SGER: Exploratory Study of Imbedded Carbon Nanotubes to Improve Thermal Performance of Flexible Electronics Packages

高性能微电子器件中的大的热负载通常需要高导热性材料来保持电子器件的健康和性能。在基于柔性的电路中，对柔性的需求限制了这种高导电性但刚性材料（如金刚石）的使用，热通孔或焊料凸块只能略微增强聚合物基板的热性能。最近的研究表明，碳纳米管（CN）可以显着改善柔性电路的热管理。初步结果表明，纳米级直径和高纵横比的高导电CN（约3000 W/mK的轴向方向）允许CN/聚合物复合材料，以实现异常高的热导率，不同于聚合物与传统的微米级颗粒复合。在我们的实验室中对与1重量%的随机分散的CN复合的商业环氧树脂进行的初始测试表明，导热率提高了1.7倍，而理论预测如果CN对齐，该数字将达到100。我们提出制造和评估两种不同类型的CN/聚酰亚胺复合材料的热性能，其中（a）随机取向的CN和（B）垂直取向的CN。该项目是一个高风险、高回报的项目。 它特别适合SGER资助，因为CN的物理特性尚未得到很好的理解，微电子行业可能从该项目开发的高导电聚合物复合材料中受益匪浅。建议活动的智力价值建议项目对纳米技术和微电子领域很重要。它不仅影响了未来电子封装的设计，而且还大大提高了我们目前对CN材料的认识。建议的工作非常新颖，原创，有组织，建议团队非常有资格执行所需的工作。PI在MEMS、仿真和传热等不同但互补的领域拥有丰富的经验。此外，该团队还可以在校园洁净室使用完整的微加工设施。拟议活动的更广泛影响拟议项目将为大学和高中学生提供重要的教育机会。在这项工作下支持的UA研究生和本科生将从开展拟议的纳米技术研究的经验中受益匪浅。为该项目招募的K-12学生和教师将更加了解纳米技术，这可能会导致更多的K-12学生追求科学和工程作为职业道路。PI将通过他目前作为女性和少数民族工程学生导师的角色积极招募代表性不足的学生。为该项目开发的加工技术和购买的设备将大大提高UA多用户微加工设施的能力。

Large heating loads in high performance microelectronics often require high thermal conductivity materials to maintain the health and performance of the electronics. In flex-based circuitry, where the need for flexibility limits the use of such highly conductive but stiff materials like diamond, thermal vias or solder bumps can only slightly enhance the thermal performance of the polymeric substrates. Recent studies suggest that carbon nanotubes (CN) can dramatically improve the thermal management of flex circuits. Preliminary results indicate that the nanoscale diameter and high aspect ratio of the highly conductive CN (~ 3000 W/mK in the axial direction) allow CN/polymer composites to achieve unusually high thermal conductivities, unlike polymers composited with the traditional microscale particles. Initial tests performed at our laboratory on a commercial epoxy composited with 1 wt% of randomly dispersed CN showed that the thermal conductivity was enhanced by a factor of 1.7, while theory predicts this number to reach 100 if the CN were aligned.Based on the results of our limited experiments, we propose to fabricate and evaluate the thermal performance of two different types of CN/Polyimide composites with (a) randomly oriented and (b) vertically aligned CN. The proposed project is both high-risk and high-payoff. It is especially suitable for SGER funding due to the fact that the physical properties of CN are not well understood and the microelectronics industry can potentially benefit tremendously from the highly conductive polymer composite developed by the project. Intellectual Merit of Proposed ActivityThe proposed project is important to the fields of nanotechnology and microelectronics. It not only impacts the design of future electronics packaging but also significantly enhances our current knowledge of CN materials. The proposed work is very novel, original, and organized, and the proposal team is well qualified to perform the required work. The PI's have extensive experience in such diverse but complementary areas as MEMS, simulation, and heat transfer. Additionally, the team has access to a complete line of micro fabrication facilities in an on-campus cleanroom. Broader Impacts of Proposed ActivityThe proposed project will generate significant educational opportunities for students at both the college and high school levels. The UA graduate and undergraduate students supported under this effort will benefit greatly from the experience of carrying out the proposed nanotechnology research. The K-12 students and teachers recruited for the project will become more aware of nanotechnology, which can lead to more K-12 students pursuing science and engineering as a career path. The PI will actively recruit underrepresented students through his current role as a mentor for women and minority engineering students. The processing techniques developed and equipment purchased for the project will significantly enhance the capability of the multi-user micro fabrication facilities at UA.