| 摘要 |
PURPOSE:To obtain the titled prepreg having excellent production operability for multilayered printed circuit boards, by increasing the hardness of peripheries forming pinholes for registration to a higher value than that in other parts. CONSTITUTION:The hardness of peripheries 2 forming pinholes 3 is increased to a higher value than that of other parts to afford the aimed prepreg. The positions 2 for increasing the hardness are preferably set in areas within the range of 2-20 times based on the pin cross-sectional area. |
