基于电化学刻蚀与微电铸工艺的微流控芯片模具制作

为解决微流控芯片模具在微电铸工艺中铸层与基底结合力差的问题,在光刻工艺的基础上,采用掩膜电化学刻蚀和微电铸相结合的方法,制作出了结合力较好的镍基双十字微流控芯片模具。针对掩膜电化学刻蚀的工艺参数进行了试验研究,选定了制作微流控芯片模具的最佳工艺参数,解决了酸洗引起胶膜脱落失效、刻蚀引起侧蚀等问题。使用剪切强度表征界面结合强度,运用剪切法测量了微电铸层与基底的剪切强度,定量分析了酸洗工艺和刻蚀工艺的参数对界面结合强度的影响。试验结果表明,酸洗20s后电铸层与基底的剪切强度相对于直接电铸提高了98.5%,刻蚀5min后剪切强度提高了203.6%。刻蚀5min后的剪切强度相对于酸洗20s后电铸的剪切强度提高了53.0%。本文提出的方法能够有效提高铸层与基底的界面结合强度,延长微流控芯片模具的使用寿命。

Fabrication of Microfluidic Chip Mold Based on Electrochemical Etching and Micro-Electroforming

The performance of microfluidic chip mold is subject to the adhesion strength between electroform-ing layer and substrate in micro-electroforming process. In order to remedy this defect, a novel, lithograph-based method combining through-mask electrochemical etching and micro-electroforming is presented, by which the nickel double cross microfluidic chip mold with high adhesion has been successfully fabricated. According to experimental studies on process parameters, not only optimal parameters were yielded, but also issues like the failure of interfacial delamination due to pickling and lateral corrosion caused by electrochemical etching were further solved. The interface adhesion strength can be determined by shearing strength between electroforming layer and substrate so that the influence of pickling and etch-ing on interfacial adhesion strength can be analyzed quantitatively. The results of the experiments indicate that the shearing strength after pickling (25℃, 20s) and etching(30℃, 5min) is increased by 98.5％ and 203.6％ respectively, compared with that of untreated samples. Furthermore, the shearing strength of samples etched is 53.0％ higher than that of samples after pickling treatment. The method presented in this paper can effectively improve the adhesion strength between the electro-forming layer and the substrate. Additionally, the service life of microfluidic chip mold can be prolonged.The performance of microfluidic chip mold is subject to the adhesion strength between electroform-ing layer and substrate in micro-electroforming process. In order to remedy this defect, a novel, lithograph-based method combining through-mask electrochemical etching and micro-electroforming is presented, by which the nickel double cross microfluidic chip mold with high adhesion has been successfully fabricated. According to experimental studies on process parameters, not only optimal parameters were yielded, but also issues like the failure of interfacial delamination due to pickling and lateral corrosion caused by electrochemical etching were further solved. The interface adhesion strength can be determined by shearing strength between electroforming layer and substrate so that the influence of pickling and etch-ing on interfacial adhesion strength can be analyzed quantitatively. The results of the experiments indicate that the shearing strength after pickling (25℃, 20s) and etching(30℃, 5min) is increased by 98.5％ and 203.6％ respectively, compared with that of untreated samples. Furthermore, the shearing strength of samples etched is 53.0％ higher than that of samples after pickling treatment. The method presented in this paper can effectively improve the adhesion strength between the electro-forming layer and the substrate. Additionally, the service life of microfluidic chip mold can be prolonged.