A series of novel quartz-fiber-cloth-reinforced polyimide substrates with low dielectric constants were successfully prepared. For this purpose, the A-stage polyimide solution was first synthesized via a polymerization-of-monomer-reactant procedure with 2,2′-bis(trifluoromethyl)benzidine and 3,3′,4,4′-oxydiphthalic anhydride as the monomers, and cis−5-norbornene-endo-2,3-dicarboxylic anhydride as the endcap. Then, an A-stage polyimide solution (TOPI) was impregnated with quartz-fiber cloth (QF) to afford the prepregs, which were thermally molded into the final substrate composites. The influence of the curing temperature and the resin content on the mechanical properties of the composite were examined. The composites exhibited a high glass-transition temperature over 360°C, a low and steady dielectric constant below 3.2 at a test frequency of 1–12 GHz, and a volume resistance over 1.8 × 10¹⁷ Ω cm. Meanwhile, they also showed a high mechanical strength with flexural and impact strengths in ranges 845–881 MPa and 141–155 KJ/m², respectively. The excellent mechanical and thermal properties and good dielectric properties indicated that they are good candidates for integrated circuit packaging substrates. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42358.

Two novel aromatic tetraamines containing bulky lateral phenyl unit and multiple trifluoromethyl groups, 1,1-bis[4-(3′,4′-diaminophenoxy)phenyl]-1-(3″-trifluoromethylphenyl)−2,2,2-trifluoroethane (6FTA) and 1,1-bis[4-(3′,4′-diaminophenoxy)phenyl]-1-[3″,5″-bis(trifluoromethyl)phenyl]-2,2,2-trifluoroethane (9FTA) were synthesized and characterized. A series of fluorinated aromatic polybenzimidazopyrrolones (polypyrrolones, PPys) were synthesized via a two-step polycondensation procedure. The inherent viscosities of the precursors, poly(amide amino acid) (PAAA), ranged from 0.39 dL/g to 0.54 dL/g. All the FPPys were amorphous. The freestanding FPPy films could be prepared, which exhibited good thermal stability with the glass transition temperature of 315–389°C, the temperatures of 5% weight loss (T_5%) of 497–535°C in nitrogen and residual weight retention at 700°C over 60%. All the FPPy films exhibited excellent alkaline-hydrolysis resistance which retained their original shapes and toughness after boiling 7 days in 10% sodium hydroxide solution. Also after boiling 8 h in 10% sodium hydroxide solution, the tensile strength could retain as high as 56% of the original values. The alkaline-hydrolysis resistance was much better than the polyimides which had similar chemical structures. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 40041.

A series of glass cloth-reinforced thermosetting polyimide composites (EG/HTPI) were prepared from E-glass cloth (EG) and polyimide matrix resins. The polyimide resins were derived from 1,4-bis(4-amino-2- trifluoromethyl-phenoxy)benzene, p-phenylenediamine, diethyl ester of 3,3′,4,4′-benzophenonetetracarboxylic acid, and monoethyl ester of cis-5-norbornene-endo-2,3-dicarboxylic acid. Based on the rheological properties of the B-staged polyimide resins, the optimized molding cycles were designed to fabricate the EG/HTPI laminates and the copper-clad laminates (Cu/EG/HTPI). Experimental results indicated that the EG/HTPI composites exhibited high thermal stability and outstanding mechanical properties. They had flexural strength of >534 MPa, flexural modulus of >20.0 GPa, and impact toughness of >46.9 kJ/m². The EG/HTPI composites also showed good electrical and dielectric properties. Moreover, the EG/HTPI laminates exhibited peel strength of ∼ 1.2 N/mm and great isothermal stability at 288°C for 60 min, showing good potential for application in high density packaging substrates. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010