Understanding the Critical Role of BOM in PCB Design

Nov 25,2021

PCBs or printed circuit boards are the nucleus of the part or product they are embedded in. The functioning of the product depends upon the PCB performance, and hence they need to be flawless in terms of structure as well as functionality. To get the right structure, number of layers, components in the right place, and so on, a flawless design is crucial. PCB design is important as the features and functionalities are becoming complex by the day. To get the right design, a well-made Bill of Materials (BOM) is important as it has all the required details such as component names, brands, part numbers, quantity required, and so on. This post discusses why BOM is important in PCB design and the role it plays.

What does a Typical PCB BOM Include?

Typically, the client generates a bill of material for the PCB manufacturer, which is verified and approved by the latter. At times, the client has their own design which they send in Gerber files. BOM and design files can be sent at a time to the PCB manufacturer. On the other hand, based on the BOM, they make the PCB design from scratch. The most basic things a BOM for circuit boards comprises are parts, part numbers, prices, brands, and quantities. Here is BOM explained at length.

• All the core PCB elements have to be listed in a BOM. Each element in a PCB, especially the components and wiring, has a unique identifier. A PCB BOM comprises a description or comment against each component as part of unique identification.

• There is a unique ID or designator for each part, such as some code number.

• Aside from these core facts, there is a lot of extra but useful information in BOM, such as product-related notes, structural details, properties, tolerances, and so on.

• You can further make BOM a comprehensive and extensive document. This depends on each business and their requirements.

• Most important, the number of boards required is also listed in BOM. Also, the quantity of each part needs to be mentioned.

• There is a DNI or Do Not Install field which implies if the components should be installed on the board or not.

• It is good to mention the design specifications or part number descriptions for each part.

• It is good to mention the size of the part number as it gives an idea of how much physical space would it occupy on the board.

• It is a good practice to give the manufacturer name and an optional name or alternative. This helps if the preferred part is not available.

Role of Bill of Materials in PCB Design

An extensive document such as a BOM would certainly be useful in PCB design, where all the details are mentioned together. This reduces the need for unnecessary searches and confusion which may otherwise be created. Also, it helps in price estimation, and also determines if any changes are required in brands or quantities for any of the parts. It also prevents wastage or storage of parts in excess. The availability of parts with vendors can be checked easily, and if not then alternatives can be considered. All this is done and finalized before the design is finalized.

If you are an OEM and require PCBs or an assembly for your product, ensure you partner with a reliable and certified PCB manufacturer and service provider in USA who would understand your requirements and deliver accordingly. Getting the right BOM must be an integral part of their process. Creative Hi-Tech is a well-known PCB manufacturer and assembly services provider offering PCBs and assemblies using good quality materials. They have a robust supply chain network of component vendors.

Related Blog Post:

• 7 Most Important Things Included in Bill of Materials (BOM)