能量控制模式下聚合物超声波微压印成形

Replication of polymer microstructure in energy control mode using ultrasonic embossing

针对聚合物微结构超声波压印成形中工艺窗口窄、可控性较差的问题,提出采用能量控制模式控制超声波能量,以聚甲基丙烯酸甲酯（PMMA）基片为被成形材料,通过设计对比实验,研究能量控制模式与时间控制模式对基片成形的影响.实验结果表明,在能量控制模式下,当热辅助温度65℃,超声压力400 N,超声振幅11.4μm,超声能量为700-1 000 J时,均能获得92%以上的深度复制率.通过测量热影响区聚合物在超声波作用下的温升曲线知,在相似工艺参数下,能量控制模式下聚合物的温度峰值低,处于成形区的时间长,因此该控制模式下工艺窗口宽、可控性好.

Ultrasonic embossing is a new replication technique for polymer microstructures, and it is difficult to control the embossing process, and the process window is very narrow. Aiming at solving this kind of problem, energy control mode for ultrasonic embossing is proposed in this paper. PMMA was selected as the substrate, and embossing experiments based on energy control mode and time control mode were carried out. The results show that, in the energy control mode, under the condition of heat-assisted temperature 65 ℃, ultrasonic pressure 400 N, ultrasonic amplitude 11.4 μm and ultrasonic energy range from 700 J to 1 000 J, the depth replication rate was better than 92%. The temperature test experiments for heat affected zone show that, using the similar embossing parameters, the peak temperature in energy control mode is low and the temperature over the glass transition point is long. And this is the main reason for energy control mode has wider processing window which makes the process more controllable.