Crack Free Flux Residue Solder Paste High reliability solder paste with “Crack free flux residue” “Special resin”enabled crack free flux residue Flux residues may cause a lowering of electrical reliability by absorbing moisture or by developing a crack. S3X58-CF100-2 has been developed to overcome these difficulties, even using air reflow, by formulating anti crack resins. Challenge of conventional flux residue Crack occurs Flux medium Cracks Moisture ingress through cracks. Activators, etc. Risk of elusion of metal and other ionized substances through cracks High reliability in heavy moisture S3X58-CF100-2 secures high insulation resistance in severe environmental changes which normally develop heavy moisture levels. Dewing cycle test results Anti-crack resins New flux formulation with special anti crack resins ensures the residues remain crack free in thermal cycling and prevents migration happening. Coverage of flux residue on fillets Humidity resistant and crack free flux residues of S3X58CF100-2 covers the solder fillets thoroughly to optimize its conformal coating effect. ●Board: IPC B 25 comb pattern Solder paste: t=100 μm printed and reflowed Coverage test with fluorescent agent added to flux ● Apply UV light to the flux residue with fluorescent agent and see if the Pretreatment: temp. cycle (-30 to +80 ºC), 1000 cycles residue covers on solder fillets ＊Normally fluorescent agent is not contained in the product. Insulation Resistance ( ) Short Circuit Conventional Rosin Type Anti-Crack Flux Conventional Rosin Type Anti-Crack Flux After reflow Flux Content (%) No ion migration (no dendrite growth) Alloy Composition (%) Evidence of Sn migration along the crack in flux residue is observed. Product name