水辅助激光诱导等离子体刻蚀Pyrex7740玻璃技术研究

发布时间：2018-04-17 16:02

本文选题：激光刻蚀 + 等离子体　；参考：《温州大学》2017年硕士论文

【摘要】：由于Pyrex7740玻璃(一种硼硅酸盐玻璃)具有良好的生物适应性、高的热阻和电绝缘性能、优良的光学性能,在一定温度内热膨胀系数与硅非常接近,并且含有适量的Na+和K+,非常适合与硅片进行阳极键合,因而越来越多的应用于生物、射频、光学等MEMS器件,微传感器和封装技术等领域。随着微机电系统(micro-electro-mechanical-system, MEMS)研究和应用的快速发展,MEMS器件对封装的可靠性、器件的互联和尺寸精度的要求越来越高。因此对Pyrex7740玻璃的加工精度和表面质量提出了非常高的加工要求。但由于Pyrex7740玻璃属于硬脆材料,具有脆性高,断裂韧性低,材料的弹性极限和强度极限非常接近。当材料所承受的载荷超过强度极限时就会发生断裂破坏,在已加工玻璃表面产生裂纹和崩边,严重影响Pyrex7740玻璃表面质量和性能。到目前为止,该材料的精密加工仍然是一件困难的事情。本论文针对目前采用激光直写加工Pyrex7740玻璃要求能量密度阈值太高,采用其他方法加工则存在加工精度低、易崩边、刻蚀深宽比小、易引入污染杂质和加工效率低等问题,提出了一种水辅助激光诱导等离子体背部刻蚀Pyrex7740玻璃的新方法。通过加工试验和理论分析探究了激光能量密度、激光加工次数对平均刻蚀深度的影响,以及刻蚀过程中去离子水的作用。实验结果表明:平均刻蚀深度与激光能量密度和激光加工次数有较大的关系;只有在有去离子水辅助的情况下才能实现持续刻蚀,在没有去离子水辅助的情况下,激光能量密度为3.4 J/cm2时,能刻蚀的最大深度为2.8 μm。通过控制变量法研究了激光能量密度、加工速度、重复频率、刻蚀次数等激光加工参数对水辅助激光诱导等离子体刻蚀Pyrex7740玻璃刻蚀质量(包括边缘是否齐整、崩边、碎裂等)的影响规律。最后,选择合适的加工参数,成功制备了沟槽宽度为77.8μm,刻蚀深度为20.4μm,刻蚀边缘齐整无明显崩边现象,槽底光滑的缩小型十字通道微流控芯片。同时,本论文提出的水辅助激光诱导等离子体刻蚀Pyrex7740玻璃工艺,也可以应用在石英玻璃、水晶、透明陶瓷等其他光学透明介质的微结构刻蚀上,有望在MEMS器件的制造和封装技术领域得到广泛的应用。
[Abstract]:Because Pyrex7740 glass (a borosilicate glass) has good biological adaptability, high thermal resistance and electrical insulation, excellent optical properties, at a certain temperature the thermal expansion coefficient is very close to silicon, and contains a proper amount of Na and K,It is very suitable for anode bonding with silicon wafer, so it is more and more used in biology, radio frequency, optics and other MEMS devices, microsensors and packaging technology and so on.With the rapid development of research and application of micro-electro-mechanical system (MEMSs), the requirements of packaging reliability, interconnection and dimensional accuracy of MEMS devices are becoming higher and higher.Therefore, the machining accuracy and surface quality of Pyrex7740 glass are very high.However, because Pyrex7740 glass is a hard brittle material with high brittleness and low fracture toughness, the elastic limit and strength limit of the material are very close.When the load of the material exceeds the strength limit, the fracture will occur, and cracks and breakdowns will occur on the surface of the processed glass, which will seriously affect the surface quality and properties of the Pyrex7740 glass.Up to now, the precise processing of this material is still a difficult task.In this paper, the energy density threshold is too high for Pyrex7740 glass fabricated by laser direct-writing, but other processing methods have some problems, such as low machining precision, easy breakage, low ratio of etching depth to width, easy introduction of contaminated impurities and low processing efficiency.A new water-assisted laser-induced plasma back etching method for Pyrex7740 glass is proposed.The effects of laser energy density, laser processing times on the average etching depth and the role of deionized water in the etching process were investigated through processing experiments and theoretical analysis.The experimental results show that the average etching depth is closely related to the laser energy density and laser processing times, and that the continuous etching can be realized only with the aid of deionized water, and without the aid of deionized water,When the laser energy density is 3.4 J/cm2, the maximum depth of energy etching is 2.8 渭 m.The effect of laser processing parameters, such as laser energy density, processing speed, repetition rate and etching times, on the etching quality of water-assisted laser-induced plasma etching of Pyrex7740 glass was studied by controlling variable method.The law of influence of fragmentation, etc.Finally, a narrow cross channel microfluidic chip with a groove width of 77.8 渭 m and a etching depth of 20.4 渭 m was successfully fabricated with suitable machining parameters.At the same time, the water-assisted laser-induced plasma etching process proposed in this paper can also be applied to the microstructure etching of quartz glass, crystal, transparent ceramics and other optical transparent media.It is expected to be widely used in manufacturing and packaging of MEMS devices.
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ171.6

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