Transforming a board design into a tangible PCB is a big step. After countless hours developing the device, it’s time for the proverbial rubber to hit the road; failures to account for manufacturing equipment precision and limitations can result in poor yields or lengthy design revisions. Designers looking for a seamless transition from prototype to product must fully understand how different design elements impact the PCB board price to ensure budgetary goals align with design intent.
Breaking Down PCB Board Prices
Layer Count
The largest cost of any board will always be the design phase (excluding reproductions of completed designs – e.g., clients reordering a new run). However, the layer count will be the largest cost driver directly related to board production. A simple double-sided board is a highly economical manufacturing job. In contrast, a board with a layer count well in the double digits is significantly more expensive (sometimes by a magnitude of 3x or more). The goal of management should always be to tamp down on the number of board layers; concurrently, designers need to ensure they have the minimum layer count to accomplish board routing while achieving optimal signal and power integrity.
Additional board layers scale directly with manufacturing processes – e.g., etching on every layer. A significantly high number of layers can also preclude normal manufacturing processes like drilling, requiring extensive accommodations or even alternate methods. Performance and reliability should always be at the heart of stackup design, taking precedence over reducing the layer count for per-board cost efficiency. Ideally, a mid-layer count board (4-8 layers) can account for a design’s routing and signal integrity complexity without undermining performance or overall functionality.
| PCB Price: Board Layer Count | ||
|---|---|---|
| Lowest | Intermediate | Highest |
| 1 or 2 layers | 4-8 layers | >>10 layers |
Board Class
Board Class is an overarching quality metric of the manufacturing process that reflects the overall board reliability. Specific applications – aerospace, medical, etc. – cannot withstand device downtime during operation without posing a significant hazard to operators/users. More general electronics usage in consumer devices should strive to optimize performance and reliability while maintaining profitability; however, there is little danger to users if a device performs intermittently or fails in the field. The higher the reliability requirements of a board, the more precise and challenging the manufacturing process, the lower the yield, and ultimately, the higher per-board costs to the customer.
While it’s critical not to under-constrain reliability lest device failure poses an imminent danger, over-constrained reliability increases the cost significantly while offering few marketable performance gains on devices that typically have short service lives. Consumers replace these products regularly as new manufacturing technologies emerge or mature, meaning their increased reliability often goes unnoticed.
| PCB Price: Board Class | ||
|---|---|---|
| Lowest | Intermediate | Highest |
| Class 1 | Class 2 | Class 3 |
HDI Design
Many designs need more routable board area, but high-density interconnect (HDI) designs take this to the extreme. Due to board thickness or layer count limitations, HDI boards must shrink vias to sizes typically far below acceptable reliability limits. This means sequential lamination for the fabricator: instead of the single-step drill-then-plate after lamination, the operators perform multiple drill-plate steps for each unique board-layer drill pair. Like the layer count, extensive blind and buried microvia structures across the stackup can quickly add up, so much so that it may be cheaper to add additional layers. However, for a moderate number of microvia structures, this is an excellent way to wring more usable space out of the board without increasing the dimensions or layer count.
| PCB Price: HDI | ||
|---|---|---|
| Lowest | Intermediate | Highest |
| None (through-holes only) | Moderate microvia structures | Extensive microvia structures |
Board Dimensions
When considering board dimensions, it’s essential to remember that designers pay by the panel, not the board! Sometimes, revising the design to shrink the board edges can produce significant savings if panelization increases correspondingly. Large boards incur additional costs if they are beyond standard panel sizes, and similarly, increasing or decreasing the board thickness drastically from the nominal 63 mils / 1.6 mm also affects the manufacturability (and thus, yield or per-board cost).
| PCB Price: Board Dimensions | ||
|---|---|---|
| Lowest | Intermediate | Highest |
| Standard size (panel and thickness) | Larger panel or moderately higher/lower thickness than nominal | Large panel size and board thickness well above/below nominal |
Board Materials
Board materials are the substrate for signal propagation. They offer electrical performance, and their thermal and mechanical properties may also provide the necessary functionality for the PCB. Determining the substrate materials will also help establish the controlled impedance structures common in today’s digital signal processing.
| PCB Price: Board Materials | ||
|---|---|---|
| Lowest | Intermediate | Highest |
| FR-4s | Specialty materials (high-speed, low-Dk, etc.) | Exotic materials (ceramics, metal core, etc.) |
Trace Width/Spacing
Trace width/spacing is a critical consideration when designing impedance structures in the stackup, but the apparent benefit to the designer is narrower traces produce more routing area. However, there is a limit to what manufacturers can reliably produce, and excessively narrow traces become costly due to poor yield and the etchant’s tendency to undercut the copper’s top surface during reaction.
| PCB Price: Trace Width/Spacing | ||
|---|---|---|
| Lowest | Intermediate | Highest |
| Large spacing, wide traces | Moderate spacing and trace width | Narrow spacing and trace width |
Your Contract Manufacturer Ensures Design Reliability and Quality
Ballparking a PCB board cost before engaging with a manufacturer can help design teams and project managers align budget constraints with the realities of manufacturing, especially for high-end or complex designs. The best bet for a cost breakdown of PCB production is to engage with a manufacturer directly. At VSE, we’re a team of engineers committed to building electronics for our customers, including a full design review and quote to get the board’s management, design, and manufacturing on the same page. As a domestic PCB manufacturer with facilities in San Jose and Reno, we provide excellent responsiveness during your business hours, customer service, fast shipping, and an in-person connection you can’t get with overseas manufacturing. We’ve been realizing life-changing and life-saving designs for over forty years with our valued manufacturing partners.
