Electric circuit board including glass substrate and method and apparatus for trimming thereof

摘要

There is disclosed a method of narrowing a focus of a powerful electromagnetic wave (17) such as excimer laser toward a capacitor formed in a glass substrate (1), and adjusting and trimming a change amount of crystallized glass formed in this portion in a limited manner. A capacity value can be trimmed without influencing an outer configuration and other peripheral components, a circuit board whose property is unchanged and whose dispersion is little can be manufactured, and the capacity value can more precisely be adjust