本文關(guān)鍵詞： LED 光通量 壽命 激活能 加速試驗(yàn) 可靠性　出處：《北京交通大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：發(fā)光二極管LED(light-emitting diode)近幾年來(lái)在我們的日常生活中并不陌生,已經(jīng)成為第四代照明光源。然而,其理論壽命長(zhǎng)達(dá)數(shù)10萬(wàn)小時(shí),與實(shí)際壽命有很大的差別,在國(guó)際上目前沒(méi)有關(guān)于LED照明產(chǎn)品壽命評(píng)估的統(tǒng)一標(biāo)準(zhǔn)。因此,如何快速有效的評(píng)估其壽命成為照明領(lǐng)域迫切需要解決的問(wèn)題。本論文針對(duì)LED球泡燈,提出了一種快速評(píng)價(jià)壽命的方法。為方便建立不同環(huán)境溫度下加速應(yīng)力與LED照明產(chǎn)品壽命之間的聯(lián)系,需要知道不同環(huán)境溫度對(duì)應(yīng)的具體LED結(jié)溫大小以及LED的激活能,所以要測(cè)試結(jié)溫和激活能。因此,本論文的主要工作如下:(1)進(jìn)行了 LED激活能的計(jì)算研究,通過(guò)恒定溫度加速壽命試驗(yàn),測(cè)試出在兩個(gè)不同環(huán)境溫度下產(chǎn)品的光通量,利用指數(shù)衰減模型和阿倫尼斯模型計(jì)算出了LED產(chǎn)品的激活能。由于計(jì)算激活能時(shí)需要知道LED的結(jié)溫,所以還進(jìn)行了 LED結(jié)溫的測(cè)試試驗(yàn),通過(guò)正向結(jié)電壓法,計(jì)算出了 LED球泡燈的溫度系數(shù)以及在不同溫度下工作時(shí)的結(jié)溫。(2)對(duì)白光LED球泡燈快速評(píng)估壽命進(jìn)行了研究,提出了三步法。第一步粗評(píng),根據(jù)LED產(chǎn)品的固有屬性,給出LED壽命的一個(gè)大致區(qū)間;第二步,通過(guò)加速壽命試驗(yàn),預(yù)估出壽命;第三步,為了得到較為科學(xué)合理的預(yù)期壽命,充分考察次要因素的影響,借助模糊數(shù)學(xué)工具,采取模糊評(píng)判的方法對(duì)第二階段給出的產(chǎn)品預(yù)期壽命值加以必要的修正。鑒于實(shí)驗(yàn)條件的限制與未聯(lián)系下專家填寫(xiě)問(wèn)卷調(diào)查表,第一步與第三步只是給出了一個(gè)粗略的方案。在第二步中,為了快速評(píng)估壽命,設(shè)計(jì)了可以縮短試驗(yàn)時(shí)間的加速壽命試驗(yàn),在不改變老化機(jī)理的前提下,以溫度作為加速應(yīng)力,光通量的衰減作為失效判據(jù),在2000h內(nèi)對(duì)LED的壽命做出了評(píng)估。對(duì)試驗(yàn)樣品在三種不同溫度下進(jìn)行了恒溫加速壽命試驗(yàn),通過(guò)測(cè)試樣品在三種不同溫度下在不同時(shí)間的光通量,對(duì)產(chǎn)品的壽命使用威布爾分布描述,加速壽命使用阿倫尼斯模型描述,結(jié)合最小二乘法對(duì)所測(cè)得的光通量數(shù)據(jù)經(jīng)過(guò)數(shù)學(xué)計(jì)算和統(tǒng)計(jì)分析,最終外推出了在常溫(25℃)下LED球泡燈的壽命。三步法是本論文的創(chuàng)新之處。
[Abstract]:Light emitting Diode (LED(light-emitting) has become a 4th generation lighting source in our daily life in recent years. Its theoretical life span is up to 100,000 hours, which is very different from the actual life. There is no uniform standard of LED lighting product life evaluation in the world at present. How to evaluate its life quickly and effectively has become an urgent problem in the field of lighting. This paper aims at LED bulb lamp. In order to establish the relationship between the accelerated stress and the life of LED lighting products at different ambient temperatures, a rapid method for evaluating the life of LED lighting products is presented in this paper. We need to know the specific LED junction temperature corresponding to different ambient temperatures and the activation energy of LED, so we need to test the junction mild activation energy. The main work of this thesis is as follows: (1) the LED activation energy is calculated and studied. The luminous flux of the product at two different ambient temperatures is measured by accelerated life test at constant temperature. The activation energy of LED products was calculated by exponential attenuation model and Arrhenis model. Because of the need to know the junction temperature of LED when calculating the activation energy, the test of LED junction temperature was also carried out. By the method of forward junction voltage, the temperature coefficient of LED bulb lamp and the junction temperature of white light LED bulb lamp working at different temperature were calculated and the rapid evaluation life of white light LED bulb lamp was studied. In this paper, a three-step method is proposed. The first step of rough evaluation is to give an approximate range of LED life according to the inherent properties of LED products. The second step is to estimate the life by accelerated life test. The third step, in order to obtain a more scientific and reasonable life expectancy, fully investigate the influence of secondary factors, with the help of fuzzy mathematics tools. The method of fuzzy evaluation is adopted to modify the life expectancy of the second stage. In view of the limitation of the experimental conditions and the lack of contact, experts fill out the questionnaire. The first and third steps only give a rough scheme. In the second step, in order to evaluate the life quickly, the accelerated life test which can shorten the test time is designed, without changing the aging mechanism. Using temperature as acceleration stress and luminous flux attenuation as failure criterion, the lifetime of LED was evaluated in 2000h. The constant temperature accelerated life test was carried out at three different temperatures. By testing the luminous flux of the sample at three different temperatures at different time, the life of the product is described by Weibull distribution, and the accelerated life is described by the Arrhenis model. Combined with the least square method, the lifetime of the LED bulb lamp at 25 鈩，

本文編號(hào)：1453895