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Flexible CCL Is A Key Material For Printed Circuit Boards

Feb 17, 2017

With the development of the microelectronics industry, polyimide adhesive properties of copper caused a great interest in the flexible printed wiring board material CCL is the key. But the presence of copper will lead polyimide decomposition, so that deterioration of mechanical properties and bonding interface. Carboxyl group of the polyamic acid will be the role of copper and copper ions diffuse into the polyimide to reduce the performance of the dielectric layer. In the case of thermal curing, the diffusion of copper and copper ions can cause decomposition of the hydrogen peroxide, the hydrogen peroxide oxidation of the polyimide it is formed on the copper at high temperatures, accelerated oxidation and production of free radicals, so that performance is further deterioration. In order to avoid the proliferation and copper oxide can be used no acid polyamide resin and poly-iso-acid is substituted for polyamide-imide. But these are difficult to synthesize prepolymer and the actual use, simultaneously with the copper bonding force is not as polyamide acid. Therefore, a more practical approach is to create a barrier layer of polyimide and one interface. Imidazole polymers and derivatives thereof can be used as such a barrier layer. N-H-imidazole you can form a stable complex with copper, copper protects against corrosion. It is a silane coupling agent to improve the stability of the polymer. Vinyl imidazole and vinyl trimethoxysilane copolymer was used as polyimide and copper decomposition inhibitor and bonding accelerator.