MANUFACTURE OF WAVEGUIDE

PURPOSE:To dissolve problems which have been caused by etching, by using a low-melting point alloy as the material of a mandrel and, when a formed product is taken out, melting the mandrel. CONSTITUTION:A mandrel 11 is formed by using a ternary eutectic alloy (of a 143 deg.C melting temperature) of, for example, 18.2% Cd, 30.6% Pd, and 51.2% Sn and electric Cu plating is performed on the surface of the mandrel 11 after performing non-electroplating Ag plating. Carbon cloth 15 is wound around the mandrel 11 to a thickness of 2mm by impregnating the cloth with epoxy resin at every one layer. The section formed with the carbon cloth is heat- hardened for about 3hr at 120 deg.C under 4kg/cm2 pressure and, after the heat- hardening treatment, put under atmospheric pressure at 130 deg.C. Then the formed product is put in a furnace of 145 deg.C where the material forming the mandrel 11 is melted and removed and a waveguide 16 is obtained.