How the Pros Buy PCBs at Volume

Buying PCBs at volume is no small task, and it comes with plenty of risk. Before a design is completed, optimized, and prepared for volume production, professional PCB buyers will be engaging with their manufacturer early to ensure they can effectively manage the production process. But before any of this happens, professional buyers take a careful approach to ensure alignment across their design, fabricator capabilities, and quality control measures.

If it's your first time taking a new design into volume production, we’ll show you how professional buyers get the job done. The best approach to buying high volume manufactured PCBs starts in the design phase, where we ensure alignment between the design team, manufacturing processes, available materials, and an integrated approach to procurement.

To better see how this works at volume, it’s worth contrasting with the process for buying PCB prototypes. Let’s take a look.

The Prototyping Approach

PCB prototype buyers can take a range of approaches to getting a basic design built, and the approach has to align with the level of resemblance to the final product. Sometimes, prototypes are needed very quickly due to pressures from scheduling or as part of a product release timeline. In other cases, prototypes can be ordered from overseas and assembled locally, especially if IP protection is not a concern. Sometimes, the prototype is used for reliability testing or functional testing, rather than just in-circuit testing.

For example, prototype PCB manufacturing might take any of these approaches:

1. Produce one-time PCBs cheaply overseas and assemble by hand or locally

2. Produce boards with a quick-turn low volume manufacturer

3. Work with a contract manufacturer who will manage build and assembly via 3rd parties

Any of these options can get you any type of prototype that has varying resemblance to the final product. For example, any of these options can give you a 1st prototype spin, or an assembly that will be used for final reliability testing (thermal, mechanical, etc.) before transferring to production.

Prototype assembled and tested on a bench.

There are some big differences that arise when engaging with these manufacturers versus taking a design into mass manufacturing with an EMS provider. For example:

• Prototype yields will be low, but the manufacturer still supplies your required boards because of their high margins

• Basic quality control is implemented to identify non-working boards

• Boards can be reworked or re-run with attrition parts

• There may not be much root-cause investigation to identify the sources of problems

Generally, you can be assured you will get the boards you ordered. But compared to production in a large factory, the approach to quality control and interaction between manufacturers and design teams leaves much to be desired. Professional buyers who procure boards at volume have to consider these points around quality, as well as the complications that result from lead times, sourcing parts, and costs.

A Professional Buyer’s Approach

A buyer of large quantities of PCBs is not going to fill out an online request for 1 million PCBs. There will be significant engagement with the manufacturer much earlier in the design phase. By the time a customer is engaging with a volume EMS, the design has likely gone through multiple rounds of prototyping just to prove functionality and reliability.

Going into high volume gets demands addressing these points with the manufacturer’s processing team and quality team:

• What capacities and lead times can be expected?

• What level of pre-production DFM qualification can be expected?

• How are parts and assemblies inventories handled?

• Who will handle procurement of which parts of the BOM?

• What inspection procedures are used to qualify boards before shipping?

• If defects are found, what level of root-cause investigation is performed?

• How are design updates that address defects handled mid-production?

• Will a prototyping round be performed to assess quality and yield?

• Is specialized testing against specific industry standards available as part of QC?

This is a long list of points to address, and it takes a lot of time to ensure points of contact are in place, a process is in place to address defects, and supply chain teams are made aware of their responsibilities.

After multiple meetings with the production team, and after thorough evaluation to ensure conformance to process capabilities, the design can be placed into volume PCB manufacturing. The process for ensuring quality involves an ongoing engagement and collaboration between the customer and manufacturing team.

When it’s time to prepare your design for high-volume production, make sure you have CAD tools that make it easy. Multi-disciplined design teams rely on the best set of PCB design features in Allegro PCB Designer from Cadence. Only Cadence offers a comprehensive set of circuit, IC, and PCB design tools for any application and any level of complexity.
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