Certifications that actually matter
A certificate only matters if it maps to your product. UL 94V-0 confirms flammability performance for the PCB. ISO 9001 shows a documented quality system is in place. IATF 16949 matters for automotive-grade work; IPC-A-600 and IPC-6012 define the acceptance criteria you will actually inspect against. Ask the supplier which class they build to (Class 2 vs Class 3) and request recent audit reports, not just the certificate on the wall.
Manufacturing capabilities to verify
Before quoting, confirm the supplier can actually build your design. Check the layer-count range, minimum trace width and spacing, minimum drilled hole size, blind/buried via capability for HDI, available copper weights (especially heavy copper above 3oz), and the material library (FR-4 grades, high-Tg, low-Dk, polyimide, Rogers, aluminum). A fabrication partner whose comfort zone ends below your requirement will quote it, but yield and lead time will suffer.
Capacity, lead time, and scalability
Monthly capacity tells you whether the factory can absorb your peak demand, not just a prototype. Ask for typical prototype lead time (7–10 days for 1–2 layer, 14–18 days for multilayer is reasonable), mass-production cycle time, and how they prioritize during peak season. A supplier running two sites (for example China plus Vietnam) gives you a built-in hedge against single-site disruption and a path to scale without re-qualifying a new vendor.
Quality control and testing
PCB quality is verified, not assumed. Standard checks include AOI (automated optical inspection) for trace integrity, electrical testing (flying probe or fixture-based) for opens and shorts, soldermask adhesion, and microsection analysis for plated-through-hole quality. For controlled impedance or RF designs, TDR (time-domain reflectometry) testing is essential. Ask whether these tests are included in the quote or billed separately — it changes the real unit price.
Geographic risk and the China+1 question
Tariff exposure and supply-chain resilience have made single-country sourcing a boardroom risk. A supplier with qualified production in both China and Vietnam lets you split volume, shift production if duty rules change, and offer your end customers a Certificate of Origin (Form E) for ASEAN preferential treatment. Verify that both sites are qualified to the same build standard, not just that both exist.
What to send when requesting a quote
A precise RFQ gets a precise quote. Send complete Gerber files (RS-274X), a stackup or impedance table if controlled, the finished board thickness, surface finish (HASL, ENIG, OSP, etc.), copper weight, the quantity breakdown (prototype vs mass), the required IPC class, and your target lead time. The more complete the package, the faster the supplier can return a firm price and a realistic ship window.
