發(fā)布時間：2018-06-04 18:56

  本文選題：環(huán)氧樹脂 + 復(fù)合材料　； 參考：《重慶大學(xué)》2015年碩士論文

【摘要】：隨著LED的廣泛應(yīng)用,如何提高它的壽命是目前普遍關(guān)注的問題。由于LED的芯片在使用的過程中產(chǎn)生熱量,熱量的大量積累導(dǎo)致其壽命縮短,所以LED封裝材料的導(dǎo)熱系數(shù)低是影響其壽命的最大挑戰(zhàn)。因此LED封裝材料的導(dǎo)熱性能的改善,是亟待解決的難題。目前已有的解決封裝材料散熱問題的方法是將導(dǎo)熱微粒填充到聚合物中,制備高導(dǎo)熱的聚合物基復(fù)合材料。聚合物基復(fù)合材料的導(dǎo)熱性能跟很多影響的因素有關(guān),主要分為導(dǎo)熱微粒和聚合物兩個方面的因素。導(dǎo)熱微粒包括本身的導(dǎo)熱性能、形狀、大小、添加量、分散性、取向性、界面結(jié)合、界面面積、種類。聚合物包括導(dǎo)熱性能、取向性等。為了解決LED封裝材料散熱問題,本課題以環(huán)氧樹脂為基體,分別以二氧化硅(Si O2)、碳化硅(Si C)為導(dǎo)熱微粒,制備了高比例導(dǎo)熱微粒陶瓷片和取向型高導(dǎo)熱聚合物基復(fù)合材料,其中高比例導(dǎo)熱微粒陶瓷片用在LED的陶瓷片上,而取向型復(fù)合材料用在LED的封裝上。為了改善導(dǎo)熱微粒與環(huán)氧樹脂基體之間界面,該課題用硅烷偶聯(lián)劑對導(dǎo)熱顆粒進(jìn)行表面處理,并對硅烷偶聯(lián)劑的作用機(jī)理進(jìn)行了詳細(xì)的分析,研究結(jié)果表明表面改性過的導(dǎo)熱微粒填充環(huán)氧樹脂,制備的復(fù)合材料的導(dǎo)熱系數(shù)要高于未改性的復(fù)合材料。在制備高比例導(dǎo)熱微粒陶瓷片的過程中,用導(dǎo)熱微粒的質(zhì)量的5%的鋁粉(Al)、氧化釔(Y2O3)、氧化鎂(Mg O)作為燒結(jié)劑,經(jīng)高壓成型,在高溫爐中660℃燒結(jié),經(jīng)研究發(fā)現(xiàn)用氧化釔(Y2O3)+氧化鎂(Mg O)作為燒結(jié)劑可使陶瓷片中導(dǎo)熱微粒在環(huán)氧樹脂中的致密性達(dá)到最大,制備出導(dǎo)熱系數(shù)達(dá)到12.753W/m K碳化硅共燒陶瓷片。通過掃描電子顯微鏡可以明顯的隨著燒結(jié)溫度的增加陶瓷片的孔的數(shù)目先增加再減小。本課題還從聚合物取向機(jī)理入手,探究了聚合物取向與玻璃化溫度之間的關(guān)系。為了使復(fù)合材料的具有取向結(jié)晶,打開聲子導(dǎo)熱通道,從而提高復(fù)合材料的導(dǎo)熱系數(shù),在本課題中通過測量復(fù)合材料的玻璃化溫度來掌握發(fā)生取向的溫度和時間,使復(fù)合材料機(jī)械拉伸下發(fā)生取向,制備出了取向復(fù)合材料。通過光學(xué)顯微鏡可以觀察到橫截面積不同的取向復(fù)合材料纖維,研究結(jié)果發(fā)現(xiàn)取向復(fù)合材料的導(dǎo)熱系數(shù)隨著導(dǎo)熱微粒的添加比例增加而增加。取向復(fù)合材料的導(dǎo)熱系數(shù)高于未取向的復(fù)合材料,取向復(fù)合材料的導(dǎo)熱系數(shù)隨著拉伸比的增加而增加。當(dāng)Si O2的質(zhì)量分?jǐn)?shù)為80%時,取向復(fù)合材料的導(dǎo)熱系數(shù)為1.2 W/mk,是純環(huán)氧樹脂的5.97倍。當(dāng)微米Si C的質(zhì)量分?jǐn)?shù)為60%時,拉伸比為4的取向復(fù)合材料的平行于取向方向上的導(dǎo)熱系數(shù)(K∥)為5.78 W/mk,它是純環(huán)氧樹脂的28.8倍。在本課題中還對Si O2/環(huán)氧樹脂取向復(fù)合材料的介電性能進(jìn)行了測試,測試結(jié)果表明取向?qū)Νh(huán)氧樹脂的絕緣性能影響并不大。
[Abstract]:With the wide application of LED, how to improve its life is a common concern. The low thermal conductivity of LED packaging materials is the biggest challenge that affects the lifetime of LED because of the heat generation in the process of using the chip and the accumulation of a large amount of heat resulting in the shortening of its life. Therefore, the improvement of thermal conductivity of LED packaging materials is an urgent problem to be solved. At present, the existing method to solve the heat dissipation problem of packaging materials is to prepare polymer matrix composites with high thermal conductivity by filling thermal conductive particles into polymers. The thermal conductivity of polymer matrix composites is related to many factors, which can be divided into two aspects: thermal conductivity particle and polymer. Thermal conductivity particles include their own thermal conductivity, shape, size, addition, dispersion, orientation, interface bonding, interface area, category. Polymers include thermal conductivity, orientation, etc. In order to solve the heat dissipation problem of LED packaging materials, high proportion thermal conductive ceramics and oriented high thermal conductivity polymer matrix composites were prepared by using epoxy resin as substrate, silicon dioxide and silicon carbide as thermal conductive particles, respectively. Among them, the high proportion of thermal conductive particulate ceramics is used on the LED ceramic chip, while the oriented composite is used in the LED package. In order to improve the interface between thermal conductive particles and epoxy resin matrix, the surface of thermal conductive particles was treated with silane coupling agent, and the mechanism of silane coupling agent was analyzed in detail. The results show that the thermal conductivity of the composites filled with epoxy resin is higher than that of the unmodified composites. In the process of preparing high proportion thermal conductive particle ceramic chip, 5% aluminum powder, yttrium oxide Y _ 2O _ 3, MgO _ 2O _ 3 were used as sintering agent, which were sintered at 660 鈩，

本文編號：1978490