Context: Each trace consists of a flat, narrow part of the copper foil that remains after etching. The resistance, determined by width and thickness, of the traces must be sufficiently low for the current the conductor will carry. Power and ground traces may need to be wider than signal traces. In a multi-layer board one entire layer may be mostly solid copper to act as a ground plane for shielding and power return. For microwave circuits, transmission lines can be laid out in the form of stripline and microstrip with carefully controlled dimensions to assure a consistent impedance. In radio-frequency and fast switching circuits the inductance and capacitance of the printed circuit board conductors become significant circuit elements, usually undesired; but they can be used as a deliberate part of the circuit design, obviating the need for additional discrete components.

Question: What process is a trace left over from?
Answer: etching

Question: Along with thickness, what determines the resistance of a trace?
Answer: width

Question: What type of trace is often narrower than a ground trace?
Answer: signal

Question: In a multi-layer board, what metal would a ground plane be mostly made out of?
Answer: copper

Question: What type of circuits use a stripline and microstrip format?
Answer: microwave circuits

Question: What consists of a wide, curved part of copper foil?
Answer: Unanswerable

Question: What needs to be narrower than signal traces?
Answer: Unanswerable

Question: For microwave boards, transmission can be laid out how?
Answer: Unanswerable

Question: What does not remain after etching?
Answer: Unanswerable