| 摘要 |
PURPOSE:To prevent sparking and to eliminate a breakdown of a substrate by punching slits in an earth conductor in a ladder pattern, and then rounding upper edge parts of those slits. CONSTITUTION:Slits 5- are punched by a press to form an earth conductor 3 of copper foil in a ladder pattern 6, and this earth conductor 3 and a center conductor 4 are bonded to a substrate by thermocompression to manufacture a microstrip line. Then, cloth buff while turned is pressed against the top surface of the substrate 2 to polish the top surface, i.e. earth conductor 3, so that upper edge parts 5' of said slits 5- are rounded. Therefore, burrs 10- and cracks 11- are eliminated. Therefore, even if a large-power microwave for heating is applied to the microstrip line, no spark is generated, eliminating the damaging of the substrate 2 due to sparks completely. |
