A Strange World of Porcelain – Electronic Ceramics
Potteries are the common face of ceramics.
Capacitors with a large capacitance could become this small using ceramics （From the website of Murata Seisakusho Co.Ltd.）.
While these have the same composition, the microstructure and properties are different depending on the processing route.
The observation of microstructure with electron microscope is essential for researching processing design.
I imagine many people would associate the word “ceramics” with potteries or space shuttle insulation tiles (Photo 1). Probably you think of a hard and heat-resistant substance. However, within ceramics there are materials that can conduct electricity, store electricity, or generate electricity by applying force. There are many kinds of ceramics that are used in electronic components, thanks to these properties. Some kinds of ceramics are called “electronic ceramics” or “electroceramics”. Electronic ceramics are essential to make light and small electronic components and the miniaturization of mobile phones is one of the examples (Photo 2).
In order to make electrical appliances that improve our lives, it is necessary to raise the efficiency of electronic components. The same goes for electronic ceramics. The properties of ceramics are decided by the chemical elements and their quantity, in other words the composition. Therefore, in order to fabricate superior ceramics, it is necessary to find the relation between the composition and properties. Based on this, an appropriate design of composition (material design) can take place.
Most ceramics are poly-crystal, which is the assemblage of small grains. The property of a ceramic will vary depending on the assemblage state, known as microstructure. Two ceramics shown in photo 3 have the same composition but totally different microstructure because of the way they are made, and accordingly have different properties. The design of preparation method (processing design) is required to fabricate these high quality ceramics.
Research relating to ceramicfabrication is carried out at the department of applied chemistry. Chemistry is a study that chiefly reveals the “relation between structure and properties of a substance” and “change in the state of matter”. Those two correspond to material design and processing design, and the “chemistry” is used everywhere in researches to improve the efficiency of ceramics (Photo 4).