EFFECT OF DISTANCE OF POLISHING PAD AND NOZZLE FROM SURFACE OF ROLL MOLD IN HYBRID POLISHING PROCESS

摘要

The BLU (Back Light Unit), the core component of display products, requires optical films in order to increase the optical functions such as uniformity and high brightness. These films are mainly produced by a roll to roll process using a roll mold with optical micro patterns, and most of these molds are fabricated by ultra-precision cutting machining. However, sharp and regular feed marks are generated by the cutting tool in the cutting process of roll molds having a mirror surface. These marks act as optical defects that are easily seen by the user in the display products. As one method to solving this problem, a FJP (Fluid Jet Polishing) process using abrasive particles and a fluid jet has been widely studied.[1-2] The FJP process using a discharging nozzle is known to have advantages of a fast material removal rate, wide polishing area, and the absence of feed marks.[3-4] However, in non-ferrous metal materials such as copper, nickel, etc., which are widely applied to roll molds with a mirror surface, there are problems such as damage to the mirror surface by the high speed of fluid jet, and quality deterioration by adhesion of the micro abrasive. Furthermore, the machined surface and surrounding environment can be contaminated by the scattered polishing liquid.