| 摘要 |
PURPOSE:To measure a potential waveform proximate to the original waveform of LSI subjected to passivation accurately by combining phase scanning of rough phase split pitch and phase scanning of fine phase split pitch for complementing between the rough phase scan pitches. CONSTITUTION:The waveform B obtained through differentiation of an original waveform A is measured by splitting 400ns period into 1,000. Since 10mus data take-in time is necessary for single point phase, 10ms is necessary for scanning the entire phase. Said measurements are executed 4,000 times to obtain an average. Waveform C is obtained by splitting into 20 where the entire phase is scanned in 20mus which is 1/50 of the case of the waveform B. Consequently, a waveform proximate to the original waveform A is obtained. But only the outline of waveform can be known because of rough splitting. Here, many waveforms C having slightly shifted phase are produced and overlapped. When combining such waveforms as complementing the portion of the waveform C having no data, a waveform proximate to the original waveform but is not the differentiated waveform can be measured accurately.
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