The　flip　chip　package　is　an　advanced　chip　interconnection　technology,　which　has　become　a　main　technology　of　high　density　package.　This　paper　mainly　studies　the　influence　of　bumps　deformation　in　the　flip　chip　bonding　process　on　connection　reliability,　which　provides　theoretical　reference　for　the　flip　bonding　process.　Bumps　deformation　is　a　key　factor　for　the　chip　reliable　connection　in　the　flip　chip　bonding.　Bonding　force　directly　determines　the　bumps　deformation.　The　quality　of　the　bumps　will　affect　the　reliability　of　reflow　soldering　and　under-fill　processes.　This　paper　builds　a　three-dimensional　model　of　flip　chip　bonding.　By　the　FEM　simulation　analysis,　the　relationship　between　bonding　force　and　bumps　deformation　is　studied.　The　process　parameters　are　optimized　by　comparing　the　experimental　data　with　simulation　result.　Finally,　the　reliability　evaluation　method　of　flip　chip　bonding　is　obtained,　which　can　be　used　to　guide　the　research　and　development　of　the　bonding　equipment.　©　2016　IEEE.