable adhesives are epoxy based silver adhesives. During the die attach reflow process, the solder material on silver can solder silver together, and die with pad together. After soldering, epoxy can encapsulate the soldered interface, so that the thermal conductivity can be as high as 58 W/mk. In comparison to Au80Sn20 reflow process, the solderable adhesive has the following advantages: (1) low process temperature – reflow peak temperature of 230°C; (2) high process yield – mass reflow process instead of thermal compression bonding process; (3) low cost ownership. In this paper we are going to present the die attach process of solderable adhesive and the reliability test. After 1000 h lighting of LED, it has been found that there is almost no decay in the light intensity by using solderable adhesive – TM 230. ...