| 摘要 |
PURPOSE:To lower dielectric constant and to meet with the trend that printed- circuits become higher density, by forming a base material in a laminated plate used for an insulating base plate where a ceramic fiber non-woven fabric is used of a ceramic fiber consisting of silicon oxide, boron oxide, aluminum oxide, calcium oxide and magnesium oxide. CONSTITUTION:A ceramic fiber of a ceramic fiber non-woven fabric used as a base material of a laminated plate consists of silicon oxide (SiO2) as the main component, and it contains boron oxide (B2O3) and 5wt.% or less of the sum of the content of aluminum oxide (Al2O3), calcium oxide (CaO) and magnesium oxide (MgO). A laminated plate is formed by laminating and molding prepregs obtained by impregnating sheet-like base materials with a resin and drying them. The dielectric constant of the above described SiO2 is 3, 5, which is low, and on the other hand, the dielectric constant of Al2O3, CaO and MgO contained in natural raw stones containing SiO2 are respectively 9-10, 11-12 and 9-10 which are all high. It is possible to form a laminated plate having low dielectric constant by using a ceramic fiber non woven fabric where the sum of the content of the components having high dielectric constant is depressed at such a small amt. as 5wt.% or less.
|
