If you're trying to utilize Backbone's wonderful Tech Pack creation feature to create a PDF of your BOM but then you need to put our Tech Pack into an excel spreadsheet - this is for you.
To start, begin in the summary of your product and then enter into the Tech Pack section to begin generating a new Tech Pack. On the first page of the creation modal, let's uncheck everything except for the BOM to simplify the export / import process.
Skip the second page of the creation modal by clicking next without changing any of the drop downs. Then choose the expanded layout - this is important as it will give us options to include important info.
On the next page make sure to include component and component variant images, and then click next. On the new page, edit the display for our BOM and component fields in the "As Columns" dropdown. Select both placement and notes and then click on Create.
Once it is created make sure to download the Tech Pack using the download icon found to the right of the Tech Pack name. Next - in the Finder / File Explorer, right click on your Tech Pack .pdf file and open it with Adobe Acrobat.
When your file is open and in view within Adobe Acrobat, go to [file] and then [export to...] and select [spreadsheet] then [Microsoft Excel Workbook] - this will create a NEW file that you will use in Microsoft Excel.
If an alert pops up - select the affirmative option that tells excel to recover info, and on the following popup select "view" and your Tech Pack BOM should appear in an excel workbook. The formatting may be slightly off, but at this point you may edit it however you wish.