A Canadian manufacturer of heavy-duty electric vehicle battery management systems (BMS) faced persistent field failures due to moisture ingress and vibration damage in their ECU PCBs. Operating in high-humidity environments with constant mechanical shock, their existing off-the-shelf potting solution proved insufficient, leading to costly warranty claims and system downtime.
The client’s application demanded an encapsulation system that could:
Additionally, the existing PCB layout had densely packed components with fine-pitch BGAs, requiring a low-viscosity potting compound that could flow without creating voids or stressing delicate solder joints.
Weller’s engineering team conducted a comprehensive review of the application environment, mechanical constraints, and assembly process. We developed a tailored encapsulation solution using a two-part epoxy potting compound with:
Material Selection: After evaluating multiple epoxy systems, we selected 3M™ DP270 for its superior adhesion to FR-4 substrates and compatibility with fine-pitch components.
Prototype Tooling: Custom-machined POM (polyoxymethylene) housings were fabricated to precisely align with the PCB outline and connector locations.
Process Validation: Vacuum encapsulation was employed to eliminate air entrapment, followed by controlled thermal curing to achieve optimal hardness (83 Shore D) and adhesion strength
Testing & Qualification: Sample units underwent rigorous testing including thermal shock (500 cycles), 96-hour salt spray, and mechanical shock (50G) to validate performance.
The customized encapsulation solution delivered measurable improvements:
| Metric | Before | After |
|---|---|---|
| 3.2% | 0.08% | |
| IP54 | IP68 | |
| 100 cycles | 500+ cycles | |
The client successfully deployed over 15,000 encapsulated units across fleet operators in Northern America, with zero moisture-related failures reported after 12 months of field operation.
This project demonstrates the critical role of a customized encapsulation process in achieving long-term reliability for electronics deployed in harsh environments. By combining precise material selection, process engineering, and rigorous testing, Weller enabled our customer to scale production with confidence.
For companies facing similar challenges in industrial, automotive, or renewable energy applications, a tailored encapsulation approach can transform product durability and reduce total cost of ownership.
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