Silicon　wafer　grinding　thinning　is　a　material　removal　method　different　from　conventional　grinding.　During　grinding,　the　silicon　wafer　and　the　grinding　wheel　rotate　simultaneously,　and　the　grinding　wheel　feeds　into　the　silicon　wafer　to　remove　excess　material.　The　grinding　force　is　a　determinative　factor　on　the　grinding　quality.　There　is　no　theoretical　model　of　grinding　force　in　silicon　wafer　self-rotating　grinding　yet.　To　develop　the　grinding　force　model,　the　grinding　mechanism　of　silicon　wafer　self-rotating　grinding　was　studied,　and　the　grinding　force　was　divided　into　a　sliding　force　and　a　chip　formation　force.　By　considering　the　grain　trajectory　during　grinding,　the　sliding　force　and　the　chip　formation　force　of　single　abrasive　grain　on　normal　and　tangential　directions　were　established.　Subsequently,　based　on　the　number　of　effective　cutting　grains,　the　total　grinding　force　model　was　established.　In　this　model,　the　influence　of　processing　parameters,　geometry　parameters　and　material　properties　of　silicon　wafer　and　grinding　wheel　were　comprehensively　considered.　Nine　sets　of　grinding　parameters　were　adopted　into　the　model　to　study　the　effects　of　feed　rate,　wafer　speed　and　wheel　speed　on　the　grinding　force.　Meanwhile,　the　effects　of　crystalline　orientation　were　discussed,　and　the　distribution　of　grinding　force　along　radius　on　silicon　wafer　surface　was　also　analyzed.　©　2018,　Engineering　Mechanics　Press.　All　right　reserved.