High reliability, improved performance and low cost “interconnect technology” for LED light engines

The LED industry is extremely price sensitive to manufacturing cost. The challenge is to produce modules (or the light engines) without compromising reliability. The present approach is to work within the standard assembly flow structure and focus on improving the manufacturing yield through efficient process control. These yield enhancements are usually achieved in small increments. Therefore, it is necessary to revolutionize the packaging and interconnect technology and implement new assembly methodology concepts. This paper presents a novel packaging & interconnect technique that has been jointly developed with materials suppliers and an equipment manufacturer, while integrating a non-conventional assembly approach. The new LED component structure improves package thermal resistance without sacrificing electrical properties. It further introduces a new and efficient concept of on-line phosphor deposition on blue LED devices, thus drastically improving the manufacturing process flow. A pre-determined phosphor layer is deposited using an in-situ thickness monitoring system to ensure that the variation in chip-to-chip CIE values lie within a very narrow range ~ thus improving the component yield. In this paper the concept of this package and its design flexibility is presented. Reliability results of assembled components are shared. Limitations of current structure and the scope for future advancement are discussed.