Research On LED Performance Of Glass Substrate COB Packaging

Under the background of highly rapid development of the global economy,global energy shortages intensified increasingly. In the face of such pressing crisis,Chinese government devotes every effort to encourage sustainable development.While the exploitation of new energy and renewable energy, but also strong proponent low-carbon life. The most popular source is Light Emitting Diodes(shot for LED) among new sources. With respect to the traditional sources, LED has been considered as the most valuable lighting source in new century with its many advantages such as high efficiency of electro-optic conversion, long life, instant reaction and good shockproof property. So, more and more extensive applied in all lighting field.Be accompanied by gradual increase of LED applications, people’s requirement its power and luminous efficiency is higher and higher. The development trend of high power and high integration makes unprecedented challenge for LED packaging industry. Researchers research or develop new packaging materials, change packaging structures to resolve a series of problems such as luminous efficiency, heat radiation, light color, costs control and etc. Taking the opportunity of latest popular research on glass substrate filament bulb with COB packaging structure(chip on board), the paper researches the performance of LED glass packaging substrate.Based on glass substrate COB device, the thesis mainly conducted the following aspects of the research work:1. According to different substrate materials, we chose normal ceramics,Borosilicate glass, silicon, copper and aluminum to make samples and performance contrast experiments. There comes the test report that under the working state of 49 v and 20 m A, 1 strip of 17 pieces glass substrate COB samples has higher rubber face temperature than other samples with 92℃, but has 76 luminous flux, very close to ceramics substrate.2. For improving the heat radiation performance of glass substrate COB devices,we designed experiments of aluminum spring piece, aluminum slot and glass substrate with silver back. We obtained that the most ideal heat radiation method isaluminum slot+ substrate back with silver brushed.3. Contrast experiments researched the relationship between silver thickness on back with heat radiation performance and luminous flux. When silver thickness reaches 15 um, it gets ideal heat radiation and luminous effect. When the temperature of rubber surface reaches 91.5℃, the luminous flux of 3.6W glass strip bulb gets to315 luminous flux under steady state.4. For examining the reliability of glass substrate COB devices, we made a series of experiments including high temperature, high humidity, thermal shock, red ink&sulfur. Contrast analysis with popular Al2O3 ceramics substrate has been also made.Experiments show that glass substrate COB devices go through the reliability tests more smoothly. When the substrate back is brushed with silver layer, reliability is more of the outstanding.This paper researched COB packaging substrate with glass material through making samples, contrast analysis, designing some simple methods to improve glass substrate’s heat radiation. The results can be as reference for the research of COB packaging with superpower glass substrate in the future.