A bill of materials or product structure (sometimes bill of material, BOM or associated list) is a list of the raw materials, sub-assemblies, intermediate assemblies, sub-components, parts and the quantities of each needed to manufacture an end product.
In electronics, the BOM represents the list of components used on the printed wiring board or printed circuit board. Once the design of the circuit is completed, the BOM list is passed on to the PCB layout engineer as well as component engineer who will procure the components required for the design.
For PCB assembly, you can find a BOM template to download on right side. The following BOM is a simple one for us to use.
1. Item: To calculate how many kind of material using for this product. This list must be filled.
2. Ref.: Indicating components’ corresponding location on PCB. This list must be filled.
3. MPN: Components’ Manufacturing Part Number like ID. This list must be filled.
4. Digikey PN/Mouser PN/Links: Components’ special ID on Digikey/Mouser or other websites.
5. Quantity: The quantity of each kind of component for this boards. This list must be filled.
6. Others: you could add the component's value, package, alternative MPN, remarks etc.