THERMALLY CONDUCTIVE INSULATING ADHESIVE SHEET, AND METHOD FOR PRODUCING THE SHEET

To provide a thermally conductive insulating adhesive sheet which can form a composite member, and shows more excellent thermal conductivity and insulation reliability performance than those of the related art, in a heating/pressurizing step at 150°C for shorter than 1 hour, and has satisfactory stability and excellent sheet life even under storage conditions at 40°C for 1 week; and a method for producing the sheet.SOLUTION: A thermally conductive insulating adhesive sheet comprising one or more layers (B) satisfies all of the following conditions (1) to (3). (1) The layer (B) is an uncured product and/or semi-cured product of a thermosetting composition containing a thermally conductive filler (F), a thermosetting resin (R) and a latent curing agent (C). (2) When the component is heated at 150°C for 1 hour, which has been obtained by removing the thermally conductive filler (F) from the layer (B), a gel fraction thereof is 60% or more. (3) When the component is heated at 40°C for 7 days, which has been obtained by removing the thermally conductive filler (F) from the layer (B), the gel fraction thereof is 10% or less.SELECTED DRAWING: Figure 1 【課題】１５０℃１時間未満の加熱・加圧工程で、従来よりも熱伝導性と、絶縁信頼性性能に優れ、かつ４０℃１週間の保管条件においても安定性が良好で優れたシートライフを有する、複合部材を形成し得る熱伝導性絶縁接着シート、及び該シートの製造方法の提供。【解決手段】１層以上の層（Ｂ）を有する熱伝導性絶縁接着シートであって、下記条件（１）〜（３）の全てを満たす、熱伝導性絶縁接着シート。（１）層（Ｂ）が、熱伝導性フィラー（Ｆ）と熱硬化性樹脂（Ｒ）と潜在性硬化剤（Ｃ）とを含有する熱硬化型組成物の未硬化物及び／又は半硬化物。（２）層（Ｂ）から熱伝導性フィラー（Ｆ）を除いた成分の１５０℃１時間加熱した時のゲル分率が６０％以上。（３）層（Ｂ）から熱伝導性フィラー（Ｆ）を除いた成分の４０℃７日間加熱した時のゲル分率が１０％以下。【選択図】図１