Defining vias

Layout provides one defined via and fifteen undefined vias. You define additional vias in the Edit Padstack dialog box (from the Padstacks spreadsheet) to make them available for routing.

To make a via available for general routing

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

2 Select an unused via and choose Properties from the pop-up menu. The Edit Padstack dialog box appears.

3 Type a new name for the via (for a free via, for example, you could use the name POWERVIA) and edit the other options to change the size or shape as desired, then choose the OK button.

4 From the Options menu, choose Route Settings. The Route Settings dialog box appears.

5 Select the Use All Via Types option and choose the OK button.

6 Close the Padstacks spreadsheet.

To place a via

1 Choose one of the routing toolbar buttons.

2 Begin routing the net on which you want to place a via.

3 Click the left mouse button to place a vertex (a corner).

4 From the pop-up menu, choose Add Via or from the pop-up menu, choose Add Free Via.

Defining free vias

You can add free vias to your design for special purposes, such as zero-length fanouts of ball grid array (BGA) components and the "stitching" of plane layers. Free vias (denoted by the letters FV) are ignored by Layout’s board cleanup routines, so you can place them on your board and have them stay there, as long as they are attached to a net. They are preserved through AutoECO, unless the net or routed track they are connected to is entirely deleted or removed from the board.

Layout regards free vias as stand-alone components: you can shove them, place them in isolation (free of tracks), or connect them to multiple tracks on the same net.