SEALING STRUCTURE OF MIC CIRCUIT

摘要

PURPOSE:To obtain a compact sealing structure having less irregularity in a MIC circuit sealing structure by coating a metallic case through a rubber ring at the part required for sealing a planer circuit and isolating the line portions crossing each other from the metallic case surface. CONSTITUTION:A metallic case 24 is clamped with screws through a rubber ring 22 on an insulating substrate 22 of a planer circuit. The wall of the case is removed within the height of the ring 23 at the portion of the lines 27 crossing with the case. The case 24 is retained at the same potential as the ground conductor 28 and the metallic plate 29 through screws to electromagnetically shield it so that the rubber ring 23 is buried in the gap between the case 24 and the substrate 22 to shield the atmospheric air sealingly. The line 27 and the case 24 can be isolated to the height of the rubber ring 23, the upper space is insulated with the ring 23 to propagate the electromagnetic field concentrated at the insulating substrate inside and outside the case without disturbance. The rubber may have low dielectric constant. In this manner, there can be obtained a planer circuit sealing structure having high productivity and uniform characteristics.