Electronics have become a particular pain point for manufacturers in all flavors of industry. So it should come as no surprise that special attention should be given to DFSC (Design For Supply Chain) when designing your medical device’s electronic PCBs (Printed Circuit Board). 

The PCB industry took a massive hit during COVID-19, when manufacturers were blocked from the global supply chain due to border closings and factory shutdowns, one whose consequences rippled throughout a wide range of industries, leaving massive price increases in its wake. Today, it continues to struggle with elevated costs and widespread shortages in both materials and labor. Because PCBs are so integral to medical technology, a critical part of DFSC in medical device development is having a keen awareness of the state of the PCB market and how it may impact your device or its production. Here, we’ll share some tips our partners offer at Advanced Assembly on how you can work with your PCB manufacturer to avoid delays and additional costs while acquiring the components you need. 

Like most aspects of medical device development, the best time to consider and mitigate supply risk concerning your PCB is at the very start of the design process. Some steps you can take during development to expedite manufacturing and prepare for potential material shortages are:

1. Designing in dual or “flexible” footprints from the beginning of development. This means planning for a stepped-part and leaving multiple options for part selection open to assembly houses. For example, while your design may take a 0603 part, leave room to accept 0402 or 0805.
2. Remaining open to substitutions and specify replacement options. Ideally, you should be willing to substitute any part matching form, fit, and function. At a minimum, consider allowing part substitutions for passive components; this guarantees the primary components will be purchased as designated but alleviates the pressure of locating specific passives.
3. Providing your manufacturer with complete data from the start. Specific data varies depending on the service you receive. Check that you have included the required data and any additional that may reduce errors thereby increadsing turn around:

• If you are only ordering boards, your manufacturer likely requires your data files (e.g., Gerber RS274x or ODB++) and fabrication drawings, but you may also include your IPC-D-356A netlist file.
• For orders including assembly, your manufacturer will require:

1. CAD-generated BOM list (.xls spreadsheet), including reference designators, value, package/decal, description, and part number.
2. CAD-Generated Component Location XYRS File (also known as the Parts Position/Rotation File or the Machine Pick ‘n Place File)
3. CAD-Generated Gerber Files for top and bottom copper, silkscreen, and solder paste.
4. Board X, Y, 0, 0 Reference Designators
5. FAB and Assembly Drawings. Including these reduce errors in the quote and tooling stages. 

It may be that your device requires a particularly hard-to-find component or one that is now considered obsolete, which sometimes happens with legacy designs. In these cases, you should:

1. Stay one step ahead at all times. Contact your PCB manufacturer with your bill of materials (BOM) as soon as available. This will allow them to advise you on the availability of materials and the length of lead times preemptively. Any materials pointed out as difficult to obtain should be purchased immediately.
2. Leverage the relationships of your manufacturer. Not only do they know the industry, but they also have access to a multitude of suppliers and likely hold priority access to available inventories. They are also likely to have connections with certified supply brokers, who have access to sought-after parts and are vetted to avoid counterfeits.

If delays due to material unavailability are of particular concern, here are some procurement tips on how you can prevent lost time and money while working with your PCB manufacturer:

• Try First Article Service if your manufacturer offers it. With this, a small batch of boards will be produced so that your design may be verified before purchasing larger quantities, which takes more time and effort.
• Split production into batches. If possible, this will speed output significantly.
• Reclaim and repurpose parts from existing and previous projects. While this requires a bit of time and experience, it pays dividends during such periods.

Of course, the cost is at the forefront of any business endeavor, and prices are high in just about every industry today. Here are a few critical engineering strategies for reducing costs:

• Fabrication: Use standard, in-stock laminates wherever possible. Use standard hole and trace/space sizes, and reduce the number of necessary drill and lamination cycles wherever possible. This allows the fabricator to avoid costly special orders with long lead times and take advantage of quantity buys.
• DFM/DFA: Be sure to put your final design through DFM/DFA software to check for errors. Advanced Assembly reports that this simple step can reduce PCB manufacturing time by up to an entire week, as even a single error can cause a significant delay.
• Future: Order additional quantities for any parts that are certain to be used in future builds.

By working closely with your PCB manufacturer and maintaining a flexible attitude towards alternatives and substitutes, you can prevent massive development delays, reduce costs in manufacturing, and avoid making unnecessary regressive design changes. Implementing these strategies will ensure you are doing all you can to help your manufacturer produce the boards you need in a manner that is both time and cost-efficient. 

To learn more about working with your manufacturer to mitigate supply chain risk when designing and purchasing PCBs, visit the MIDI Innovation Vault.

To hear more about Advanced DFX Strategy at MIDI, check out our new MIDI Innovation Vault™ podcast series: Advanced DFX Strategy & Supply Chain Paradigm Shift for Medical Device Development.