The　no-clean　soldering　fluxes　used　presently　contained　a　high　concentration　of　organic　solvents　which　would　generally　turn　into　volatile　organic　compounds　(VOC).　VOC　are　one　of　main　pollutant　sources　that　contaminate　air,　and　the　VOC　could　cause　much　harm　to　environment　and　human　health.　Consequently,　a　new　type　of　no-clean　flux　which　was　VOC-free　and　water-based　was　developed.　Many　performance　tests　had　been　carried　out　using　Sn-3.8Ag-0.7Cu　lead-free　solder.　The　results　show　that　the　flux　has　measured　up　to　the　industry　standards.　The　appearance,　stability,　viscosity　and　content　of　halide　are　up　to　the　standard.　The　flux　works　well　with　Sn-3.8Ag-0.7Cu　lead-free　solder　and　the　rate　of　spread　is　80.1%.　It　has　little　residues　after　soldering　and　the　residues　have　no　corrosion.　The　surface　insulation　resistance　(SIR)　test　was　carried　out　at　the　condition　of　ambient　temperature　85°C,　relative　humidity　85　%　in　the　moist-heat　chamber.　After　wave　soldering　with　this　new　no-clean　flux,　and　the　testing　panels　of　comb　type　circuits　laid　in　the　chamber　for　24　hours,　96　hours　and　168　hours　respectively,　SIR　values　were　measured　at　the　room　temperature.　The　minimum　value　of　testing　panels　was　3.8　×　1011　Ω.　This　new　no-clean　flux　has　fulfilled　the　reliability　requirements　of　the　standards　of　no-clean　soldering　flux.