  We present a study of the Higgs boson decay branching ratios to $b\bar{b}$,
$c\bar{c}$ and gluons, one of the cornerstones of the physics program at the
International Linear Collider (ILC). A standard model Higgs boson of 120\,GeV
mass, produced in the Higgs-strahlung process at $\sqrt{s} = 250$\,GeV was
investigated using the full detector simulation and reconstruction procedures.
The analysis was performed in the framework of the Silicon Detector (SiD)
concept with full account of inclusive standard model backgrounds. The selected
decay modes contained two heavy flavour jets in the final state and required
excellent flavour tagging through precise reconstruction of interaction and
decay vertices in the detector. A new signal discrimination technique using
correlations of neural network outputs was used to determine the branching
ratios and estimate their uncertainties, 4.8\%, 8.4\% and 12.2\% for
$b\bar{b}$, $c\bar{c}$ and gluons respectively.
