This paper presents measurement and FEM (Finite Element Method) analysis of metal adhesion force to a parylene substrate for implantable neural probe. A test device composed of 300 nm-thick gold and 30 nm-thick titanium metal electrodes on top of parylene substrate was prepared. The metal electrodes suffer from delamination during wet metal patterning process; thus, CF₄ plasma treatment was applied to the parylene substrate before metal deposition. The two thin film metal layers were deposited by e-beam evaporation process. Metal electrodes had 200 μm in width, 300 μm spacing between the metal lines, and 5 mm length as the neural probe. Adhesion force of the metal lines to parylene substrate was measured with scotch tape test. Angle between the scotch tape and the test device substrate changed from 60° to 90° during characterization. Force exerted the scotch tape was recorded as the function of displacement of the scotch tape. It was found that a peak was created in measured force-displacement curve due to metal delamination. Metal adhesion was estimated 1.3 J/m² by referring to the force peak and metal width at the force-displacement curve. Besides, the scotch tape test was simulated to comprehend delamination behavior of the test through FEM modeling.

中文翻译：

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外围神经探针的透明胶带测试表征和分析金属对聚对二甲苯聚合物基底的粘附力。

本文介绍了对可植入神经探针的聚对二甲苯基体上金属附着力的测量和有限元分析。制备了由聚对二甲苯衬底顶部的300 nm厚的金和30 nm厚的钛金属电极组成的测试装置。金属电极在湿式金属构图过程中会分层。因此，CF ₄在金属沉积之前，对聚对二甲苯衬底进行了等离子体处理。通过电子束蒸发工艺沉积两个薄膜金属层。金属电极的宽度为200μm，金属线之间的间距为300μm，作为神经探针的长度为5 mm。用透明胶带测试法测量金属线对聚对二甲苯基材的粘附力。在表征期间，透明胶带和测试装置基板之间的角度从60°变为90°。将施加在透明胶带上的力记录为透明胶带的位移的函数。发现由于金属分层而在测得的力-位移曲线中产生了一个峰值。金属附着力估计为1.3 J / m ²通过参考力-位移曲线上的力峰值和金属宽度。此外，还对透明胶带测试进行了模拟，以通过FEM建模理解测试的分层行为。