ELECTRON SOURCE BLOCK WAFER DICING METHOD, ELECTRON SOURCE BLOCK, AND X-RAY DIAGNOSTIC DEVICE USING ITS ELECTRON SOURCE BLOCK

PROBLEM TO BE SOLVED: To diagnose an electron source block wafer with a narrow dicing street width at high accuracy without giving thermal damage on an electron emission element.SOLUTION: This method include the steps of: adhering a silicon substrate 33 on a lower face of a glass substrate 32; forming a group of electron emission elements 45 on an upper surface of the glass substrate 32 for every electron source block 35 and manufacturing an electron source block wafer 43; radiating laser light along a cutting schedule line of a street 34 between the electron source blocks 35 on the electron source block wafer 43 while a condensing point is focused to the inside of the silicon substrate 33 adhered to the lower face of the glass substrate 32 rather than the upper face of the glass substrate 32 to form a modified region 37 in the silicon substrate 33; and dividing the glass substrate 32 and the silicon substrate 33 along the cutting schedule line with the modified region 37 as a starting point.