NEMA publishes white-LED binning standard (SSL 3-2010)
The new NEMA standard SSL 3-2010 covers high-power white LED binning for general illumination.
Produced by NEMA’s Solid State Lighting Section, SSL 3 provides standardized categorization areas (bins) for the colors of white LEDs used for general lighting. LED manufacturers use binning to manage variations in LED performance during mass production. When manufacturers use different binning structures and labeling, LED system integrators and assemblers face unnecessary testing, verification, qualification, and validation processes.
The bin structures established by SSL 3 promote continuity among suppliers. The standard also sets a level of expectation for color characterization that results in a reasonable number of bins for stocking purposes. The bin structures are based on ANSI color standards for fluorescent lamps as specific in ANSI_NEMA_ANSLG C78.377-2008.
“As the first SSL application standard for color in general lighting, SSL 3 will streamline the binning process, alleviating stock and consistency issues for LED integrators,” said Robert Hick of Leviton, and chair of the section. “Upcoming revisions of the standard will address additional characteristics for binning. SSL 3 demonstrates lighting manufacturers’ commitment to work together to make energy-efficient SSL technology easier for integrators to adopt on a large scale.”
Introduction to the SSL 3 standard (NEMA text)
The binning of LEDs is a practice used by LED manufacturers to manage the variation of LED performance in mass production processes. The inefficiencies of binning may create structural vulnerability in the supply chain for the market. To reduce the risk and at the same time protect product yields, LED manufacturers often choose binning schemes in accordance with their specific or unique mass production process. As a result, the LED components or packages produced by the manufacturers maintain structured variations for their performance characteristics.
Because of the uniqueness of the mass production and quality control process used by each LED manufacturer, the LED products supplied to LED system integrators or assemblers (module makers, luminaire makers, etc.) with similar performance characteristics produced by different manufacturers are binned and labeled differently. The binning structures and labeling (marking) used varies from manufacturer to manufacturer.
Binning structure inconsistency, as a result, requires more effort on the part of LED system integrators and assemblers. More unnecessary testing, verifications, qualification, and validations processes have to take place. As a result, overall solid state lighting (SSL) industry productivity may be negatively influenced. With a rapidly growing SSL market, more LED products will be manufactured and more manufacturers will be participating in the market. This makes it necessary and important to establish industry agreed-upon guidelines to ensure product consistency.
This standard applies to LEDs emitting incoherent, visible radiation in Solid State Lighting applications. It specifies bins and bin codes for LEDs for the characteristic of color.