Creating Staggered Pin BGAs can be tricky. There are a couple ways:

BGA with Alphanumeric Rows:

 

BGA with Alphanumeric Columns:

 

You need the package dimensions for Length, Width and Height. For this demo we'll use 7, 5, 2. You'll also need to know the Pin Pitch and Pad Diameter. For this demo we'll use 0.75 and 0.40.

Select the "Designer" button and insert the package dimensions.

 

Select the OK button and the Drafting Outlines for Silkscreen, Assembly, Component, Courtyard and Origin will be auto generated.

 

The Pad Stack Designer will automatically appear. Create a Round surface mount pad 0.40 diameter and select "Add Pad Stack to Design Queue" and then "Add Queue to Design".

 

The Pad Stack Manager will automatically open to allow you to edit the pad stack layer sizes and shapes. If there are no edits, select "Save and Close".

 

In the Define Placement menu select the "Open Wizard" button. When you enter simple values in the Wizard for Pin Count, Pin Pitch and Offset. Select "Apply Wizard" to populate the X/Y coordinates in the Pin Placement menu. Then enter the X Stagger dimension and enter "A" in the Alpha pin options. You will see an Example of the Alphanumeric Pin Assignments.

Select the "Open Wizard" button.

Select the "Add To Design" button

The pads will display in the Footprint Viewer with Alphanumeric Rows

For Alphanumeric Columns select the Undo button

Then select the Pin Array Wizard Pin Direction to Column (Blue highlight)

The new values will auto-populate the Pin Options cells. See the Example Pin Assignments.

Select "Add To Design" button.

The pads will be added to the footprint in alphanumeric columns

Add the footprint to your master FPX file and export to any CAD format.

The BGA pin quantity limit is 99,999 pins.

You can build any staggered pin BGA in minutes using the Pin Array Wizard