Prototyping your new rigid-flex PCB design is critical. It’s best to test your design, ensure everything fits, and look for obvious issues before jumping into full-scale production. As necessary as this step is, it also comes with a cost that can be tough to justify to stakeholders and decision-makers.
In this blog post, you’ll learn how to reduce your prototyping costs while maximizing the impact of your prototyping efforts.
What is Prototyping and Why is it So Important for Rigid-Flex PCBs?
Rigid-flex PCB prototypes are printed circuit boards (PCBs) that combine flexible and rigid materials in the same unit. This is done by laminating together flexible and rigid layers, where sections of the rigid layers are missing to allow for flexible portions of the design. The flexible sections can bend and twist while the rigid sections stay in the same position, which allows designers to create complex 3D configurations.
Rigid-flex PCB design with complex configurations.
These circuit boards need to be well laid out, designed well and put together in a specific way before you can start full-scale production, which is why prototyping is so important.
Prototyping allows you to catch issues early and correct them before you waste time or money on fabrication. However, prototyping can also be an expense that teams aren’t ready to pay but can be necessary to identify those issues and possibly save more money.
7 Prototype Design Tips
To strike a balance between the criticality of doing a full prototype phase and saving money, we put together these cost-effective design practices for your next rigid-flex PCB project. These steps are geared towards saving you money specifically during the prototyping phase.
Tip #1:
Combine Layers Where Possible
As you know, every layer added can increase material costs and manufacturing costs. A quick and easy way to save money on your prototypes is to combine layers whenever possible and optimize every layer in your design.
The goal is to use the minimum number of layers without sacrificing the quality and function of your design. In other words, the PCB still needs to work mechanically and electrically, but there shouldn’t be any redundant or unnecessary layers.
Not only does this save money during prototyping, but it can lead to larger savings during full-scale production runs. A few layers might seem small, but the compounding cost can be unbelievable when you start manufacturing thousands of PCBs.
Tip #2:
Opt for Lower Copper Weights (Wherever Possible)
Testing during prototyping is the best time to determine exactly which copper weight is needed. Our next tip to save money is to opt for lower copper weights and work your way up.
Thicker copper costs more to source and adds time to the manufacturing process, so you want to use the thinnest copper possible. Testing during prototyping will show you whether higher copper weights are necessary or if reducing copper weights is feasible, which can sometimes drive costs down.
Tip #3:
Simplify the Design
Adding extra features, steps, or complications to your rigid-flex PCB will require more money during prototyping and when going into mass manufacturing. For that reason, the physical design and layout should be as simple as possible.
Avoid pitfalls like complicated bends, intricate layout geometries, unnecessary vias, or tight radii. All of these require added tooling, assembling, or processing which can add to the total cost of your project.
Tip #4:
Reduce the Overall Part Size
It might seem obvious, but it’s worth looking at the overall size of your PCB. In the past, we’ve found that the circuit boards footprint can be reduced by cutting out unnecessary components or by routing designs differently, which can greatly reduce the price of the PCB.
Something as simple as routing traces or vias differently across a single layer or multiple layers can reduce the overall size of your parts. Additionally, reducing the hole counts and removing redundant components can also help to reduce the overall part size.
Simply put, the more time put into minimizing the size of the PCB, the more savings can be found, since that translates to less material usage and less time fabricating each board.
Tip #5:
Minimize Your Production Run Sizes
Prototyping is a necessary step in any design process. By creating a small batch of parts, problems can be found and fixed before moving straight to larger-scale productions where those flaws or problems may be found too late and would necessitate large-scale remakes or redesigns.
These runs will add up and can end up incurring large costs over the lifetime of a part. The best practice is to start with a small prototype run, do some testing, and then gradually ramp up production until full-scale production. Barring that, it can be best to do production runs in batches, to allow for alterations to each batch if needed.
Making only a handful of rigid-flex PCB prototypes at one time will also provide the opportunity to run full tests and look for items beyond surface-level issues then correct them before spending more money on further batches or losing money by going straight to production with flawed designs.
Spending less by doing prototype runs can also make it easier to try different iterations or variations of a design without wasting the budget.
Tip #6:
Reduce Unnecessary Ancillary Materials and Components
In another effort to simplify manufacturing costs, designers should all see how many components and how much material can be removed without sacrificing the function of the part.
Removing features where applicable such as shielding, stiffeners, and material thickness can streamline a design and save money during prototyping, and better still, save time by reducing production times for both prototypes and larger-scale productions.
Since prototyping involves functional testing, you can fine-tune over different iterations and revisions how many ancillary materials and features are needed as you go through the full prototyping phase.
Tip #7:
Stick to Standard Materials
It’s commonplace in the PCB manufacturing industry for projects to show up where PCB designers are calling for specialized or exotic materials. In many of these cases, the design will end up costing more from the start on just materials and manufacturing, which might have been avoided if standard materials were chosen from the beginning.
The best practice is to stick to standard materials that are easier to find and work with. While this can be different for different manufacturers and locations, the best solution is to contact the manufacturer prior or to allow for equivalents on the design where possible.
Summary
Creating functional prototypes for rigid-flex printed circuit boards is an important part of any design workflow. Although this step is critical, it shouldn’t cost more money than it can save. By combining layers, simplifying the design, sticking to smaller test run sizes, and opting for lower copper weights, money can be saved throughout the prototyping phase and going into production.
Engineers should take extra time upfront to avoid extra costs and complications since it saves time and money during the life of every PCB. Our team of experienced engineers is here to help you design and manufacture high-quality rigid-flex PCB prototypes that will meet your functional needs, while also helping to find ways to reduce costs where possible.
Key Takeaways
- Optimize Layer Count: Reducing unnecessary PCB layers during prototyping helps lower material and manufacturing costs while ensuring mechanical and electrical functionality.
- Start with Lower Copper Weights: Testing thinner copper weights first can minimize expenses, as heavier copper increases both material and processing costs.
- Simplify the Design: Avoiding complex bends, tight radii, excessive vias, and intricate layouts reduces tooling, assembly, and processing expenses.
- Minimize Prototyping and Batch Sizes: Smaller production runs allow for testing and iterative design improvements, preventing costly large-scale errors.
- Stick to Standard Materials: Using commonly available PCB materials instead of exotic options keeps costs down and ensures manufacturability across different suppliers.
