With the wide use of VLSI, the percentage of the open faults, bridging faults and stuck logic faults are rising in the complex PCB, and the testability of PCB is becoming more difficult.

• 摘要随著VLSI电路的广泛使用，复杂PCB板上的开路、桥接和固定逻辑故障的比例逐渐上升，可测试性明显下降。