Electric Vehicle Battery Management System PCB

This project involves the design and manufacturing of an automotive-grade printed circuit board assembly (PCB) for an electric vehicle battery management system (BMS). This PCB serves as the guardian of the high-voltage battery pack, continuously monitoring cell voltages, balancing charge distribution, and ensuring safe operation under all driving conditions.

Key PCB Specifications:
Base Material: High-Tg FR4 with enhanced thermal performance and UL 94V-0 flammability rating
Layer Stackup: 6-layer construction with dedicated analog, digital, and high-voltage isolation zones
Copper Weight: 2 Oz on power distribution layers for balanced current sharing
Board Thickness: 2.0 mm, with reinforced isolation barriers meeting IEC 60664-1 requirements
Surface Finish: ENIG with 5μ" gold for reliable connector contacts in automotive vibration environments
Isolation: Reinforced isolation (4kV) between high-voltage (up to 800V) and low-voltage sections using optocouplers and isolated ADCs
Quality Assurance: 100% functional testing including cell simulator validation and thermal chamber testing (-40°C to +105°C)
Functional Role:
This PCB ensures the safety, performance, and longevity of EV battery systems:
Cell Monitoring: Precision voltage measurement (1mV accuracy) for up to 96 series-connected cells with dedicated AFE ICs
Temperature Sensing: 12 NTC thermistor inputs for comprehensive thermal monitoring of battery modules
Cell Balancing: Passive balancing with 100mA bypass current for charge equalization during charging cycles
Current Measurement: Hall-effect sensor interface for bidirectional current sensing with 0.5% accuracy
Safety Functions: Multiple protection layers including over-voltage, under-voltage, over-temperature, and over-current detection with hardware-based fault response
Communication: Isolated CAN 2.0B interface for real-time battery data transmission to vehicle control unit