| abstract |
[Problem] To provide a stiffener comprising a polyimide film laminate with more excellent heat resistance and rigidity than a polyimide film of a single layer-thick body, and to provide a production method thereof.n[Solution] The polyimide film surface is activated, and subsequently subjected to silane coupling agent treatment. Subsequently, the obtained silane coupling agent-treated polyimide films are stacked on each other, and pressurized and heated to obtain a polyimide film laminate. The obtained polyimide film laminate has a cross-sectional structure comprising alternating polyimide film layers and silane coupling agent condensate layers. This polyimide film laminate has a high modulus of elasticity of 0.5 GPa or higher, even at 400°C. |