Method for manufacturing active metal-brazed nitride ceramic substrate with excellent joining strength

A method for manufacturing active metal-brazed a nitride ceramics substrate having excellent joining strength, comprising:

• a step of preparing a mixed raw material by adding 3 wt. % of Y2O3 and 1 wt. % of one or two rare-earth elements (La2O3, Gd2O3, Ce2O3, Dy2O3, and Yb2O3) as a sintering aid to 10 wt. % of aluminum nitride powder having a β-phasing rate of 90% or higher and 86 wt. % of α-type aluminum nitride powder;
• a step of forming a green sheet of the mixed raw material by a tape casting method;
• a step of removing a binder by performing degreasing at a temperature of 400 to 700° C. for two to five hours in a nitrogen gas atmosphere;
• a step of performing sintering at a temperature of 1,800 to 1,900° C. for two to ten hours under 1 to 10 atm of nitrogen and hydrogen gas;
• a step of forming an aluminum nitride sintered substrate by performing gradual cooling at a speed of 50 to 100° C. per hour;
• a step of printing a conductive wiring pattern with active metal paste on the aluminum nitride sintered substrate;
• and
• a step of forming unevenness at a surface of the aluminum nitride sintered substrate by a sandblasting method to further increase the joining strength.