| 摘要 |
PURPOSE:To obtain a multilayer circuit substrate for a heat resistant high frequency circuit with excellent dimensional stability by laminating integrally a laminate in which an outer layer material is arranged through a stress alleviating fluorine resin layer on the upper and/or lower surface of an inner layer material. CONSTITUTION:A laminate in which an outer layer material is arranged through a stress alleviating fluorine resin layer on the upper and/or lower layers of an inner layer material is integrally laminated. For example, one ethylene tetrafluoride film having 30mum of thickness which is stress-alleviated by heat treating in advance at 250 deg.C for 30 min is, for example, arranged on the upper and lower surfaces of one fluorine resin impregnated base material obtained by so impregnating and baking ethylene tetrafluoride resin on a glass cloth having 0.1 mm of thickness that the resin amount becomes 45 wt.% to obtain one set of stress alleviating fluorine resin layer. The resin layers are arranged at one sets on the upper and lower surfaces of the inner layer material formed with circuits on both side faces of a both-side fluorine resin copper-laminated plate, and a laminate in which 0.035 mm of thickness of copper foils are arranged on the outsides is formed by laminating at 380 deg.C under the molding pressure of 30 kg/cm<2> for 70 min, thereby obtaining a 4-layer circuit substrate. |
