| 摘要 |
PURPOSE:To lessen vias in disconnection rate after they are fired by a method wherein via forming material is uniformly filled into viaholes provided to a green sheet when fine vias are provided to form a ceramic circuit substrate, and conductive metal powder is uniformly dispersed into holes when a ceramic circuit substrate of multilayered structure is formed. CONSTITUTION:A green sheet 2 provided with via forming holes 1 formed thorugh a Mylar sheet 3 is placed on a suction paper 6 provided onto a control table 7, a powder mixture 4 is placed on the sheet 3 and sucked from the underside of the suction paper 6 through a suction path 9 by a vacuum pump 8 to be filled into the holes 1, Thereafter, the sheet 3 is separated off, a pattern is printed, then the sheets 2 are made to overlap each other and laminated at a prescribed temperature by a certain pressure. In this constitution, the powder mixture 4 contains 1-10% by volume of alumina, mullite, silica powder, or the like whose melting point is higher than that of a substrate material and grain diameter is 0.2-5.0mum. When a glass ceramic circuit board of multilayered structure is formed, copper powder containing 0.5-1% by weight of stearic acid is used. |
