| 摘要 |
PROBLEM TO BE SOLVED: To prevent a failure in external form due to burr or crack, etc., when a ceramic substrate is divided into wiring boards. SOLUTION: When a ceramic substrate 7 is cut and separated along a splitting groove 6 to form a number of wiring boards 9, a cavity part 5 provided with corners on its upper and lower sides is formed in advance within an area just beneath the splitting groove 6 of the ceramic substrate 7. Therefore, cutting becomes easy, and multiple wiring boards having a specified wiring conductor and external dimension can be formed at the same time. |
