| 摘要 |
PROBLEM TO BE SOLVED: To provide an LC resonator which is free from producing carbide on a circuit board due to laser beams heating when trimmed, and features of which are satisfactorily maintained. SOLUTION: In the intermediate layer of a multilayer circuit board (20) laminated with glass-ceramic-based ceramic insulators, there is incorporated an internal layer conductor (2) composing the inductor of LC oscillation circuit. To make a laser beam directly irradiate the internal layer conductor (2), a surface layer conductor (5) forming a grounded section on the multilayer circuit board (20) and an opening (24) on the opposite insulator faced with the surface layer conductor (5) are molded to expose the internal layer conductor (2) of the portion to be trimmed, thus the inductance value of the internal layer conductor (2) is adjusted depending on the cutting of it by a laser beam trimming locus (23). |
