The choice of LED encapsulants-HongYe silicone

First LED package mainly have the lamp in-line SMD SMD high power molding or lens, integrated modules, COB packaging and so on, the glue used in a variety of packages are not the same lamp epoxy resin, a few other basic silica gel, but now they have company in the development of modified epoxy resin to increase the thermal performance and reduce the performance of its yellow side to replace the silicone use, relatively cheap silicone price is more expensive epoxy. The main difference between epoxy and silicone Price Stress Epoxy resin stress exist, and the silicone basic stress Stress exists will lead to the accumulation of heat, a lot of LED failure is heat accumulation caused by (2) the epoxy resin on the market is divided into the following categories Bisphenol A epoxy resin, hydrogenated epoxy resin, alicyclic class epoxy resins. The price of these products from highest to lowest The application of the occasion is very different For example, bisphenol A epoxy resin can not be applied to Blu-ray products, but at present in order to lower prices we are used indiscriminately while ignoring the quality 3. Silica gel into two categories Types of methyl silicone, refractive index 1.41 A phenyl-class silicone refractive index 1.5 The advantages and disadvantages of these two types of silicone Types of methyl yellowing resistance and temperature resistance of the domicile of class, but relatively phenyl made to the product of the luminous flux will be relatively weak Under consideration in different situations, careful selection of materials, in particular, is the glue High power 3W package, do not blindly pursue high-brightness, so I chose a high refractive index of the glue, because of the high refractive index of the glue which contains phenyl is the benzene ring (See the 23rd Floor, brothers explain), this structure of high temperature performance, especially 3W current heat high heat is not good fluorescent plastic black (please see forum post I made 1W high-power colloid black), so that would be counterproductive, the luminous flux will drop a lot of the low refractive index of the glue temperature performance and reliability, so the choice of this place glue refractive index must be careful, depending on customer choice to do the brightness then high refractive index, requiring reliable and it is low refractive index of the glue, if you heat well, with a high refractive index, heat is the biggest problem.