Aluminum Oxide Lapping Film consist of an aluminum oxide, which is a naturally occurring material (Bauxite). It exits in either the softer gamma (mohs 8) or harder alpha (mohs 9, 2000 HV) phase. Alumina abrasives are used primarily as a final polishing abrasive because of its high hardness and durability.The applications for lapping films range from polishing semiconductor dies, fiber optics, optical components, ceramic capacitors, computer hard drive read-write heads, ceramic seals, etc. The main characteristic of lapping films is that they produce very flat surfaces, especially across a materials having a wide range in hardness. Lapping films consist of a polyester backing (typically 3 mils) on which the abrasive is rigidly fixed with an epoxy binder. The most common abrasives used for lapping films include diamond, silicon carbide, alumina and to a lesser extent ceria.