A mid-power LED is a semiconductor emitter package that operates at a maximum of 1 watt. Within the lighting industry, it typically refers to a polymer-based package that is architecturally evolved from the plastic leaded chip carrier (PLCC) type of electronic packages. PLCC packages for mid-power LEDs come in physical specifications that follow the standard nomenclature for SMT packages such as 2835 (3.5 x 2.8 mm), 3030 (3.0 x 3.0 mm), 3014 (3.0 x 1.4 mm), 5630 (5.6 x 3.0 mm), and 3535 (3.5 x 3.5 mm). Mid-power LEDs are the usual choice for residential and commercial lighting products such as ceiling lights, troffers, wall sconces, floor lamps, table lamps, GLS retrofit lamps and tubular lamps. Among all LED package types, PLCC LEDs provide the best architecture for non-directional lighting applications in residential and commercial settings. The small size supports retrofit applications and enables more freedom in new lighting form factors. The controlled environment of an indoor space and lower power designs of most indoor lighting products set the stage for these vulnerable LED packages. Moreover, their cost and efficacy advantages lend them a killer punch in the commoditized lighting markets.
A mid-power polymer-based LED package is characterized with a structure wherein a metal lead frame mounted with one or more small LED dies is embedded in a polymer cavity. The polymer cavity is filled with a phosphor-polymer mixture which act as the wavelength down-converter and encapsulant. In addition to providing mechanical support, the lead frame serves as a medium for electrical connection and thermal dissipation. The die can be either attached through a silver containing glue or soldered onto the lead frame surface to create electrical connection for the cathode of the p-n junction. The anode of the LED die is connected electrically by a bond wire. Both the lead frame and plastic housing act as reflectors that maximize light extraction efficiency (LEE), allowing the LEDs to deliver the highest luminous efficacy among all package types.
at the Open Lighting Product Directory (OLPD)
