Patent ID: 7996969

Claim:
A method for adjusting a capacitance value of a built-in capacitor of a multilayer ceramic substrate, the method comprising the steps of: forming the multilayer ceramic substrate to include a ceramic laminate including a plurality of ceramic layers laminated to each other and first and second capacitor electrodes arranged to face each other with one of the plurality of ceramic layers interposed therebetween so as to define the built-in capacitor; and performing laser trimming of the first capacitor electrode; wherein the one of the plurality of ceramic layers interposed between the first and second electrodes is a TiO 2 -based dielectric glass ceramic layer which includes about 10 percent to about 35 percent by volume of dielectric grains including TiO 2 ; the TiO 2 -based dielectric glass ceramic layer includes: (A) about 10 percent to about 35 percent by volume of a BaO—TiO 2 —ReO 3/2 -based ceramic represented by xBaO-yTiO 2 -zReO 3/2 , where x, y, and z each indicate molar percent; 8≦x≦18, 52.5≦y≦65, and 20≦z≦40 hold; x+y+z=100 holds; and Re indicates a rare earth element; (B) about 5 percent to about 42 percent by volume of an alumina ceramic; and (C) about 50 percent to about 79 percent by volume of a borosilicate glass which includes about 4 percent to about 17.5 percent by weight of B 2 O 3 , about 28 percent to about 50 percent by weight of SiO 2 , about 0 percent to about 20 percent by weight of Al 2 O 3 , and about 36 percent to about 50 percent by weight of MO, where MO is at least one selected from the group consisting of CaO, MgO, SrO, and BaO; and the TiO 2 -based dielectric glass ceramic layer is formed by firing a glass ceramic composition including the BaO—TiO 2 —ReO 3/2 -based ceramic and the alumina ceramic in a total amount of at least about 21 percent by volume.