Micro-rolling Of Light Extraction Structure For Multi-chip LED Package Substrate

Light-emitting diodes (LEDs) as a new generation of green light source, has theadvantages of small volume, high efficiency, energy saving and environmental protection hasbeen widely used in electronic field. But due to the flux is small, light uniformity, is difficultto be applied to the traditional lighting field and will be high-power integrated LEDs lightsource module to replace. However, the low light efficiency, high heat flow density, lack ofprocessing efficiency and other problems, restricting the promotion of high-power integratedLED light source module. Based on that this paper proposes an integrated LED substrate withhigh light extraction structure rolling processing method, roll forming cutter with conestructure is developed, and working out with light extraction structure of inverted pyramidblind hole is four. The main research contents aresummarized as follows:(1) Optimization design of substrates light extraction structureAccording to the requirement of multi-chip package light source module structure,establishing a high power LED light source module optical model, by ray tracing simulationusing Monte Carlo method, analysis of the phenomenon of total internal reflection effect onthe optical efficiency of light extraction structure; calculation of cone angle size effects on thelight efficiency of LED light source module, compare the LED light source module ofCandela distribution, light intensity and light radiation power with different parameters.Simulation to calculate the ideal intensity distribution, the maximum light extractionefficiency of extraction light structure, considering intensity distribution, obtained the lightextraction efficiency of optimization design for light structure characteristic parameters.(2) Light extraction structure rolling mechanism and finite element simulationanalysisAs the light extraction structure of roll forming scale effect showed, by means of elasticmetal plastic deformation, considering different plate thickness, different grain size effects ofthe micro-rolling light extraction structure forming and establishingconstitutive model,description the feature of microscopic scale characteristics of materials. According to theoptimized for micro-rolling forming characteristics of light extraction structure, considering the influence of geometrical scale of the boundary condition, the thermodynamic couplingrelations and the constitutive relation, establishing a substrate of light extraction structurerolling process simulation model reveals the law of forming, rolling process parameters andtool parameters influence on rolling pressure and forming quality. The use of Deform-3Dfinite element simulation software analysis the metal plastic flow rules of light extractionstructure rolling process (volume transfer), in order to control the substrate without localprotuberance (metal accumulation) and convex deformation. According to the result of finiteelement simulation analysis, developingthe substrate distribution regularity of stress andstrain under different process parameters, elastic recovery and residual stress distribution,setting up the mechanism of substrate deformation prediction.(3)Rolling process parameters optimization and experimental research of Lightextraction structureLight extraction structure with four pyramids is manufactured using the new rollingmolding tool. The effect of tool parameters and process parameters to the light extractionstructure shape and appearance through the experimental observation, reveal the formingprocess parameters influence law on the formability, forming quality and rolling pressure.Through research the substrate of optical structure robust design method to improve therobustness between the substrate qualities with process parameters of optical structureforming. According to optimization theory of the structural parameters, choosethe maininfluence factors and levels. Throughthe single factor experiment, determine the optimalprocess parameters of light extraction structure, realizelight extraction structure characteristicparameters design and make it the deformation of the substrate in control under the demand offunction.