Electrophoretic Deposition on Non Conducting Substrates: A Demonstration of the Application to Microwave Devices.

Langmuir : the ACS journal of surfaces and colloids

PubMedID: 25635508

Vilarinho PM, Fu Z, Wu A, Axelsson AK, Kingon AI. Electrophoretic Deposition on Non Conducting Substrates: A Demonstration of the Application to Microwave Devices. Langmuir. 2015;.
Through the use of a sacrificial carbon layer, this work reports a method of performing electrophoretic deposition (EPD) of thick films on fully non-conducting 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 co-fired ceramics (LTTCs), biotech devices). Furthermore, in conjunction with work reported elsewhere, development of specific BaNd2Ti5O14 (BNT) thick film microwave dielectrics opens up a technology platform for a range of high Q devices. More specifically, 100 ┬Ám thick BNT layers were achieved with 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.