High-Density High Thermal Conductivity PCBs – Capel’s Breakthrough Solutions for Automotive ECU and BMS Systems

Introduction: Technical Challenges in Automotive Electronics and Capel’s Innovations

As autonomous driving evolves toward L5 and electric vehicle (EV) battery management systems (BMS) demand higher energy density and safety, traditional PCB technologies struggle to address critical issues:

Thermal Runaway Risks: ECU chipsets exceed 80W power consumption, with localized temperatures reaching 150°C
3D Integration Limits: BMS requires 256+ signal channels within 0.6mm board thickness
Vibration Failures: Autonomous sensors must withstand 20G mechanical shocks
Miniaturization Demands: LiDAR controllers require 0.03mm trace widths and 32-layer stacking

Capel Technology, leveraging 15 years of R&D, introduces a transformative solution combining high thermal conductivity PCBs (2.0W/mK), high-temperature resistant PCBs (-55°C~260°C), and 32-layer HDI buried/blind via technology (0.075mm microvias).

Section 1: Thermal Management Revolution for Autonomous Driving ECUs

1.1 ECU Thermal Challenges

Nvidia Orin chipset heat flux density: 120W/cm²
Conventional FR-4 substrates (0.3W/mK) cause 35% chip junction temperature overshoot
62% of ECU failures originate from thermal stress-induced solder fatigue

1.2 Capel’s Thermal Optimization Technology

Material Innovations:

Nano-alumina reinforced polyimide substrates (2.0±0.2W/mK thermal conductivity)
3D copper pillar arrays (400% increased heat dissipation area)

Process Breakthroughs:

Laser Direct Structuring (LDS) for optimized thermal pathways
Hybrid stacking: 0.15mm ultra-thin copper + 2oz heavy copper layers

Performance Comparison:

Parameter	Industry Standard	Capel Solution
Chip Junction Temp (°C)	158	92
Thermal Cycling Life	1,500 cycles	5,000+ cycles
Power Density (W/mm²)	0.8	2.5

Section 2: BMS Wiring Revolution with 32-Layer HDI Technology

2.1 Industry Pain Points in BMS Design

800V platforms require 256+ cell voltage monitoring channels
Conventional designs exceed space limits by 200% with 15% impedance mismatch

2.2 Capel’s High-Density Interconnect Solutions

Stackup Engineering:

1+N+1 any-layer HDI structure (32 layers at 0.035mm thickness)
±5% differential impedance control (10Gbps high-speed signals)

Microvia Technology:

0.075mm laser-blind vias (12:1 aspect ratio)
<5% plating void rate (IPC-6012B Class 3 compliant)

Benchmark Results:

Metric	Industry Average	Capel Solution
Channel Density (ch/cm²)	48	126
Voltage Accuracy (mV)	±25	±5
Signal Delay (ns/m)	6.2	5.1

Section 3: Extreme Environment Reliability – MIL-SPEC Certified Solutions

3.1 High-Temperature Material Performance

Glass Transition Temp (Tg): 280°C (IPC-TM-650 2.4.24C)
Decomposition Temp (Td): 385°C (5% weight loss)
Thermal Shock Survival: 1,000 cycles (-55°C↔260°C)

3.2 Proprietary Protection Technologies

Plasma-grafted polymer coating (1,000h salt spray resistance)
3D EMI shielding cavities (60dB attenuation @10GHz)

Section 4: Case Study – Collaboration with Global Top 3 EV OEM

4.1 800V BMS Control Module

Challenge: Integrate 512-channel AFE in 85×60mm space
Solution:
1. 20-layer rigid-flex PCB (3mm bend radius)
2. Embedded temperature sensor network (0.03mm trace width)
3. Localized metal-core cooling (0.15°C·cm²/W thermal resistance)

4.2 L4 Autonomous Domain Controller

Results:
- 40% power reduction (72W → 43W)
- 66% size reduction vs. conventional designs
- ASIL-D functional safety certification

Section 5: Certifications and Quality Assurance

Capel’s quality system exceeds automotive standards:

MIL-SPEC Certification: Compliant with GJB 9001C-2017
Automotive Compliance: IATF 16949:2016 + AEC-Q200 validation
Reliability Testing:
- 1,000h HAST (130°C/85% RH)
- 50G mechanical shock (MIL-STD-883H)