Abstract The elastic-plastic and low-cycle fatigue behaviors of copper films are studied experimentally and identified for further simulation works. A rolled annealed copper grade is considered here, as it is often used in flexible printed circuit boards for its mechanical resistance to high elongations. During operation, the printed circuit board (PCB) will undergo various loadings, whether purely mechanical or environmental. These loadings can lead to the fracture of copper and thus to the disconnection of the electrical signal in the PCB. Copper has a low yield stress, so it undergoes easily plastic deformation. In the present work, a predominant kinematic hardening has been observed experimentally and modeled with the combined hardening model of Lemaitre-Chaboche. The fatigue behavior has been identified on cyclic loadings at different strain amplitudes. A Coffin-Manson model has been adopted to reproduce experimental data. Identified behaviors have been introduced in a numerical simulation of a flexible PCB under cyclic bending/reverse bending, in order to estimate its mechanical reliability.

中文翻译：

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用于柔性印刷电路板的轧制退火铜膜的实验表征：弹塑性和低周疲劳行为的鉴定

摘要 通过实验研究了铜膜的弹塑性和低周疲劳行为，并确定了进一步的模拟工作。这里考虑了轧制退火铜牌号，因为它经常用于柔性印刷电路板，因为它具有高伸长率的机械阻力。在运行期间，印刷电路板 (PCB) 将承受各种载荷，无论是纯机械载荷还是环境载荷。这些负载会导致铜的断裂，从而导致 PCB 中电信号的断开。铜的屈服应力低，容易发生塑性变形。在目前的工作中，通过实验观察到了主要的运动硬化，并使用 Lemaitre-Chaboche 的组合硬化模型进行建模。疲劳行为已在不同应变幅度下的循环载荷下确定。已采用 Coffin-Manson 模型来重现实验数据。在循环弯曲/反向弯曲下的柔性 PCB 的数值模拟中引入了已识别的行为，以估计其机械可靠性。