Mixed Rigid and Flexible Component Design for High-Performance Polyimide Films

Abstract

To develop the polyimide (PI) which is closely matched to the coefficient of the thermal expansion (CTE) of copper, a series of PIs are prepared from 5,4′-diamino-2-phenyl benzimidazole (DAPBI), 4,4′-diaminodiphenyl ether (ODA), and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) using a sequential copolymerization, blade coating, and thermal imidization process. The physical properties of the PIs are effectively regulated and optimized by adjusting the ratio of the rigid DAPBI and flexible ODA components. By increasing the DAPBI content, thermal stability, dimensional stability, and mechanical properties, the resultant polymer is enhanced. PI-80 exhibits an excellent comprehensive performance, a glass transition temperature of 370 °C, and a tensile strength of 210 MPa. Furthermore, the CTE as calculated in the range 50–250 °C is ca. 19 ppm/K, which is equal to that of copper. A highly dimensionally stable, curl-free, and high T-style peel strength (6.4 N/cm) of copper/PI laminate was obtained by casting the polyamic acid onto copper foil (13 μm) and thermally curing at 360 °C, which indicates that it has the potential to be applied as an electronic film for flexible displays and flexible printed circuit boards. A structural rationalization for these remarkable properties is also presented.

Synthesis of polyimides with lower H2O‐absorption and higher thermal properties by incorporation of intramolecular H‐bonding

“…As is known to all, the interchain interaction and stiffness/linearity of polymer backbones had a great influence on the molecular‐chain orientation to determine the CTE values of PIs . In the results (Figure ), PyPABZ–PMDA with relatively low CTE value down to 2.4 ppm/K was superior to previous reported PIs, and the value of CPIc (ODA:PyPABZ = 25:75) decreased 68% in comparison with that of ODA–PMDA. Overall, the thermal dimensional stability of the PI–PyPABZ was elevated by incorporating PyPABZ content.…”

MPPE/SEBS Composites with Low Dielectric Loss for High-Frequency Copper Clad Laminates Applications

“…Up to now, numerous polymeric composites are synthesized and analyzed for the potential application in electronics devices. The resin matrices including modified epoxy resins, polytetrafluoroethylene (PTFE), cyanate ester (CE), polyimide resin (PI), polyphenylene ether (PPE), and other hydrocarbon resins [ 3 , 4 , 5 , 6 , 7 ]. Despite modified epoxy resins, CE and PI show relatively good dielectric and thermal properties, they still cannot meet the requirement of ultra-low dielectric loss (<0.003) at high-frequency.…”

Synthesis of Superheat-Resistant Polyimides with Enhanced Dielectric Constant by Introduction of Cu(ΙΙ)-Coordination

“…PIs with excellent thermal and mechanical properties have been studied as a kind of high-performance engineering polymer [8][9][10]. It is one of the most promising polymers with outstanding T g s, nevertheless, their dielectric constant is typically~3.5, which limits their use as high dielectric materials [11,12].…”