基于柔性掩膜的高可靠性玻璃喷砂微加工工艺

喷砂是一种高效率的表面加工技术,将其应用于微加工领域可以实现对玻璃、硅和陶瓷等脆性材料的选择性刻蚀.本文着重探讨了掩膜性质及刻蚀条件对喷砂微加工刻蚀效率及刻蚀形貌的影响.实验中对柔性聚二甲基硅氧烷(PDMS)掩膜微结构的制备方法进行了改良,即借助精密切削工艺实现PDMS/SU-8微结构边界精确互补成形,制备了可以满足选择性刻蚀要求的掩膜结构.同时改变实验条件,研究了掩膜开口尺寸、压缩空气压强以及砂材粒径对喷砂速率及刻蚀形貌的影响.结果表明:适当增大压缩空气气压有助于待刻蚀材料从塑性到脆性的转变,刻蚀速率有明显提高.而将砂材粒径从30μm减小至20μm,可以改善成形形貌.初步研究结果表明,文中提出的玻璃喷砂微加工方法能够满足深度为500μm的玻璃通孔阵列的刻蚀要求.

High-Reliable Powder Blasting Micro-Machining Technology of Glass with Elastomer Mask

Powder blasting is an efficient surface machining technology. When applied to micro-maching, it can selectively etch substrate materials, such as glass, silicon, ceramics and other brittle materials. This paper focused on the influence of mask＇s properties and etching conditions on the erosion rate and the etched surface morphology of powder blasting micro-machining. Specifically, we modified the fabrication methods of the polydimenthylsiloxane （PDMS） mask structure to meet the requirements of the selective etching micro-machining. That is, through a precise cutting process, we successfully fabricated the micro structure of PDMS/SU-8, whose boundaries are exactly complementary with each other. Meanwhile, we changed etching conditions to study the influence of the compressed air pressure, the scale of mask structure and the particle＇s size on the powder blasting rate and the etched surface morphology. Experimental results show that appropriate increment of the compressed air pressure can improve the etching transition from ductile etching to brittle etching, which raises the erosion rate obviously. Moreover, the surface morphology can be improved by decreasing the particle＇s size from 30 μm to 20 μm. Preliminary results prove that the powder blasting micro-machining technology of glass presented in this paper can meet the requirement of fabricating the array of 500 μm-depth vias through the glass substrate.