摘要 |
PROBLEM TO BE SOLVED: To improve reliability for use for a long period by providing a necessary property to the capillary part without deteriorating the property of the body part. SOLUTION: After alumina powder is mixed, kneaded and formed, the water absorption ratio of the formed product is controlled between 15-30% wt.% at the first temporary firing process (S5), and the frit-adhered part of the capillary top end is steeped (S6) in the water solution of magnesium nitric acid of 0.06-0.9 mol/l and temporarily fired in the second temporary firing process (S7), and then it is fired (S8) in the hydrogen atmosphere at 1750-1900 deg.C and the average particle size at the frit sealing portion is made smaller as 20%-90% of the average particle size of the body part. |