PCB assembly is one of the final steps in creating a new product, where your electronic components are placed onto the PCB and put through reflow. But those components have to be purchased from somewhere, and someone will need to be responsible for purchasing decisions and managing logistics. If you're planning a prototype run or scaling into volume manufacturing, strategies for sourcing components can be quite different.

When you look at services provided by sub-manufacturers, both at low volume and high volume, many factors will offer a turnkey service where they provide components sourcing services and manage logistics. What is the process they are using and how are they managing those logistics? Sometimes this can be very opaque, but we will break down how this works in this article.

PCB Assembler Sourcing Versus Consigned Assembly

Turnkey Assembly

PCB assemblers offer turnkey services, where the customer can be almost totally hands-off throughout the assembly process. This means that the PCB assembler will handle sourcing of the components and manage the delivery schedule so that the quoted lead time can be satisfied. This is a great option for engineering firms and even for OEMs during prototyping or low-volume production, particularly when the engineering group doesn't have the time or inclination to manage component orders.

Consigned Assembly

When a design team is capable or has time to handle sourcing and logistics themselves, they can consign components to a PCB assembler. Most commonly this is seen in low-volume runs or PCB prototype runs, and typically all parts are ordered from the smallest number of authorized vendors as possible. The design team will usually order from one or two of the big electronics distributors (such as Mouser), and the components kit will be sent directly to the PCB assembly house. Once the run is completed, the assembly house will ship the remaining components and finished PCBs back to the customer.

The savvy engineer who is supply chain aware will probably ask, where is the risk in each approach? And furthermore, what's wrong with handling orders on consignment? I created the table below to outline the benefits and risks of each approach.

	Turnkey Assembly	Consigned Assembly
Benefits	The PCB assembler handles interactions with brokers or overseas distributors If alternates are specified in the BOM, the PCB assembler can mix and match Some assemblers have engineering experience and can recommend alternate parts	The design team avoids the assembler's markup and can manage their own costs Design team has faster response time when replacements are needed Design team can order from their preferred vendors or brokers
Risks	Budget overrun if not costed correctly Receiving counterfeit components if ordering overseas Misreading or misinterpretation of the bill of materials	Design team orders incorrect attrition amounts Backordering mistake causes huge production delay Different shipping times from multiple parts vendors create production delay

In all cases, the biggest risk to consigned assembly is a production delay, primarily surrounding logistics and attrition. Teams that are experienced in ordering their own parts and managing those orders can avoid these problems, but of course, not all design teams have the time available to order parts and manage deliveries. Getting it right takes experience and a process that addresses all the potential risks before getting started with a PCB assembly run.

A Managed Approach to PCB Assembly

For the design and engineering projects we oversee, we take a different approach that fuses consignment and turnkey. Essentially, we act as a turnkey service provider for our clients, but we manage the process and handle consignments to our PCB assembly partners. We have found that this is an excellent option for companies that do not have experience manufacturing electronics or who have been burned in the past by overseas turnkey manufacturers.

 

 

We have a process we use to handle quoting and sourcing in parallel, which allows a customer to very quickly move into production once they decide to go ahead with an order. We are able to do this thanks to the systems we use and due to the fact that we work with a select group of partners, so we know their process and data requirements.

At a high level, our process for qualifying your order for production is as follows:

1. We review your Gerbers or ODB++ files to identify potential footprint violations.
2. Your BOM is reviewed with our preferred distributors and parts manufacturers to ensure all components can be purchased.
3. We look across our vendors and brokers to find the right balance of prices and quantity for your order.
4. We use this information and fabrication/assembly costs to prepare a quote.
5. Once we receive your PO, we can immediately move to purchasing and put your order into manufacturing.

This process has helped us keep clients on tight production schedules and avoid surprise costs that can occur when parts are suddenly out of stock. It also allows some design problems to be identified early, changed quickly, and sent for production without recreating a quote. Because we manage the process, we can get you through production as soon as possible while you focus on your next PCB projects.

To learn more about what we do and how we operate, take a look at our other resources to learn about the production process, supply chain strategy, and how we have helped aerospace OEMs control costs and meet time for their PCB manufacturing runs.

 

Whether you're designing high-speed PCBs for mil-aero embedded systems or a complex RF product, you should work with a design and development firm that can ensure your product will be reliable and manufacturable at scale. NWES helps aerospace OEMs, defense primes, and private companies in multiple industries design modern PCBs and create cutting-edge embedded technology, including power systems for high reliability applications and precision control systems. We've also partnered directly with EDA companies and advanced ITAR-compliant PCB manufacturers, and we'll make sure your design is fully manufacturable at scale. Contact NWES for a consultation.

 

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