Checking the board, place, and insertion outlines

The board outline is used by Layout to determine the overall board placement boundary, and it must be present on the global layer of the board. It can be defined as part of the board template, or you can create it when you set up the board. A place outline defines the extent of the area that is reserved for a component’s placement. Each footprint must have one. Layout uses place outlines to determine whether component spacing violations occur during placement.

A place outline can be assigned a height and a layer. One or more place outlines of different heights and shapes, and on different layers, can be used to more closely represent the placement area required by a component. An insertion outline is optional, and is used by Layout to provide clearance for auto-insertion machines.

Note An insertion outline can overlap another insertion outline, but a place outline cannot overlap another place outline.

1 Choose the spreadsheet toolbar button, then choose Obstacles. The Obstacles spreadsheet appears.

2 Review the Obstacle Type column in the spreadsheet to check that the board, place, and insertion outlines have the correct width and height, and that they are on the correct layer (for example, the board outline must be on the global layer).

3 Close the Obstacles spreadsheet so that you can view the board outline in the design window. If there are "cutouts" in the board outline where no components should be placed, you need to create zero-height keepouts inside the cutouts, to ensure that no components are placed in these areas.

Checking the place grid

The place grid affects the spacing used for component placement. Before placing components, check the setting for the place grid in the System Settings dialog box. The default placement grid is 100 mils, with which you can use routing grids of 25 mils, 20 mils, 121/2 mils, 10 mils, 81/3 mils, 61/4 mils, or 5 mils (because 100 mils is a multiple of these values). The standard metric placement grids are 2 mm, 1 mm, and 0.5 mm.

Tip If you use a 50 mils or 25 mils placement grid, you can use routing grids of 25 mils, 121/2 mils, 10 mils, 81/3 mils, or 61/4 mils.