Integrated Cell Contact System (CCS): Busbar, FPC, and Injection-Molded Tray Assembly for EV Packs

Integrated Cell Contact System (CCS) replaces traditional battery module wiring harnesses with an integrated assembly combining stamped copper/aluminum busbars, FPC signal circuits, NTC temperature sensors, and injection-molded insulation trays. The system reduces module wiring volume, improves assembly consistency, and enables automated EV battery pack production with controlled electrical performance.

 

Xiamen Apollo Stamping Welding Technology Co., Ltd. manufactures customized CCS assemblies through precision metal stamping, laser welding, resistance welding, injection molding integration, and automated electrical testing for EV battery modules and energy storage systems.

 

 

 

From Wire Harnesses to Integrated Cell Contact Systems with Higher Assembly Density
Traditional battery modules use multiple cable harnesses for:
Cell voltage sampling
Temperature monitoring
Current conduction
Signal transmission

This structure creates several engineering limitations:
Large wiring volume
Complex assembly routing
Higher manual installation requirements
Increased risk of connection errors

An Integrated Cell Contact System combines:
Copper or aluminum current busbars
Flexible Printed Circuit (FPC)
NTC temperature sensors
Injection-molded insulation carrier
Terminal connection structures

The CCS assembly is mounted directly above battery cells, creating a compact electrical interface between cells and the Battery Management System (BMS).

Typical CCS application parameters:

 

Parameter	Engineering Requirement
Current path material	C1100 pure copper/aluminum alloy
Electrical conductivity	Copper busbar ≥100% IACS
Signal transmission	FPC copper circuit
Temperature sensing	NTC thermistor integration
Insulation material	PPE / PC-ABS UL 94 V-0
Assembly tolerance	±0.05mm–±0.1mm depending on structure
Quality documentation	IATF 16949, PPAP Level 3

 

CCS Design Benefits for EV and ESS Battery Modules
The integrated structure provides:
Reduced module height
Improved internal space utilization
Reduced assembly cycle time
Stable cell voltage monitoring
Automated production compatibility

For high-capacity battery modules, CCS design must balance:
High current-carrying capability
Thermal expansion tolerance
Electrical insulation distance
Mechanical vibration resistance

 

 

 

Copper and Aluminum Busbar Manufacturing with ±0.01mm Stamping Accuracy
The current-carrying component inside CCS requires stable electrical conductivity and mechanical strength.

Apollo produces CCS busbars through:
Progressive stamping
CNC secondary processing
In-die riveting
Laser cutting
Surface plating

Common materials include:
 

Material	Conductivity	Mechanical Characteristics	CCS Application
C1100 Pure Copper	≥100% IACS	Excellent electrical conductivity	High-current connection
C2680 Brass	Lower conductivity than copper	Higher strength	Structural terminals
Aluminum Alloy	Lightweight	Lower density	Weight-sensitive modules

 

Copper busbar design parameters:
Thickness: customized according to current load
Surface treatment: nickel plating/tin plating
Insulation clearance: designed according to voltage requirements
Contact resistance control: validated by electrical testing

Laser Welding Cu-Al and Resistance Welding for CCS Current Paths
Battery module CCS often requires joining different conductive materials.

Common welding technologies:
Laser welding Cu-Al
Resistance welding
Molecular diffusion welding
Resistance silver brazing
Process comparison:

 

Welding Method	Advantages	Engineering Consideration
Laser welding Cu-Al	Precise heat input, low deformation	Requires oxide layer control
Resistance welding	High production efficiency	Electrode wear monitoring required
Molecular diffusion welding	Low interface resistance	Higher equipment requirement
Resistance silver brazing	Excellent conductivity	Temperature process control required

 

Critical welding quality indicators:
Weld penetration depth
Interface resistance
Tensile strength
Metallographic structure
Porosity inspection

Apollo applies welding parameter monitoring to reduce:
Cold welding defects
Excessive heat-affected zones
Material oxidation
Electrical resistance increase

FPC and NTC Sensor Assembly for Battery Signal Monitoring
The FPC layer replaces multiple independent signal cables.
Integrated components include:
Copper foil circuit
Polyimide insulation film
NTC temperature sensors
Connector terminals
Protective cover structures

Signal reliability depends on:
Circuit impedance stability
Sensor positioning accuracy
Solder joint strength
Mechanical protection

 

Request Free DFM Evaluation & Quote

 

 

PPE and PC-ABS Flame-Retardant Material Selection for CCS Trays
The insulation tray provides:
Busbar positioning
Electrical isolation
Mechanical protection
FPC support

Material selection must consider:
Flame resistance
Thermal stability
Mechanical strength
Dimensional stability

Comparison:

 

Material	Flame Standard	Temperature Performance	Application
PPE	UL 94 V-0	High thermal stability	High-voltage insulation tray
PC-ABS	UL 94 V-0 available	Good impact resistance	Battery module housing
PA66 GF	UL 94 V-0	High mechanical strength	Structural brackets

 

Creepage Distance and Clearance Control in High Voltage Battery Modules
High-voltage battery modules require strict insulation design.
CCS tray design evaluates:
Creepage distance
Air clearance
Material dielectric strength
Contamination resistance
Typical insulation requirements:

 

Parameter	Verification Method
Dielectric strength	High voltage withstand test
Insulation resistance	Megohmmeter testing
Flame resistance	UL 94 V-0 testing
Mechanical retention	Pull-out force test

 

The tray structure prevents:

Busbar short circuits

Terminal displacement

Foreign object contact

 

 

 

Signal Integrity and Anti-Interference Design for Battery Sampling Circuits
Battery management systems require accurate voltage and temperature data.
CCS signal design considers:
Electromagnetic interference
Signal routing distance
Grounding strategy
Connector locking structure
For high-current battery modules, busbar current switching generates electromagnetic fields that may affect low-voltage sensing circuits.

Design methods include:
Optimized FPC routing
Separation between power and signal paths
Shielding structures
Stable grounding design

Mechanical and Environmental Reliability Testing
CCS assemblies must withstand long-term EV operating conditions.
Apollo performs validation including:
 

Test Item	Purpose
Pull-out force test	Verify terminal retention
Thermal cycling test	Evaluate expansion stress
Vibration test	Simulate vehicle operation
Humidity test	Check corrosion resistance
High voltage insulation test	Verify electrical safety
CMM inspection	Confirm dimensional stability

 

Thermal cycling evaluates:

Copper expansion

Plastic deformation

Weld joint reliability

Sensor connection stability

 

Download Busbar Design Specification

 

 

Integrated Production Capability with PPAP Level 3 Support
Apollo provides complete CCS manufacturing processes:
Precision metal stamping
Copper busbar forming
Laser welding Cu-Al
FPC integration
Injection molding
Automated assembly
Electrical inspection

Production quality follows automotive supply chain requirements:
IATF 16949 certified management system
PPAP Level 3 submission capability
SPC process control
Material traceability
Batch inspection reports

Automated CCS Assembly for EV and ESS Battery Module Programs
Automation improves:
Assembly consistency
Welding repeatability
Sensor placement accuracy
Production efficiency

Inspection systems include:
Vision inspection
Electrical resistance testing
High-voltage insulation testing
CMM dimensional verification

Manufacturing targets:
Stable batch production
Reduced manual assembly variation
Controlled electrical performance
Reliable supplier delivery

 

 

Evaluation Factor	Required Capability
Busbar manufacturing	Precision stamping and forming
Welding technology	Laser welding Cu-Al, resistance welding
Plastic integration	UL94 V-0 injection molding
Quality system	IATF 16949
Automotive approval	PPAP Level 3
Inspection capability	CMM, electrical testing, reliability testing

 

A qualified CCS supplier must control the complete process chain from conductive metal processing to final module assembly.

 

 

What is the typical lead time for an EV battery CCS busbar assembly OEM project?
Prototype CCS samples typically require tooling validation first. Production timing depends on design approval, tooling complexity, and PPAP Level 3 requirements.

How does Apollo ensure CCS busbar welding reliability for automotive battery modules?
Apollo controls laser welding and resistance welding parameters through process monitoring, metallographic inspection, resistance testing, and mechanical validation.

Can Apollo provide customized CCS assemblies combining busbars, FPC, and injection-molded trays?
Yes. Apollo integrates stamping, welding, injection molding, and automated assembly for customized EV battery CCS supplier programs.