By　ignoring　some　cell　overlaps,　the　common　objective　of　the　very　large　scale　integration　(VLSI)　global　placement　problem　is　to　minimize　its　total　half-perimeter　wirelength　(HP-WL).　As　the　HPWL　is　not　differentiable,　the　log-sum-exponential　(LSE)　wirelength　model,　one　of　the　most　powerful　differentiable　wirelength　approximation　functions,　has　been　adopted　in　several　nonlinear　programming-based　placers.　In　this　paper,　a　scaled　LSE　(sLSE)　wirelength　model　is　proposed　to　approximate　HPWL.　In　the　sLSE　wirelength　model,　the　wirelength　is　calculated　according　to　the　exact　wirelength　of　each　net,　which　is　a　more　exact　approximation　of　HPWL.　Based　on　the　sLSE　wirelength　model　and　the　framework　of　placer　NTUplace3,　an　sLSE　based　nonlinear　solver　is　generated　to　solve　the　VLSI　global　placement　problem.　Comparisons　of　experimental　results　show　that　the　sLSE　wirelength　model　can　approximate　HPWL　more　accurately　than　the　LSE　wirelength　model.　©　2014　IEEE.