INSULATION CIRCUIT BOARD MANUFACTURING METHOD AND INSULATION CIRCUIT BOARD MANUFACTURED USING THE METHOD

To provide an insulation circuit board having a high bonding reliability while suppressing occurrence of a foreign material by preventing peeling of a brazing material solidified layer.SOLUTION: A first brazing material layer containing a metal component made of Ag and an active metal is formed for a surface of a ceramic substrate, and a second brazing material layer containing a metal component made of Ag, Cu and an active metal is formed so as to surround the periphery of the first brazing material layer. Then, a copper plate is laminated on the first brazing material layer under a state where the second brazing material layer protrudes from an outer peripheral edge of the copper plate. Following this, the ceramic substrate and the copper plate are bonded while causing eutectic reaction between Ag and Cu through heat application to the first brazing material layer and the second brazing material layer, thereby forming a copper layer for a surface of the ceramic substrate. A brazing material solidified layer obtained by melting and solidifying the second brazing material layer is formed around the copper layer.SELECTED DRAWING: Figure 2 【課題】ろう材固化層の剥離を防止して異物の発生を抑制しつつ、接合信頼性の高い絶縁回路基板を提供する。【解決手段】セラミックス基板の表面にＡｇ及び活性金属からなる金属成分を含有する第１のろう材層を形成するとともに、前記第１のろう材層の周囲を囲んだ状態となるようにＡｇ、Ｃｕ及び活性金属からなる金属成分を含有する第２のろう材層を形成した後、第２のろう材層を銅板の外周縁からはみ出させるようにして第１のろう材層の上に銅板を積層し、その後、第１のろう材層及び第２のろう材層を加熱することによりＡｇとＣｕの共晶反応を生じさせながらセラミックス基板と銅板を接合して、セラミックス基板の表面に銅層を形成し、銅層の周囲に第２のろう材層が溶融固化してなるろう材固化層を形成する。【選択図】 図２