| 摘要 |
<p>PURPOSE:To improve accuracy of static capacity of a built-in capacitor by providing a hole or a recess for laser trimming formed on the surface of a multilayer ceramic substrate for enabling trimming by laser beam to be made later. CONSTITUTION:Ceramic substrates 12 to 20 are laminated on a multilayer board 10. Then, a capacitor electrode 22 is formed on the lower surface of the substrates 12, 16, and 20, while a capacitor electrode 24 is formed on the lower surface of the substrates 14 and 18. Electrodes 22 and 24 are connected to through-hole conductors 26 and 28 penetrating the one-piece boards 12 to 20 and the conductors 26 and 28 are connected to pattern conductors 30 and 32 formed on the surface of the substrate 12. A hole 34 for laser trimming is formed directly above the electrode 22 and the electrode 22 is exposed. Thus, a laser beam is irradiated through a hole 34 to allow one part of the electrode 22 to be eliminated and the opposing area with the electrode 24 to be reduced. In this manner, after calcination, by irradiating the laser beam through the hole 34, the value of static electricity built into the board 10 is adjusted.</p> |
