| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of a partial discharge taking place between metallic circuit boards upon application of a high voltage to cause dielectric breakdown between the metallic circuit boards. SOLUTION: A metal plate 3 for mounting a semiconductor element and a metal circuit board 4 being connected electrically with the semiconductor element are bonded to the surface of a ceramic substrate 1 through an active metal brazing material 2, while being spaced apart by 0.05-2.0 mm to produce a ceramic circuit board. The linearity of the metal plate 3, the metal circuit board 4 and the active metal brazing material 2 is not higher than 0.05 mm at a part facing each other between the metal plate 3 and the metal circuit board 4. Since generation of partial discharge can be suppressed between the metallic circuit boards 4 upon application of a high voltage, while mounting a semiconductor element, insulation of the ceramic circuit board will not deteriorate and the semiconductor element can operate for a long term.
|
