the same manner as in example 1 but effecting the defoaming under normal pressure for 3 minutes after the paste has been applied onto the junction surfaces of the green materials the obtained aluminum nitride junction structure was measured for its heat conductivity and bending strength at the junction portion in the same manner as in example 1 the results were as shown in table 1 the junction portion exhibited a heat conductivity equal to that of the base material and a bending strength which was 88 that of the base material an aluminum nitride junction structure was obtained in the same manner as in example 1 but effecting the defoaming under normal pressure for 7 minutes after the paste has been applied onto the junction surfaces of the green materials the obtained aluminum nitride junction structure was measured for its heat conductivity and bending strength at the junction portion in the same manner as in example 1 the results were as shown in table 1 the junction portion exhibited a heat conductivity equal to that of the base material and a bending strength which was 96 that of the base material two green materials having the same composition as the green materials of example 1 and measuring 50 u00d7 40 u00d7 15 mm were molded in the same manner as the method of example 1 like in comparative example 1 the same paste as that of example 1 was printed on the.