Thermal analysis on heat treatment of glass backplanes for large-scale displays in a precompaction furnace

In current display manufacturing processes, thermal treatment of glass backplanes is widely applied for hydrogen degassing, crystallization of thin-films, tempering, forming, and precompaction processes and so on. Since thermal uniformity during those processes is critical to homogeneity of mechanical and electronic characteristics of nano/micro structures of end products, it is important to estimate the duration of transient heating stages and thermal non-uniformities on a single glass substrate or in a stack of glasses. An electric muffle furnace for glass backplanes of 1.5 x 1.85 m in size and 0.5 mm in thickness was manufactured and temperature fields of the muffle and glass backplanes were measured to estimate the effective emissivity of the furnace. Using the simplified heat transfer model based on thermal radiation and natural convection, thermal fields for a glass stack of the number of sheets from 1 to 12 and for glasses of size, 2.2 x 2.5 m were calculated for practical design and manufacturing of the muffle furnace for large-scale displays, e.g. up to 8th generation. (C) 2013 Elsevier Masson SAS. All rights reserved.