| 摘要 |
PROBLEM TO BE SOLVED: To detect variations in a small through-hole (or contact) resistance with higher accuracy, without having to receive the influence of variation of wiring resistance and contact resistance between a measuring probe and electrode. SOLUTION: A circuit like a Wheatstone bridge is formed by preparing for four sets of the side of upper layer wiring (terminal) - through-hole - lower layer wiring - through-hole - upper layer wiring (terminal). The upper layer wiring and the lower layer wiring are designed so as to have identical resistance in the object shape between the terminals A-C, C-B, A-D and D-B. Regarding the through-hole connecting each terminal, the diameter and numbers are set identical for the through-hole groups 2, 3, 4 between the terminals C-B, A-D, D-B. The through-hole group 1 (1a, 1b) changes its diameter so as to result from the influence of process variation which is different from that of the through-hole groups 2 (2a, 2b), 3 (3a, 3b) and 4 (4a, 4b). |
