RAW SUBSTRATE USED FOR MANUFACTURING AN INSULATING SUBSTRATE IN A LINE-TYPE HEATER AND METHOD OF MANUFACTURING THEREOF

摘要

The scribe line 4 is constituted by a large number of depressed portions of desired depth formed by radiation of a laser beam in a surface of the raw substrate correspondingly to a boundary line between adjacent insulating substrates so that the depressed portions are arranged in a line at fixed pitch intervals along the boundary line, and a portion where the pitch intervals of the depressed portions are reduced is provided over a desired length on the way of the scribe line, or a portion where the depth of the depressed portions is increased is provided over a desired length on the way of each of the scribe lines.