| 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 7 along dividing grooves 6 to form a number of wiring boards, a plurality of metal pieces 5 are formed in a vertical array in regions just beneath the dividing grooves 7 of the ceramic board 7 within a range meeting 0.35×(t-c1-c2)<=Σd<=0.45×(t-c1-c2), d<=0.55×1+log(c1/w)}, (t: thickness (mm) of insulation base, c1: depth (mm) of the dividing groove at a cut start point, c2: depth (mm) of the dividing groove at a cut end point, w: maximum opening width (mm) of the dividing groove, d: inner diameter (mm) of the metal piece in the vertical direction, Σd: sum (mm) of the inner diameter of the metal piece in the vertical direction). |
