CLASS 4 - SOFT, BRITTLE NONMETALS (Electronics)
Examples include silicon, GaAs, ferrites, PZT’s, MEMS devices.
Ceramic capacitors are an example of a Class 4 softer more brittle types of material. These materials are typically very small, inexpensive devices used in cell phones, MP3 players, computers and other electronic products. MLC devices are constructed of alternating layers of metal and ceramic, with the ceramic material acting as the dielectric.
Microstructural analysis of a BaTiO3 ceramic capacitor includes looking for missing metal layers, as well as examining for gaps and voids in the ceramic substrate. Microstructural preparation of multi-layer BaTiO3 ceramic capacitors requires minimizing polishing relief and damage to the coating or ceramic substrate. This is accomplished by filling the existing voids with a castable resin under vacuum and then curing at a higher pressure. Initial grinding is required to open up the capacitor. The goal is to minimize microstructural damage at this step. Rough and final polishing are recommended on low napped woven polishing pads using diamond and colloidal silica, respectively.