Materials for Optical Disc Substrates

Optical data storage has become the mainstream technology during the past two decades for distributing audio, video, and software content as well as for recording and archiving personal data. The continuous demand for ever-higher storage capacities and faster data transfer has led to the development of three disc format families using infrared (compact discs), red (digital versatile discs), and blue lasers (Blu-ray discs or high-density DvDs). Substrate materials used in optical discs need to possess a complex property profile with sufficient optical, rheological, mechanical, and processing characteristics to ensure cost-efficient replication, good read/write performance, and long-term media stability. Bisphenol-A polycarbonate (BPA-PC) is the substrate material of choice and has undergone several optimization cycles to always meet new format specifications.