Defects　such　as　interfacial　delaminations　degrade　the　yield　rate　and　reliability　of　the　device.　It＇s　important　to　find　and　evaluate　these　defects　on　time.　Infrared　Thermography　is　proved　to　be　a　valuable　tool　for　non-destructive　testing　of　materials.　In　this　paper　the　relationship　between　the　thermal　characteristics　of　the　sample　surface　and　the　defect　feature　parameters　is　investigated　using　Infrared　Thermography;　while　an　approach　to　quantitatively　evaluate　the　defect　is　proposed.