Best Practices in PCB Design: Placing Parts in Ultiboard

Publish Date: Mar 27, 2012 | 2 Ratings | 5.00 out of 5 |  PDF

In this tutorial, we take a look at best practices in part placement in NI Ultiboard in preparation for routing a PCB.

Step 1: Configure the Board Outline

If you are working under size or mechanical constraints, the first thing you'll want to do is configure your board outline.For more information on configuring the board outline, refer to the article How to Customize a Board Outline in NI Ultiboard.

Step 2: Select the Part Filter

To make component selection easier, deselect all filters except for the Part filter, as shown in the image below. This will ensure that only the desired footprint is selected during placement.

Step 3: Activate the Layer Where the Part is Located

In order to be able to select the part, the layer upon which it is located must be made active:

  1. Select View > Design Toolbox
  2. Select the Layers tab
  3. Make a particular layer active by double-clicking on it
  4. Hide or dim layers by clicking on the checkboxes beside the layer names. This will allow you to toggle between visible, dim and invisible settings, allowing you to control the visualization of your board.

Tip: It is sometimes helpful to dim the Ratsnest layer to keep the lines from cluttering the screen

Tip: Use F2 to toggle between layer pairs (ex: Copper Top/Copper Bottom, or Silkscreen Top/Silkscreen Bottom)

Step 4: Choose the Correct Layer for the Part

By default, parts will be placed on the Copper Top layer. However, if you are creating a double-sided board, you can also move parts to the bottom side.

  1. Double-click on the part
  2. In the Position tab, change the Board side to Bottom

Alternatively, you can use the Alt+S shortcut key to toggle between top and bottom layers.

Step 5: Place the Parts at The Desired Locations

Use the mouse to select the desired part and move it to a location on the board. Start with connectors and other components with specific location constraints since their placement is critical. Once these parts have been placed, their location can be fixed in that position by locking them. To do this, right-click on the part you would like to lock, and select the Lock option. You can continue the process for the remaining parts, or use the autoplacer (Autoroute > Start Autoplacement). There is also the option to autoplace only a selection of parts (Autoroute > Autoroute Selected Parts).

An alternative method is to drag components from the Parts tab of the Spreadsheet View. To do this, select the part placement icon as shown below. This will allow part placement to be complete based on reference designator information, or any other associated information (part group, value, etc.) (Note: This option is only available in the PowerPro edition)

Tip: To rotate a part in 90 degree increments, select Ctrl+R. For greater angle precision, double click on the part and select the Position tab. Change the Angle (degrees) to the desired value. Another way to set the angle is to select  Edit -> Orientation -> Angle…

Tip: To prevent DRC errors, turn on Part Shoving (Design > Part Shoving) to ensure that parts are nudged if they come within the boundaries of another part. (Note: this option is only available in the PowerPro edition)

Tip: To set the exact location of a part, select the * on the keypad  after selecting a part. This will allow you to set the exact X/Y coordinates of the part using the part's reference point to set its location.

Step 6: Pay Attention to the Ratsnest

When moving parts into place pay close attention to the orientation of the ratsnest. A ratsnest that is short and does not frequently cross other ratsnest elements will be easier to route. Where possible, create parallel ratsnest lines. To easily see a component's ratsnest, set the Ratsnest layer visibility to the dim setting in the Layers tab of the Design Toolbox. The ratsnest associated with the part is highlighted when the part is selected.

Notes

Part Location: The location of all objects, incluing parts, are set in relation to the board’s reference point (0,0). To change the location of the board’s reference point, see the article Changing a Board’s Reference Point in NI Ultiboard.

More Resouces

  1. Download a Free Evaluation of NI Multisim and Ultiboard 11

  2. Check out the NI Ultiboard Getting Started Guide

  3. Watch Multisim 11 in Action

Back to Top

Bookmark & Share

Ratings

Rate this document

Answered Your Question?
Yes No

Submit