A procedure is developed to find optimal supporting positions for the large glass panels used for TFT-LCD monitors, when they are stored in a cassette or moved to load during manufacturing process. Because the panels are very thin and displacements are large, nonlinear structural analysis is necessary. Also, since a panel is supported by many supports, some of which can separate, a contact analysis scheme is devised. The criterion taken is to minimize the maximum deflection of the panel. Two formulations are considered; in the first one the number of supports is assumed prescribed, while in the second formulation the number is also to be found. The region where the support can be located is restricted. The optimized positions and the number of supports obtained are very satisfactory comparing with initial designs. The procedure utilized can be efficiently applied to similar problems where the shape of the structure is complex and where both the deflection of the structure and the number of supports are considered as objective functions. A commercial code, Ansys6.0, is used for contact analysis between the glass panel and supporting structures.
In other to find optimal supporting positions of a glass panel when on move by a pickand-place robot arm, a simplified model of the supporting structures is used. The suction effect of supports is handled by an equivalent spring element. Based on this simplified model, optimal supporting positions are calculated, using the same procedure described above. In order to consider the vibration of the glass panel, the fundamental frequency of the glass panel is also studied as an objective function. The optimal support positions obtained are very satisfactory improving the initial design significantly. Although both of the results for storing and loading purpose indicate large improvement, to have practical results, however, it is necessary to compare with experimental results for the analysis used and to evaluate the values of spring constants, constraints on natural frequency and contacting surface conditions.
