This article walks through the four main phases of PCB procurement — EVT, DVT, PVT, and mass production — with specific guidance on what to prioritize, which type of manufacturer to use, and how to manage handoffs between phases without losing quality or specification accuracy.
Each phase of product development has a different primary objective — and that objective determines which PCB sourcing approach is optimal.
EVT
Concept Prototype
5–20 boards
Priority: Speed & flexibility
DVT
Design Verification
50–200 boards
Priority: Quality + start MP eval
PVT
Production Validation
100s–1,000s
Priority: MP process validation
MP
Mass Production
1,000+
Priority: Cost & stable supply
The most expensive mistake: running PVT at a prototype manufacturer, then switching to a volume manufacturer for production. Quality differences between manufacturers with identical specifications are common. By the time you discover them, you're mid-production.
The design is not yet stable — revisions are frequent. The primary objective is to get boards in hand quickly for circuit validation. Cost optimization is irrelevant at this stage; if a design iteration takes a week because you're waiting for boards, you're losing development time worth far more than any unit price savings.
Recommended supplier type: Quick-turn prototype specialist
- Target 24-hour turnaround for 2-layer boards; 48–72 hours for 4-layer
- Shenzhen-area manufacturers offer this at competitive prices; domestic options are available at higher cost
- One or two pre-qualified quick-turn suppliers is sufficient at this stage
- Don't over-specify: use standard materials and finish to keep turnaround fast
The design is mostly stable. Boards go to real users or into functional testing environments. Quality consistency (low lot-to-lot variation) matters now. This is also the right time to start evaluating your target volume production manufacturer — ideally by placing your DVT order there.
Recommended: Start transitioning to volume manufacturer candidate
- You can continue with your EVT prototype manufacturer if design changes are still happening
- Placing your DVT order at the target volume manufacturer means your functional testing uses boards from the actual production process
- Begin finalizing your quality acceptance criteria (IPC-A-600 class, dimensional tolerances)
- Get the manufacturer to confirm their impedance control process if relevant
PVT uses production-equivalent conditions — same line, same equipment, same materials, same workforce — to validate that the manufacturing process can consistently produce boards within specification at volume. This is the final quality gate before committing to mass production.
Required: Volume production manufacturer only
- PVT must be executed at your volume manufacturer. Running PVT at a prototype shop does not validate your production manufacturer's process
- Confirm yield rate during PVT; address any yield issues before MP commitment
- Finalize all quality agreements: IPC Class, inspection method, AQL level, defect escalation procedure
- Document any process deviations or notes from PVT before they become informal "agreements"
Production is stable. The focus shifts to cost optimization, supply reliability, and continuous quality improvement. The manufacturer relationship becomes a long-term partnership rather than a transactional exchange.
Focus: Cost, supply stability, quality partnership
- Negotiate pricing based on annual volume commitments — predictable volume gives the manufacturer planning certainty they will price for
- Implement regular (quarterly or semi-annual) quality review meetings
- Monitor defect rates across lots; use data to drive improvement, not just complaints
- Maintain a secondary qualified supplier as contingency — don't become single-source dependent
The implicit specification problem
When you've worked with a prototype manufacturer for months, a body of informal, undocumented understanding accumulates. "Same as last time." "You know how we do it." "Just check with me if anything looks different." These instructions work in a relationship — but they transfer nothing to a new manufacturer who receives only your formal specification documents.
⚠ Document everything before changing manufacturers. Before any transition, convert every informal agreement into written specification. Review your Gerber package, fabrication notes, and purchase order with the question: "Could a manufacturer who has never worked with us before build this correctly from these documents alone?" If the answer is no, close the gap first.
Specification handover checklist
- Complete Gerber package with all layers, drill data, board outline, and fabrication drawing
- Stack-up diagram with material specification (manufacturer name and grade)
- Impedance requirements with target values and reference layers
- IPC-A-600 class specified explicitly (Class 1, 2, or 3)
- Surface finish type and any areas requiring selective treatment
- Electrical test method and required coverage rate
- Dimensional tolerances for board thickness, outer dimensions, and hole diameters
- Packaging requirements (vacuum seal, moisture barrier, orientation)
- Any previous quality issues documented with resolution — so the new manufacturer knows what to watch for
The single-manufacturer alternative
An alternative to phased supplier transitions is using one manufacturer from prototype through mass production. This eliminates handover risk entirely — process knowledge accumulated during prototyping carries directly into production.
| Approach | Phases | Advantage | Watch out for |
|---|
| Split by phase |
EVT/DVT → PVT/MP |
Best specialist at each stage |
Spec handover gaps, implicit knowledge loss |
| Single manufacturer |
EVT through MP |
Zero handover risk, process continuity |
Must have both quick-turn AND volume cost competitiveness |
Finding the right single manufacturer: Large volume manufacturers tend to deprioritize small prototype orders — your 10-board EVT sits in the queue behind production runs. Pure prototype shops struggle to compete on volume pricing. Mid-size manufacturers with capacity in both areas are often the best fit for a single-supplier strategy. Denro Keikaku can help identify manufacturers in this profile —
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Summary
PCB procurement strategy must be matched to the product development phase. EVT prioritizes speed and flexibility; DVT begins the volume manufacturer evaluation; PVT must be run at the volume manufacturer — no exceptions; MP focuses on cost optimization and supply stability. Plan your manufacturer transitions early, document specifications completely before any handover, and treat PVT as the quality gate it is designed to be.