| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a short-circuit between electrodes of an inner layer capacitor of an alumina multilayer substrate and reduce warp or dimension fluctuation of the alumina multilayer substrate after sintered. SOLUTION: Metal powders of W, etc., are added to alumina powders, resin, solvent and plasticizer are added thereto, and they are pulverized and mixed by a ball mill to make slurry. At this time, in a spherulite accommodated in the ball mill, by using a spherulite of an outer diameter 10 to 20mm, a particle size of the slurry after pulverized and mixed is D10=0.4 to 0.5μm, D50=1.3 to 1.5μm and D90=3.0 to 4.0μm. If a high dielectric constant alumina green sheet is formed by this slurry and this and a normal low dielectric constant alumina green sheet are stacked to sinter an alumina multilayer substrate integral with a capacitor, a short-circuit does not occur due to rough particles of metal powders and further a particle size distribution becomes sharp, so that it is possible to reduce warp or dimension fluctuation of the alumina multilayer substrate after sintered.</p> |
