Putting Your PCB Design Tools to Work for Manufacturing Cost Estimation

Many years ago when home video recording technology was still new, my parents bought a videocassette recorder (VCR) and asked me to set it up for them. I plugged it in, set the clock, and then programmed it for their favorite late night show. I found out a week later that they had stayed up waiting for their show to begin, and then manually turned on the VCR to record it before going to bed. They simply didn’t understand that the VCR already had the ability to automatically do the work for them.

How often do we run into similar situations where we don’t realize that those tasks that we are used to doing by hand can be greatly helped by the tools that we are already using. PCB design tools are a great example of this. I bet that you’ve probably had many times where you’ve found commands and features in your design tools that did something that you didn’t know about. I know that I have. Did you also know that your PCB design tools can help you with estimating the manufacturing cost of your design? When we start using our PCB design tools to help us with these tasks it will make our jobs a lot easier. Let me show you what I’m talking about.

Getting a Manufacturing Cost Estimation the Traditional Way

It used to be that to get a manufacturing cost estimation required a lot of effort with some guesswork thrown into the mix too. The components for the design would be extracted from the design database, but often those components weren’t finalized until right before the project was ready to be sent out the door for manufacturing. The schematic and the layout would be filled with preliminary parts that didn’t have actual part numbers and were identified by pseudo reference designators. This made estimating the cost of the necessary components very difficult without real parts or quantities to work with.

The extracted CAD data would have to be manually completed and formatted for the manufacturer which afforded plenty of opportunity for human error and guesswork along the way. Because of the temporary nature of this document, it would have to be updated regularly as part numbers and quantities were finalized. The manufacturer would have to update their cost estimates on a regular basis after the new data that would be provided to them.

Incomplete component data would often mean that the design would physically change while in progress. It wasn’t unusual for the preliminary parts in the CAD database to be completely different from what would end up being used on the final design. This could result in eleventh-hour redesigns to accommodate board layer stackup and dimensional changes, all of which could affect the cost estimation. PCB manufacturers need accurate data in order to give you a realistic cost estimation.

The more accurate data you can get to your manufacturer, the more realistic the cost estimate

What Your PCB Manufacturer Needs from You

To get the best cost estimation results from your PCB manufacturer, you need to give them as accurate information as possible. What they are looking for would include:

• Accurate BOM Data: To correctly compute the cost of components on your board, your manufacturer needs to know part numbers, reference designators, and quantities. With this information they can research the components and give you an accurate cost estimation. As an added bonus, accurate BOM data will also allow manufacturers to pre-order your parts at a better price than parts that are ordered at the last minute.

• Board Specifications: Your manufacturer needs to know what the function of your design will be, its dimensions, high speed requirements, and its operating environment. With this data, the manufacturer will be able to accurately estimate the materials needed to fabricate the board as well as processing and labor costs.

• Clear Expectations and Accurate Design Files: PCB manufacturers often have to wade through documentation packages from their customers, and then ask questions or return data and documents that aren’t clear or usable. In addition, some customers are not clear in their requests which in turn forces manufacturers to go back a few steps to reanalyze some of their estimates in light of what the customer actually wanted.

The best way to make sure that the manufacturing cost estimation data that you give your manufacturer is complete and accurate is to leverage the power of your PCB design tools in creating the data.

OrCAD’s cross section editor is a great tool to use for organizing board stackup information

How to Put Your Design Tools to Work

Your PCB design tools can help a lot in getting more accurate cost estimations as long as you are willing to leverage all of their capabilities. Instead of constantly updating BOM information as preliminary CAD library parts are replaced with actual parts, start the design with as many actual parts as possible. This can be done by using CAD library parts from component vendors, library services, or by leveraging the built in part generators in your PCB design tools to quickly build accurate parts.

Another problem in getting accurate cost estimations is in the quality of data that you send to the manufacturer. Instead of relying on manually formatted reports and documentation, use the features in your CAD tools to automatically create the reports in a style and format that your vendors require. Specifically, utilizing the IPC-2581 will enable you to have one file to give to each vendor. The BOM creation functionality within your PCB design tools will have different formatting features to create documentation that is usable without manual intervention.

All of these features can be a great help to you, the key is to use PCB design tools that are best suited to generate the accurate data needed for your manufacturing cost estimations. For us that means using OrCAD PCB Designer with its different documentation and report generating functionality.

If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts.