Design and optimization of heat dissipation and illumination patterns in novel recessed chip-on-board designs for high-power LED lighting applications

热管理是固态照明应用的一个基本限制因素，影响器件的可靠性和发光效率。在高功率应用中，芯片密度的增加加剧了对高效散热途径的需求。板上芯片（COB）方法通过消除单独封装LED芯片的需要来提高技术水平，同时通过在芯片和散热器之间提供更紧密的热接触来提高冷却效率。然而，在COB LED产品中，平板设计限制了与散热器接口处可能发生的热量传播。提出了一种携带COB的嵌入式散热器，以改善散热器内的热量传播，从而提高COB组件的冷却效率。虽然这个想法很有吸引力，但在冷却能力、凹槽深度和形状以及它们对发光强度空间分布的影响方面的设计权衡尚不清楚。此外，凹进式散热片材料和荧光粉的相对放置可能对灯具的颜色输出产生不利影响。对散热器嵌入式COB设计的系统研究有助于深入了解这些权衡和最佳工作点。该研究可以提高高功率固态照明在工业应用中的采用，具有巨大的环境效益，因为每瓦消耗的光输出的增加大大减少了不可再生能源的能源浪费和温室气体排放。

Thermal management is a fundamental limiting factor in solid state lighting applications, affecting the devicereliability and luminous efficacy. In high-power applications, the increased chip density exacerbates the needfor efficient heat dissipation pathways. Chip-on-board (COB) approaches improved the state of the art byremoving the need to individually package LED chips, while yielding better cooling efficiencies by providing amore intimate thermal contact between the chip and heat sink. However, in COB LED products the flat boarddesign limits the heat spreading that can take place at the interface with heat sinks. A recessed heat sinkcarrying the COB is proposed as an approach to improve the heat spread within the heat sink, and therebyimprove the cooling efficiency of the COB assembly. While the idea is attractive, the design trade-offs in termsof cooling capabilities, recess depth & shape and their impact on the luminous intensity spatial distribution areunknown. Additionally, the recessed heat sink material and relative placement of the phosphor may have anadverse effect on the color output of the light fixture. Systematic studies of heat sink-recessed COB designs canyield insights into these trade-offs and optimum operating points. The research can improve the adoption ofhigh-power solid state lighting in industrial applications, with tremendous environmental benefits, as theincrease in light output per watt consumed greatly reduces energy waste and green-house gas emission fromnon-renewable energy sources.