采用这种技术时，电路板的元件侧专用于接地层，信号走线则布设在焊接侧。

In this technique, the component side of the board is dedicated to the ground plane, and signal traces are placed on the solder side.

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电路板至少需要4层才能实现最佳布局和性能：一个接地层、一个电源层和两个信号层。

Best layout and performance are achieved with at least a 4-layer multilayer board, where there is a ground plane layer, a power supply layer, and two signal layers.

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