How to create a PCB Bill of Materials (BOM)

The following article goes over how to create a PCB BOM using KiCAD

Assigning footprints and part numbers

Before generating a BOM, you want to make sure that every part number is filled in.

The way you can edit it is in the KiCAD schematic editor go Tools → Edit Symbol Fields. The table that pops up will show you all the data for each component.

Ensure the following:

• Every PN field is filled out
  • Note that KiCAD will consider different cases or spellings as different fields (such as PN, P/N, p/n). Make sure the field is consistent throughout the board, which you can edit through this table.
  • Essentially ensure that one of the fields has every correct part number
• Group by part number
  • The left of the table has a field for Grouping, which will group the rows based on having the same field. You want to group by the part number field since when you generate the CSV the quantities for each part will be correct and not split up
• Uncheck not needed fields in the Show menu
  • You only need Reference, Part Number, PN, and Quantity really for a BOM, the rest you can uncheck
  • If you think you need another field then feel free to keep it in
• Check the Standardized Mouser List and Inventory for part numbers

MAKE SURE YOU CLICK "Apply Save & Schematic" FREQUENTLY

Generating a BOM

Click the "Export as CSV" button and pick the directory you want to export to.

In my opinion, it's best to convert it to an Excel file since it's easy to edit and you can make multiple sheets which you'll need later

Checking BOM with Inventory

We don't need to order every component for each board since we have a lot of parts in the inventory from previous boards

In your Excel sheet, you should have 2 sheets: one with the full BOM, and one with your shortened BOM after you check from the Inventory

Usually, connectors or passives are in the inventory, so those are the first things you should compare

Even if things aren't the same part number, there may be a matching component that's different like if they share the same footprint or value. Keep this in mind when making your shorter list

Processing BOM in Mouser

Mouser can autogenerate carts given BOMs.

The steps are as follows:

• Export your shortened BOM after comparing it with the Inventory as a CSV or XLS file 
• Login to your Mouser account (or create an account)
  • This is because you need to save your cart 
• If you have items currently in your
• Go to the cart icon and upload your sheet
• Make sure the starting line is row 2 since your first row is likely field names
• Select which columns are "Mouser or Mfr #", and "Qty 1"
• Once the cart is generated and you've reviewed it you can press "Add to Cart" and share your cart as a link
  • This step might be weird if you currently have things in your cart so make sure you've removed what you have or it's saved somewhere else