四氟化碳等离子体处理对聚酰亚胺介电性能的影响

采用等离子体活化的方法，使用四氟化碳（CF4）气体，对印刷线路板常用基材聚酰亚胺薄膜进行了处理，将含氟基团引入到聚酰亚胺薄膜表面。通过测量材料表面的接触角、x射线光电子能谱分析等，验证了通过等离子体处理，含氟基团成功引入了聚酰亚胺薄膜表面。通过改变等离子体处理的功率及反应时间，研究了不同处理条件对聚酰亚胺薄膜介电常数和介电损耗的影响。结果显示：随着处理功率和处理时间的增加，聚酰亚胺薄膜的介电常数和介电损耗在低频区域有显著的降低（频率范围1～100Hz）。在最优条件下，聚酰亚胺薄膜的介电常数从平均2．7降至平均1．9（频率范围1～100Hz），介电损耗正切值从平均0．145降至平均0．06左右（频率范围1～100Hz）。

Influence of CF4 plasma treatment on dielectric properties of polyimide film

The polyimide film used in printed substrate is treated by CF4 plasma activation, and fluoric group is introduced to the surface of polyimide film. The results of the experiment are verified by measuring the contact angle and X-ray photoelectron spectrosco- py. The influence of different conditions on the dielectric constant and dielectric loss of polyimide film is studied by changing the power and reaction time of plasma activation. The results show that with treatment power and treatment time up, the dielectric constant and di- electric loss obviously drops in low frequency area （1～ 100 Hz）. At the optimized condition, the average dielectric constant changes from 2. 7 to 1.9 （ 1 ～ 100 Hz）, and the average dielectric loss changes from 0. 145 to 0. 06 （ 1 ～ 100 Hz）.