薄膜太阳电池生产过程中玻璃基板传热特性及变形原因研究

HEAT TRANSFER CHARACTERISTICS AND DEFORMATION RESEARCH OF GLASS SUBSTRATE DURING THIN FILM SOLAR CELLS PRODUCTION

针对应用某型扩散炉生产薄膜太阳电池玻璃基板易变形的问题,应用经过验证的数值方法对扩散炉中玻璃基板的辐射及对流传热特性进行研究,获得玻璃基板的温升特性和受热机制。发现远离炉壁的玻璃基板两侧都以受均匀对流加热作用为主;而最靠近炉壁的玻璃基板一侧受辐射作用加热的同时另一侧受对流作用冷却,在基板内部厚度方向产生了较大温度梯度。以玻璃基板的热流分布规律为条件进行板件"热-结构"耦合的有限元应力应变模拟,发现最靠近炉壁玻璃基板翘曲变形严重且与实际生产现象相符。最后提出改进措施并进行效果验证。

Aiming at the deformation problem of glass substrate in a certain kind of diffusion furnace for thin-film solar cells production, radiation and convection heat transfer characteristics of glass substrate in diffusion furnace were investigated with verified numerical method, by which the temperature rising characteristics and heating mechanism of glass substrate were obtained. It is found that the heating situation of glass substrate close to the furnace wall is different from that of substrate away from the wall. For the substrate closest to the wall, one side is heated by radiation while the other side is cooled by convection which will lead to temperature gradient in thickness direction of substrate and heat flux will flow from side towards the furnace to the backside. For the substrate away from the wall, both sides are heated by convection which will lead to low heat flux in the thickness direction. The heat-structure coupled finite simulation of stress and strain is carried out, basing on heat flux distribution of substrate. Serious warpage deformation is observed on the substrate closest to the furnace wall which matches the actual production phenomenon. Eventually method of improvement is given and verified.