Research of 3D Printing Technology for Polyimide Film based on Micropen Direct-writing

Micropen direct-writing is a feasible and viable method for low cost, flexible and rapid manufacturing for polyimide materials in microelectronic packaging. In this paper, two-step synthetic process of 4,4’-oxybisbenzenamine (ODA), pyromellitic dianhydride (PMDA) and N,N-dimethylacetamide (DMAc) is used to synthesize polyimide precursors. Based on sintering solidification and secondary blade-coating verification of polyimide precursors, the optimized concentration is selected for subsequent micropen direct-writing experiments. Through micropen direct-writing tests with the choices of process parameters such as printing speed, driving pressure, pinhead diameter, and direct-writing height, mutli-layer polyimide film is fabricated directly. The means of tape and tensile test of adhesive force and measurement of film thickness is used to study and analyze performance of polyimide film. The results show that the optimized concentration of polyimide precursors is 0.3g/ml; the exceeding 100μm in thickness of mutli-layer polyimide film is printed with 5mm/s of printing speed, 0.15MPa of driving gas pressure, 0.31mm of pinhead diameter, and 0.18mm of direct-writing height, which thickness presents M-shaped distribution; the classification of adhesion between polyimide film and aluminum substrate is 5B; then, all polyimide film of specimens still attach to the surface of aluminum substrate tightly and there is no cracking and warping at the junction.