| 摘要 |
PROBLEM TO BE SOLVED: To obtain a via-holed ceramic green sheet of which via-holes and through-holes are formed very easily and accurately and, moreover, minute holes are formed surely at a low cost and to provide a production process therefor. SOLUTION: This sheet is prepd. by selectively exposing a ceramic green sheet contg. a ceramic powder, an ultraviolet absorber, and a photosensitive compsn. to light followed by development, and in this sheet, the difference between the diameter of a via-hole on the surface of a substrate at the side closer to a light source and that of the via-hole in the direction of thickness is within 25%. Since a via-hole with a small difference in diameter in the thickness direction of a green sheet, conventionally difficult to form, can be formed, a high-density multilayer board having a via-hole pitch of 0.15mm or lower can be formed. Moreover, filling up of via-holes with a conductive paste becomes easy, thus enabling insufficiency and missing in filling up to be avoided. |
