本文選題：廢棄線路板 + 拆解��； 參考：《清華大學(xué)》2015年碩士論文

【摘要】：廢棄線路板(Printed Circuit Board,PCB)是廢棄電器電子產(chǎn)品(Waste Electrical and Electronic Equipment,WEEE)的常見部件。廢舊塑封芯片是廢棄線路板上的重要元器件,具有較高的可重用價(jià)值。在廢棄線路板拆解加熱過(guò)程中,線路板加熱不均勻很容易引起板面局部高溫,導(dǎo)致塑封芯片分層損傷,不利于重用。因此,本文進(jìn)行廢舊塑封芯片分層熱影響分析和線路板拆解加熱均勻性分析與優(yōu)化,這對(duì)實(shí)現(xiàn)廢舊塑封芯片的高價(jià)值重用具有重要意義。首先提出廢舊塑封芯片的熱力學(xué)仿真分析方法,利用該方法分析了不同拆解溫度對(duì)芯片翹曲變形、內(nèi)部結(jié)構(gòu)最大應(yīng)力分布和內(nèi)部結(jié)合面應(yīng)力分布的影響規(guī)律,并給出了舊芯片內(nèi)部的易分層區(qū)域。進(jìn)行塑封芯片界面剪切強(qiáng)度實(shí)驗(yàn),對(duì)比分析了拆解溫度的高低對(duì)新舊芯片界面強(qiáng)度的影響規(guī)律,得到了廢舊塑封芯片分層的熱影響關(guān)系,為線路板加熱均勻性分析與優(yōu)化提供理論依據(jù)。根據(jù)線路板拆解加熱均勻性分析結(jié)果,指出影響線路板加熱均勻性的關(guān)鍵因素�；跊_擊射流模型計(jì)算出熱風(fēng)與線路板之間的對(duì)流換熱系數(shù),建立了線路板表面?zhèn)鳠崮Ｐ?利用傳熱模型分析了出流高度、整流板結(jié)構(gòu)參數(shù)對(duì)線路板換熱的影響規(guī)律,利用流場(chǎng)仿真的方法分析了風(fēng)機(jī)轉(zhuǎn)速對(duì)線路板加熱均勻性的影響,最終確定了出流高度、整流板結(jié)構(gòu)參數(shù)、風(fēng)機(jī)轉(zhuǎn)速等溫區(qū)參數(shù)對(duì)線路板加熱均勻性的影響水平,為加熱溫區(qū)結(jié)構(gòu)的優(yōu)化設(shè)計(jì)提供決策支持。基于線路板加熱影響特性分析的結(jié)果,重點(diǎn)對(duì)整流板結(jié)構(gòu)參數(shù)進(jìn)行優(yōu)化設(shè)計(jì)。提出了將多孔整流板等效為多孔介質(zhì)阻抗模型的方法,利用該方法建立了整流板兩側(cè)熱風(fēng)的壓力、速度等物性參數(shù)與多孔介質(zhì)阻抗的數(shù)學(xué)關(guān)系,基于多孔介質(zhì)模型進(jìn)行了整流板阻抗的優(yōu)化設(shè)計(jì),獲得優(yōu)化后的板面阻抗分布。最后根據(jù)阻抗特性優(yōu)化結(jié)果提出了幾何拓?fù)湔{(diào)整方案,將優(yōu)化后的板面阻抗轉(zhuǎn)化為具體的整流板幾何結(jié)構(gòu),實(shí)現(xiàn)了面向線路板加熱均勻性的溫區(qū)結(jié)構(gòu)優(yōu)化設(shè)計(jì)。利用自主研制的廢棄線路板拆解設(shè)備及輔助測(cè)量?jī)x器進(jìn)行了整流板出口風(fēng)速檢測(cè)實(shí)驗(yàn)和線路板拆解升溫監(jiān)測(cè)實(shí)驗(yàn)。結(jié)果表明,整流板出口風(fēng)速的不均勻度由優(yōu)化前的31.8%降低至優(yōu)化后的8.3%,線路板加熱過(guò)程中,板面最大溫差由優(yōu)化前的50℃降低至優(yōu)化后的20℃,驗(yàn)證了整流板結(jié)構(gòu)優(yōu)化方法的合理性和優(yōu)化結(jié)果的可行性,為面向元器件重用的廢棄線路板加熱拆解提供技術(shù)支持。
[Abstract]:Waste Circuit printed Circuit (PCB) is a common component of waste Electrical and Electronic equipment (WEEE). The waste plastic seal chip is an important component of the waste circuit board, and has high reusable value. In the process of disassembling and heating the waste circuit board, the uneven heating of the circuit board can easily lead to the local high temperature of the board, resulting in the lamination damage of the plastic seal chip, which is not conducive to reuse. Therefore, it is of great significance to analyze and optimize the lamination thermal effect of waste plastic seal chip and the uniformity of circuit board disassembly and heating, which is of great significance to realize the high value reuse of waste plastic seal chip. Firstly, a thermodynamic simulation analysis method of waste plastic seal chip is put forward. By using this method, the influence of different dismantling temperatures on the warpage deformation, the maximum stress distribution of internal structure and the stress distribution of internal bonding surface are analyzed. The easily stratified region inside the old chip is also given. Experiments on the interfacial shear strength of plastic seal chip were carried out, and the effect of dismantling temperature on the interface strength of new and old chips was compared and analyzed, and the thermal effect relationship of lamination of waste plastic seal chip was obtained. It provides theoretical basis for the analysis and optimization of circuit board heating uniformity. According to the analysis results of the heating uniformity of circuit board disassembly, the key factors affecting the heating uniformity of circuit board are pointed out. Based on the impinging jet model, the convection heat transfer coefficient between the hot air and the circuit board is calculated, and the heat transfer model on the surface of the circuit board is established. By using the heat transfer model, the influence of the outlet height and the structure parameters of the rectifier board on the heat transfer of the circuit board is analyzed. By using the method of flow field simulation, the influence of fan speed on the heating uniformity of circuit board is analyzed. Finally, the influence level of outlet height, structure parameter of rectifier board, isothermal zone parameter of fan speed on the uniformity of circuit board heating is determined. It provides decision support for optimal design of heating temperature region structure. Based on the analysis of heating characteristics of circuit board, the structural parameters of rectifier board are optimized. A method of equating porous rectifier plate to porous dielectric impedance model is proposed. The mathematical relationship between the physical parameters such as pressure and velocity of hot air on both sides of the rectifier plate and the impedance of porous medium is established by using this method. Based on the porous media model, the impedance of rectifier plate is optimized and the optimized impedance distribution is obtained. Finally, according to the results of impedance characteristics optimization, a geometric topology adjustment scheme is proposed. The optimized plate surface impedance is transformed into a specific rectifier board geometry structure, and the optimal design of the temperature region structure oriented to the uniformity of circuit board heating is realized. The test of wind speed at the outlet of rectifier board and the temperature monitoring experiment of circuit board disassembly were carried out by using the disassembly equipment and the auxiliary measuring instrument of the waste circuit board developed by ourselves. The results show that the unevenness of wind velocity at the outlet of the rectifier board is reduced from 31.8% before optimization to 8.3% after optimization. During the heating process of the circuit board, the maximum temperature difference of the plate surface decreases from 50 鈩，

本文編號(hào)：1901593