As　a　key　step　in　the　physical　design　of　very　large　scale　integration　layer　assignment　plays　a　very　important　role　in　determining　the　delay　of　routing　solution.　At　the　same　timewith　the　continuous　progress　of　technical　nodes　the　density　of　the　nets　is　increasing.　Interconnect　delay　is　an　important　factor　to　evaluate　the　performance　of　the　routing　results.　In　order　to　optimize　the　delay　in　integrated　circuits　the　existing　layer　assignment　algorithms　usually　focus　on　minimizing　interconnect　delay　and　via　count.　Howeverthe　existing　work　either　does　not　consider　the　assignment　of　the　timing-critical　segments　in　nets　or　the　time　critical　representation　of　wire　segments　is　not　reasonable　which　ultimately　makes　the　delay　optimization　not　ideal.　For　this　reason　this　paper　proposes　a　multi-strategy　delay-driven　layer　assignment　for　non-default-rule　wire　techniquewhich　mainly　includes　the　following　key　strategies1In　order　to　avoid　the　local　optimization　of　the　netsa　track　number　aware　layer　selection　strategy　is　proposed.　This　strategy　enhances　the　ability　of　layer　assigner　to　select　suitable　routing　layers　for　wire　segments　so　that　it　allows　the　layer　with　the　largest　number　of　remaining　tracks　to　be　given　priority　in　the　layer　assignment　to　avoid　overflow　in　the　routing　layer.　2A　multi-index　driven　initial　net　sorting　strategy　is　proposed.　This　strategy　fully　considers　the　characteristics　of　different　nets　to　determine　the　priority　of　netsand　comprehensively　considers　multiple　indicators　such　as　the　wirelengththe　number　of　sink　points　and　the　resource　of　routing　tracks　to　determine　the　priority　of　layer　assignment　for　the　network　so　that　the　high-quality　initial　layer　assignment　results　is　obtained.　3In　order　to　further　optimize　the　delay　a　wire　segment　adjusting　strategy　is　proposed.　This　strategy　is　adopted　to　optimize　the　delay　of　nets　by　re-assigning　nets　and　assigning　the　timing-critical　segments　on　upper　layers.　4A　wire　segment　delay　optimization　strategy　is　proposed　to　optimize　the　delay　of　nets　while　eliminating　overflow　by　ripping　up　and　re-assigning　the　nets　which　have　overflow.　This　strategy　not　only　makes　the　final　routing　result　not　overflowbut　also　makes　it　have　better　delay.　And　the　proposed　algorithm　is　mainly　composed　of　three　stages.　First　a　better　initial　layer　assignment　result　is　obtained　through　the　multi-index　driven　initial　net　sorting　strategy.　Then　the　proposed　algorithm　adjusts　the　routing　layer　of　the　timing-critical　segments　through　the　wire　segment　adjusting　strategy　and　then　eliminates　the　overflow　while　optimizing　delay　through　the　wire　segment　delay　optimization　strategy.　Finally　under　the　condition　of　satisfying　the　congestion　constraint　the　proposed　algorithm　rips　up　and　re-assigns　the　nets　to　select　a　better　layer　assignment　result.　In　each　stage　the　track　number　aware　layer　selection　strategy　is　used　in　the　single　net　layer　assignment　so　that　the　track　resources　of　upper　layers　can　be　fully　utilized.　This　paper　uses　the　DAC12　benchmarks　to　verify　the　effectiveness　of　the　related　strategies　and　the　proposed　algorithm.　The　experimental　results　show　that　the　proposed　algorithm　can　achieve　the　best　performance　in　both　delay　and　via　count　among　the　existing　algorithms　without　overflow.　©　2023　Science　Press.　All　rights　reserved.