【摘要】：白光LED具有高效節(jié)能、壽命長、綠色環(huán)保等優(yōu)點(diǎn),在顯示和照明領(lǐng)域有著廣泛的應(yīng)用。藍(lán)光LED芯片與黃色熒光粉組合是最主要的白光LED實(shí)現(xiàn)形式。在白光LED封裝工藝中的點(diǎn)膠和烘烤環(huán)節(jié),熒光粉都會產(chǎn)生明顯的沉降,而導(dǎo)致白光LED色溫嚴(yán)重漂移、產(chǎn)品光色性能不一致等問題。為研究此現(xiàn)象,本文設(shè)計(jì)出白光LED光譜實(shí)時觀測系統(tǒng),并對實(shí)際SMD型白光LED封裝結(jié)構(gòu)中的熒光粉沉降狀態(tài)進(jìn)行橫截面觀察,解釋了熒光粉沉降對白光LED色溫的影響原因。在此基礎(chǔ)上,本文嘗試了幾種色溫漂移問題的解決方法,最終發(fā)現(xiàn)在熒光粉膠中摻入輕密度的散射顆粒,可以有效解決熒光粉沉降導(dǎo)致的色溫漂移問題。1)本文設(shè)計(jì)并制作出白光LED光譜實(shí)時觀測系統(tǒng),研究了熒光粉沉降現(xiàn)象與白光LED色溫的關(guān)系。結(jié)果表明：熒光粉的沉降會使得白光LED光譜中的藍(lán)光強(qiáng)度下降,黃光強(qiáng)度升高,導(dǎo)致色溫下降。本文認(rèn)為,熒光粉沉降會導(dǎo)致其在封裝膠中的分布變化,在熒光粉沉降聚集的過程中,熒光粉層的透射率下降,反射率上升,對光的背散射／反射程度不斷上升,藍(lán)光在支架反射層與熒光粉層之間多次反射激發(fā)Ce產(chǎn)生更多黃光,藍(lán)黃轉(zhuǎn)換率升高,從而色溫逐漸降低。2)研究表明,熒光粉中摻入適量Si02散射顆�；蛴眉�(xì)粒徑熒光粉能在一定程度上減輕沉降導(dǎo)致的色溫漂移現(xiàn)象,但是都會對白光LED的初始亮度產(chǎn)生較大影響;本文嘗試在熒光膠中加入輕密度、粒徑適宜的空心玻璃微珠,微珠在封裝膠中會逐漸上浮,其對光的背散射／反射程度逐漸下降,與熒光粉沉降對光散射的影響正好相反。空心微珠的摻入能夠基本消除沉降過程的色溫變化,且對初始亮度影響很小3)本文使用透明硅樹脂鑲嵌的方法,制作出SMD型白光LED的橫截面切片,研究了熒光粉在實(shí)際SMD型白光LED中的沉降現(xiàn)象。研究發(fā)現(xiàn),由于藍(lán)光LED芯片具有一定高度,部分熒光粉會沉降到LED芯片出光表面的下方,導(dǎo)致側(cè)向漏光,從而使藍(lán)光出射增多,色溫升高。4)本文對SMD型白光LED做了預(yù)墊平處理,并在熒光粉中摻入精選空心玻璃微珠,緩解了熒光粉沉降過程導(dǎo)致的色溫漂移現(xiàn)象。實(shí)際SMD封裝試驗(yàn)表明,該工藝應(yīng)用效果良好。
[Abstract]:White LED is widely used in display and lighting field because of its advantages of high efficiency and energy saving, long life and green environment. The combination of blue LED chip and yellow phosphor is the most important white light LED realization form. In the process of dispensing and baking in white LED packaging process, the phosphors will produce obvious deposition, which will lead to the serious drift of white LED color temperature and the inconsistent photochromic properties of the products. In order to study this phenomenon, a real-time measurement system of white LED spectrum is designed, and the deposition state of phosphors in SMD type white LED packaging structure is observed cross-section, which explains the influence of phosphor deposition on the color temperature of white LED. On this basis, several methods to solve the problem of color temperature drift are tried, and it is found that the scattering particles with light density are mixed in the phosphor gel. It can effectively solve the problem of color temperature drift caused by phosphor deposition. 1) the real-time measurement system of white LED spectrum is designed and fabricated. The relationship between the phenomenon of phosphor deposition and the color temperature of white LED is studied. The results show that the deposition of phosphors will decrease the intensity of blue light in white LED spectrum and increase the intensity of yellow light, which will lead to the decrease of color temperature. In this paper, it is concluded that the deposition of phosphors will lead to the change of their distribution in the encapsulated adhesive. During the deposition and aggregation of the phosphors, the transmittance of the phosphors decreases, the reflectivity increases, and the backscattering / reflectance of the phosphors increases. Blue light produced more yellow light and blue yellow conversion rate by multiple reflection between the reflector layer and phosphor layer, and the color temperature decreased gradually. 2) The addition of appropriate amount of Si02 scattering particles or the use of fine particle size phosphors can reduce the color temperature drift caused by deposition to a certain extent, but all of them have a great effect on the initial brightness of white LED. In this paper, we try to add hollow glass beads with light density and suitable diameter to fluorescent adhesive, which will float up gradually in encapsulation adhesive, and the backscattering / reflection degree of fluorescent beads will decrease gradually, which is contrary to the effect of phosphor deposition on light scattering. The incorporation of hollow beads can basically eliminate the color temperature change in the sedimentation process, and has little effect on the initial brightness. 3) in this paper, the cross section sections of SMD type white light LED are made by using transparent silicone resin mosaic method. The deposition of phosphors in SMD type white LED was studied. It is found that due to the height of the blue LED chip, some phosphors will sink below the surface of the LED chip, resulting in lateral leakage of light, thus increasing the blue emission. The color temperature is raised. 4) the SMD type white light LED is pre-padded and the fine hollow glass beads are added into the phosphor to alleviate the phenomenon of color temperature drift caused by the deposition process of the phosphor. The practical SMD package test shows that the process has good application effect.
【學(xué)位授予單位】：東南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN104.3;TN312.8;TQ422

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 陳云霞;;LED封裝過程中出現(xiàn)若干問題的探討[J];硅谷;2014年16期

2 李俊生;趙琳;孫晶;郭瑞紅;;對丁達(dá)爾效應(yīng)的研究[J];化學(xué)教學(xué);2014年01期

3 韓絮;孫陽昭;吳建民;王祖光;方莉;;科學(xué)看待熒光燈推廣過程中的汞污染問題[J];環(huán)境保護(hù)與循環(huán)經(jīng)濟(jì);2013年05期

4 沈立;;LED,向白熾燈Say Good Night[J];環(huán)境;2013年04期

5 牟秋紅;劉月濤;彭丹;李金輝;王林;張敏;;LED封裝用甲基苯基有機(jī)硅材料的性能研究[J];有機(jī)硅材料;2013年01期

6 董向坤;杜曉晴;鐘廣明;唐杰靈;陳偉民;;GaN基倒裝焊LED芯片的熱學(xué)特性模擬與分析[J];光電子技術(shù);2012年02期

7 高南;劉偉區(qū);閆振龍;孫越;陳海生;;功率型LED封裝用高分子材料的研究進(jìn)展[J];廣州化學(xué);2012年02期

8 鄭智斌;;LED環(huán)氧灌封工藝對其可靠性的影響[J];半導(dǎo)體技術(shù);2012年06期

9 劉榮輝;何華強(qiáng);黃小衛(wèi);胡運(yùn)生;劉元紅;莊衛(wèi)東;;白光LED熒光粉研究及應(yīng)用新進(jìn)展[J];半導(dǎo)體技術(shù);2012年03期

10 宋國華;繆建文;姜斌;郁幸超;;近紫外芯片激發(fā)三基色熒光粉制作的白光LED[J];半導(dǎo)體技術(shù);2011年08期

相關(guān)博士學(xué)位論文 前1條

1 劉宗源;大功率LED封裝設(shè)計(jì)與制造的關(guān)鍵問題研究[D];華中科技大學(xué);2010年

相關(guān)碩士學(xué)位論文 前10條

1 李威;LED背光液晶電視色彩一致性的研究[D];山東大學(xué);2013年

2 詹鈺君;大功率白光LED熒光粉測試系統(tǒng)的設(shè)計(jì)與實(shí)現(xiàn)[D];武漢理工大學(xué);2012年

3 曹宇杰;高顯色指數(shù)高光效LED球泡燈的研究[D];中國計(jì)量學(xué)院;2012年

4 陳麗;大功率白光LED光源集成封裝技術(shù)研究[D];華南理工大學(xué);2011年

5 馮瀚;熒光粉沉降問題對LED光學(xué)一致性的影響[D];華中科技大學(xué);2011年

6 楊傳超;大功率LED多芯片模塊散熱器設(shè)計(jì)與封裝結(jié)構(gòu)熱阻分析[D];哈爾濱工業(yè)大學(xué);2010年

7 肖友鵬;Si襯底GaN基功率型LED芯片性能研究[D];南昌大學(xué);2010年

8 楊柳濱;LED芯片工藝參數(shù)分析測試技術(shù)的研究[D];復(fù)旦大學(xué);2009年

9 蘇達(dá);大功率LED封裝散熱性能的若干問題研究[D];浙江大學(xué);2008年

10 陳樂君;基于快速光譜分析測試系統(tǒng)的研究[D];浙江大學(xué);2006年

，

本文編號：2419030