基于倒装芯片制备白光LED灯丝研究

发布时间：2018-08-16 08:57

【摘要】：在全球禁用白炽灯的热潮下,LED灯丝以节能环保、造型独特、全角度发光的特点成为了可以取代白炽灯的新光源。倒装LED芯片(FC-LED)具有更好的散热结构和出光效率,利用倒装芯片制备LED灯丝可以有效的提升灯丝的散热性能。本文采用高温锡膏固晶倒装芯片,通过表面涂覆荧光粉的方式,制备出白光倒装LED灯丝。研究了基板、固晶焊料以及荧光粉涂覆方法对倒装LED灯丝的芯片剪切力、光电性能和热学性能的影响。试验结果表明:同等条件制备的倒装灯丝,陶瓷基板产品光效(125.2 Lm/W)要高于铝基板(118.4 Lm/W),陶瓷基板双面发光,更适用于光效要求较高的灯丝;铝基板的正反面表面温度(332.2 K/336.6 K)低于陶瓷基板(339.7 K/341.6K),铝基板的热分布更均匀,适合大功率、散热要求较高的灯丝。在直接烘烤条件下,助焊剂在接合处产生的孔洞多于锡膏,经过1000小时老化后助焊剂和锡膏样品的光通维持率分别为87.07%和91.51%。锡膏焊料层厚度从32μm增加到82μm时,剪切力提升了135%,单颗芯片的电压降低了2.56 mV(@30 mA),结温升高了1.5K。灯丝单面涂覆荧光粉正反面色温相差235 K,光效为112 Lm/W;正反面涂覆相同荧光粉正反面色温相差285 K,光效为115 Lm/W;将反面荧光粉浓度降低为正面荧光粉浓度的20%后,正反面色温相差53 K,光效高达121Lm/W,并且改变浓度对灯丝的温度影响不大。试验结果提供了低成本、高光效、适合白光倒装LED灯丝的固晶工艺和荧光粉涂覆工艺。
[Abstract]:Under the trend of banning incandescent lamp in the world, LED filament has become a new light source which can replace incandescent lamp with the characteristics of energy saving, environmental protection, unique shape and full angle luminescence. The inverted LED chip (FC-LED) has better heat dissipation structure and light efficiency. Using the inverted chip to prepare LED filament can effectively improve the heat dissipation performance of the filament. In this paper, the white LED filament was prepared by high temperature tin paste solid crystal inversion chip and phosphor coated on the surface. The effects of substrate, solid solder and phosphor coating on the chip shearing force, optoelectronic and thermal properties of inverted LED filament were studied. The results showed that the light efficiency of ceramic substrate (125.2 Lm/W) was higher than that of aluminum substrate (118.4 Lm/W), and that of ceramic substrate was better than that of aluminum substrate (118.4 Lm/W). The surface temperature of the aluminum substrate (332.2 K / 336.6K) is lower than that of the ceramic substrate (339.7 K / 341.6K). The heat distribution of the aluminum substrate is more uniform, which is suitable for the filament with high power and high heat dissipation. Under the direct baking condition, the flux produced more holes than tin paste at the joint. After 1000 hours of aging, the light flux and tin paste samples were maintained by 87.07% and 91.51%, respectively. When the thickness of solder layer increased from 32 渭 m to 82 渭 m, the shear stress increased by 135 and the voltage of single chip decreased by 2.56 MV (30 mA), and 1.5 KV higher than 30 渭 m). The difference of positive and negative color temperature is 235K, the luminous effect is 112Lm / W, the difference of positive and negative color temperature is 285K, and the luminous effect is 115Lm / W. after the concentration of the reverse phosphor is reduced to 20% of the concentration of the positive phosphor, The difference of positive and negative color temperature is 53 K, the light efficiency is up to 121 Lm / W, and the change of concentration has little effect on the filament temperature. The test results provide a low cost, high light efficiency, suitable for white inverted LED filament solid crystal process and phosphor coating process.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM923.34

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