PHOTOCURABLE AND THERMOSETTING RESIN COMPOSITION AND CURED PRODUCT OF THE SAME

To provide a photocurable and thermosetting resin composition that allows formation of a pattern of a cured film excellent in various properties such as sensitivity, resolution and heat resistance and can provide a multilayer build-up substrate and a high-frequency inductor substrate with higher reliability, and a cured product of the resin composition.SOLUTION: The photocurable and thermosetting resin composition comprises an epoxy resin, a carboxyl group-containing photosensitive resin, a photopolymerization initiator, and a filler, in which a value of (equivalent number of epoxy groups)/(equivalent number of carboxyl groups) is more than 1 and less than 2. A cured product of the above resin composition is also provided. From the composition, a cured product can be formed that minimizes problems such as a residue at a bottom of a via hole, a tapered shape of a via hole, and the like, and that has excellent thermal properties.SELECTED DRAWING: Figure 3 【課題】感度、解像性及び耐熱性などの諸特性に優れた硬化被膜のパターンを形成することができ、信頼性の向上された多層ビルドアップ基板及び高周波インダクタ基板を提供することができる、光硬化性及び熱硬化性樹脂組成物、並びにその硬化物の提供。【解決手段】エポキシ樹脂；カルボキシル基含有感光性樹脂；光重合開始剤；及び充填材を含み、エポキシ基の当量数／カルボキシル基の当量数の値が１超過２未満である光硬化性及び熱硬化性樹脂組成物、及びその硬化物を提供する。ビアホールの底部の残渣、ビアホールのテーパー（ｔａｐｅｒ）等の問題を最小化し、優れた熱特性を有する硬化物を形成することができる。【選択図】図３