RESIN FLUX SOLDER PASTE AND MOUNTING STRUCTURE

To provide a solder paste which can be applied for connection of high melting point solder and has excellent heat resistance and heat cycle reliability.SOLUTION: In a solder paste as the solder paste which includes solder powder and flux, the flux includes epoxy resin, hardener, hardener accelerator and activator, the epoxy resin contains at least one of biphenyl aralkyl type epoxy resin, naphthalene type epoxy resin and dicyclopentadiene type epoxy resin which have epoxy equivalent of 200 to 400 by 10 to 90 wt.% with respect to the total epoxy, and the hardener contains biphenyl aralkyl phenol resin which has hydro oxide group equivalent of 150 to 350 by 30 to 95 wt.% with respect to the total hardener, and contains phenol novolak resin having allyl group of which the hydro oxide group equivalent is 100 to 200, by 5 to 70 wt.% with respect to the total hardener.SELECTED DRAWING: Figure 1 【課題】高融点はんだの接続に適用でき、優れた耐熱性とヒートサイクル信頼性を有するはんだペーストを提供する。【解決手段】はんだ粉末とフラックスとを含むはんだペーストであって、前記フラックスは、エポキシ樹脂と硬化剤と硬化促進剤と活性剤を含み、前記エポキシ樹脂は、エポキシ当量が２００〜４００のビフェニルアラルキル型エポキシ樹脂、ナフタレン型エポキシ樹脂、ジシクロペンタジエン型エポキシ樹脂のうちの一つ以上を全エポキシに対して１０〜９０重量％含み、前記硬化剤は、水酸基当量が１５０〜３５０のビフェニルアラルキルフェノール樹脂を全硬化剤に対して３０〜９５重量％と水酸基当量が１００〜２００のアリル基を有するフェノールノボラック樹脂を全硬化剤に対して５〜７０重量％含むはんだペースト。【選択図】図１