Ceramic powder for a green sheet and multilayer ceramic substrate

Abstract

Provided is a ceramic powder for a green sheet that gives a low-temperature fired ceramic substrate that can be fired at a temperature of 900° C. or lower and has excellent dielectric properties in the higher frequency bands such as microwave and millimeter-wave bands, has a low hygroscopicity, and has minor warping and creasing even in the case of co-firing with a silver-based conductor paste, the ceramic powder for a green sheet including a glass powder and an alumina powder, in which the glass powder contains 35 to 39% by weight of SiO 2 , 9 to 17% by weight of Al 2 O 3 , 21 to 40% by weight of B 2 O 3 , 10 to 20% by weight of R′O, wherein R′ is one or more kinds selected from the group consisting of Mg, Ca and Ba, 0.2 to 2% by weight of Li 2 O, and 0.5 to 2% by weight of MO 2 , wherein M is one or more kinds selected from the group consisting of Ti and Zr, so that the total is 100% by weight.

1 . A multilayer ceramic substrate, comprising an insulator layer obtained by firing a green sheet comprising a ceramic powder for a green sheet at 800 to 900° C., wherein the ceramic power comprises a glass powder and an alumina powder; and the glass powder comprises, based on the total weight of the glass powder, 35 to 39% by weight of SiO 2 , 9 to 17% by weight of Al 2 O 3 , 21 to 40% by weight of B 2 O 3 , 10 to 20% by weight of R′O, wherein R′ is at least one selected from the group consisting of Mg, Ca and Ba, 0.2 to 2% by weight of Li 2 O, and 0.5 to 2% by weight of MO 2 , wherein M is at least one selected from the group consisting of Ti and Zr. 
   
   
       2 . The multilayer ceramic substrate according to  claim 1 , further comprising a wiring layer comprising wiring obtained by firing a conductor paste comprising silver at 800 to 900° C., 
   
   
       3 . The multilayer ceramic substrate according to  claim 1 , wherein the insulator layer and the wiring layer are laminated.