基于柔性模板的微坑阵列光刻电解加工技术研究

发布时间：2018-10-21 09:16

【摘要】：微坑阵列可以改善摩擦副表面的摩擦磨损性能,减小摩擦力,降低磨损,提高摩擦副的使用寿命。微坑阵列的大面积、高精度加工技术成为一个研究重点。光刻电解加工技术是微坑阵列的一种有效加工方法。传统的光刻电解加工技术采用光刻胶作为掩模,光刻工艺复杂;电解加工后需要去除光刻胶,生产成本高,制作时间长。由于阳极工件表面的电场边缘效应,微坑阵列的大面积电解加工时,存在加工精度低等问题。针对上述问题,本文采用基于PDMS柔性模板的光刻电解加工方法进行微坑阵列的大面积、高精度加工。本文完成的研究内容主要包含以下部分:(1)采用抽真空注模的方式制作PDMS模板。提出采用电火花线切割技术制备不锈钢微群柱模具,并基于此模具制作出PDMS模板。采用一种改进的双层SU-8胶光刻工艺制备光刻胶模具,所制作的模板直径达90 mm,适用于微坑阵列的大面积加工。(2)提出一种微坑阵列的高压低流速电解加工方法。PDMS模板上方的电解液处于高压低流速状态,利用电解液的压力和重力促使PDMS模板与工件紧密贴合。试验研究了加工电压、时间、占空比对微坑形貌的影响。试验结果表明,微坑内电解产物的堆积可以抑制电场边缘效应,微坑尺寸对一定范围内的电压变化不敏感。占空比是影响微坑尺寸的重要因素,高占空比的电流效率低。试验加工出圆形阵列区域为直径40mm的微坑,微坑的边长和深度分别是94.6和18.8μm,标准差分别为0.84和0.23μm,实现了微坑阵列的大面积、高精度电解加工。(3)提出一种基于高压静液的电解加工方法。电解加工过程中,电解液处于高压强静止状态,抑制了电解产物的逸出,同时提高PDMS模板与工件的贴合度。试验研究表明高压强的电解液有助于提高微坑尺寸的光刻电解加工精度,而且压强为0.5 MPa的电解液适用于微坑阵列的高精度电解加工。(4)开展微坑阵列的大面积高精度电解加工应用。采用PDMS模板在通孔工件表面进行微坑阵列的电解加工,制备出高精度的微坑阵列。采用高压静液的方式,在回转体表面进行微坑阵列的电解加工。
[Abstract]:The microcrater array can improve the friction and wear performance of the friction pair, reduce the friction force, reduce the wear, and improve the service life of the friction pair. The large-area and high-precision machining technology of microcrater array has become a research focus. Photolithography is an effective method for machining microcrater arrays. The traditional ECM technology uses photoresist as mask, and the lithography process is complex. After ECM, the photoresist needs to be removed, the production cost is high and the production time is long. Due to the electric field edge effect on the surface of anode workpiece, the machining accuracy is low in the large area ECM of microcrater array. In order to solve the above problems, this paper adopts PDMS flexible template based lithography electrolysis machining method for large area and high precision machining of microcrater array. The main contents of this paper are as follows: (1) PDMS template is fabricated by vacuum injection. A stainless steel micro group column die was fabricated by WEDM, and PDMS template was made based on the die. An improved double-layer SU-8 lithography process was used to prepare the photoresist mould. The template diameter of 90 mm, is suitable for large area machining of microcrater array. (2) A high voltage and low velocity ECM method for microcrater array is proposed. The electrolyte above the PDMS template is in the state of high pressure and low velocity. The pressure and gravity of the electrolyte are used to make the PDMS template fit closely with the workpiece. The effects of processing voltage, time and duty ratio on the morphology of micropits were investigated. The experimental results show that the accumulation of electrolytic products in the microcrater can suppress the electric field edge effect and the size of the microcrater is not sensitive to the voltage change in a certain range. Duty cycle is an important factor affecting the size of microcrater, and the current efficiency of high duty cycle is low. Micropits with diameter 40mm in circular array region were fabricated. The side length and depth of micropits were 94.6 渭 m and 18.8 渭 m, respectively, and the standard deviations were 0.84 渭 m and 0.23 渭 m, respectively. A large area of microcrater array was realized. High precision ECM. (3) A method based on high pressure hydrostatic machining is proposed. In the process of ECM, the electrolyte is in a static state at high pressure, which inhibits the escape of the electrolysis product and improves the adhesion between the PDMS template and the workpiece. The experimental results show that the high pressure electrolyte is helpful to improve the precision of lithography with microcrater size. The electrolyte with a pressure of 0. 5 MPa is suitable for high precision ECM of microcrater array. (4) the application of large area and high precision ECM of microcrater array is carried out. The PDMS template was used to fabricate the high precision microcrater array by electrolytic machining of the through hole workpiece surface. Electrochemical machining of microcrater array was carried out on the surface of rotary body by high pressure hydrostatic method.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG662

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