CAE (computer aided engineering) simulation of thin-wall injection molded parts was investigated using commodity thermoplastics and thermotropic liquid crystal polymers. Micro-injection molded parts using thermotropic liquid cyrstal polymer are widely used in the electronics and telecommunication terminals. During the filling process at injection molding, the shape of the viscosity distribution across the cavity is a consequence of its dependence on both shear rate and temperature. viscosities of the materials used may have an important effect on the level of molecular organization, a transitory structure, and ease of processing. Using the modified power law model for melt viscosity in the simulation, the strength of weld line and the capability of short shot have been determined. The best location of the gate in the micro-injection molded thin parts was found to be at the middle of the products.