An ultraviolet radiation generating system and methods is disclosed for treating a coating on a substrate, such as a coating on a fiber optic cable. The system comprises a microwave chamber having one or more ports capable of permitting the substrate to travel within or through a processing space of the microwave chamber. A microwave generator is coupled to the microwave chamber for exciting a longitudinally-extending plasma lamp mounted within the processing space of the microwave chamber. The plasma lamp emits ultraviolet radiation for irradiating the substrate in the processing space. A reflector is mounted within the processing space of the microwave chamber and is capable of reflecting ultraviolet radiation to uniformly irradiate the substrate in a surrounding fashion. When the system is operating, the microwave chamber is substantially closed to emission of microwave energy and ultraviolet radiation.
In microwave energized ultraviolet bulbs, much of the input energy is converted to heat emissions. It has been found that the efficiency of such a bulb can be optimized by monitoring power density of different portions of the UV spectrum (for example, UVA and UVC) and adjusting input power to the bulb and/or the bulbs temperature accordingly. This may be used not only to improve efficiency of the bulb but also to improve the efficiency of emissions at either UVA or UVC. A control system and suitable control parameters are described.
A radiation generating system for treating a coating on a substrate. A high voltage circuit provides power to a microwave generator that, in turn, supplies microwave radiation to drive a lamp. A current limiting device is connected between the high voltage circuit and the microwave generator, and a fault detector is connected to the high voltage circuit for providing an error signal in response to excess current being supplied to the microwave generator. A control is operative to interrupt a supply of AC power to the high voltage circuit in response to the error signal.
Embodiments of the invention relate generally to an ultraviolet (UV) cure chamber for curing a dielectric material disposed on a substrate and to methods of curing dielectric materials using UV radiation. A substrate processing tool according to one embodiment comprises a body defining a substrate processing region; a substrate support adapted to support a substrate within the substrate processing region; an ultraviolet radiation lamp spaced apart from the substrate support, the lamp configured to transmit ultraviolet radiation to a substrate positioned on the substrate support; and a motor operatively coupled to rotate at least one of the ultraviolet radiation lamp or substrate support at least 180 degrees relative to each other. The substrate processing tool may further comprise one or more reflectors adapted to generate a flood pattern of ultraviolet radiation over the substrate that has complementary high and low intensity areas which combine to generate a substantially uniform irradiance pattern if rotated. Other embodiments are also disclosed.
