Method of manufacturing optical component having micro-structures

A method of manufacturing an optical component having micro-structures applicable to an injection molding device of the optical component having micro-structures, wherein the optical component having micro-structure is a reflective optical component with a reflective film, and the injection molding device comprises a stationary structure, a fixed side mold, a movable structure having a movable side mold, a pressure sensor, and a piezoelectric actuator, and wherein the movable side mold is disposed opposite to the fixed side mold, the method comprising the steps of:

• (a) forming a mold cavity between the fixed side mold and the movable side mold when the stationary structure and the movable structure are closed and locked;
• (b) injecting a molding material into the mold cavity of a side edge to fill the molding material to the mold cavity, and performing, by the movable side mold, an injection step of the molding material, wherein the molding material is liquid crystalline polymer (LCP) material;
• (c) sensing, by a pressure sensor, a pressure of the mold cavity, and outputting a pressure sensing signal;
• (d) sensing, by a temperature sensor, a process temperature of the molding material in the mold cavity, and outputting a temperature sensing signal corresponding to the process temperature;
• (e) when the pressure sensing signal is smaller than a peak pressure of the mold cavity, and when a temperature sensing signal of a solidified layer on a surface of the molding material is within a crystallization temperature interval of the molding material, reciprocating, by the piezoelectric actuator, to push the movable side mold so that the movable side mold performs a reciprocating vibration motion along a predetermined direction, wherein during a filling stage of the step (a) through the step (e), the molding material is filled into the mold cavity to form the optical component having micro-structures, and
• (f) forming the reflective film on a micro-structure surface of the optical component having a micro-structure by chemical vapor deposition (CVD) or physical vapor deposition (PVD), wherein the reflective film is composed of an aluminum film and a silicon dioxide film;
• wherein the crystallization temperature interval is defined as a temperature interval including a crystallization temperature of the molding material, a surface of the solidified layer is adjacent to a wall of the mold cavity, and the surface of the solidified layer is formed according to the crystallization temperature interval when the molding material contacts the mold wall of the mold cavity to generate an instantaneous heat exchange state;
• wherein the temperature sensing signal is within the crystallization temperature interval of the molding material, and based on a viscosity, a volume shrinkage rate, a thermal expansion coefficient, and the combinations of the molding material, the ratio of micro-structure depth and a thickness of the optical component is between 1:90 to 1:90000.