Support plate for localized heating in thermal processing systems
Support plates for localized heating in thermal processing systems to uniformly heat workpieces are provided. In one example implementation, localized heating is achieved by modifying a heat transmittance of a support plate such that one or more portions of the support plate proximate the areas that cause cold spots transmit more heat than the rest of the support plate. For example, the one or more portions (e.g., areas proximate to one or more support pins) of the support plate have a higher heat transmittance (e.g., a higher optical transmission) than the rest of the support plate. In another example implementation, localized heating is achieved by heating a workpiece via a coherent light source through a transmissive support structure (e.g., one or more support pins, or a ring support) in addition to heating the workpiece globally by light from heat sources.
1 . A thermal processing apparatus, comprising:
a plurality of heat sources configured to heat a workpiece;
a rotatable support plate operable to support the workpiece during thermal processing, the rotatable support plate comprising:
a transmissive support structure configured to contact the workpiece, the transmissive support structure comprising a first end and a second end, wherein the first end of the transmissive support structure is arranged to support the workpiece; and
a light source operable to emit coherent light through the transmissive support structure such that the coherent light heats a portion of the workpiece contacting the transmissive support structure;
a controller configured to generate instructions defining a rotation orientation and a rotation speed of the rotatable support plate and synchronize the emission of the coherent light from the coherent light source with the rotation orientation and the rotation speed of the rotatable support plate based on a sensor signal indicative of the rotation orientation and the rotation speed.
2 . The thermal processing apparatus of claim 1 , wherein the transmissive support structure comprises one or more support pins.
3 . The thermal processing apparatus of claim 1 , wherein the controller comprises an electrical control circuit that generates a trigger signal to trigger the coherent light source to emit coherent light based on the sensor signal indicative of the rotation orientation and the rotation speed of the base.
4 . The thermal processing apparatus of claim 1 , wherein the controller controls the rotatable support plate to rotate the workpiece with the defined rotation orientation and rotation speed.