At 3.5 × 3.5 mm, a series of 0.5-W SMD LEDs from Kingbright Corp. (City of Industry, CA, U.S.; www.kingbrightusa.com) features compact design with a wide 120° viewing angle. The AA3535-series ultra-bright LEDs, available in industry-standard PLCC4 package, can achieve high-intensity illumination up to 30 lm at 150 mA.

“More and more major appliances are requiring brighter lights whether to enhance the interior ambience of refrigerators or to announce the current operation status of dishwashers,� says Man Yu, engineering manager at Kingbright. “This LED series is able to achieve high illumination and at the same time, its compact package enhances design maneuverability and flexibility for design engineers in various appliance applications.�

Designers can choose from a selection of colors to match their designs, including blue, green, yellow, red, and white in various color temperature such as cool white (6000K), neutral white (4000K), and warm white (3000K). “Depending on the nature and usage of the appliance application, it will require a specific color temperature option,� Yu says. “For example, dishwashers usually use a warm white tone for its interior lighting (3000K) while refrigerators tend to use cool white interior lighting (6000K).�

The package encompasses low thermal resistance, providing heat-dissipating capability. According to Yu, “the maximum thermal resistance from junction to soldering point is 60°C/W. The heat dissipating design of the package helps transfer the heat from LED die to its metal leads and eventually release the heat from the LED package.�

Yu says that low power consumption is known as a key advantage of LED technology. But the heat dissipating design, along with the use of high-performance ultra-bright LED chips, allows the LED series to achieve even better performance—it delivers high lumen output while consuming only 0.5 W of power.

The series contains a built-in zener diode that can withstand electrostatic discharge (ESD) voltage up to 8000 V. “During high ESD, the overcurrent goes through zener diode instead of the LED chip, protecting the LED from high transient voltage,� Yu explains.

The IR reflow solderable LEDs sport a flat lens design and tape-and-reel configuration. This design facilitates automatic pick-and-place mounting process, thus increasing productivity and reducing assembly costs. In addition, the device comprises moisture sensitivity level (MSL) rating of 2a with longer floor time of 4 weeks. “The elements can be exposed to ambient room conditions for a longer period of time, enabling designers to have great flexibility during assembly process,� Yu says.