BOM

Once the first draft of the schematic is complete it is time to create the Bill of Materials (BOM) for the project. This is a critical step before attempting any layout, and it is important to be very careful. This is were I can catch designs that use parts that are either obsolete or prohibitively expensive before spending time on a layout that will be thrown away.

The BOM is one of the three critical documents for the project, along with the schematic and layout, and is the most important document during the assembly phase. Trying to build a project without a proper BOM ends up recreating the schematic and layout all over again. A "proper" BOM includes all the information needed to order the parts and to find all the engineering data. This includes not only the specific part number, but also the vendor stock number and a reference to the datasheet for every part.

One of the reasons why I like Digikey is how they remember every order. This makes it easy to look up parts after the fact. They also have a system to create online build kits for specific projects.

The BOM for this project is stored in an Excel spreadsheet, JumpMtr02_Thermal_Parts.xlsx. The vendor information is incomplete because some of the generic parts were surplus stock from Halted.

This table was created by exporting the spreadsheet as CSV and then running some regex/macro magic on it. The definitive reference should be the spreadsheet; update that and then update this page from the spreadsheet.

Datasheets

It is a good idea to archive the datasheets for any special components, just in case the company goes out of business.