GOALI: Core/Shell Sinterable Advanced Ceramic Materials Using Particle Atomic Layer Deposition

GOALI：利用粒子原子层沉积的核/壳可烧结先进陶瓷材料

• 批准号: 1563537
• 负责人: Alan Weimer
• 金额: $ 33.58万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-15 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1563537&HistoricalAwards=false
• 关键词: GOALI; Core; Shell; Sinterable; Advanced

A recent Department of Energy analysis concluded that the adoption of light-emitting diodes (LEDs) in 2013 was correlated with a one-year energy cost savings of $1.8 billion, which is less than 5 percent of the expected savings with complete adoption of LEDs. A key driver in the cost and performance of LEDs is the heat sink as LED lumen efficiency decreases by 0.3-0.5 percent for each 1°C increase in operating temperature. However, the costs of manufacturing the desired heat sink material, aluminum nitride (AlN), are substantial as a result of the high sintering temperature required to form dense AlN parts and the proclivity for AlN to degrade in the presence of water. The benefits of atomic layer deposition (ALD) for densification and processing of AlN are expected to be transformative in enabling lower-cost production of AlN parts and present a domestic route to manufacturing ceramic thermal packages, an area currently dominated by foreign manufacturers. This Grant Opportunity for Academic Liaison with Industry (GOALI) research program will promote collaboration between university and industry and enable the education of both graduate and undergraduate students.The densification of AlN with yttria (Y2O3) currently requires temperatures in excess of 1700°C, mandating the use of expensive graphite furnaces. Through ALD of the sintering aid, Y2O3, onto AlN substrate particles, it is expected that a conformal and pinhole-free Y2O3 film will protect the AlN particles from degradation by water, allowing processing in water instead of more expensive solvent-based processing. Further, the precisely thick and uniform ALD Y2O3 films around primary AlN substrate particles, are expected to provide for beneficial liquid phase sintering in the intergranular region of the densifying matrix - promoting low temperature densification. A decrease in densification temperature not only lowers the energy input required to form dense AlN parts but may also enable the use of more inexpensive alumina furnaces in lieu of graphite furnaces. For gel-casting, the ALD Y2O3 coatings will also simplify the processing of colloidal gels since only one surface (i.e. Y2O3) will be present, not two - AlN and Y2O3. The uniform nature of ALD coatings should be a substantial improvement over conventional ball milling techniques where the incorporation of Y2O3 is not uniform with respect to each AlN particle, leading to inconsistencies in densification behavior and the properties of dense AlN parts. The combination of AlN particles resistant to hydrolysis and lower temperature densification may dramatically decrease the costs of manufacturing the AlN heat sink and thus, LEDs.

能源部最近的一项分析得出结论，2013年发光二极管(LED)的采用与一年节省的18亿美元能源成本相关，这还不到完全采用LED预期节省的5%。LED成本和性能的一个关键驱动因素是散热片，因为工作温度每升高1°C，LED流明效率就会下降0.3-0.5%。然而，由于形成致密的氮化铝部件所需的较高烧结温度以及氮化铝在有水的情况下容易降解，制造所需的散热材料氮化铝(AlN)的成本相当高。原子层沉积(ALD)对AlN致密化和加工的好处预计将在实现AlN部件的低成本生产方面产生变革，并为制造陶瓷热封装提供一条国内路线，这一领域目前由外国制造商主导。这项GOALI研究计划将促进大学与工业之间的合作，并使研究生和本科生的教育成为可能。目前，氮化铝的氧化钇致密化需要超过1700°C的温度，这要求使用昂贵的石墨炉。通过在AlN衬底颗粒上添加助烧剂Y_2O_3，预计共形的、无针孔的Y_2O_3薄膜将保护AlN颗粒不被水降解，从而允许在水中进行处理，而不是更昂贵的基于溶剂的处理。此外，围绕主要AlN基片颗粒的AlD Y2O3薄膜非常厚且均匀，有望在致密基质的晶间区域提供有利的液态烧结，从而促进低温致密化。致密化温度的降低不仅降低了形成致密AlN零件所需的能量输入，而且还可以使用更便宜的氧化铝炉来代替石墨炉。对于凝胶浇注，由于只有一个表面(即Y2O_3)，而不是两个-AlN和Y_2O_3，因此ALD Y_2O_3涂层还将简化胶体凝胶的加工。与传统球磨技术相比，ALD涂层的一致性应该是一个实质性的改进，在传统球磨技术中，Y_2O_3的加入相对于每个AlN颗粒并不均匀，导致致密化行为和致密AlN部件的性能不一致。耐水解的氮化铝颗粒和较低温度致密化的结合可以显著降低制造氮化铝散热器的成本，从而降低LED的制造成本。