| 摘要 |
PROBLEM TO BE SOLVED: To prevent occurrences of oblique cracking in dividing a wafer and to enhance productivity and reliability by ensuring connectability between a leading portion of an electrode layer and an external electrode. SOLUTION: The electrode layers 22, 24, 26, 28 and insulating layers 23, 25, 27 are alternately stacked on the surface of an alumina substrate 21, and the uppermost electrode layer 28 is covered with an insulating protection layer 29 to form a wafer 30. Surface breaking grooves 31 are formed on the surface of the wafer 30 with their depth D1 being smaller than a thickness T2 of the insulating protection layer 29. Further, rear breaking grooves 32 are formed on the rear of the wafer 30, being consisting of primary division breaking grooves 32A whose depth D1 is 30-50% of a thickness T1 of the alumina substrate 21 and secondary division breaking grooves 32B whose depth D2 is 20-35% of the thickness T1. Thus, occurrences of oblique cracking or the like are prevented at the time of dividing the wafer 30. COPYRIGHT: (C)2004,JPO
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