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How do I generate XY centroid data from my gerber files?

Automated equipment is used to place the surface mount components on your pcbs. To rapidly program these machines, a Part Centroid file is required. Some CAD packages will automatically generate this file and some will not. Fab It! can easily create this centroid file from your existing gerber files.

Note: Centroid files are primarily used for placement of SMT components.  For best results when generating a Centroid File from gerber, use the paste layer.  If you do not have a Solder Paste Layer, please create one by using function: Generate Paste Layer(s)...

Here's a tutorial movie showing all steps, followed by written instructions:
 

First Step: Add Parts
 
1. Turn-off all layers except for Top Paste & Top Silkscreen.

2. Locate a footprint, and select the entire component.

Note: This function requires that you select objects before proceeding.
Note: For more information about object selection see Viewing & Selection Basics
Note: Add Parts requires flashed footprints and will ignore anything else, so it's fine to select a window around the entire part (any selected Silkscreen objects would  be ignored).

3.  Go to menu: Assembly | Build Components...

4. Select Pin One

Note: Usually Pin One is the Top-Leftmost pin for Top side (assuming no rotation), and Top-Rightmost for Bottom side (assuming no rotation).

5. Assign Part Description, and press OK when done.

Note: Enter Part Rotation as it appears on the board.  If you have selected a component that is rotated 90 degrees on the board, than make sure to enter that here.
Note: If Apply All is checked (recommended), Fab It! will go out and seek all similar footprints.
Note: You will notice (if Apply All is checked) that all similar footprints have been detected and assigned a generic reference designator value ( for example "?21" ).

6. Repeat Steps 2 thru 5, until all footprints on the paste layer have been completed.

Note: You can also add parts individually by using function:  Insert Component  (menu:  Assembly / Insert Component...)
 
Now its time for the Bottom Side (if required)

7. Set FAB 3000 into back side view mode.  Menu:  View / Backside...

8. Turn off all layers except Bottom Paste & Bottom Silkscreen, and repeat steps 2-6.

Second Step: Assign Reference Designators to Parts

1. Turn-off all layers except for Top Part & Top Silkscreen.

2. Go to the Parts Tab Browser, and select the a part (from the list).

Note: When a part is selected from the list, it will be highlighted. If you want to also zoom in towards the selected part, make sure to check the item "Zoom To Part"
Note: You can use the arrow keys (up/down) to navigate through the parts list.

3. Click into the edit control "RefDes:", and type-in the correct reference designator. Press Enter Key to update.

Note: Having the silkscreen visible is a great way to determine which reference designator to assign the the part.

4. Repeat Step 3 - until all parts have been assigned their reference designators.


Export Centroid File

Note: You must at least have one or more parts defined before exporting to a centroid file.
Note: The centroid file is a comma separated file that can be loaded into almost any spreadsheet program or text editor.
 
1. Go to menu: File | Export | Part Centroid File...

2. Choose from available options and press button 'Next'

3.  Select File Name & location.

Congratulations - You have exported a centroid file!
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Automated equipment is used to place the surface mount components on your pcbs. To rapidly program these machines, a Part Centroid file is required. Some CAD packages will automatically generate this file and some will not. Fab It! can easily create this centroid file from your existing gerber files.

Note: Centroid files are primarily used for placement of SMT components.  For best results when generating a Centroid File from gerber, use the paste layer.  If you do not have a Solder Paste Layer, please create one by using function: Generate Paste Layer(s)...

Note: All pads on the Paste Layer must be "Flashed".  If there are any pads on the Paste Layer that are not "Flashed" , use function:  Draw to Flash

Note: To determine if all pads are "Flashes" on the Paste Layer, goto  Layers Table and try assigning a different color for the Flashed objects.  Then when you view the Paste layer, all Flashed Pads will use the different color you have assigned.  You may also try using function: Query



First Step: Add Parts
 
1. Turn-off all layers except for Top Paste & Top Silkscreen.

2. Locate a footprint, and select the entire component.

Note: This function requires that you select objects before proceeding.
Note: For more information about object selection see Viewing & Selection Basics
Note: Add Parts requires flashed footprints and will ignore anything else, so it's fine to select a window around the entire part (any selected Silkscreen objects would  be ignored).

3.  Goto menu: Tools | Parts | Add Parts...

4. Select Pin One

Note: Usually Pin One is the Top-Leftmost pin for Top side (assuming no rotation), and Top-Rightmost for Bottom side (assuming no rotation).

5. Assign Part Description, and press OK when done.

Note: Enter Part Rotation as it appears on the board.  If you have selected a component that is rotated 90 degrees on the board, than make sure to enter that here.
Note: If Apply All is checked (recommended), Fab It! will go out and seek all similar footprints.
Note: You will notice (if Apply All is checked) that all similar footprints have been detected and assigned a generic reference designator value ( for example "?21" ).

6. Repeat Steps 2 thru 5, until all footprints on the paste layer have been completed.

Note: You can also add parts individually by using function:  Insert Single Part
 

Now its time for the Bottom Side (if required)

7. Turn off all layers except Bottom Paste & Bottom Silkscreen, and repeat steps 2-6.



Second Step: Assign Reference Designators to Parts

1. Turn-off all layers except for Top Part & Top Silkscreen.

2. Go to the Parts Tab Browser, and select the a part (from the list).

Note: When a part is selected from the list, it will be highlighted. If you want to also zoom in towards the selected part, make sure to check the item "Zoom To Part"
Note: You can use the arrow keys (up/down) to navigate through the parts list.

3. Click into the edit control "RefDes:", and type-in the correct reference designator. Press Enter Key to update.

Note: Having the silkscreen visible is a great way to determine which reference designator to assign the the part.

4. Repeat Step 3 - until all parts have been assigned their reference designators.



Export Centroid File

Note: You must at least have one or more parts defined before exporting to a centroid file.
Note: The centroid file is a comma separated file that can be loaded into almost any spreadsheet program or text editor.
 
1. Go to menu: File | Export | Part Centroid File...

2. Choose from available options and press button 'Next'

3.  Select File Name & location.

Congratulations - You have exported a centroid file!




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