| 摘要 |
<p>A ceramic circuit board having a metal circuit board joined onto an alumina substrate, wherein the alumina substrate contains at least 99.5 mass% of alumina (Al2O3) and less than 0.5 mass% of a sintering aid-derived component generated from a sintering aid admixed before sintering, the sintering aid-derived component is an inorganic oxide containing sodium, the sodium in terms of sodium oxide (Na2O) in the sintering aid-derived component is contained at 0.001-0.1 mass% for every 100 mass% of the alumina substrate, and the alumina substrate has a maximum void size of no greater than 12 µm, an average void size of no greater than 10 µm, and a Vickers hardness of at least 1500.</p> |
