本文關(guān)鍵詞：功率型LED結(jié)溫檢測(cè)與ANSYS仿真分析　出處：《杭州電子科技大學(xué)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

  更多相關(guān)文章： 發(fā)光二極管 結(jié)溫測(cè)量 ANSYS仿真 紅外測(cè)溫 電壓法測(cè)溫

【摘要】：LED(light emitting diode,發(fā)光二極管)是一種可將電能轉(zhuǎn)變?yōu)楣饽艿陌雽?dǎo)體發(fā)光器件,本文主要圍繞LED結(jié)溫?zé)釂?wèn)題所引起的光電特性影響而展開(kāi)研究,主要提出間接LED結(jié)溫測(cè)試方案與ANSYS仿真分析。間接式LED結(jié)溫測(cè)試方案主要采用電壓法測(cè)量結(jié)溫的原理,由半導(dǎo)體伏安特性關(guān)系式和反向飽和電流關(guān)系式,推導(dǎo)出LED結(jié)溫與正向電壓存在近似線性關(guān)系,即電壓法的原理推導(dǎo)。基于這個(gè)原理,采用最小二乘法線性擬合求出小電流下的K系數(shù)值,并求出結(jié)溫。通過(guò)對(duì)同一批次同一型號(hào)的LED器件進(jìn)行K系數(shù)值測(cè)試,證實(shí)具有相同制造工藝的同一批次同一型號(hào)LED的K系數(shù)值很接近,K系數(shù)最大最小差值僅為5.7%。論文對(duì)小電流結(jié)溫測(cè)試中存在的不足進(jìn)行相關(guān)闡述,提出大電流LED結(jié)溫測(cè)試方案,大電流LED結(jié)溫測(cè)試方案基于LED瞬態(tài)熱學(xué)方程式,根據(jù)瞬態(tài)熱學(xué)方程式推算出LED導(dǎo)通的初始電壓,并與結(jié)溫進(jìn)行擬合得到大電流下的K系數(shù)值,根據(jù)此K系數(shù)值計(jì)算出最后的工作結(jié)溫。實(shí)驗(yàn)對(duì)六組功率型LED樣品分別進(jìn)行小電流結(jié)溫測(cè)試、大電流結(jié)溫測(cè)試和紅外熱成像測(cè)試,通過(guò)對(duì)測(cè)試結(jié)果進(jìn)行比較分析,證實(shí)大電流測(cè)試方案的可行性。ANSYS仿真分析主要是結(jié)合Pro/E強(qiáng)大的建模功能和ANSYS完善的熱分析功能,模擬分析LED器件溫度分布。采用薄膜鉑電阻精確測(cè)量LED器件局部溫度,根據(jù)局部溫度確定ANSYS熱仿真中的空氣對(duì)流系數(shù)的取值,從而使得仿真結(jié)果更加準(zhǔn)確。將此方法分別與標(biāo)準(zhǔn)電壓法和紅外熱像法實(shí)測(cè)結(jié)溫結(jié)果作對(duì)比,利用該方法獲得的仿真結(jié)果與電壓法和紅外熱像法實(shí)測(cè)結(jié)果具有很好的一致性,實(shí)驗(yàn)結(jié)果說(shuō)明模型建立和ANSYS仿真分析過(guò)程是正確的,證實(shí)ANSYS熱仿真分析可以作為一種有效的LED結(jié)溫估測(cè)方法。同時(shí)利用ANSYS有限元熱仿真法還分析了三芯片COB封裝LED溫度分布,證實(shí)在透明硅膠區(qū)域范圍內(nèi),隨著芯片間距的不斷增大,三芯片表面溫度分布越來(lái)越均勻,其最高芯片結(jié)溫也隨著芯片間距的增大而變小。
[Abstract]:LED(light emitting diode is a semiconductor light-emitting device that can convert electrical energy into light energy. This paper focuses on the influence of the photoelectric characteristics caused by the temperature and heat problem of LED junction. Indirect LED junction temperature measurement scheme and ANSYS simulation analysis are put forward. Indirect LED junction temperature measurement scheme mainly adopts the principle of voltage method to measure junction temperature. An approximate linear relationship between the temperature and the forward voltage of the LED junction is derived from the relationship between the volt-ampere characteristic of the semiconductor and the reverse saturation current, that is, the principle of the voltage method. The value of K coefficient and junction temperature are obtained by using the least square linear fitting method. The K coefficient values of the same batch and the same type of LED devices are tested. It is proved that the K coefficient value of the same batch and same type LED with the same manufacturing process is very close to the maximum and minimum difference of K coefficient of the same batch is only 5.7. the deficiency of the small current junction temperature test is expounded in this paper. A high current LED junction temperature measurement scheme is proposed. The high current LED junction temperature measurement scheme is based on the LED transient thermal equation, according to the transient thermal equation to calculate the initial voltage of LED conduction. The value of K coefficient under high current is obtained by fitting with junction temperature, and the final working junction temperature is calculated according to the value of K coefficient. Six groups of power type LED samples are tested with small current junction temperature. High current junction temperature test and infrared thermal imaging test, through the test results are compared and analyzed. It is proved that the feasibility of high current test scheme... ANSYS simulation analysis is mainly combined with the powerful modeling function of Pro/E and the perfect thermal analysis function of ANSYS. The temperature distribution of LED device is simulated and analyzed. The local temperature of LED device is accurately measured by thin film platinum resistance, and the value of air convection coefficient in ANSYS thermal simulation is determined according to the local temperature. So that the simulation results are more accurate. The method is compared with the results measured by standard voltage method and infrared thermal image method respectively. The simulation results obtained by this method are in good agreement with the measured results by the voltage method and the infrared thermal image method. The experimental results show that the modeling and ANSYS simulation are correct. It is proved that ANSYS thermal simulation can be used as an effective method to estimate the junction temperature of LED, and the LED temperature distribution of three-chip COB package is also analyzed by using ANSYS finite element method. It is proved that in the region of transparent silica gel, with the increasing of chip spacing, the surface temperature distribution of the three chips becomes more and more uniform, and the highest chip junction temperature becomes smaller with the increase of chip spacing.
【學(xué)位授予單位】：杭州電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TN312.8

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本文編號(hào)：1423663