| 摘要 |
PURPOSE:To reduce the cost of brazing and improve reliability by joining a composite metal material made by compounding three layers of upper and lower copper layers and a molybdenum intermediate layer in a rate where a thermal expansion coefficient thereof is a specific value in a specific temperature range, with an aluminum ceramic frame. CONSTITUTION:Upper and lower layers 2 is of Cu and an intermediate layer 3 of Mo. A composite metal material of a three layered structure formed with the three layers by compounding the three layers in a ratio where a thermal expansion coefficient is 6-8X10<-6> in a temperature range of from 20 to 700 deg.C is employed as a bottom plate metal material layer 1. An alumina ceramic frame 5 is joined with the periphery of the upper surface of the layer 1 using a silver brazing material 4. For the bottom plate metal material layer 1 the ratio of plate thicknesses of the Cu 2 and the Mo 3 is set to be 0.95-3.5 Mo to be Cu 1 in order for the expansion coefficient at 20-700 deg.C to approach that of Al being a material of the ceramic frame 5. Accordingly, the thin alumina ceramic frame 5 and the composite metal material 1 can be joined with each other without deformation thereof. Hereby, the cost of brazing is reduced and reliability is improved. |
