RESIN COMPOSITION LAYER

PROBLEM TO BE SOLVED: To provide a resin composition layer capable of obtaining an insulating layer which can suppress a haloing phenomenon even when a thickness is thin and can form a via hole having a good shape.SOLUTION: A resin composition layer has a thickness of 15 μm or less, and contains (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler having an average particle diameter of 100 nm or less, and (D) a compound represented by formula (1): XSi(OR)or formula (2): (RO)Si-Z-Si(OR). In formula (1), X represents a monovalent aliphatic hydrocarbon group; Rrepresents a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms; m and n represent integers satisfying 1≤m≤3, 1≤n≤3 and m+n=4; Z represents a divalent aliphatic hydrocarbon group; Rrepresents a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms; and Rrepresents a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms.SELECTED DRAWING: Figure 1 【課題】厚みが薄くてもハローイング現象を抑制でき且つ良好な形状のビアホールの形成が可能な絶縁層を得られる樹脂組成物層を提供する。【解決手段】厚み１５μｍ以下の樹脂組成物層であって、（Ａ）エポキシ樹脂、（Ｂ）硬化剤、（Ｃ）平均粒径１００ｎｍ以下の無機充填材、及び、（Ｄ）式（１）又は式（２）で表される化合物を含む。ＸｍＳｉ（ＯＲ１）ｎ（１）（Ｒ２Ｏ）３Ｓｉ−Ｚ−Ｓｉ（ＯＲ３）３（２）（Ｘは、１価の脂肪族炭化水素基を表し、Ｒ１は、水素原子又は炭素原子数１〜３の１価の脂肪族炭化水素基を表し、ｍ及びｎは１≦ｍ≦３、１≦ｎ≦３且つｍ＋ｎ＝４を満たす整数を表し、Ｚは２価の脂肪族炭化水素基を表し、Ｒ２は水素原子又は炭素原子数１〜３の１価の脂肪族炭化水素基を表し、Ｒ３は水素原子又は炭素原子数１〜３の１価の脂肪族炭化水素基を表す。【選択図】図１