PCB assembly suppliers near me: what to verify before a PO

Pick a PCB assembly supplier by verifying measurable capabilities, process controls, and documented compliance—not by proximity alone.

Start with evidence, not promises

Ask for recent artifacts before you share Gerbers: a machine list with placement accuracy specs (3σ) and oven zone count; a sample reflow profile for SAC305 showing ramp/soak/peak and time-above-liquidus; SPI and AOI summary reports with escape/false-call data; first‑pass yield (FPY) and DPPM from the last 90 days; and a sample certificate of conformance with lot‑level traceability.

Which capabilities should I quantify?

• Component range: confirm smallest passives (0402 vs 0201), QFN/BGA pitch (≥0.40 mm common; ask for 0.35 mm if needed) and 100% x‑ray for BGAs/QFNs

• Stencil/paste: 80–150 µm stencil support; Type 4/5 paste; documented aperture reductions for fine pitch and BTC windowpaneing

• Print control: SPI coverage at 100%; CpK ≥1.33 on paste height/area at 0.5 mm pitch

• Placement: ±35–50 µm at 3σ on the stated P&P platforms; feeder calibration interval and record

• Reflow: SAC305 profile with 1–3 °C/s ramp, soak ~150–200 °C for 60–120 s, TAL 30–90 s, peak 235–250 °C; profile saved per product/lot

• THT/selective solder: programmable wave/jet; barrel fill to the specified IPC class; nitrogen availability

• Cleanliness: ROSE/ionic contamination ≤1.56 µg/cm² NaCl eq where no‑clean residues are constrained, or documented no‑clean chemistry compatibility if ROSE is not applicable

• Conformal coat: material type (e.g., acrylic/urethane), mask strategy, UV inspection coverage

• Test: flying‑probe or ICT coverage %, boundary‑scan if applicable, power‑on functional test limits and fixtures

• Traceability: lot or unit‑level IDs linking materials, operators, equipment, profiles, and inspection outcomes

What process controls prove line stability?

Look for documented SPI→P&P→AOI closed‑loop adjustments, not just offline rework. Each product should have a locked recipe (stencil, paste type, placements, reflow profile) with ECN/MRN change history. MSL handling must be logged (floor‑life start/stop, 125 °C bake for MSL3+ exposures, humidity cards). ESD controls should reference ANSI/ESD S20.20 with daily wrist‑strap checks (≈1 MΩ) and workstation resistance audits. For selective solder, verify nitrogen flow and conveyor planarity checks. Ask to see quarterly GR&R on measurement tools (scales, pin gauges, microscopes) and AOI false‑call/escape trend charts.

What documents should ship with every lot?

At minimum: a CoC listing revision, serial/lot IDs, IPC class, and acceptance criteria; material CoCs (solder paste, adhesives, conformal coat), RoHS/REACH statements if required; the exact reflow profile used; SPI/AOI/AXI summaries and any BGA x‑ray images on first‑article; rework logs tied to unit IDs; and if cleanliness is specified, the ROSE or process‑equivalency report.

How do IPC classes map to my product?

State the exact revision and class in your PO and drawings (e.g., J‑STD‑001 + IPC‑A‑610 Class 2 or Class 3). For THT, call out plated‑through‑hole fill and wetting per the chosen class; for BTCs and BGAs, specify voiding and coplanarity guidance (referencing IPC‑7093/7095 where applicable). Align inspection magnification, sampling plans, and accept/reject codes with the same standards to avoid ambiguity at FAIs.

When should I request controlled impedance or stack-up data?

If your assembly includes impedance‑controlled traces, include target values (e.g., 50 Ω single‑ended, 90 Ω differential on 100 Ω spec buses) and tolerance (±10% typical) on the fab drawing. Require the assembler to keep laminate lot IDs with your boards and retain impedance coupons or vendor reports in the DHR.

HyperPCB credentials you can verify

HyperPCB operates an ISO 9001:2015 certified quality management system (SGS certificate CN-2023-Q1156, valid until June 2027). We return quotes within 24 hours and provide DFM feedback within 1 business day. Boards can be built and inspected to IPC Class 2 or IPC Class 3 acceptance criteria, and RoHS/REACH compliance is supported. Our partner factory AEGIS maintains ISO 9001:2015, ISO 14001:2015, and ISO 45001:2018, as well as ISO 13485:2016 and IATF 16949. AEGIS also manufactures its own high‑frequency laminates and supplies RF PCB fabricators in China, including publicly listed PCB companies.