| 摘要 |
PURPOSE:To secure of operable frequencies as a multichip module by series- connecting AC characteristic measuring circuit formed in an IC chip and by measuring signal delay time from an input terminal to an output terminal. CONSTITUTION:AC characteristics measurement is conducted by using a circuit whose input terminal is an external connection pad 6a to series-connect gate circuits 11-14 and whose output terminal is an external connection pad 6b. Signal delay time tpd from the pad 6a to the pad 6b is measured. This provides tpd=SIGMA (delay time of AC characteristics measuring gate circuits 11-14)+SIGMA (delay time of an internal wiring 8 used for AC characteristic measurement). That is, it follows that signal delay time tpd as the whole multichip module has been measured. In the relation between this signal delay time tpd and operable frequencies, in the case of securing an operable frequency of 50MHz, a signal delay time tpd of 7.5nsec or less can be selected. |
