SMT practices with compact pad size LEDs

With the evolution of LED manufacture industry, LED efficacy increases around 10% annually in the past years and now it has already been ready to replace most of the conventional light sources including incandescent, halogen, high/low pressure sodium and even ceramic discharge halide (CDM). Meanwhile its price drops rapidly in the past years which gives LED a yearly increasing penetration to lighting industry. To further improve performance and reduce cost, some LED manufactures release some compact footprint LEDs such as LUXEON Z ES^[1] or LUXEON T^[2] by Philips Lumileds and XQ^[3] series by Cree. With its compact footprint and compact pad size it brings some SMT issue to this industry. In this paper we will present some practices on how to do SMT well with these compact pad size LEDs.