A CCS Combo PCB is a high-reliability circuit board used in Combined Charging System (CCS) electric vehicle charging equipment. Unlike a conventional control board, it must combine high-voltage power routing, communication interfaces, safety monitoring, and long-term environmental reliability.
CCS systems combine AC charging and DC fast charging through Combo 1 or Combo 2 interfaces. The PCB architecture must support high-voltage isolation, current handling, signal integrity, and automotive-grade reliability.
For EV charger developers and procurement teams, the key question is not simply whether a PCB can be manufactured. The decision is whether the board structure, materials, testing strategy, and supplier process can support thousands of charging cycles in harsh environments.
Key Takeaways
- CCS Combo PCB designs require separation between high-voltage power paths and communication circuits.
- High CTI laminate materials, controlled creepage, and clearance distances are critical for 400V–1000V systems.
- Heavy copper PCB technology is commonly required for high-current DC charging paths.
- PLC communication requires controlled impedance and noise-aware routing.
- Hi-Pot testing and electrical isolation verification are essential production controls.
- CCS1 and CCS2 designs have different mechanical and electrical interface requirements.
What is a CCS Combo PCB and where is it used?
A CCS Combo PCB supports the electronic functions required between an EV charger and vehicle battery system. The board may be located in several areas:
| Application | PCB role | Main design priority |
|---|---|---|
| EVSE controller PCB | Controls charging handshake, contactors, protection and communication | Isolation, communication reliability |
| Vehicle inlet PCB | Routes charging interface signals and power | Mechanical reliability, vibration resistance |
| DC fast charger control PCB | Manages charging modules and safety functions | Thermal performance and EMC |
| Power conversion PCB | Controls AC-DC or DC-DC conversion stages | Current capacity and heat dissipation |
A CCS system contains both high-power and low-voltage domains. Control Pilot (CP), Proximity Pilot (PP), PLC communication, and safety circuits must operate reliably alongside high-voltage DC rails.
Which CCS Combo PCB parameters determine reliability?
A reliable CCS PCB must be evaluated using measurable engineering parameters rather than general PCB specifications.
| Metric | Why it matters | Typical range or influencing factors | How to measure |
|---|---|---|---|
| CTI (Comparative Tracking Index) | Prevents electrical tracking under high voltage | PLC 0 (≥600V) preferred for high-voltage circuits | IEC 60112 testing |
| Copper Weight | Determines current capacity and heat spreading | 3oz to 6oz copper for high-current paths | Micro-section analysis |
| Tg (Glass Transition Temp) | Supports thermal cycling reliability | High Tg ≥170°C recommended | DSC testing |
| Dielectric Breakdown Voltage | Confirms insulation capability | >40kV/mm preferred for insulation layers | Hi-Pot testing |
| Impedance Control | Maintains PLC communication quality | 50Ω or 100Ω differential ±10% | TDR measurement |
| Solder Mask Web | Reduces bridging risk | Around 4 mil depending on design | AOI inspection |
| CAF Resistance | Prevents internal conductive growth | Anti-CAF laminate required | THB testing |
How should engineers select a CCS Combo PCB structure?
Different charging applications require different PCB architectures.
| Charging scenario | Recommended PCB approach | Main trade-off |
|---|---|---|
| Home AC wallbox (7kW–22kW) | FR4, Tg 150°C, around 2oz copper | Lower cost with limited thermal margin |
| Public DC charger (50kW class) | High Tg FR4, 3oz copper, improved thermal design | Higher manufacturing cost |
| HPC charger (350kW class) | Heavy Copper PCB or Metal Core PCB for power sections | Higher complexity and cost |
| Vehicle inlet interface | Automotive-grade materials, Anti-CAF laminate | More qualification effort |
| Portable EVSE | Rigid-Flex PCB options | Higher material cost |
| V2G systems | Multilayer PCB with strong EMI control | More complex signal integrity design |
For high-power CCS systems, the PCB supplier should review current paths, thermal zones, insulation distances, and assembly conditions before fabrication.
How is CCS Combo PCB manufacturing controlled from design to production?
A production-ready CCS PCB requires more than standard Gerber review.
- Validate CP, PP, PLC, and high-voltage isolation zones in the schematic.
- Select laminate materials with documented CTI and thermal properties.
- Define stackup dielectric thickness according to voltage requirements.
- Verify creepage and clearance distances based on system voltage.
- Design heavy copper structures with appropriate etching compensation.
- Use thermal vias or copper structures for heat transfer.
- Control impedance on communication traces.
- Apply suitable surface finishes such as ENIG for fine-pitch communication contacts.
- Perform electrical testing including isolation verification.
- Complete final inspection for copper defects and contamination.
What are the most common CCS Combo PCB design failures?
Insufficient creepage and clearance
High-voltage CCS boards require dedicated isolation design. Standard low-voltage PCB spacing rules are not sufficient.
Under-designed thermal paths
DC fast charging creates significant heat in copper paths, connectors, MOSFET areas, and power modules. Thermal simulation and copper optimization are required.
Poor PLC communication routing
Communication lines should be separated from noisy switching nodes. Controlled impedance and grounding strategy improve communication stability.
Incorrect copper specification
High-current paths should not rely on solder thickness. Copper weight, via capacity, and current density must be calculated during design.
Weak environmental protection
Charging systems operate outdoors and may experience humidity, dust, and temperature cycling. Protective coatings and suitable materials improve service life.
What should be included in a CCS Combo PCB supplier checklist?
Before requesting production quotes, provide:
| Requirement | Supplier information needed |
|---|---|
| PCB files | Gerber, drill files, fabrication drawing |
| Stackup | Layer count, copper thickness, dielectric thickness |
| Electrical requirements | Voltage rating, isolation zones, test voltage |
| Thermal data | Maximum current, temperature limits |
| Communication requirements | Impedance targets for PLC lines |
| Quality requirements | IPC class, inspection standards, traceability |
A capable CCS PCB supplier should provide manufacturing evidence, not only a price quotation.
CCS Combo PCB FAQ
What voltage can CCS systems support?
CCS charging systems are designed for high-voltage EV charging applications, with many systems operating around 400V–1000V DC depending on architecture.
Is standard FR4 suitable for CCS PCB manufacturing?
Standard FR4 may be insufficient for high-voltage areas. High CTI materials and automotive-grade laminates are often required.
How much copper is needed for CCS power paths?
Many high-current designs use 3oz–6oz copper depending on current level, thermal conditions, and board construction.
Why is Hi-Pot testing required?
Hi-Pot testing verifies that isolated circuits withstand high voltage without breakdown or excessive leakage current.
Does CCS PCB require automotive qualification?
Vehicle-side applications usually require stronger reliability controls, including vibration, thermal cycling, and long-term environmental testing.
Resources for CCS Combo PCB Design
- For high-power requirements, review our Heavy Copper PCB capabilities.
- For thermal challenges, explore High Thermal PCB solutions.
- For automotive applications, see our Automotive Electronics PCB capabilities.
- For assembly requirements, review our Turnkey Assembly service.
CCS Combo PCB Glossary
| Term | Definition |
|---|---|
| CCS | Combined Charging System for EV charging using Combo 1 or Combo 2 connectors |
| EVSE | Electric Vehicle Supply Equipment |
| CP | Control Pilot communication line |
| PP | Proximity Pilot safety line |
| PLC | Power Line Communication used for charging communication |
| BMS | Battery Management System |
| OBC | Onboard Charger |
| Creepage | Surface distance between conductive parts |
| Clearance | Air distance between conductive parts |
| CTI | Comparative Tracking Index |
| Heavy Copper | PCB technology using increased copper thickness for current handling |
| ISO 15118 | EV charging communication standard |
Conclusion: How to prepare a CCS Combo PCB project for manufacturing
A CCS Combo PCB is a critical component in EV charging infrastructure. Successful production depends on balancing electrical isolation, current capacity, thermal performance, communication integrity, and manufacturing capability.
When preparing an RFQ, include:
- Gerber files.
- Stackup requirements.
- Copper thickness requirements.
- High-voltage isolation specifications.
- Hi-Pot testing requirements.
- Environmental reliability expectations.
Early supplier involvement reduces redesign cycles and helps ensure that the final CCS charging system meets safety and reliability targets.