Achieving Faster DVD Cure Time with Pulsed UV

An important advantage of pulsed UV light curing systems in Optical Disc applications is the ability to deliver high peak UV energy in short pulses, at low substrate temperatures. This results in the UV penetrating the polycarbonate substrate layer with sufficient energy to complete the cure of the adhesive sandwiched in between the polycarbonate layers. For emerging formats, such as Blu-ray Disc and HD Disc, thick top coat and multiple layer penetration is a more demanding requirement. Extensive tests on DVD manufacturing lines, confirm that effective curing is achieved when a critical total UV energy is delivered to the adhesive. As disc handling times are reduced, cycle time reduction becomes limited by cure time. The challenge to reduce cure time is to deliver that critical energy in as short a time as possible. A pulsed UV system instant on/off lamp control, narrow (168 µs) high energy pulses, and its ability to deliver pulses at increasing rates, offers a means to reduce cure times by simply increasing the pulse rate.