The present invention provides an optical sheet that excels in a light convergence function or a light diffusion function, has excellent brightness increase ratio in the desired angular direction, in particular the front surface direction, and greatly inhibits the side lobe, and a method for manufacturing such an optical sheet with good efficiency and high accuracy. The main frame is connected to the pivot shaft via the pivoting seat. Different types molding or rebounding pads may be used. An under bump metallization is then electroplated onto the etched seed metallization, and a lead-free solder composition, such as SnCu, is electroplated onto the UBM.