Industrial electronics
Industrial multilayer controller: fab + mixed-technology assembly
6-layer rigid FR-4 · SMT + through-hole
A controls OEM needed a reliable path from revised Gerbers to assembled controllers—without juggling separate fab and assembly vendors mid-spin.
Challenge
- Design was mid-revision: impedance notes and connector footprint updates arrived late relative to the target EVT date.
- Mixed-technology BOM included fine-pitch MCU packages plus through-hole power connectors that needed a clear process sequence.
- Purchasing wanted one technical owner for stackup questions and kit shortages instead of parallel email threads.
Approach
- Fabrication intake locked layer map, finish (ENIG), and coupon requirements before tooling; open DFM items were closed in one review cycle.
- Assembly ran as a coordinated traveler: SMT first, selective through-hole for connectors, AOI on SMT fields, and a documented first-article checklist.
- Partial population was used on early boards so power and MCU bring-up could proceed while a long-lead connector alternate was approved.
Outcome
- Engineering received boards and assemblies on the same revision index, with inspection notes tied to the traveler.
- Subsequent DVT quantity reused the locked process—only the ECO delta was re-reviewed.
- The program later expanded into a small-batch cadence under the same fab + assembly interface.