【作者】 王冲；

【导师】 安茂忠；

【作者基本信息】 哈尔滨工业大学 ， 化学工程与技术， 2013， 博士

【摘要】 印刷电路板（Printed-Circuit-Board, PCB）是电子产品的必要组成部分，特别是多层印制电路板的出现为电子产品向小型化、便捷化、智能化发展提供了基础。通孔电镀铜是实现多层PCB层与层之间导通的主要途径之一，也是当今PCB制造工艺中非常重要的一项技术。但是在直流电镀过程中，由于通孔内的电流密度分布不均匀，为了在孔内获得均匀镀层，使用有机添加剂是一个有效而且经济的方法，但完全通过实验筛选添加剂是一项非常费时费力的工作。在本文中，使用分子动力学（MD）模拟的方法对4种整平剂候选物进行预测，并设计了7种复合添加剂体系，对负载通孔的PCB板进行电镀，考察了添加剂体系的均镀能力，利用电化学测试、原子力显微镜（AFM）、X射线光电子能谱（XPS）和量子化学计算手段对添加剂在阴极表面的行为和作用机理进行了探究。通过动态极化曲线对比实验，选定了促进剂噻唑啉基二硫代丙烷磺酸钠（SH110）和抑制剂聚乙二醇（PEG, MW=10000），认为SH110是一种促进剂和抑制剂或整平剂的结合体。使用分子动力学方法预测了两种新型整平剂：N-丁基-N-甲基溴化哌啶(PP₁₄Br)和氯化硝基四氮唑蓝（NTBC），并预测出与健那绿B（JGB）有类似结构的藏红T（ST）不是一种有效的整平剂。对SH110进行的分子动力学模拟和电化学测试表明其可以作为通孔电镀封孔的单一添加剂。使用SH110和PEG分别做促进剂和抑制剂，设计了4种促进剂-抑制剂-整平剂和3种促进剂-抑制剂-走位剂体系。利用预测和设计的添加剂体系，使用直流电镀的方法对不同厚径比和不同孔径的PCB通孔进行了电镀实验，验证了前文的分析和添加剂体系的性能，并探索了添加剂的较佳使用浓度范围。使用通孔剖孔的方法检测了孔内镀层的均匀程度，使用扫描电子显微镜（SEM）观察了镀层的微观结构。结果表明：当SH110浓度为10mg/L时，经过短时间电镀，就出现了“蝴蝶现象”，经过18h电镀，实现了超填充电镀封孔。对厚径比为10的通孔进行电镀，通过调节添加剂的使用浓度，得到了4种均镀能力超过90%的优良添加剂体系。这4种添加剂体系和最佳使用浓度为：SH110（1mg/L）-PEG （100mg/L）-PP₁₄Br （20mg/L），SH110（1mg/L）-PEG （200mg/L）-NTBC （3mg/L）， SH110（1mg/L）-PEG （200mg/L）-JGB（1mg/L），SH110（1mg/L）-PEG （100mg/L）-脂肪胺聚氧乙烯醚（AEO,10mg/L）。同时验证了ST不是一种有效整平剂的预测。对于厚径比为20的通孔电镀，使用SH110（50mg/L）-PEG （200mg/L）-PP₁₄Br （40mg/L）时，得到的均镀能力为76.1%，达到了对厚径比为20的通孔的电镀要求。使用旋转圆盘电极，结合动态极化曲线、恒电流E^t曲线对添加剂的电化学行为进行了测试，使用AFM、XPS对添加剂的吸附行为进行了表征，使用量子化学计算的方法获得并对比了一些添加剂的电子结构信息，系统研究了添加剂在通孔电镀过程中的作用机理。结果表明：SH110是一种促进剂和抑制剂或整平剂的结合体，它可以在铜表面形成一层吸附膜，体现出抑制剂的作用方式，这种抑制作用更容易出现在阴极的强对流区；其促进作用主要出现在阴极的弱对流区，这是在通孔电镀中出现“蝴蝶现象”和实现超填充完美封孔的原因。整平剂PP₁₄Br和NTBC的加入不仅增大了镀液的阴极极化，而且增大了不同强度对流下的阴极电势差值，这使得Cu²⁺在孔口等强对流区受到的抑制作用更强，有助于提升孔内镀层的均匀性。NTBC会在阴极铜表面形成一个吸附层，此吸附层导致了对Cu²⁺沉积过程的强烈抑制作用。JGB可以影响阴极电势和阴极极化，而ST对于阴极极化和阴极电势几乎没有影响。JGB分子的最高占据轨道（HOMO）值大于ST的HOMO值，表明JGB具有更强的电子供给能力，这使得JGB能够通过向铜原子的空d轨道贡献电子成键而形成吸附，这种吸附作用最终使得其可做为整平剂使用，而ST不具有这种作用。JGB在铜表面的化学吸附过程中，对氨基偶氮苯和N=N区域的作用比季铵化的N原子的作用强得多，而ST不具有这种结构，这很好地解释了ST不是有效整平剂的原因。更多还原

【Abstract】 Printed circuit board （PCB） is the necessary component of electronic products,and the emergence of multi-layer PCB helps to develope small, convenient,intelligent electronic products. Through-hole （TH） copper electroplating is one ofthe main methodes to realize the conduction among PCB layers, which is also veryimportant technology of PCB manufacturing process. It is very difficult to obtaincoatings with uniform thickness using traditional plating bacause of the unevendistribution of current density in the TH during DC plating process. For obtaining anuniform plating in the TH, using organic additives is an effective and economicalway. However, choosing and exploration of additives by experiments are verytime-consuming and laborious. In this paper,4levelers and7additive systems werepredicted using molecular dynamics （MD） simulation, and the TH wereelectroplated using these additives. The uniform power （UP） of additives wereexamined, and the actions of additives on the surfaces of cathodes and mechanismswere explored by electrochemical test, atomic force microscopy （AFM）, X-rayphotoelectron spectroscopy （XPS） and quantum chemical calculations.The accelerator thiazoline dithio-propane sulfonate poly （ethylene glycol）（SH110） which were considered as a combination of accelerator and inhibitor orleveler agent and inhibitor PEG, MW=10000were selected by electrochemicalcomparative experiments. Two new levelers of N-butyl-N-bromide in piperidine(PP₁₄Br) and nitro blue tetrazolium （NTBC） were predicted using MD, andSafranine T （ST） with the structure similar to Janus Green B （JGB） was predicted asan uneffective leveler. The results of MD simulations and electrochemical testsabout SH110indicated that SH110could be used as a single TH plating sealingadditive. Accelerator-inhibitor-leveler and accelerator-inhibitor-walk agent systemswere designed by using SH110and PEG as accelerators and inhibitors, respectively.THs on PCB with different aspect ratio and hole diametres were electroplatedby DC using predicted and designed additive systems. The previous analysis and theproperties of of additive systems were verified and the preferred concentration scopeof additives were explored. The uniformity of the plating in TH was examined fromthe view of cross sections of THs. SEM results indicated that butterfly technology（BF） emerged after short-time electroplating and superfilling perfect sealinggenerated after18h electroplating when the concentration of SH110was10mg/L.Four excellent additive systems with UP more than90%were obtained for THelectroplating with the aspect ratio of10by adjusting the concentration of additives. These4kinds of additive systems were SH110（1mg/L）-PEG （100mg/L）-PP₁₄Br（20mg/L）, SH110（1mg/L）-PEG （200mg/L）-NTBC （3mg/L）, SH110（1mg/L）-PEG（200mg/L）-JGB （1mg/L） SH110（1mg/L）-PEG （100mg/L）-fatty amines, andpolyoxyethylene ether （AEO,10mg/L）, respectively. The prediction of ST whichwas not an effective leveler was also verified. The UP was76.1%in TH with aspectratio of20using SH110（50mg/L）-PEG （200mg/L）-PP₁₄Br （40mg/L）, which metwith the requirement of the TH with a aspect ratio of20in TH electroplating.The electrochemical behavior of the additives were tested by rotating diskelectrode combination of dynamic polarization curves and constant current E^tcurve, and adsorption behaviors of the additives were characterized using AFM andXPS. Electronic structure informations about some additives were obtained andcompared by quantum chemical calculations and the mechanisms of actions of theadditives in the Th electroplating process were studied. The results showed thatSH110was a combination of an accelerator and inhibitor or a leveler, which may ledto the formation of adsorbed film on the copper surface and reflected theperformance of SH110as an inhibitor. The inhibition of SH110could take part instrong convection zone of the cathode more easily, and the acceleration mainlyappeared in weak convection zone of the cathode, which accounted for BF andsuperfilling during the TH eclectroplating. The addition of levelers of PP₁₄Br andNTBC not only increased the cathodic polarization of the bath, but also increasedcathode potential differences at different convection strength, which inhibitedcopper ions in the area of convection at the mouth of TH more strongly and helpedto inhance the uniformity of plating inside the holes. NTBC could lead to theformation of an absorption layer on the copper cathode surface, which caused stronginhibition of copper ion deposition. JGB had an impact on the cathode potential andcathode polarization, and ST had little effect on the cathode potential and cathodepolarization. The highest occupied molecular orbital （HOMO） value of JGBmolecular was larger than that of ST, which demonstrated that JGB having astronger electron-donating ability could be adsorped by contributing electrons toempty d orbital of copper atom and bonding. The adsorption made JGB as a levelereventually but ST did not have the adsorption. The actions of aminoazobenzene andN=N were much stronger than that of quaternized N atom during the chemicalsorption of JSB on copper surface, and ST did not have such a structure, whichexplained that ST was not effect leveler.更多还原