Optimised copper ribbon for laser bonding

This optimised copper ribbon is proven to effectively achieve more efficiency and stability in power electronic systems. It enables module operation temperatures higher than 250°C and allows the highest power density designs.

In power electronics, the limit of current carrying capacity using wire bonding will be reached one day. Ribbon bonding offers an alternative to wire bonding and tape automated bonding (TAB) and is attractive since many conventional ultrasonic wedge/wedge wire bonding equipment can be easily adapted to handle ribbons.

Laser ribbon bonding is a new field of application for laser micro welding in the electronics industry, especially in the area of power electronics. It is particularly suitable for joining bonding wire onto battery terminals and onto DCB substrates and copper terminals in power electronic modules. With laser bonding, the application of ribbon bonding for much higher currents is accomplished.

In comparison with standard copper bonding ribbons, PowerCu-Soft LRB comes along with a special one-sided roughening to guarantee a more reliable coupling of the laser beam on to the highly reflective copper surface. The roughening process allows a residual-free clean and homogeneous surface. The PowerCu-Soft LRB can be processed with all currently available laser bond equipment.

PowerCu-Soft LRB is ideal for power devices and battery packages dedicated for high currents. In addition, cost optimisation within production (UPH improvement) can be achieved by upgrading wires to ribbons. One PowerCu-Soft LRB (0.3x2mm) can replace up to three 500µm Cu wires.