MANUFACTURE OF ALUMINUM NITRIDE CIRCUIT BOARD

PROBLEM TO BE SOLVED: To produce a low cost copper-clad AlN circuit board excellent in bond strength to a copper plate and alkaline corrosion resistance, and having excellent thermal conductivity to be capable of sintering the board at a lower temperature range of 1,600 to 1,700 deg.C. SOLUTION: In this manufacture, to powdery aluminum nitride(AlN), a sintering aid which contains an aluminum compound, a calcium compound and an yttrium compound in contents sufficient to provide a 35 to 70mol% aluminum compound molar ratio expressed in terms of Al2 O3 (including Al2 O3 in the powdery AlN), a 20 to 60mol% calcium compound molar ratio in terms of CaO and a 5 to 30mol% yttrium compound molar ratio in terms of Y2 O3 is added. The resulting mixture is sintered at a temp. in the range of 1,600 to 1,700 deg.C to manufacture an AlN board and thereafter, a copper sheet is joined to the resulting AlN board.