Blu-ray Disc production is much more complex than the manufacturing process of previous formats. New processes from Mastering to Replication result in new requirements in terms of production equipment and process flow. Structural conditions like the asymmetric layer stack make Blu-ray Discs highly sensitive with respect to environmental changes. A careful control of the process as well as the environmental conditions, i.e. temperature, humidity and cleanliness, are essential for BD production.
Together with tighter specifications, inspecting and testing also proceed to a new level. It is no longer sufficient just to check the quality, i.e. the playability or the signal quality of the finished product. For an effective production process it is necessary to isolate process deficiencies in the earliest stages in order to be able for timely reaction and a stabilization of the process.
A field study has been carried out, in which the performance of production lines and the main reasons for yield loss are analyzed on several BD manufacturing sites.
A clear strategy for improving and stabilizing the manufacturing process can be derived. Specific process control tools can be recommended to stabilize the process. The main goal of this strategy is to achieve optimum disc quality combined with high production yield, while maintaining the following rule:
Reducing costs by improving quality.