Structure Design And Thermal Analysis Of Flip-chip Packaged LED Light Source Module

LED(Light-Emitting-Diode)have many advantages such as small size,long life,low energy consumption and fast start-up time,and have become the first choice for a new generation of application lighting.Therefore,this paper focuses on the following research work for high-power flip-chip LED light source modules:First,In this paper,through finite element simulation,it was found that under the same heat dissipation condition,the junction temperature of the face-mounted lamp was 17.763°C higher than that of the flip-chip lamp.Then,the heat transfer process in the thermoelectric separation substrate and the ordinary substrate was studied.Finally,the heat conduction process in thick plates and thin plates was discussed.A more effective conduction of the thick plates to the heat is proposed,which lays a theoretical foundation for the structural design of the light source module in the following text.Secondly,a slice light source module suitable for high-power LED flip chip was proposed.Through finite element simulation analysis,when the junction temperature of the LED chip reached 120°C,the power of the light source of the flip-chip slice light source module was 18.4 W higher than that of the formal chip slice light source module 17.8 W.The equivalent thermal resistance of flip-chip slice light source was 4.9°C/W lower than 5.2°C/W of formal slice light source module.The heat flux density and the maximum package thermal stress at the LED chip in the flip-chip slice light source module are lower than the formal-chip slice light source module.A light source module was then fabricated,and its lamp junction temperature was measured as 83°C.Again,on the basis of the flip-chip slice light source,a plane light source module suitable for high power LED flip chip was proposed.Through finite element simulation analysis,it was found that when the junction temperature of the LED chip reaches 90°C,the light source power of the flip-chip plane module is 16.2 W higher than 14.4 W of the formal-chip plane light source module;the equivalent thermal resistance of the flip-chip plane light source was 3.07°C/W lower than the 3.57°C/W of the formal-chip plane light source module;The heat flux density and the maximum package thermal stress at the LED chip in the flip-chip plane light source module were lower than that of formal-chip palne light source module.Then,a light source module was manufactured and its lamp junction temperature was measured as 58°C.Finally,the chip junction temperature was used as the standard of the heat dissipation performance of the light sources module to investigate the influence of thesize of the each part of the light sources on the heat dissipation performance of the slice light source and the plane light source.At the same time,the optimal design parameters of the plate-fin heat sink were obtained by optimizing the design of the plate-fin heat sink structure through the orthogonal test method.The thermal simulation of the optimized light source module showed that it had better heat dissipation performance and then the fin efficiency of the fins was calculated.