EV Charger PCB Procurement Checklist

An EV charger PCB RFQ should identify the board’s function, voltage domains, insulation barriers, actual current and temperature exposure, and required evidence at delivery. Separate bare-board acceptance from assembled charger qualification. A control board, an AC switching board and a DC power-conversion board can belong to the same product while needing very different construction, inspection and validation plans.

Begin with a one-page mission profile before discussing copper weight or laminate grade. This guide concerns the information a buyer should transfer to the fabricator and assembler; it does not select a charger topology or establish product certification. Our quotation file checklist covers the accompanying manufacturing files.

Describe the board’s job inside the charger

Texas Instruments’ EV charging reference-design selection guide, SBAA819, distinguishes control, communication, protection, metering and conversion functions. It also distinguishes AC charging, where conversion occurs in the vehicle, from a DC station’s power-conversion responsibilities. That distinction is a useful first RFQ field: the name “EV charger PCB” does not identify which electrical stress the board carries.

Mark the board boundary on a system diagram. Show which connectors lead to mains, a DC bus, protective earth, a vehicle, sensors and user-accessible interfaces. Identify external devices that carry the main current rather than implying that every ampere passes through the PCB. Include normal operating states and relevant abnormal states already defined by the product team.

Where multiple boards share one order, give each a separate part number, revision and acceptance schedule. A common enclosure temperature does not mean a communications board and a switching board share the same local temperature, contamination exposure or conductor requirements. Buyers should be able to match every exception in a quotation to one identifiable board.

Turn insulation decisions into controlled drawing inputs

The product design authority must define the required insulation arrangement. TI’s high-creepage and high-clearance application brief identifies working and transient voltages, pollution degree and altitude as relevant inputs. These considerations explain why a single spacing value copied from another charger is inadequate; this guide deliberately supplies no universal barrier distance.

Provide a barrier drawing with named domains and the required finished geometry. Identify slots, keepouts, exposed copper restrictions and any limits on supplier CAM changes. State whether a dimension is a nominal design target or a minimum finished requirement, and specify which layers it applies to. A note that merely says “high voltage” cannot resolve an ambiguity between a top-layer opening and an all-layer copper exclusion.

Attach the product team’s approved requirement reference and revision. Ask the supplier to identify exceptions to that drawing, rather than asking it to infer the regulatory classification from a Gerber archive. If coating or encapsulation participates in the insulation design, identify the controlled material and process and the party responsible for applying and inspecting it. Do not silently credit solder mask with a function that the product design has not established.

Use a mission-profile RFQ matrix

Include an “unresolved” column in the working RFQ even though it is omitted from this compact example. An open cooling-interface question should stay visible until the mechanical owner answers it. Treating an assumption as a released requirement creates a false sense of agreement between quotations.

Specify the electrical path, not just copper weight

A useful current-path description follows the circuit through terminal contact, pad, trace or plane, layer transition and return connection. Identify the narrowest features and the interfaces at which current enters or leaves the board. Ask the supplier to review manufacturability of the released geometry and the proposed finished copper construction. Nominal starting foil alone does not document every finished conductor.

Illustrative calculation: suppose an engineering test measures 2 milliohms across a defined board path at its stated test temperature. At 40 A DC, the path dissipates I²R = 40² × 0.002 = 3.2 W and drops IR = 40 × 0.002 = 0.08 V. These invented inputs demonstrate why both voltage drop and heating deserve attention. They are not current ratings, temperature predictions or a copper-thickness recommendation.

Repeat the assessment with the actual resistance at the relevant operating condition and include connection losses where the measurement boundary requires them. Record the sense-point locations so a later test does not accidentally measure a different path. For construction review, send the approved stack-up alongside the current-path drawing.

Make thermal and duty-cycle assumptions testable

State how long full load persists, what idle and restart sequences occur, and which ambient condition is associated with the claimed operating point. “Continuous service” and “intermittent peak current” are different input descriptions. Include the cooling plate, airflow or enclosure assumptions that the thermal analysis used, with mounting interfaces and tolerance-sensitive contact areas identified.

Give the assembly team the expected soldering and repair sequence. Ask how the proposed construction is supported for that thermal history and for the product’s qualification exposure. Material selection should follow the complete requirement set; a familiar laminate property or a higher headline temperature value is not a substitute for the build-specific review. The FR-4 grade selection guide explains how to retain exact grades and substitution controls.

Plan sensors and measurement locations before the qualification build. If a component temperature matters, a thermocouple on a distant board corner is not evidence of that location. Preserve the load condition, enclosure state, measurement method and sample identity with each result so a later supplier transfer has a meaningful comparison.

Release the board and the product through separate gates

Bare-board electrical continuity, dimensional checks and material records answer manufacturing acceptance questions. Charger functional behavior, protection response and environmental performance require the appropriate assembled system evidence. Write both sets of requirements, assign owners and avoid treating a passed bare-board test as approval of the charger.

1. Freeze the board revision, system boundary and voltage-domain drawing.
2. Resolve minimum finished barrier geometry and any prohibited CAM changes.
3. Record the current, duty, temperature and cooling assumptions for critical paths.
4. Approve the exact construction and any material-substitution procedure.
5. Define first-article measurements and the evidence required with production lots.
6. Identify who accepts the bare board, the assembly and the charger qualification results.

Use the quality evidence checklist to request records that identify the supplied revision and lot. If qualification remains pending, the purchase order should describe the build as an engineering or qualification lot and state the hold point for subsequent production. This makes the commercial release match the evidence actually available.

Primary sources checked October 9, 2026. The RFQ matrix and numerical example are editorial tools, not product approval or universal design limits.