面向扇出型封装再布线的低介电光敏聚酰亚胺的制备及构效关系研究

The development of high frequency and high speed communication chip package of 5th generation (5G) device is confronted with the serious problems of signal delay and dissipation, etc. The key to overcome such issue is to develop new interlayer dielectrics for the redistribution layers (RDLs) in fan-out packaging with low dielectric constant. Photosensitive polyimides (PSPIs) have been widely employed in RDLs for the significant advantages such as excellent lithographic performance, adhesion, mechanical property, thermal stability and etc. However, the dielectric constant of the present PSPIs are too high to support the package of high frequency communication chips. This project propose to employ the graphene oxide quantum dots (GOQDs) with ultra-small size and ultra-large specific surface area to achieve low dielectric constant by the increase the free volume from loose stack of the chains and restrict the electron polarization by forming heterostructure when embedding into the matrix. The scientific issues of the influencing mechanism of the size and dispersion of GOQDs as well as the interface interaction of GOQDs and PSPIs will be studied. Then, the problems of the dispersion of fillers and the scattering effect of UV light which limited the application of the PSPIs can be solved. The radical motive of this project is to provide basic experimental data and theoretical support for low dielectric PSPIs in fan-out packaging for high frequency communication chip package of 5G devices.

开发用于扇出型封装再布线层（RDL）的低介电介质材料是解决5G等高频高速通讯芯片信号延迟和信号损失等问题的关键。光敏聚酰亚胺具有优异的光刻成型、粘附、力学和热稳定等性能而在RDL中得到广泛应用。然而，当前光敏聚酰亚胺的介电常数较高，已经成为制约其在高频通信芯片封装中应用的关键。本项目拟采用超小尺寸、超大比表面积的氧化石墨烯量子点作为新型填料，在少量添加的情况下充分破坏聚酰亚胺分子链堆砌，增加自由体积，并通过与基体形成的异质结限制和削弱电子极化效应，从而有效降低介电常数。通过研究氧化石墨烯量子点的尺寸和分散性影响机制及氧化石墨烯量子点与光敏聚酰亚胺的界面作用等科学问题，解决此前研究中填料分散性和紫外光散射作用对低介电光敏聚酰亚胺的制约，实现低介电光敏聚酰亚胺的开发。为开发满足5G等高频通信芯片扇出型封装RDL中低介电光敏聚酰亚胺提供基础实验数据和理论支撑。

开发用于扇出型封装再布线层（RDL）的低介电光敏聚酰亚胺材料是解决5G等高频高速通讯芯片信号延迟和信号损失等问题的关键。本项目采用超小尺寸的石墨烯量子点作为新型填料，在少量添加的情况下充分破坏聚酰亚胺分子链堆砌，增加自由体积，并通过与基体形成的异质结限制和削弱电子极化效应，从而有效降低介电常数。所制备材料表现出低介电常数和损耗（2.65@1 MHz，0.009 @1 MHz）。同时，光刻后可以得到无缺陷高分辨率(3 μm)的聚酰亚胺图案。项目解决了此前研究中填料分散性和紫外光散射作用对低介电光敏聚酰亚胺的制约，实现低介电光敏聚酰亚胺的开发。为开发满足5G等高频通信芯片扇出型封装RDL中低介电光敏聚酰亚胺提供基础实验数据和理论支撑。项目组系统开展结构与性能的深入研究，已较好地完成了项目计划内容及目标，并针对低温固化、铜粘附性等光敏聚酰亚胺的重要性能开展了探索研究。相关工作发表在Polymer、Composites Part B: Engneering等材料化学领域著名期刊发表论文14篇（标明资助），其中SCI论文9篇，申请发明专利5件（2件已获得授权），参加国内外学术交流3次。