PV string inverters combine high-voltage DC, surge events and outdoor humidity in a compact enclosure. Terminal geometry and finish must support both the electrical boundary and a repeatable reflow process.
Define the DC and surge envelope
List string voltage, continuous current, surge waveform, interruption condition, altitude and enclosure temperature. Use those inputs to choose the bar section, contact interface, insulation and protection path rather than copying an indoor inverter design.
Design for damp heat and automated placement
SMT terminals need a stable land pattern, pickup surface and coplanarity window. Plating boundaries should keep exposed copper away from condensate paths, while the enclosure and conformal coating preserve creepage and service access.
- Measure contact resistance and rise before and after damp-heat exposure
- Check surge and dielectric tests at the actual spacing
- Verify feeder, nozzle and reflow profile with production packaging
Make the outdoor RFQ auditable
Include string count, voltage class, current, surge, pollution degree, coating, enclosure sealing, target life and annual volume. Request finish thickness, insulation inspection, thermal images, dielectric results and lot traceability as acceptance evidence.