Vilarinho Paula M, Fu Zhi, Wu Aiying, Axelsson Anna, Kingon Angus I
Department of Materials and Ceramics Engineering, CICECO - Aveiro Institute of Materials, University of Aveiro , 3810-193 Aveiro, Portugal.
Langmuir. 2015 Feb 24;31(7):2127-35. doi: 10.1021/la504184k. Epub 2015 Feb 10.
Through the use of a sacrificial carbon layer, this work reports a method of performing electrophoretic deposition (EPD) of thick films on fully nonconducting substrates, overcoming the restricting requirement for EPD of a conducting or partially conducting substrate. As a proof of concept, the method was applied to the development of microwave-thick films on insulating alumina substrates. The key parameter to be controlled is the thickness of the sacrificial carbon layer; this is expected to be a general result for the application of the processing method. The method allows direct patterning of the structure and leads to the potential use of EPD in a far wider range of electronic applications (multilayer ceramic capacitors (MLCCs), low-temperature cofired ceramics (LTTCs), and biotech devices). Furthermore, in conjunction with work reported elsewhere, the development of specific BaNd2Ti5O14 (BNT) thick-film microwave dielectrics opens up a technology platform for a range of high-quality factor (Q) devices. More specifically, 100-μm-thick BNT layers were achieved with a dielectric constant of 149 and Q of 1161 (10 GHz). These materials can now be integrated with tunable dielectrics or dielectrics on metal substrates to provide a platform for devices in the front end of communication systems and cellular base stations.
通过使用牺牲碳层，本工作报道了一种在完全不导电的衬底上进行厚膜电泳沉积（EPD）的方法，克服了对导电或部分导电衬底进行EPD的限制要求。作为概念验证，该方法被应用于在绝缘氧化铝衬底上制备微波厚膜。需要控制的关键参数是牺牲碳层的厚度；这预计是该加工方法应用的一个普遍结果。该方法允许对结构进行直接图案化，并使EPD在更广泛的电子应用（多层陶瓷电容器（MLCC）、低温共烧陶瓷（LTTC）和生物技术设备）中具有潜在用途。此外，结合其他地方报道的工作，特定的BaNd2Ti5O14（BNT）厚膜微波电介质的开发为一系列高品质因数（Q）器件开辟了一个技术平台。更具体地说，实现了厚度为100μm的BNT层，其介电常数为149，Q值为1161（10GHz）。这些材料现在可以与可调电介质或金属衬底上的电介质集成，为通信系统前端和蜂窝基站中的器件提供一个平台。
