INSULATING SHEET FOR MULTILAYER SUBSTRATE, MULTILAYER SUBSTRATE, AND MANUFACTURING METHOD OF THE SAME

To provide an insulating sheet for a multilayer substrate capable of good connection between a post electrode of one substrate unit and a conductor wiring layer of adjacent another substrate unit in the multilayer substrate, a multilayer substrate, and a manufacturing method of the same.SOLUTION: By stacking a plurality of substrate units on which a post electrode 10 is formed and heat-pressing them all at once using an insulating sheet 6 for a multilayer substrate having a reducing agent, a multilayer substrate 2 is manufactured in which a conductor connecting film 28 on the post electrode 10 and adjacent wiring conductor films (a surface wiring layer 8a, an intermediate wiring layer 8b) are well thermal fusion bonded by an action of the reducing agent.SELECTED DRAWING: Figure 1 【課題】多層基板における一の基板ユニットのポスト電極と隣接する他の基板ユニットの導体配線層との接続を良好にできる多層基板用絶縁シート、多層基板および多層基板の製造方法を提供する。【解決手段】還元剤を有する多層基板用絶縁シート６を用いて、ポスト電極１０が形成された基板ユニットを複数枚重ねて一括積層熱プレスすることにより、ポスト電極１０上の導体接続膜２８と隣接する配線導体膜（表面配線層８ａ、中間配線層８ｂ）とが還元剤の作用により、良好に熱融着接合された多層基板２を製造する。【選択図】図１