Laminated Copper Shunts & Flexible Laminated Shunts
Carsai manufactures custom laminated copper shunt products for transformers, switchgear, batteries, rectifiers, busducts, generators and other high-current electrical equipment.
A laminated shunt is usually made from multiple thin copper foils or sheets stacked together. The central laminated section provides controlled flexibility, while the ends are compressed, welded, brazed or formed into solid terminal areas.
This construction allows the shunt to carry high current while absorbing vibration, thermal expansion and small alignment differences between connected components.
We manufacture laminated copper shunts according to customer drawings, samples and operating requirements. Available customization includes:
- Copper grade
- Individual foil thickness
- Number of copper layers
- Total conductor cross-section
- Flexible-section length
- Terminal width and thickness
- Hole diameter and spacing
- Straight, bent or offset terminals
- Bare, tin-, nickel- or silver-plated surfaces
- Optional insulation
- Prototype and production quantities
Send us the shunt length, layer quantity, terminal dimensions, current requirement and order quantity for a project-specific quotation.
For a complete overview of multilayer conductor products, visit our Laminated Busbar Manufacturer page.
What Is a Laminated Copper Shunt?
A laminated copper shunt is a flexible electrical connector made from several thin copper laminations.
The copper layers are electrically connected at the terminal ends, allowing them to operate together as one conductor. Because the middle section consists of separate thin layers rather than one thick solid bar, it can flex more easily.
A typical structure includes:
- Multiple copper foils or thin sheets
- A flexible central section
- Consolidated terminal ends
- Mounting holes or slots
- Optional terminal bends
- Optional plating or insulation
The product may also be described as a:
- laminated shunt
- multilayer copper shunt
- flexible copper foil shunt
- laminated flexible connector
- copper lamination shunt
- flexible busbar shunt
Multiple products may be referred to as laminated shunts or laminated copper shunts.
The exact name is less important than the internal layer structure, conductor cross-section, terminal design and required movement.
Laminated Shunt Versus Solid Copper Busbar
A solid copper busbar is rigid and maintains a fixed shape. It is suitable for distributing current between components that remain accurately aligned.
A laminated shunt provides more movement because it contains several thin copper layers.
This can help compensate for:
- Transformer vibration
- Generator vibration
- Thermal expansion
- Equipment movement
- Assembly tolerances
- Terminal misalignment
- Mechanical stress during installation
When a rigid busbar is forced into position, it can transfer mechanical loading to transformer terminals, insulators, battery terminals or electrical components.
A flexible laminated shunt reduces this stress while maintaining a flat, high-current conductor structure.
Shunt Laminated Busbar Construction
The phrase shunt laminated busbar is sometimes used for a laminated conductor installed as a flexible bridge between two rigid busbars or equipment terminals.
The product combines features of both a shunt and a flexible busbar:
- Large electrical cross-section
- Flat conductor geometry
- Multiple flexible copper layers
- Solid terminal contact areas
- Custom mounting holes
- Controlled bending direction
A shunt laminated busbar may be installed between:
- A transformer and rigid busbar
- A circuit breaker and distribution bar
- Two busduct sections
- A battery module and contactor
- A generator and switchgear assembly
- A rectifier and output terminal
- Two misaligned copper bars
The layer quantity and foil thickness should be selected according to the required current and flexibility.
Copper Layer Thickness and Quantity
The internal copper construction directly affects the shunt’s electrical and mechanical performance.
For example, the required conductor thickness may be produced using:
- Ten layers of 0.2 mm copper
- Eight layers of 0.3 mm copper
- Six layers of 0.5 mm copper
- Four layers of 0.8 mm copper
- Another customized layer combination
More thin layers generally create a softer flexible section.
Fewer, thicker layers normally create a stiffer shunt even when the total copper cross-section is similar.
However, flexibility also depends on:
- Shunt width
- Flexible-section length
- Copper temper
- Terminal consolidation method
- Terminal thickness
- Bend direction
- Insulation coverage
- Installed movement
A short, wide shunt may remain relatively stiff. Increasing only the number of layers does not guarantee sufficient movement if the flexible section is too short.
Laminated Flexible Copper Shunts
Laminated flexible copper shunts are designed for installations requiring both high current capacity and controlled movement.
The flexible section can help isolate vibration or allow components to expand at different rates.
Typical applications include:
Transformers
Transformer terminals may vibrate continuously during operation.
A laminated shunt can connect the transformer to switchgear, a rigid busbar or a busduct while reducing the mechanical force transferred to terminal palms and bushings.
Switchgear
Flexible shunts may connect:
- Circuit breakers
- Disconnect switches
- Contactors
- Main copper busbars
- Distribution bars
- Generator terminals
They are useful where a rigid copper bar would require precise alignment or several complex bends.
Battery and energy storage systems
A laminated copper shunt can connect battery modules, fuses, contactors and output terminals.
The flexible section can accommodate vibration, thermal movement and small installation differences between modules.
Rectifiers and industrial power supplies
High-current rectifiers, welding power supplies and electroplating equipment may use flexible laminated conductors between semiconductor devices, transformers and output busbars.
Generators and rotating equipment
Generators produce vibration that should not be transferred directly to rigid power-distribution components.
A laminated shunt provides an electrical connection while helping isolate this movement.
Terminal Designs
The terminal areas of a laminated shunt must provide stable mechanical mounting and low electrical resistance.
Custom options include:
- Single-hole terminals
- Two-hole terminals
- Four-hole connection pads
- Multiple-hole terminal palms
- Round mounting holes
- Slotted holes
- Different terminal widths
- Unequal hole patterns at each end
- Bent terminals
- Offset terminals
- L-shaped terminal arrangements
- Attached solid copper end plates
The two ends do not need to be identical.
One terminal may connect to a wide transformer palm, while the other connects to a narrower rigid busbar.
The terminal contact surfaces should remain flat, clean and free from burrs or severe deformation.
Poor terminal flatness can reduce the effective contact area and create localized heating.
Terminal Consolidation Methods
The individual copper layers must be joined at the terminal areas so they function as one electrical conductor.
Depending on the design, the terminal sections may be:
- Compressed
- Welded
- Brazed
- Diffusion-bonded
- Joined to solid copper terminal plates
- Formed using another approved manufacturing process
The process should create a stable terminal without damaging the flexible section.
The transition between the consolidated end and the flexible copper layers must be smooth enough to avoid excessive mechanical stress.
An abrupt or poorly controlled transition may become a fatigue point during repeated vibration.
Current Capacity and Shunt Sizing
A laminated shunt should not be sized only from a general current chart.
The required copper cross-section depends on:
- Continuous current
- Peak current
- Short-circuit current
- Duty cycle
- Ambient temperature
- Cooling and ventilation
- Conductor length
- Insulation coverage
- Allowable temperature rise
- Terminal contact resistance
The terminal design is just as important as the flexible conductor section.
A shunt may contain sufficient copper, but undersized terminal pads, poor surface contact or inadequate bolt pressure can still cause overheating.
For high-current projects, customers should provide:
- Continuous current
- Maximum peak current
- Peak-current duration
- Short-circuit requirement
- Ambient temperature
- Allowable temperature rise
- Mounting conditions
- Mating-terminal material
The equipment designer should confirm the final current rating under actual operating conditions.
Copper Materials
Common copper options include:
- C11000 copper
- Cu-ETP copper
- T2 copper
- Oxygen-free copper for special applications
The selected copper should provide suitable conductivity, formability and consistency for the required layer thickness.
Very thin copper foils require careful handling during cutting, stacking and terminal preparation.
The drawing should identify the copper grade whenever a specific material standard is required.
Surface Treatment Options
Laminated copper shunts can be supplied bare or plated.
Bare copper
Bare copper provides high conductivity and may be suitable for clean, controlled indoor environments.
Tin plating
Tin plating is commonly selected for transformer, battery and industrial power connections.
It can be applied to:
- The full shunt
- Only the consolidated terminals
- Only the mating contact surfaces
- Selected areas defined on the drawing
Nickel plating
Nickel may be considered for elevated-temperature environments or particular corrosion-resistance requirements.
Silver plating
Silver plating may be used where high contact performance is required.
Plating type, thickness and coverage should be specified before quotation.
Insulated Laminated Shunts
A laminated shunt can be supplied bare or with insulation over the central conductor section.
Possible insulation options include:
- Heat-shrink tubing
- PVC sleeves
- Flexible insulating films
- Epoxy coating
- Powder coating
- Custom protective covers
The terminal contact areas normally remain exposed.
Insulation should not prevent the copper layers from moving as intended.
The design should consider:
- Operating voltage
- Required dielectric strength
- Conductor temperature
- Insulation thickness
- Flexible movement
- Creepage and clearance
- Exposed terminal length
- Flame-resistance requirements
For highly flexible sections, the insulation material must tolerate the expected bending without cracking or separating.
Laminated Shunt Versus Braided Copper Shunt
Both laminated and braided shunts can provide flexible high-current connections.
Laminated copper shunt
A laminated shunt generally provides:
- Flat conductor geometry
- Controlled bending direction
- Precise terminal position
- High copper density
- Clean installation profile
- Custom layer construction
Braided copper shunt
A braided shunt generally provides:
- Greater softness
- Movement in several directions
- Better accommodation of repeated vibration
- More flexible routing
- Woven copper construction
A laminated shunt may be preferred where space is limited and a flat, organized conductor is required.
A braided shunt may be preferred where maximum softness or multidirectional movement is more important.
Manufacturing Process
A typical custom laminated shunt project includes:
- Reviewing the drawing and application
- Confirming copper grade
- Selecting layer thickness and quantity
- Cutting copper foils or sheets
- Stacking and aligning the layers
- Consolidating the terminal areas
- Punching or machining mounting holes
- Forming bends or offsets
- Deburring and cleaning
- Applying plating
- Adding insulation when required
- Inspecting dimensions and terminal surfaces
- Protecting contact areas for shipment
Key inspection points include:
- Overall length
- Flexible-section length
- Shunt width
- Individual layer thickness
- Total copper thickness
- Terminal dimensions
- Hole diameter and spacing
- Terminal flatness
- Bend position
- Plating coverage
- Insulation position
- Surface cleanliness
Information Needed for a Quotation
To quote a laminated copper shunt, please provide:
- 2D or 3D drawing
- Copper grade
- Continuous current
- Peak or short-circuit current
- Overall shunt length
- Flexible-section length
- Shunt width
- Individual copper-layer thickness
- Number of layers
- Terminal width and thickness
- Hole diameter and spacing
- Bend or offset requirements
- Plating type and thickness
- Insulation requirement
- Prototype quantity
- Production quantity
- Annual demand
A sample, sketch or installation photograph can also be reviewed when the final drawing is unavailable.
Frequently Asked Questions
What is the difference between a laminated shunt and a laminated busbar?
A laminated shunt usually emphasizes mechanical flexibility between two terminals. A laminated busbar may also contain multiple insulated electrical potentials for organized power distribution.
Can all copper layers have the same thickness?
Yes. They can also use another customer-defined layer arrangement when required by the design.
Can the two terminal ends be different?
Yes. Each end can have a different width, thickness, hole pattern, bend or mounting direction.
Can laminated copper shunts be tin plated?
Yes. Tin plating can cover the entire product or only selected terminal areas.
Can you add insulation to the flexible section?
Yes. Heat-shrink, PVC, films and other insulation methods can be evaluated according to voltage and movement requirements.
Can you manufacture prototypes?
Yes. Prototype and small-batch production can be evaluated before regular-volume manufacturing.
Request a Laminated Copper Shunt Quotation
Carsai manufactures laminated copper shunts and flexible multilayer connectors for transformers, batteries, switchgear, generators, rectifiers and industrial power systems.
Send your shunt length, layer quantity, terminal dimensions, current, plating, insulation and required quantity.
