While the manufacturing of a regular production run of circuit boards is a tightly controlled process, the building of a PCB prototype is usually more flexible. Production boards will have had their designs proven and validated, their components approved, and their manufacturing processes fine-tuned for peak efficiency. Prototypes, alternatively, are paving the way for the production run, and these design and manufacturing details are typically not finalized yet.
There’s a lot the designer should understand when building a PCB prototype to be prepared. In addition to the board’s build’s purpose and requirements, it’s also essential to know fabrication and assembly processes that will impact design. This article will discuss the process of custom circuit boards manufacturing prototypes and how the right PCB contract manufacturer can help guide you through your next prototype design.
Custom Prototype Circuit Board Requirements
Before we look at the manufacturing processes of prototype circuit boards, let’s review first the goals of building a PCB prototype in the first place.
Proof of concept
Before a circuit board is ready for production, it usually goes through a proof of concept process. This process is often accomplished with simulation software and breadboards at first. It’s completed with circuit board prototypes to finalize the functional performance of the circuit board. The proof of concept phase allows designers to test and confirm or alter their design to meet the project’s functional requirements.
Resolve design issues
Once the proof of concept has been validated, there are usually design issues that still have to be resolved. Circuitry performance needs to be fine-tuned. The physical layout of the system and human interfaces must be validated, and the board’s manufacturability has to be refined for peak efficiency.
Reduce time to market
Ultimately the purpose of a custom prototype is to decrease the amount of time it will take to get the new product to market. By quickly building these rapid prototypes to prove the concept and resolve the design issues, the circuit board can get through its new product introduction processes sooner and be ready for regular production.
Now let’s move onto the processes for building a custom circuit board prototype.
How Custom Circuit Boards for Manufacturing Prototypes are Built
When a prototype circuit board is submitted to a PCB contract manufacturer, it will first be evaluated for its manufacturability. By definition, prototypes are a new project to produce, which can make them a lot more complex to build than a production circuit board. Here are some of the details that can add complexity to the manufacturing of a prototype:
- Documentation: The bill of materials (BoM), assembly drawings and other essential pieces of documentation may not yet be “production-ready,” which can add a lot of additional work to the project.
- Components: On prototype designs, it’s not unusual to find functionally correct parts that are unsatisfactory for production. These parts may be too expensive, have long lead times, are going end of life, or are simply no longer available. Many of these parts can be directly replaced. But in the case of parts that are no longer available, it may require re-engineering the circuitry to use different parts.
- Engineering: Since a prototype circuit board is not yet wholly validated for production, there are often problems in how the schematic has been designed or how the board has been laid out. This issue requires engineering analysis to find and correct any subtle errors that can impact functionality or manufacturing.
- Testing: The purpose of a prototype is to validate the design, and yet many prototypes are submitted for manufacturing without design for test (DFT) and debug features built into them. It is essential to identify the design areas that need to be verified and add the appropriate DFT features to facilitate test and debug to complete validation.
Once the design is ready to proceed, the next step for the PCB CM will be to select a fabrication vendor that is best suited to build the raw board. Simultaneously, the procurement team will be ordering the components for the board so that they’re available at the same time as the fabricated boards. When the raw fabs and the parts are ready, the CM will begin the board’s assembly.
While the assembly processes are the same for a prototype board as a regular production board, the PCB CM will exercise greater oversight of the prototype’s production. For instance, an in-house engineer will closely monitor the assembly of a prototype to watch for manufacturing errors and make instant corrections as needed. The board will also have a different tracking system to help with this monitoring instead of a regular production board. This difference makes it easier to stop or change a prototype board’s assembly to make component or production changes as necessary.
However, the key to all of this is working together with a PCB contract manufacturer that is very adept at the prototype manufacturing processes.
The Value that the Right PCB Contract Manufacturer Will Add to Your Prototype Build
All circuit board assembly shops can build a circuit board, but to truly stand out as an expert at building prototypes requires the following capabilities:
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At VSE, we have a long history of helping our clients with custom circuit board prototyping. We are well-known for our ability to take a circuit board from its initial prototype phase and work through its development until it is production-ready.
