Patent ID: 9718726
Date: 2017-08-01
CPC Classifications: B32B,C01F,C01P,C03C,H05K,Y10T

Claim:
1. A glass ceramic substrate, comprising: an inner layer part having a first thermal expansion coefficient; and a surface layer part having a second thermal expansion coefficient smaller than the first thermal expansion coefficient, wherein a crystallinity of the glass ceramic substrate is 25% or less, the inner layer part contains a first glass matrix having a crystallinity of 25% or less, and flat alumina particles, the flat alumina particles are dispersed in the glass matrix in a direction in which individual thickness directions are substantially perpendicular to a surface direction of one of main surfaces of the inner layer part, and a mean aspect ratio of the flat alumina particles is 3 or more in one of cross sections along the thickness directions of the flat alumina particles out of cross sections of the inner layer part.