| 摘要 |
PROBLEM TO BE SOLVED: To achieve a higher driving speed by matching the impedance of a signal transmitting path from a driver of a blanking aperture array controlling circuit to an electrode of that array. SOLUTION: A voltage signal output from a driver 70 of a blanking aperture array (BAA) controlling circuit provided on a substrate 62 is applied to a blanking electrode of a BAA 30 via an output resistor 71 and a signal transmitting path 72 having predetermined impedance. The output resistor 71 is a resistor of 50Ω, and a coaxial cable 65 connected between a probe card 61 and the substrate 62 has impedance of 50Ω, and a signal transmitting path provided on the substrate 62 and the probe card 61 also has impedance of 50Ω. Further, the signal transmitting path is made to branch near the probe 64 of the probe card 61 and is connected to an auxiliary resistor 83 of 50Ωprovided on a substrate 81 via an auxiliary transmitting path having impedance of 50Ωextending to the outside of a column. The other end thereof is connected to the ground.
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