Build-up electrical insulation material with low-dielectric tangent, low-CTE and low-surface roughness

With the increasing speed of information and communications equipment in recent years, together with high-speed signal processing of LSIs, there is a requirement for build-up electrical insulation materials to be used as IC package substrates with low-dielectric tangent, and to reduce the dielectric loss to achieve low transmission loss in the high-frequency GHz bands. At the same time, there is an increasing need for low-CTEs (Coefficient of Thermal Expansion) to ensure highly reliable substrates. With our formulation technology, we have developed a next-generation film-shaped build-up electrical insulation material compatible with high-frequency signal transmission by using composition of practical thermosetting epoxy resin, that has realized both a low-dielectric tangent and a low-CTE at the same time. Furthermore, this material can show a low-surface roughness after the film desmear process. It is thus expected to help reduce not only the dielectric loss by low-dielectric tangent but also the conductor loss caused by the skin effect, and promote the fine line formation by SAP (Semi Additive Process).