A flexible double-sided copper-clad printed-circuit base board comprises two copper foils and a resin layer formed directly therebetween, the resin layer being a composite material comprising a polyimide having recurring units of the formula:
wherein some of the groups R¹ are bivalent aromatic hydrocarbon groups of the formula
(in which Y is -O-, -CO-, -SO₂- or -CH₂-) and the others are bivalent aromatic groups of the formula
and a polyimide-silicone of formula:
in which R² is a monovalent aliphatic hydrocarbon group having at most 5 carbon atoms or a monovalent aromatic hydrocarbon group having at most 9 carbon atoms; R³ is a tetravalent aromatic hydrocarbon group; R⁴ is a bivalent aromatic hydrocarbon group; R⁵ is a siloxane chain; R⁶ is a bivalent aliphatic hydrocarbon having 3 to 5 carbon atoms or a bivalent aromatic hydrocarbon group having 6 to 9 carbon atoms; r is 2 or 3; the molar ratio of x : y is in the range of 97-60 : 3-40; and the molar ratio of m : n is in the range of 50-100 : 50-0.
一种柔性双面覆
铜箔印刷电路基板由两片
铜箔和直接形成于其间的
树脂层组成,
树脂层是一种复合材料,由具有式中重复单元的聚
酰亚胺组成:
其中一些基团 R¹ 是式中的二价
芳香烃基团
(其中 Y 为 -O-、-CO-、-SO₂- 或 -CH₂-),其他为式中的二价芳香族基团
和式中的聚
酰亚胺硅氧烷:
其中 R² 是最多具有 5 个碳原子的一价脂肪族烃基或最多具有 9 个碳原子的一价芳香族烃基;R³ 是四价芳香族烃基;R⁴ 是二价
芳香烃基团; R⁵ 是
硅氧烷链; R⁶ 是具有 3 至 5 个碳原子的二价脂肪烃或具有 6 至 9 个碳原子的二价
芳香烃基团; r 是 2 或 3; x :y 的摩尔比在 97-60 : 3-40 之间;m : n 的摩尔比在 50-100 : 50-0 之间。