Sleeve for optical communication and method of manufacturing the sleeve for optical communication
A sleeve for optical communication and method for manufacture for the sleeve for optical communication, for which withdrawal force for ferrules, which are generally used in the technical field of optical communication, or connection loss between ferrules is a predetermined value, and for which manufacturing steps are reduced so as to allow reduction of manufacturing cost. The invention is made by press-molding ceramic feedstock, which after cold isostatic pressing and sintering are performed thereto, and is made so that an inner circumferential surface, of a through-hole for inserting a ferrule formed on the length-direction of the axis, has a sintered state.
1. A method of manufacturing a sleeve for optical communication apparatus, comprising the steps of:
forming a cylindrical sleeve having an inner peripheral surface by press-forming a powder of a ceramics raw materials added binder therein;
pressing the cylindrical sleeve to 200 MPa and a water pressure being maintained for two minutes by a cold isostatic pressing apparatus to eliminate variation of a density distribution of the ceramics raw materials in the cylindrically formed sleeve;
degreasing the cold isostatic pressed cylindrical sleeve by application of a firing treatment at a temperature of 400 to 500° C. for a predetermined time to obtain a cylindrical sleeve decreased and to eliminate binders therein where a portion where the binders existed between the ceramic raw materials becomes a void; and
heating and firing the degreased cylindrical sleeve subsequently conducted with firing treatment at a temperature of 1300 to 1500° C. within a predetermined time to reduce a surface roughness R a of the inner peripheral surface within 0.08 to 0.20 μm and to have different grain sizes appeared thereon and to form a crystal grain boundary between the crystal grains to each other on an inner peripheral surface to possess a pull-out force satisfied with a value provided in standards in use, to reduce a connection loss in use, and to prevent distortion of the cylindrical sleeve after the degreasing and firing treatments.
2. The method of manufacturing a sleeve for optical communication according to claim 1 , wherein the fired formed body is processed to have a predetermined length.
3. The method of manufacturing a sleeve for optical communication according to claim 1 , wherein an outer periphery of the fired formed body is processed.
4. The method of manufacturing a sleeve for optical communication according to claim 1 , wherein finishing processing is performed after cooling the fired formed body.