布线选定策略

Parent page: Routing the PCB

One of the great challenges with interactive software tools is interfacing those tools to the designer's fingertips so they can easily and fluidly move between the various tasks, such as creating, reshaping and cleaning the routing. For this to happen, it must be easy to select the routes of interest.

To select a routed net (or nets):

• Click to select an object anywhere along the route then press Tab to extend that selection to all connected track segments on the layer(s) on which the original object is present. A second press of the Tab key will extend the selection to all connected objects on that net, on all used layers. If there are other sections of the net that are not directly connected to the currently selected objects, a third press of the Tab key will extend the selection to include all objects in that net. The next press of Tab will revert back to the original selection set.
• Click+Drag to select a rectangle, from right to left, to invoke the (green) select touching rectangle mode to quickly select a track segment in multiple nets then use the Tab key to select all connected tracks on that layer for all of the nets you have selected.

Extending the Selection

A common situation is needing to select many objects that are touching, for example, the track segments in a routed net, or the connection lines in an unrouted net. It is relatively easy to select a set of track segments that run parallel to each other using the Select Touching technique just described, however, interactively selecting entire routes can be difficult.

This can easily be achieved by selecting one or more track segments and then pressing Tab to extend the selection to include touching track segments.

When you press Tab:

• The first time to select all connected routing objects on the same layer
• The second time to select all connected routing objects on all layers
• The third time to select all objects on that net in the design space (skipped if there are no unconnected net objects)
• The fourth time to return to the initial selection set

Techniques to Select Connections or Existing Routes

To Select	Use Mouse + Keys	Outcome
Connections		All visible connection lines that are touched by the green selection rectangle are selected.
Existing Routes		All unlocked track segments that are touched by the green selection rectangle are selected. Use the Tab key to select additional track segments in those nets.
Routes under a component		All unlocked track segments that are touched by the green selection rectangle are selected. Without Shift, the click and drag can be interpreted as Move Object; if it is the component above the routes will move. The component will also be selected, however when you press Tab to select connected track segments, the component will be deselected. Alternatively, use the Selection Filter in the Properties panel to disable the selection of large objects, such as components and polygons.
Component pads		All unlocked component pads that are touched by the green selection rectangle are selected.
Other objects in the net		First press of Tab adds other objects on a layer(s) that the selected object touches. Second press of Tab adds all same-net objects on other layers. Continue to press Tab to cycle through the available selection states.
Additional routes	+ combinations shown above	Retain current selection as additional objects are selected.

Demonstration of the Selection Techniques

Demonstration of the selection techniques.

Other Useful Selection Strategies

The Backspace key also has a useful behavior that can help remove selectively remove routing segments. If an individual track segment is selected, and that segment only touches one other segment, then when Backspace is pressed the selected segment will be deleted and the touching segment will become selected. Press Backspace again; that segment deletes, and the touching one selects. Continue to press Backspace to unroute back to the required location.

Note that if the selected segment has more than one segment touching it, no other segments will be selected when Backspace is pressed.

Use the Backspace key to remove a segment and then select the last-touching segment.