Bond Wire Inductance Calculator
Bond wires connecting a die to its package are an unavoidable series parasitic inductance — roughly 1 nH/mm. At GHz frequencies even a short wire has significant reactance, causing impedance transformation and gain roll-off. Estimate it before committing to a layout. For plated-through-hole parasitics, see the PCB Via calculator.
Equations & Parameters ▸
\(L_{wire}=0.2\,\ell\left[\ln\!\left(\tfrac{2\ell}{d}\right)-0.75\right]\ \text{nH}\qquad X=2\pi f L\)
| ℓ | Wire length (mm) — centre-to-centre arc length between bond pads. |
| d | Wire diameter (mm). Gold: 0.018–0.033 mm, aluminium: 0.025–0.125 mm. |
| h | Loop height above the pads (mm) — affects the exact value; shown for reference. |
| L_wire | Grover formula, ℓ and d in mm. Exact value also depends on loop shape and nearby conductors. |
Reference: F. W. Grover, Inductance Calculations, §15 (Dover, 1946)
Inputs
mm
centre-to-centre arc lengthmm
gold: 0.018–0.033 mm, Al: 0.025–0.125 mmmm
loop height above bond padsResults
Bond Wire
Inductance, L_wire—
Reactance at 1 GHz—
Reactance at 10 GHz—
Diagram