本文選題：大功率LED + 熱阻　； 參考：《重慶大學(xué)》2014年碩士論文

【摘要】：LED燈因其節(jié)能、環(huán)保、壽命長(zhǎng)等特點(diǎn)被稱為新一代綠色光源，但其發(fā)光效率低。隨著LED功率不斷增大，若不進(jìn)行有效散熱，LED的壽命及發(fā)光性能都受到影響甚至完全失效。開(kāi)發(fā)新型成本低且具有良好散熱性能的LED燈具，是大力推廣新一代光源的關(guān)鍵。單顆LED芯片功率較小，在場(chǎng)地照明燈等領(lǐng)域?yàn)楂@得足夠光通量必須封裝多顆芯片，其散熱問(wèn)題更為突出。 論文通過(guò)實(shí)驗(yàn)與數(shù)值模擬相結(jié)合方法研究了自然對(duì)流條件下的多芯片LED散熱情況。從芯片、封裝、界面、系統(tǒng)方面，對(duì)多芯片銅基板COB封裝直焊LED燈散熱進(jìn)行一些研究。在此基礎(chǔ)上設(shè)計(jì)了一款大功率場(chǎng)地照明用LED燈，并分析了包括電源在內(nèi)的整個(gè)燈具的散熱性能。 芯片與封裝方面，分析研究芯片間距、覆銅層厚度、噴涂銅層厚度對(duì)擴(kuò)散熱阻的影響；界面方面，將冷噴涂直焊與傳統(tǒng)壓接方式進(jìn)行對(duì)比，分析冷噴涂直焊對(duì)整個(gè)燈具熱阻減小的作用；系統(tǒng)級(jí)散熱方面，主要針對(duì)自然對(duì)流這一被動(dòng)散熱方式，通過(guò)改進(jìn)現(xiàn)有散熱器，分析了散熱器面積增加對(duì)整個(gè)燈具散熱的重要性。 基于以上的分析和結(jié)論，提出了一款用以代替?zhèn)鹘y(tǒng)場(chǎng)地照明的LED燈具。該燈具利用冷噴涂直焊方法將250W銅基板多芯片集成封裝模組與設(shè)計(jì)的純鋁疊片散熱器相結(jié)合制造而成。其中，疊片式散熱器用純鋁代替鋁合金，減小了散熱器熱阻；同時(shí)，疊片散熱器實(shí)現(xiàn)了低成本加工薄純鋁板，有效增加散熱面積。通過(guò)分析，結(jié)合冷噴涂直焊技術(shù)該疊片散熱器完全滿足設(shè)計(jì)場(chǎng)地照明LED燈具的散熱要求。即使在35℃環(huán)境和275W功率下，芯片結(jié)溫也能控制在110℃以下。
[Abstract]:LED lamp is called the new generation green light source because of its energy saving, environmental protection, long life and so on, but its luminous efficiency is low. With the increasing of LED power, the lifetime and luminescence performance of LED without effective heat dissipation are affected or even completely invalidated. Developing a new type of LED lamps with low cost and good heat dissipation is the key to popularize the new generation of light sources. The power of a single LED chip is small. In order to obtain sufficient luminous flux, it is necessary to encapsulate multiple chips in the field of field lighting, so the heat dissipation problem is more prominent. In this paper, the heat dissipation of multi-chip LED under natural convection is studied by the combination of experiment and numerical simulation. From the aspects of chip, package, interface and system, the heat dissipation of LED lamp for COB packaging of multi-chip copper substrate is studied. On this basis, a LED lamp for high power field lighting is designed, and the heat dissipation performance of the whole lamp, including power supply, is analyzed. In chip and package, the influence of chip spacing, copper coating thickness and spray copper coating thickness on diffusion thermal resistance is analyzed. This paper analyzes the effect of cold spray direct welding on the decrease of thermal resistance of the whole lamp, and analyzes the importance of the increase of radiator area to the heat dissipation of the whole lamp by improving the existing radiator, aiming at the passive heat dissipation mode of natural convection. Based on the above analysis and conclusion, a new LED lamp is proposed to replace the traditional site lighting. This lamp is fabricated by cold spray direct welding method, which combines 250W copper substrate multi-chip integrated packaging module with the designed pure aluminum laminated radiator. The laminated radiator uses pure aluminum instead of aluminum alloy to reduce the thermal resistance of the radiator. At the same time the laminated radiator can process thin aluminum plate at low cost and increase the heat dissipation area effectively. Through analysis, the laminated radiator can fully meet the heat dissipation requirements of the design site lighting LED lamps combined with the cold spray direct welding technology. Even at 35 鈩，

本文編號(hào)：1951857