PCB Walk-through 2: Mechanical Symbols

This walk-through demonstrates how to create and place mechanical symbols. After you complete this topic, you will be able to:  

  • Create a mounting hole 
  • Place mechanical symbols on your PCB 

To follow along, continue working with the design completed in PCB Walkthrough 1 or open the provided board file in the folder directory, PCB Walkthrough 2_Mechanical Symbols.     

If materials were not downloaded at the beginning of the walk-through, they can be accessed through the Materials tab above.

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Note: Included in the design files for PCB-Walk-through 2: Mechanical Symbols, is a mechanical library.  If you do not want to create the mechanical symbol, copy the .bsm and .dra files included in the mechanical library and paste the files in the standard PCB footprint library: C:\Cadence\SPB_17.4\share\pcb\pcb_lib\symbols 

  1. Select File > New from the menu. 
PW2 step2
  1. Select Mechanical Symbol as the Drawing Type.  
  1. Assign Mounting_hole1 as the Drawing Name
  1. Select Browse and select the path to the PCB symbol library: C:/Cadence/SPB_17.4/share/pcb/pcb_lib/symbols 
  1. Select Open and OK
PW2 step6
  1. Select Layout > Pins from the menu.  
Pw2 step7
  1. Browse for a padstack and select Hole 150
PW2 step7 note

Note: The Options window will need to be activated for the ability to browse for a padstack. If you do not see the options window, select View > Windows > Options from the menu.

  1. In the Command Window, type x 0 0 and Enter to place the padstack at the origin. 
Pw2 step8note

Note: If you do not see the command window, select View > Windows > Command from the menu. If you receive an error that the pin cannot be placed outside of the drawing extents, you need to change the origin. Select Setup > Design Parameters > Design. Under Move Origin, add 100 in the x and y locations to move origin. Click OK.

  1. Select Shape > Circular from the menu.  
Pw2 step10
  1. In the Options tab, select Route Keepout and Top as the Active Class and Subclass. 
  1. Click to place at the origin.  
  1. In the Command Window, type x 3 and Enter to define the radius.  

Note: This sets the radius of the circle. You can also drag the circle to the desired size and click to place. 

Pw2 step13
  1. In the Options tab, select Package Keepout and All as the Active Class and Subclass.  
  1. Select Place Circle under Circular Shape Creation. 
  1. Set the Radius as 3
  1. Click to place the keepout. 
  1. Right Click and select Done
  1. Select File > Save from the menu. 
  1. Open the PCB design. 
  1. Select Place > Mechanical Symbol from the menu. 
Pw2 step21
  1. In the Placement List, select Mechanical symbols from the drop-down. 
Pw2 step22
  1. Check the box next to Mounting_hole1
  1. Click to place on the board.  
  1. Repeat this process and place four mounting holes.  
  1. Close the placement window. 

Note: To place all four mounting holes consecutively, select Advanced Settings and set AutoNext to Disable. Make sure to Close the placement window. Do not out the window or the last hole will not be placed. To move the mounting hole, select Setup > Application Mode > Placement Edit from the menu. Click to select the hole and click to place. 

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