A Development of Optimization Tool for Mechanical Shock Proof Design of a Digital Display Panel

Because of the harsh user environment of Lap-Top (Notebook) PCs, developing rugged components and assembly is to be one of the major interests in the industry. User requirements for the reliability of the PCs have been rapidly raised as the market grows. Especially mechanical shock failures of a display unit of those PC kinds have been an important concern of designers. Brittle and non-homogeneous material characteristics of the thin TFT-LCD display panel have hampered to make a reliable design strategy to meet the tightening shock user specification. In order to satisfy the requirement, many different design cases should be elaborated in both numerical simulations and prototypings prior to the volume production that usually consist of tedious time consuming processes. As compared the life cycle of the fast changing product, the reduction of design processes gets tremendous attention from not only PC designers but LCD makers. In order to achieve the mechanical shock requirement of a couple of hundred times of gravitation, an explicit Lagrangian FE model is being used as a major analysis tool. Since the nature of the explicit formulation and the relatively large deformation of thin parts in a LCD panel, the FE model should be carefully built especially in terms of element distribution. Otherwise the analysis could be very expensive either by the lengthy computation or the singularity occurring in middle of the calculation. Meanwhile, the LCD display manufacturers often have many production models similar in exterior shape but different in construction for the various customers. Each different construction may perform differently under the same mechanical shock loading. This paper presents an optimization tool for the shock-proof design of notebook TFT-LCDs. Constructing geometries of the key design features, generating proper meshes for the entire display unit, cranking up an explicit FE codes, and analyzing the results are combined in a unified tool with user friendly features. A good agreement to the prototyping test also has been shown using a design example.