Detailed Explanation of Laminated Busbar Manufacturing Process: Key Flow Analysis from Design to Testing

With the rapid development of new energy vehicles, energy storage systems, rail transit, and industrial frequency conversion equipment, laminated busbars have become crucial connection components in high-power power electronic systems. Compared to traditional cable connection solutions, laminated busbars offer advantages such as low inductance, compact structure, high current carrying capacity, and high installation efficiency, and are widely used in inverters, IGBT modules, battery packs, and high-voltage power distribution systems.

 

As a typical multi-layer composite structure connection bar, the performance of laminated busbars depends not only on material selection but also on the manufacturing process. This article will systematically introduce the main production processes and key control points of laminated busbars.

 

 

 

The first step in laminated busbar manufacturing is product design. Engineers need to determine the number of conductor layers, insulation structure, and overall dimensions based on the equipment's operating voltage, current rating, installation space, and electromagnetic compatibility requirements.

 

For the Laminated Busbar for Electric Cars in new energy vehicle drive systems, the design typically focuses on current density, thermal management capabilities, and vibration resistance. Laminated busbars used in high-power converters for industrial applications prioritize low parasitic inductance and high-frequency current transmission capabilities.

 

A well-designed structure can effectively reduce system losses and improve overall operating efficiency.

 

 

The conductor material for laminated busbars is typically high-purity copper or aluminum, with copper being widely used due to its excellent conductivity.

 

Before entering the production process, conductor materials need to undergo:

Raw material composition testing

Conductivity testing

Thickness and dimensional inspection

Surface oxidation status inspection

 

High-quality conductor materials ensure the stability of subsequent production processes and improve the conductivity and mechanical strength of the final product.

 

 

 

The conductor layer is the core component of the laminated busbar, and its processing precision directly affects product performance.

Common processing techniques include:

 

CNC precision stamping

Laser cutting

CNC bending

Precision drilling

Forming

For customized laminated busbars for IGBT products, due to limited installation space, the requirements for dimensional tolerances and hole position accuracy are usually more stringent.

 

After processing, the conductor surface needs to be cleaned to remove oil, oxide layers, and impurities to ensure the quality of subsequent lamination processes.

 

 

The main function of the insulation layer is to isolate different conductor layers, prevent short circuits, and reduce electromagnetic interference.

Common insulation materials include:

Polyester film (PET)
Polyimide film (PI)
Epoxy resin composites
Special insulating composite films

For high-voltage applications, such as High Voltage Explosion-Proof Inverter Busbars, the insulation material not only needs excellent dielectric properties but also needs to meet the requirements for high temperature resistance, damp heat resistance, and long-term aging resistance.

 

Insulation layer thickness control and surface flatness control are important quality indicators for this process.

 

 

The lamination process is one of the most critical steps in the production of laminated busbars.

During production, the conductor layers and insulation layers are stacked according to the designed sequence and formed into an integral structure through hot pressing or cold pressing.

 

Key control parameters include:

Lamination temperature
Pressure
Holding time
Cooling rate

For example, in the production of three-layer laminated busbars, the interlayer bonding strength directly affects the long-term reliability of the product.

 

A high-quality lamination process ensures:

No bubbles
No delamination
No warping
Uniform distribution of insulation

Thus forming a stable and reliable partially laminated busbar or fully laminated structure.

 

 

 

After lamination, secondary machining is required according to customer drawings.

Common processes include:

 

Shape cutting
Mounting hole machining
Welding connection
Riveting assembly
End treatment

Laminated busbars used in complex equipment for complex busbar installations often require irregular shape machining to meet special installation requirements.

 

During machining, dimensional accuracy and geometric tolerances must be strictly controlled to ensure smooth subsequent system assembly.

 

 

After product manufacturing, conductivity testing is required to verify the current transmission capacity of each conductor layer.

 

Key testing items include:

DC resistance test
Continuity test
Contact resistance test

For IGBT Laminated Busbar applications, low-resistance connections effectively reduce power loss and improve system efficiency.

 

Continuity testing can promptly detect potential problems such as open circuits, loose connections, or conductor damage.

 

 

Insulation performance testing is a crucial step in evaluating the safety of laminated busbars.

 

Common test items include:

Insulation resistance test
Power frequency withstand voltage test
Impulse withstand voltage test
Partial discharge test

 

Especially in Subway Laminated Busbars used in rail transportation and in high-voltage inverter equipment, the requirements for insulation reliability are extremely high.

 

Through rigorous testing, stable insulation performance can be ensured during long-term operation.

 

 

To improve the corrosion resistance and service life of the product, laminated busbars typically undergo surface treatment.

 

Common processes include:

Tin plating
Silver plating
Nickel plating
Anti-oxidation coating treatment

 

Surface treatment effectively reduces contact resistance and enhances product stability in high humidity, high salt spray, and industrial pollution environments.

 

For Laminated Low Inductive Bus Bar products, excellent surface treatment can further improve high-frequency current transmission performance.

 

 

With the continuous upgrading of power electronics technology, laminated busbars are developing towards high integration, high power density, and intelligence.

 

Currently, they are widely used in:

New energy vehicle drive systems
Energy storage converters (PCS)
Photovoltaic inverters
Three-level inverters
Industrial automation equipment
Rail transit systems

 

Especially in high-performance power electronic devices such as Laminated Busbar for Three-Level Inverters, laminated busbars have become key components for improving system efficiency and reliability. Meanwhile, as typical Laminated bus bars, passive electronic components, their design and manufacturing levels are continuously driving the development of modern power conversion technologies.

 

 

 

The manufacturing of laminated busbars is a systematic engineering project encompassing materials, machining, electrical design, and quality control. From structural design, conductor processing, and insulation layer preparation to lamination and performance testing, every step affects the electrical performance and lifespan of the final product. With the development of new energy, electric vehicles, and high-end equipment manufacturing industries, high-performance laminated busbars will play an increasingly important role in future power electronic systems.