| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of appearance failure due to burr, breaks, etc., formed when a ceramic board is divided into individual wiring boards. SOLUTION: For cutting off one ceramic board 9 along dividing grooves 4 to form a number of wiring boards 8, first notches like a letter V of 23-28 deg. and second notches like a letter V of 35-40 deg. at the top end angle are formed into the bottoms of the dividing grooves 4, and the first notches are located nearer to an insulation base than the second recesses and made deeper than the second recesses. |
