| abstract |
In a metal base substrate in which a low-temperature sintered ceramic layer is formed on a metal plate made of copper, the bonding reliability between the metal plate and the low-temperature sintered ceramic layer is improved. A low-temperature-sintered ceramic green layer containing a low-temperature-sintered ceramic material containing 10 to 40 mol% of barium in terms of BaO and 40 to 80 mol% of silicon in terms of SiO2 on the surface of the metal plate (14) made of copper By laminating, a raw laminate is produced, and this raw laminate is fired at a temperature at which the low-temperature sintered ceramic green layer is sintered. Between the metal plate (14) and the low-temperature sintered ceramic layer (15) in the metal base substrate (12) obtained in this way, a glass having a thickness of 1 to 5 μm made of Cu-Ba-Si-based glass. A layer (22) is formed. This glass layer (22) exhibits good bonding reliability. |