MANUFACTURE OF CIRCUIT BOARD AND POROUS SHEET USED THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method of a circuit board which uses a printing stage which does not need suction holes in a via-hole printing process and a porous sheet used for the manufacturing method. SOLUTION: The manufacturing method of a circuit board includes a process in which a circuit board material 1 in which via-holes 6 are formed in placed on a printing stage and, while the circuit board material 1 is sucked from the rear side of the printing stage through the printing stage, the via-holes 6 are filled with conductive material 5 from the surface side of the circuit board material 1. The printing stage is composed of a porous plate 8 and a porous sheet 9 which is replaceably put on the porous plate 8. A cellulose system sheet which contains 90-98 wt.% of cellulose composed of 20-40 wt.% coniferous kraft pulp and 60-80 wt.% broad-leaf tree kraft pulp is used as the porous sheet 9.