Research Initiation: Novel Processing of Tape-Cast Ceramic Layers

本研究的目的是确定悬浮液配方和流变学对流延陶瓷板材微观结构均匀性的影响。二维的组件几何形状和简单的成型技术将有助于流延过程的建模。氧化铝基悬浮液将被配制成含有双峰分布的聚甲基丙烯酸甲酯，具有宽或窄的多分散性。研究了聚合物的相对分子质量和分布对悬浮流变学、颗粒堆积和胶带中自由/吸附聚合物的相对比例的影响。陶瓷颗粒和聚合物组分的微观分布将通过重量分析和扫描电子显微镜以及测量这些层在储存、分层和致密化过程中经历的宏观尺寸变化来探索。最终，将设计出能够改善带铸层的微观结构一致性的工艺。这些知识将在多层陶瓷制造过程中提供更大的尺寸控制，这将影响一项关键技术--多芯片电子封装。流延成型是形成陶瓷印制线路板陶瓷基板的关键工序，板材的均匀性决定了可获得的布线密度。

The objective of the research is to determine the effects of suspension formulation and rheology on the microstructural uniformity of tape-cast ceramic sheets. The two-dimensional component geometry and simple forming technique will facilitate modeling of the tape-casting process. Alumina-based suspensions will be formulated that contain a bimodal molecular weight (MW) distribution of polymethyl methacrylate, with either broad or narrow polydispersity. The effects of polymer MW and distribution on suspension rheology, particle packing, and the relative ratio of free to adsorbed polymer in the tapes will be investigated. The microscopic distribution of ceramic particles and polymeric constituents as a function of direction will be probed by themogravimetric analysis and scanning electron microscopy as well as by measuring the macroscopic dimensional changes these layers experience during storage, lamination, and densification. Ultimately, processes will be designed which lead to improvements in the microstructural uniformity of tape-cast layers. This knowledge will afford greater dimensional control during multilayer ceramic fabrication which impacts a critical technology--multichip electronic packaging. Tape-casting is a critical process for forming the ceramic substrates for ceramic printed wiring boards and the uniformity of the sheet determines the attainable wiring density.