With　the　miniaturization　of　electronic　devices,　thermal　management　has　become　a　critical　challenge,　especially　for　high-power　systems　where　efficient　heat　dissipation　is　essential.　Polycrystalline　diamond　films,　renowned　for　their　exceptional　thermal　conductivity,　offer　a　promising　solution.　However,　the　thermal　boundary　resistance　(TBR)　at　the　diamond/substrate　interface　remains　a　significant　bottleneck,　severely　impacting　heat　dissipation　efficiency.　This　study　presents　a　measurement　approach　tailored　for　quantifying　TBR　in　thick-film　diamond　heterostructures,　focusing　on　diamond-on-silicon　(Diamond-on-Si)　systems　with　a　silicon　nitride　barrier　layer.　Compared　to　conventional　methods,　such　as　transient　thermoreflectance　techniques,　which　often　exhibit　limited　sensitivity　for　thick　layers,　this　approach　demonstrates　greater　reliability　and　applicability.　The　findings　establish　a　foundation　for　advancing　strategies　to　reduce　TBR　and　improve　the　thermal　management　performance　of　diamond　films　in　high-power　electronic　applications.