Planning Rigid & Flex Regions for Your PCB in Standard Rigid-Flex Mode in Altium Designer

You've just opened a PCB and are wondering if it is using the standard rigid-flex mode or the advanced rigid-flex mode?

You could open the Layer Stack Manager to check. Alternatively, switch to Board Planning Mode (1 shortcut) and have a look at the Active Bar:

	Standard Rigid-Flex mode
	Advanced Rigid-Flex mode

You divide the Board Shape into two regions by placing a split line. This is done with the PCB editor in Board Planning Mode. Board Regions are the areas between the Split Lines, and are assigned a default region name.

Placing a Split Line

To place a Split Line:

1. Select View » Board Planning Mode (or press the 1 shortcut) to enter Board Planning Mode.
2. Select Design » Define Split Line to enter Split Line placement mode (access this command quickly by using the D, S keyboard sequence).
3. Click within the board shape to begin the Split Line definition process. One end of the line will attach to the closest point on the board shape outline to where you clicked, the other end of the line will attach to the cursor.
4. Position the cursor in the required location then click once to place the second end. The split line will remain blue if the location is valid. An invalid location (e.g., outside of the board shape) will cause the split line to turn red. If you click to place while it is red, the split line will be removed.
5. You remain in Split Line placement mode, ready to place another Split Line if required. If not, right-click or press Esc to exit Split Line placement mode.

Board Regions are the areas between the Split Lines, and are assigned a default region name.

A board is split into distinct regions by placing a Split Line, which runs from one edge of the board shape to another edge.

The board has been split into a number of distinct regions by placing Split Lines. Note that bending lines have also been placed.

Moving a Split Line

To move a Split Line:

1. Select View » Board Planning Mode or press the 1 shortcut to enter Board Planning Mode.
2. To relocate the end of a line, click, hold and drag it to the required location around the perimeter of the board shape. The cursor will be constrained to the current snap grid.

The Board Region will be redefined by the new position of the edited Split Line.

Select and drag a Split Line end node to redefine a Board Region area.

Removing a Split Line

To delete a Split Line:

1. Select View » Board Planning Mode or press the 1 shortcut to enter Board Planning Mode.
2. Click and hold by one of its end points, then press the Delete key. Alternatively, click, hold then move an endpoint to a point around the board shape that results in the split turning red (signifying an invalid split), then release.

To delete one or more existing split lines from the active board, you can also use the Design » Delete Split Line command from the main menus when in Board Planning Mode. After launching the command, the cursor will change to a cross-hair and you will enter split line deletion mode. To delete a split line, position the cursor over one of its ends (its editing handles) then click or press Enter. Continue removing further split lines in this way or right-click or press Esc to exit split line deletion mode.

Assigning a Layer Stack and Editing the Board Region Name

Related page: Defining the Layer Stack

When a new board is created, it will have a single region, named Default Layer Stack Region. This region will be assigned the default layer stack named Board Layer Stack.

When you split a board shape into multiple regions, each new region is also assigned the default layer stack, with the original region named Default Layer Stack Region, and subsequent regions named using the format Layer Stack Region. If the required layer stacks have been defined in the Layer Stack Manager, then each region can have its stack assigned and also can be given a meaningful name.

To assign a layer stack and name a region:

1. Select View » Board Planning Mode or press the 1 shortcut to enter Board Planning Mode.
2. Click the Multi-Layer tab at the bottom of the workspace to make it the active layer (if the layer tab is not visible, press L to open the View Configuration panel to enable it).
3. Double-click on the board region to open the Board Region dialog. If the region does not select and the dialog open, make sure that the Selection Filter is not excluding Regions.
4. Assign the Layer Stack by selecting the required stack from the Layer stack drop-down.
5. Edit the Name as required.
6. One board region must have the 3D Locked option enabled to define the physical ground reference for the 3D display mode.
7. Click OK to accept the settings and close the dialog.

Double-click on a board region to define the region's name and assign a layer stack.

Summary of Creating Regions by Splitting the Board Outline

The board shape is divided into separate board regions by placing Split Lines. There are a number of ways the board shape can be defined. The video below demonstrates using an outline created from lines and arcs on a mechanical layer. Once the overall outline has been defined, it is split into the different rigid and flex regions.

Defining the Board Shape and Regions:

• The board shape can be defined interactively in Board Planning Mode (View » Board Planning Mode), or it can be defined based on an existing outline in 2D layout mode (View » 2D Layout Mode), as demonstrated in the video above.
• To define the board shape from an existing outline, select the outline in 2D layout mode and run the Design » Board Shape » Define Board Shape from Selected Objects command. The software will trace along the centerline of the selected track/arc objects to define the outer edge of the board shape. Note that the ends of the outline tracks/arcs must be coincident for the tracing algorithm to be able to follow the centerline. If it fails, the tracing algorithm will offer to attempt to trace along the outer edge of the selected objects.
• To define the board shape interactively, switch to Board Planning Mode (1 shortcut) and select the Design » Redefine Board Shape command. The standard region object placement behaviors apply during board shape definition, use the Snap Grid and workspace Guides to help with this process. Enable the Board Shape option in the Snap Options palette to give the best level of control during board shape editing. Learn more about Understanding the Snap Behavior.
• To define the Name and assign a Layer stack for each region, double-click on the region. Alternatively, set the PCB panel to Layer Stack Regions mode, where you can examine and edit the regions and bending lines.
• To split a Board Region into two smaller regions, use the Design » Define Split Line command. The command places a straight line between two click locations, when you click within the board shape the first location will be on the board edge closest to where you clicked. Move the cursor to locate the second location, then click a second time. Click and hold on the vertex of a Split Line to move it to a new location.
• The location and shape of an existing Board Region can be edited. Run the Design Design » Edit Board Shape command, then use the standard polygonal object editing techniques to adjust the shape.