High curvature bending characterization of ultra-thin chips and chip-on-foil assemblies
High curvature bending characterization of ultra-thin chips and chip-on-foil assemblies
复制标题
超薄芯片和箔上芯片组件的高曲率弯曲表征
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
J. van den Brand
中科院分区：
文献类型：
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作者：
D. A. van den Ende;F. Verhoeven;Pepijn van der Eijnden;R. Kusters;A. Sridhar;M. Cauwe;J. van den Brand
小于20μm的超薄芯片变得灵活，允许将硅IC技术与高度灵活的电子产品集成。这种组合允许高度智能化的产品前所未有的薄，灵活性和成本。例如，传感器系统集成到食品包装或医疗保健和运动监测标签中，作为可穿戴贴片，甚至直接集成到服装纺织品中。在使用过程中，这些产品中的超薄芯片可能会弯曲到非常高的曲率，这会对芯片产生很大的应变。本文用改进的四点弯曲法对极高曲率超薄切屑的强度进行了计算。独立超薄芯片进行评估，实现最小弯曲半径低于1毫米，以及包含集成超薄芯片的组件。利用该方法研究了芯片厚度、弯曲方向和背面光洁度对强度和最小弯曲半径的影响。突出了空白超薄硅芯片和具有焊盘和凸块的菊花链超薄芯片之间的差异。最后，高曲率行为的超薄芯片，集成在低成本的聚酯箔基板上使用几种不同的低温集成技术进行了研究。这些超薄芯片的低成本箔组件高度灵活的大面积设备的出色的适用性。
Ultra-thin chips of less than 20μm become flexible, allowing integration of silicon IC technology with highly flexible electronics. This combination allows for highly intelligent products of unprecedented thinness, flexibility and cost. Examples include sensor systems integrated into food packaging or healthcare and sport monitoring tags as wearable patches or even directly in clothing textile. During use the ultra-thin chips in these products can be bent to a very high curvature, which puts a large strain on the chips. In this paper the strength of ultra-thin chips at very high curvatures is evaluated, using a modified four-point bending method. Stand-alone ultra-thin chips are evaluated which achieve a minimum bending radius below 1mm, as well as assemblies containing integrated ultra-thin chips. The effect of chip thickness, bending direction and backside finish on strength and minimum bending radius is investigated using the developed method. The difference between blank ultra-thin silicon dies and daisy chain ultra-thin chips with bond pads and bumps is highlighted. Finally the high curvature behaviour is investigated of ultra-thin chips that were integrated on low-cost polyester foil substrates using several different low-temperature integration techniques. The excellent suitability of these ultra-thin chips on low-cost foil assemblies for highly flexible large area devices is shown.