Every project starts with a prototype, often with early versions that have only basic functionalities. Over time, more elements are added until we get a more or less working device. The firmware boots up, individual sections undergo testing, and the microcontroller starts connecting to the cloud and transmitting data. Moving a successful prototype IoT device to a market-ready product requires expert preparation. Avoid the risks of scaling by collaborating with an IoT PCB design partner to manage documentation, DFM (design for manufacturing), and the entire assembly process. This is an extremely important step in the development of any project. We are now dealing with working equipment, and none of this would be possible without the proper preparation of PCBs (Printed Circuit Boards) for production.
But before everything comes to life, the project has a long way to go. Anyone who has developed a device from concept to finished product knows that the most difficult stage is preparing the PCB design and getting all the components to work together. Along the way, there may be problems with electromagnetic compatibility, interference, placing components on the board so that it fits perfectly with the dimensions of the device, or, as in the medical device industry, complying with all legal regulations. This is also the point at which most projects come to a halt.
Therefore, preparing the first production batch of PCBs is not just about sending a Gerber file, but a real test of the team’s engineering, project management, and risk management capabilities. In addition, there is pressure from costs, scalability, and tight deadlines, which are of concern to decision-makers. All this means that preparing a PCB for production is not just about the design itself, but about taking into account all elements of the project. But how do you actually prepare such a board for production?
Where to start PCB production?
Once all design requirements are known, taking into account scalability, risks, and other factors, preparation of the PCB for production should begin with the development of a schematic. A correct, clear, and error-free schematic is a key element that directly affects the board design and its overall functionality.
To ensure that the diagram is correct, it is worth performing an ERC (Electrical Rules Check) analysis. This will confirm that the voltage levels are correct and the connections are logically correct. In addition, an in-depth analysis will indicate whether there are any potential problems related to signal reflections or electromagnetic interference.
How to determine PCB structure?
To prepare a PCB for production, you must first decide on the number of layers, because the design’s complexity dictates the internal structure. After settling on the layer count – whether it’s a simple single, double, quadruple, or complex multi-layer board – we immediately need to think strategically about the right type of vias to connect those layers.
How to select right vias for your PCB?
We distinguish between three types of vias, each with its own trade-offs between density optimization and cost:
- Through holes, which are the simplest and cheapest solution. These vias pass through the entire thickness of the board. They are great for digital connections and low-density power supplies.
- Blind vias, connecting the outer layer with the inner layer, but not passing through. We use them when we need to save space, e.g., under BGA components, because they do not take up valuable space on the bottom layer. They are more expensive to manufacture than through holes, but they improve routing density.
- Buried vias are used to connect two inner layers. They are completely invisible from the outside. This is the highest level of density optimization, allowing us to place a large number of components on the PCB surface. They are typically used in very complex multilayer designs. They are the most expensive and complicated to manufacture.
How to choose your PCB Dielectric Material?
While preparing PCB for production it’s also essential to consider the dielectric layers – the material that separates each individual copper layer.
- FR4 (Flame Retardant 4), a glass-epoxy laminate, serves as the standard in most designs, offering a great balance of mechanical strength, electrical insulation, and cost-effectiveness.
- However, engineers must consider specialized laminates for special requirements. For instance, we might use Rogers materials (like ceramic-filled PTFE) for high-frequency or microwave systems where superior dielectric constant, low loss, and better thermal management are critical, despite the higher cost.
- For flexible designs, like Rigid-Flex PCBs, we often turn to Polyamide (or Polyimide). This offers the necessary flexibility and durability needed to connect rigid sections without cables, which is a key requirement in compact, three-dimensional electronic solutions, say, in advanced medical devices or wearables.
How to design a PCB Layout?
When designing a PCB, it is important to precisely define design rules. Thanks to these rules, tools such as Altium Designer, KiCAD, and Eagle automatically control key parameters, such as minimum track width and maintaining the required isolation between high and low voltages.
At this stage, it is crucial for effective board preparation to ensure that the design complies with both the design requirements and the PCB manufacturer‘s specifications. This is also the moment when components are selected and arranged. They must fit into the available space while meeting the electrical and environmental requirements in which the device will operate.
Once you’ve selected all components, you must place them on the board to optimize space utilization and minimize potential interference. Run a Design Rule Check (DRC) to verify that spacing, tracks, and layers comply with design rules.
How to prepare files for PCB production?
At first glance, it might seem that at this stage, once the Gerber files have been sent to the manufacturer, the process is complete. However, creating a board is not just a matter of clicking the “export Gerber” button. In fact, it involves providing a complete set of documentation. This clarity prevents the manufacturer from asking questions or guessing component connections. Unambiguous design eliminates costly delays.
The PCB manufacturer needs detailed instructions containing all the physical details of the board. For this purpose, we use the Extended Gerber format, such as RS-274X or Gerber X2, which is a modern standard that contains precise information for each layer.
Example PCB layer stackup checklist:
| Required File Layer | Description and Purpose | Risk Mitigation Note |
|---|---|---|
|
Copper Layers (Top, Bottom, Internal) |
The exact layout of all traces, pads, and copper fills. |
Must comply with your fabricator’s DFM rules (min. width/spacing). |
|
Solder Mask (Top & Bottom) |
Defines areas where the protective solder mask will not cover the copper (i.e., pads for soldering). |
Critically check for solder mask slivers. Too small a sliver can tear during fabrication, leading to solder shorts in assembly. |
|
Silkscreen/Legend (Top & Bottom) |
The component legends, reference designators (R1, C12), and polarity marks. |
Ensure silkscreen does not overlap bare copper (pads) to avoid issues during the plating or assembly process. |
|
Board Outline / Edge Cuts |
The precise shape and dimensions of the PCB. Includes any internal cutouts or slots. |
Must be accurate to ensure proper fit into the final enclosure or panel. |
|
Drill Files (Excellon format) |
Specifies the location and size of all holes (Plated and Non-Plated Through-Holes). |
Must be generated separately from the Gerbers. Double-check that all drill sizes adhere to your fabricator’s minimum limits. |
Additional files to PCB assembly
If, in addition to the PCB itself, we want to order the assembly of components, we must provide the manufacturer with additional files.
| File / Document Name | Purpose and Technical Function | Required Detail |
|---|---|---|
|
Solder Paste Stencil File (Top) |
Used to create the metal stencil for the precise application of solder paste onto the top copper layer. |
As an essential fabrication layer (often derived from the paste mask layer), we use this to precisely control the aperture size for fine pitch components (e.g., BGAs, QFNs) to manage paste volume and prevent solder bridging. |
|
Solder Paste Stencil File (Bottom) |
Required only if components are placed on both sides of the PCB. It creates the stencil for the bottom layer assembly run. |
Its parameters must account for the required reflow profile sequence and component mass to ensure components placed during the first run don’t fall off during the second reflow process. |
|
Bill of Materials (BOM) |
The authoritative list for procurement (ordering components) and for the assembly house (verifying components received). |
Must include the Reference Designator (e.g., R5), Component Value, Package/Footprint (e.g., 0402, TQFP), Side (Top/Bottom), Manufacturer Part Number (MPN), and approved Alternate Part Numbers (for supply chain resilience). |
|
Pick-and-Place (P&P) / Centroid File |
A machine-readable data file (usually CSV or TXT) that programs the automated Pick-and-Place machine. |
Contains the list of X/Y Coordinates (relative to the board origin), Rotation (angle), and Layer (Top/Bottom) for every Surface Mount Device (SMD). Ensures high-precision component placement. |
|
Assembly Drawing (Top/Bottom) |
A human-readable graphical reference (PDF or DXF) used by assembly line operators for visual inspection and handling non-automated steps. |
Shows component outlines, polarity markings, designators, and critical assembly notes. Must clearly indicate the location of all Fiducials (optical reference points) used by the P&P machine. |
PCB Fiducial marker
It is good practice to place so-called fiducials, i.e., small reference points, in the corners of the PCB board. They are helpful for machines that assemble components in determining the position on the board. In order for the machine to correctly determine the position of the board, a minimum of 2 points should be placed. The coordinates of the points themselves should be placed in the P&P file.
Moving from prototype to market-ready product
We discussed the entire PCB development path from concept to finished files for the manufacturer, with detailed information on how we should assemble it. However, a key question remains unanswered: How does this fit into the product roadmap? And we aren’t asking where we can manufacture it, but how we make it reliable, economical to produce, and functional for its intended product life cycle.
The preparation of the PCB for production is a key moment that separates effective R&D from its ability to be a scalable market-ready product. That is why it is so important that the technical details of the design also take risk assessment into account. After all, there is never 100% certainty that everything will be manufactured correctly.
The risk concerns both manufacturing defects on the part of the contractor and potential errors in the design itself (e.g., problems with interference filtering, noise generation by components, or inaccuracies in electrical parameters). The risks associated with the automatic assembly of components on the board must also be taken into account. Well-prepared documentation acts as our insurance, ensuring manufacturer accountability. Clear documentation minimizes guesswork, which, in turn, minimizes defect risk.
Good practice
Before starting full PCB production, it is also worth conducting a pilot run. This involves producing the first small batch (usually 50–100 boards), which will then undergo detailed testing. This allows us to verify the supplier’s production capacity and the correctness of the design itself. In addition, having ready-made boards at an early stage speeds up the CE certification process. PCB can be subjected to preliminary testing before the rest of the components are assembled into the final device.
At WizzDev, we provide comprehensive IoT device development services – from concept to finished product, including PCB design and preparation for mass production. Thanks to our agile approach and full IP handover, when you work with us, you gain full insight into all files and project details.
