探討聚亞醯胺與金屬層之介面破壞行為

Abstract

探討聚亞醯胺與金屬層 之介面破壞行為

研究生：王泰元 指導教授：蔡佳霖 博士

國立交通大學機械工程學系碩士班

摘 要 本研究著重在調查具有不同原子間作用力時polyimide(PI)聚合物與膠黏接合面金屬層之間的介面間破壞現象。藉由分子動力模擬，施加負載於膠黏接合面(三明治)結構─將PI夾於上下兩層薄金屬板間，進行拉伸測試，並討論三種不同程度的凡得瓦(van der Waals, vdW)作用力下PI與金屬板的破壞現象。結果指出當分子間的vdW作用力較大時，PI變得較為脆性，其降伏強度以及楊氏係數皆上升，而在三明治介面間連結的部份，當PI表現出較脆的性質時，破壞過程(從裂縫成長開始到結束)相當的短，幾乎為瞬間的破壞；而另外一方面，當凡得瓦力較弱時，則表現出破壞過程較長的延性破壞。此外，在不同溫度下考慮水氣對於PI的影響，大致上 2 wt%的水氣可以強化其勁度，並且這個強化的效果在低溫時更加明顯。在未來將針對水氣對於PI與金屬板介面間破壞的影響進行研究。

Investigating the interfacial failure between polyimide and metal layer

Student : Tai-Yuan Wang Advisor : Dr. Jia-Lin Tsai

Department of Mechanical Engineering

National Chiao Tung University

Abstract This research aims to investigate the interfacial failure between the polyimide polymer and the metal layer associated with different atomistic interaction. Three different degrees of vdW interactions between the polyimide chains were considered in characterizing the mechanical behaviors of the bulk polyimide polymer as well as the interfacial bonding strength. The failure between the polyimide and metal sheet was evaluated by performing tensile loading on the designed sandwich structures with polyimide embedded with the thin metal sheet using molecular dynamic simulation. Results indicated that when the vdW interaction between the molecular chains is getting stronger, the polyimide is becoming brittle resulting in the increase of the yielding stress as well as the modulus. For the interfacial bonding, it is found that when the polyimide is brittle, the failure process (failure begin to failure end) is quite short and almost close to sudden failure. On the other hand, when the extent of vdW interaction is reducing, the associated failure mechanism is dominated by the ductile failure in which the failure process is longer. In addition, the moisture is taken into account in the modeling of the polyimide polymer at different temperatures. Basically, 2 wt% moisture can enhance the stiffness of the polyimide and moreover, the enhancement is more significant as the temperature is lower. In the future, the investigation will be focusing on the influence of moisture on the interfacial failure between the polyimide polymer and the metal sheet.