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The COB package of advantages and disadvantages

COB light efficiency is low, I believe that the solution should be thinking from the substrate principle. LED luminous efficiency upgrade package we usually talk about the external quantum efficiency, how to improve that in the case of the same chip package product, or the luminous flux of the entire module.

     First, the substrate material of a high reflectivity, the reflectivity of the chip placement area directly affects the entire flux output, whether it is a copper substrate, aluminum plate, ceramic substrate, should follow this rule. Moreover, it must be noted that, in a COB assembly applications, the area outside the light emitting surface of the substrate should be considered, if the light emitting surface without a reflective cup, should the region outside of the light emitting surface and a reflective material. Second, large particles, high brightness phosphor high transmittance package of silica gel, this traditional discrete LED light effect to enhance the same way.

    Again, the solid crystal chip arrangement when pitch and drive to be reasonable, drive current program under the same power as much as possible, avoid staying too much heat in the interior of the substrate. Further, when the smaller size of the light emitting surface, in the lens profile of the phosphor surface points silica, not only increasing the angle, and the light efficiency can be further improved. COB has many advantages, but the lighting market is not mainstream. In the current COB-optimistic about the same time, we should see behind the shortcomings in order to find the reasons for restricting the application.

   First the COB light efficiency is still low. COB plane luminous, like discrete LED PPA chip the sidelight auxiliary output, resulting in the loss of part of the light.

   Secondly, the COB is currently no standardized shape, most of the domestic manufacturers in accordance with their respective partners manufacturing COB match the appropriate lighting, drive mode, a shape is not uniform limit of a large-scale use of the COB.