The Zhaga Consortium, a global association of lighting companies that is standardizing LED lighting components, has published its eagerly-awaited specification on chip-on-board (COB) LED arrays. The specification, known as Zhaga Book 12, can be downloaded from the Zhaga website (http://www.zhagastandard.org/books/book12).

Book 12 defines a family of six rectangular and square LED modules with a circular light-emitting surface (LES). These modules require a separate LED driver, and can be used either with or without holders, depending on the luminaire type and application. Most Book 12 modules will use COB technology for the light-emitting section.

By defining a small family of COB form-factors, Book 12 removes arbitrary variations in non-competitive properties such as outer dimensions and electrode positions. This reduces the complexity of luminaire development, and simplifies the supply chain for luminaire manufacturers. For COB makers, standardization of non-competitive properties allows them to focus on areas where they can add value, such as efficacy or lifetime (which are not included in the Zhaga specification).

Book 12 defines a family of modules with the following PCB dimensions:

• Rectangular 12 x 15 mm (category C12x15)

• Rectangular 16 x 19 mm (C16x19)

• Square 19 x 19 mm (C19x19)

• Rectangular 20 x 24 mm (C20x24)

• Square 24 x 24 mm (C24x24)

• Square 28 x 28 mm (C28x28)

Three test labs – DEKRA, Intertek and VDE – are authorized to perform testing procedures that will enable manufacturers to certify their COB products according to Zhaga Book 12. All certified products are listed in Zhaga’s online database.