本文選題：大功率LED　切入點(diǎn)：熱柱　出處：《華南理工大學(xué)》2016年碩士論文

【摘要】：隨著半導(dǎo)體技術(shù)的飛速發(fā)展,以大功率LED為代表的電子芯片集成化、小型化和高頻化程度日益提高,由此帶來的空間狹小、熱流密度過高等散熱問題越來越凸顯。本文針對(duì)LED芯片在使用中遇到的熱流密度過高和普通散熱器難以滿足其散熱需求的現(xiàn)狀,提出一種具備高效傳熱性能的新型復(fù)合毛細(xì)芯熱柱散熱器,提出利用犁切-擠壓加工方法在銅管內(nèi)壁加工出三維翅結(jié)構(gòu),進(jìn)一步在三維翅表面復(fù)合一層銅粉燒結(jié)芯以形成復(fù)合毛細(xì)芯;分析了燒結(jié)溫度、燒結(jié)時(shí)間以及銅粉形狀和粒度對(duì)復(fù)合燒結(jié)毛細(xì)芯形貌的影響機(jī)制;研究了加熱功率、充液率以及毛細(xì)芯尺寸等多種關(guān)鍵參數(shù)對(duì)熱柱傳熱性能的影響規(guī)律。將復(fù)合毛細(xì)芯熱柱的傳熱性能與普通熱沉以及市場同類散熱產(chǎn)品進(jìn)行了對(duì)比,測試結(jié)果表明,復(fù)合毛細(xì)芯熱柱具備高效傳熱性能。本文主要研究內(nèi)容如下:(1)提出采用犁切-擠壓成形方法加工三維翅溝槽結(jié)構(gòu),重點(diǎn)研究了包括犁切深度ap、徑向溝槽間距fr以及軸向溝槽間距fz在內(nèi)的三個(gè)關(guān)鍵加工參數(shù)對(duì)三維翅溝槽形貌結(jié)構(gòu)的影響規(guī)律。結(jié)果表明,在犁切深度為ap=0.4mm,徑向溝槽間距為fr=0.4mm以及軸向溝槽間距為fz=π/25rad的組合參數(shù)下得到三維溝槽翅的形貌最優(yōu)。(2)結(jié)合粉末燒結(jié)理論,分析了燒結(jié)頸的生長機(jī)制,并研究了燒結(jié)溫度、燒結(jié)時(shí)間以及銅粉粒徑和形狀對(duì)燒結(jié)毛細(xì)芯形貌的影響規(guī)律。結(jié)果表明,當(dāng)燒結(jié)溫度和燒結(jié)時(shí)間分別為900℃和60min時(shí),獲得毛細(xì)芯孔隙結(jié)構(gòu)形貌最好;枝狀銅粉燒結(jié)毛細(xì)芯的孔隙率大于球狀銅粉,并且銅粉燒結(jié)毛細(xì)芯綜合性能隨著銅粉粒度減小而變得更好。(3)根據(jù)LED散熱需求,設(shè)計(jì)出熱柱系統(tǒng)整體結(jié)構(gòu),主要由蒸發(fā)段、工質(zhì)、冷凝段以及復(fù)合毛細(xì)芯構(gòu)成。制定出熱柱整體制造工藝流程,對(duì)材料選擇、端蓋加工、清洗、焊接以及工質(zhì)灌注等每一道工序進(jìn)行了分析,確保制造出滿足實(shí)驗(yàn)要求的熱柱樣品。(4)搭建實(shí)驗(yàn)平臺(tái)對(duì)熱柱快速啟動(dòng)性能和熱柱在不同加熱功率、充液率以及毛細(xì)芯規(guī)格參數(shù)下的傳熱性能進(jìn)行了測試。結(jié)果表明,熱柱具備良好的熱啟動(dòng)性能,最大傳熱載荷達(dá)到120W;熱柱傳熱性能與毛細(xì)芯長度、直徑以及銅粉粒徑之間呈現(xiàn)出單向線性關(guān)系;對(duì)復(fù)合毛細(xì)芯熱柱、普通熱沉、單一溝槽芯熱柱以及市場同類散熱產(chǎn)品的傳熱性能進(jìn)行了對(duì)比,結(jié)果證明復(fù)合毛細(xì)芯熱柱在傳熱性能上具有極大優(yōu)勢;最后,對(duì)相同熱柱樣品分別在模擬熱源和LED熱源下的傳熱性能進(jìn)行了比對(duì),結(jié)果表明本文在模擬熱源下獲得的實(shí)驗(yàn)數(shù)據(jù)具備可靠性,可以為熱柱應(yīng)用于解決大功率LED散熱提供支撐。
[Abstract]:With the rapid development of semiconductor technology, the integration, miniaturization and high frequency of electronic chips, represented by high power LED, are becoming more and more important. The problem of heat dissipation such as high heat flux is becoming more and more prominent. This paper aims at the current situation that the heat flux of LED chip is too high and the ordinary radiator can not meet its heat dissipation demand. A new type of composite capillary core heat sink with high heat transfer performance is proposed. The three-dimensional fin structure is fabricated by plough-extrusion method in the inner wall of copper pipe. The effect of sintering temperature, sintering time, shape and particle size of copper powder on the morphology of composite sintering capillary core was analyzed, and the heating power was studied. The effect of several key parameters, such as liquid filling rate and capillary core size, on heat transfer performance of hot column is studied. The heat transfer performance of composite capillary core is compared with that of common heat sink and similar heat dissipation products in the market. The composite capillary core hot column has high heat transfer performance. The main contents of this paper are as follows: 1) A plough cutting and extrusion forming method is proposed to process three dimensional fin grooves. The effects of three key machining parameters, including ploughing depth app, radial groove spacing fr and axial groove spacing fz, on the morphology and structure of three-dimensional fin grooves are studied. Under the combined parameters of ploughing depth of 0.4mm, radial groove spacing of fr=0.4mm and axial groove spacing of fz = 蟺 / 25rad, the optimum morphology of three-dimensional grooves was obtained by combining the theory of powder sintering, the growth mechanism of the sintered neck was analyzed, and the sintering temperature was studied. The effect of sintering time, particle size and shape of copper powder on the morphology of sintered capillary core was studied. The results showed that the pore structure and morphology of capillary core were the best when sintering temperature and sintering time were 900 鈩，

本文編號(hào)：1676273