| 摘要 |
PROBLEM TO BE SOLVED: To provide a ceramic circuit board having excellent thermal cycle resistance.SOLUTION: The ceramic circuit board is obtained by forming a copper circuit on one surface of a ceramic board and joining a copper heat radiating sheet to the other surface thereof while interposing a Ag-Cu brazing filler metal therebetween, which metal contains tin and at least one active metal selected from titanium, zirconium, hafnium and niobium. The ceramic circuit board is characterized in that the copper heat radiating sheet is joined at 1×10Pa or lower degree of vacuum, at 780-850°C joint temperature, and for 10-60 minutes holding time, the diffusion distance of a Ag component of the Ag-Cu brazing filler metal to the copper heat radiating sheet is 10-80 μm, a difference between the diffusion distance of the Ag component to the copper circuit side and that of the Ag component to the copper heat radiating sheet side is smaller than 10 μm and the horizontal crack generation rate after a thermal cycle test is conducted becomes smaller than 1%.SELECTED DRAWING: None |
