HEATING FURNACE INCLUDING VERTICALLY SPACED-APART DOUBLE-SIDED FAR-INFRARED-RADIATION PANEL HEATERS DEFINING MULTI-STAGE DRYING CHAMBERS

摘要

A multi-stage heating furnace for drying large-sized substrates arranged in a stack, including a furnace body, and shelf heaters arranged within the furnace body such that the shelf heaters are spaced from each other in a vertical direction at a predetermined spacing pitch and such that adjacent ones of the shelf heaters partially define drying chambers for accommodating the respective substrates, wherein each shelf heater consists of a far-infrared-radiation panel heater of double-side heating type including a heat radiating plate in which a heat-generating body is embedded, and the panel heater has opposite major surfaces covered with respective thin ceramic layers which emit a far infrared radiation when the heat radiating plate is heated by energization of the heat-generating body.