Stretchable Multilayer Printed Circuit Boards: Fabrication, Surface Mount Challenge, Fundamental Research, and Applications

背景和动机：该提案是电子技术和材料科学的交叉部分。它描述了能够实现可拉伸电子组件的研究。该团队认为，今天已知的许多电子系统可以被设计为变形，以在未来呈现新的形状。最常见的技术方法是使用“单片”晶圆级工艺来制造可拉伸的波浪形电子器件。这一提议虽然有趣，但将遵循一种非单一和更多样化的替代方案。所提出的方法建立在板级连接和组装方法的基础上，该方法对来自各种来源的具有各种尺寸的器件开放。 - 分类研究：研究人员的切入点来自先前的研究，该团队（i）学会了生产和加工芯片级功能器件部分，以及（ii）在独特的放置和互连技术方面的开创性工作，该技术基于流体自组装和转移，以实现功能芯片级和微观器件部分在非常规衬底上的放置和互连。研究人员在拟议的研究领域内收集了支持结果;支持结果包括实现（i）可拉伸和可充气的照明结构，（ii）变形为球体的麦克风阵列，以及（iii）球形触摸板。 - 获得的信息摘要：支持的研究表明，瓶颈不是应用程序，而是一些技术限制和对系统级故障模式的理解滞后，我们建议在本提案中研究和克服这些问题。- 第一个目标和挑战解决了以下事实：研究仅限于具有单个金属化层的设计;目前不可能制造其间具有通孔的可拉伸多个金属化层。这就限制了可以生产的系统的路线和复杂性。此外，AC和HF性质尚未研究，这是另一个重要任务。第二个目标和挑战涉及有源器件的组装和电连接。提出了潜在的解决方案，使组装不仅宏观，而且微观芯片。将产生有关机械和电气故障的组件尺寸相关比例定律的新知识。第三个目标和挑战涉及系统级故障类型的研究。已经确定了几个关键区域。故障机制和更深入的理解，使用计算模型需要推导。应建立计算指导设计和设计规则。所获得的知识将被连续应用，并提出合适的示范。拟议的演示包括一个变形贴片天线，一个球形触摸板，以及一个有源矩阵LED阵列。从一年到下一年，复杂性会增加。

BACKGROUND AND MOTIVATION: This proposal is at the cross-section of electronics technology and material science. It describes research to enable the realization of stretchable electronic assemblies. The team believes that many electronic system known today can be designed to morph to take on new shapes in the future. The most common technical approach is to use "monolithic" wafer scale processes to fabricate stretchable wavy electronics. While interesting, this proposal will follow a non-monolithic and more heterogeneous alternative. The proposed approach builds on a board level connection and assembly methodology which are open to devices from various sources with various dimensions. -SUPPORTING STUDIES: The points of entry for the investigators comes from prior research where the team has (i) learned to produce and process chip scale functional device segments and (ii) pioneering work on a unique placement and interconnection technology, which is based on fluidic self-assembly and transfer to enable the placement and interconnection of functional chip scale and microscopic device segments on unconventional substrates. The investigators gathered supporting results within the proposed field of research; the supporting results include the realization of (i) a stretchable and inflatable lighting structure, (ii) a microphone array which morphs into a sphere, and (iii) a spherical touchpad. -SUMMARY OF GAINED INSIGHTS: The supporting studies have shown that the bottlenecks are not the applications but a number of technical limitations and a lag of understanding of system level failure modes, which we propose to study and overcome in this proposal. -The FIRST GOAL and challenge addresses the fact that the research has been limited to designs with a single metallization layer; the fabrication of stretchable multiple metallization layers with vias in between, is presently not possible. This puts constraints on the routing and complexity of the systems that can be produced. Moreover, AC and HF properties have not been studid, which is another important task.-The SECOND GOAL and challenge deals with the assembly and electrical connection of active devices. Potential solutions are proposed to enable the assembly of not only macroscopic but also microscopic chips. New knowledge on component-size dependent scaling-laws concerning mechanical and electrical failure will be generated.-The THIRD GOAL and challenge deals with the study of system level failure types. Several critical regions have been identified. Failure mechanisms and a deeper understanding using computational models need to be derived. Computational guided designs and design rules are to be established.-The gained knowledge will be applied consecutively and suitable demonstrators are proposed. The proposed demonstrators include a metamorphic patch antenna, a spherical touch pad, as well as an active matrix LED array. The complexity increases from one year to the next.