Wirebond current rating

Hi,
Can anyone point me to a good reference which derives the current rating/current density of Au wirebonds or ribbon? All new for me.
I am intending to pass approx. 1amp rms current through some bonds so I need to determine how many i will need in parallel without overstress.
How is the thermal limit calculated? Is it due to temperature rise in the center of the bond?
Any help appreciated.......

Cheers

You can calculate or look-up the fusing current, then de-rate. I de-rate by 50%. I had one situation where the RF currents were stronger than the DC currents due to a very low impedance.

http://www.rfcafe.com/references/ele...wire_specs.htm