| 摘要 |
PURPOSE:To obtain a multilayered printed circuit board having small thermal expansion coefficients in X, Y and Z directions, adapted for surface mounting of a ceramic chip, etc., and high through hole reliability by employing fiber reinforced plastic using noncrimping cloth as an insulating layer. CONSTITUTION:Noncrimping cloth 11 has warps 4 and wefts 5 made of glass fiber, etc., all arranged linearly and so arranged that they are not overlapped each other like a normal plainly woven cloth. In order to prevent the warps 4 and the wefts 5 from disordering, auxiliary warps 12 and auxiliary wefts 13 are respectively woven with the warps 4 and the wefts 5. The noncrimping cloth is used as an insulating layer. Accordingly, fiber volume content rate Vf is raised, and thermal expansion coefficients in X, Y and Z directions are reduced. Thus, a printed circuit board having small thermal expansion coefficients and high through hole reliability is obtained. |
