高速伝送基板用低誘電・高接着ポリイミド樹脂

抄録

Wireless communication and broadband technology such as 5G has progressed dramatically and the market of high performance portable devices like 5G mobile phones is expanding. To meet the ever-increasing requirements of transmission data, high-frequency substrates and their raw materials with low dielectric properties and good adhesivity for low transmission loss are required. We developed solvent-soluble polyimides with good heat resistance and low dielectric constant（ Dk） / dissipation factor （Df） characteristics by optimizing the composition ratio of the aliphatic, cycloaliphatic, and aromatic groups present in the polyimide back bone. We found that the adhesives prepared using our polyimides showed low Dk / Df and good adhesion to polyimide films and low profile copper foils. Furthermore, we developed a three-layer flexible copper clad laminate （3LFCCL） with our polyimde （PI） adhesives, low-pofile copper foils, and normal PI films. This 3LFCCL showed a transmission loss similar to that of liquid crystal polymer （LCP） FCCLs at frequencies less than 20GHz. This result indicates that by using our PI adhesives, lower cost FCCLs can be prepared, which can then be used as high-frequency substrates.