PowerCu Soft: Copper Power Bonding Wires and Ribbons

The outstanding properties of large-diameter copper bonding wires and ribbons from Heraeus' PowerCu Soft family let you solve many technical challenges in electronics applications while at the same time reducing costs.

Heavy Copper Bonding Wires

Copper as an interconnect material provides excellent electrical conductivity and fusing current values. That enables the use of thinner wires compared to aluminum wire connecting, resulting in better heat dissipation. In addition, copper is a mechanically stable metal, resulting in stronger wire connections and high loop stability.

PowerCu Soft Wires and Ribbons exhibit outstanding long-term reliability and result in highly robust bonds able to resist high temperatures and mechanical stresses. Wires and Ribbons of the PowerCu Soft family are ideal for helping you solve the challenges posed by thermal management, the need for high robustness, miniaturization and weight reduction, as well as increased reliability. This includes power management in high-voltage modules and systems, even at high energy densities and temperatures.

We are unique in focusing on thick bonding wires as part of our core business, while in parallel offering solder and sinter pastes, substrate materials, and other power electronics products. We supply these products in forms that simplify and streamline your own processes by enabling lean, cost-effective production with standardized methods.

Heavy copper bonding wires from Heraeus may be just the solution you’re looking for.

Your benefits at a glance:

  • Optimal bondability due to extreme softness and minimal resistance to deformation
  • Uniformly fine grain structure
  • Extremely high thermal stability
  • Minimal electrical resistivity
  • A very wide bonding process window
  • High productivity: special Heraeus spools enable extra-long lengths
  • UPH improvement possible by upgrating wires to ribbons
  • High reliability in longlife and reliability tests, especially when combined with other advanced technologies for die top connecting and die attach
  • Compliance with legal requirements including REACH and RoHS


  • Engine management (engine control units)
  • Transmission controllers
  • Power electronics modules for drivetrains in electric and hybrid vehicles
  • Generator control
  • SiC (silicon carbide) technology for reducing electric power losses
  • Gallium nitride (GaN)-based electronics

Power electronics in industrial use:

  • State-of-the-art IGBT modules for drives, current inverters, and power supplies
  • Inverters for wind and water power, solar energy, and other renewable energy sources
  • Trains and other types of transportation

PowerCu Soft:

PowerCu Soft bonding wire is our most popular material for advanced semiconductor packaging. It performs excellently in next-generation applications that need to be highly robust and withstand temperatures more then 250 °C. In lifetime tests, Heraeus PowerCu Soft bonding wire used for wedge applications lasts 10 to 30 times as long as conventional aluminum technology.

 PowerCu Soft Factsheet

PowerCu Soft Ribbons:

PowerCu Soft Ribbons give you the opportunity to optimize your production in regard to UPH, by upgrading wires to ribbons.

 PowerCu Soft Ribbon Factsheet

Calculation example for improving UPH with ribbons:


  • Power Module with Cu 300 µm wires
  • Typically number of wire bonds within a power module: 240
  • Time per single wire bond: 150 ms ≙ 36 s processing time per module + 10 s handling time
  • UPH: 78 modules per hour & machine

UPH improvement potential:

  • Four 300 µm wires can be replaced by one 0.2x1.5 mm2 Cu ribbon ≙ 60 ribbon bonds
  • Time per single ribbon bond: 240 ms ≙ 15 s processing time per module + 10 s handling time
  • UPH: 144 modules per hour & machine

Significant improvement in output (here 85 %) possible.