“ on ▁board ” ▁sens ors ) ▁can ▁provide ▁direct ▁measurement ▁of ▁the ▁thermal ▁b ump ▁performance ▁and ▁provide ▁feedback ▁to ▁the ▁driver ▁circuit . ▁ ▁P rec ision ▁temperature ▁control ▁Since ▁thermal ▁b umps ▁can ▁either ▁cool ▁or ▁heat ▁the ▁chip ▁depending ▁on ▁the ▁current ▁direction , ▁they ▁can ▁be ▁used ▁to ▁provide ▁precision ▁control ▁of ▁temperature ▁for ▁ch ips ▁that ▁must ▁operate ▁within ▁specific ▁temperature ▁ranges ▁ir res pective ▁of ▁ambient ▁conditions . ▁ ▁For ▁example , ▁this ▁is ▁a ▁common ▁problem ▁for ▁many ▁opt oe lect ron ic ▁components . ▁ ▁Hot spot ▁cool ing ▁In ▁micro process ors , ▁graphics ▁process ors ▁and ▁other ▁high - end ▁ch ips , ▁hot sp ots ▁can ▁occur ▁as ▁power ▁dens ities ▁vary ▁significantly ▁across ▁a ▁chip . ▁ ▁These ▁hot sp ots ▁can ▁sever ely ▁limit ▁the ▁performance ▁of ▁the ▁devices . ▁ ▁Because ▁of ▁the ▁small ▁size ▁of ▁the ▁thermal ▁b umps ▁and ▁the ▁relatively ▁high ▁density ▁at ▁which ▁they ▁can ▁be ▁placed ▁on ▁the ▁active ▁surface ▁of ▁the ▁chip , ▁these ▁structures ▁are ▁ide ally ▁su ited ▁for ▁cool ing ▁hot sp ots . ▁ ▁In ▁such ▁a ▁case , ▁the ▁distribution ▁of ▁the ▁thermal ▁b umps ▁may ▁not ▁need ▁to ▁be ▁even . ▁ ▁R ather , ▁the ▁thermal ▁b umps ▁would ▁be ▁concentr ated ▁in ▁the ▁area ▁of ▁the ▁hot spot ▁while ▁areas ▁of ▁lower ▁heat ▁density ▁would ▁have ▁fewer ▁thermal ▁b umps ▁per ▁unit ▁area . ▁ ▁In ▁this ▁way , ▁cool ing ▁from ▁the ▁thermal