The water temperature should be between 120-140☏. We recommend cleaning with an aqueous cleaning system, it can be either batch type or in-line. This will lead to ‘catastrophic failure’ of the assembly in question. Over time the residues will absorb moisture and the halides will become mobile and corrosive. The flux residues from organic fluxes are hygroscopic, they contain organic acids and they may contain halides. It is required to remove the residues of OA fluxes? You will get corrosion if you do not fully remove all the flux residues. The addition of a saponifier (Kester # 5768) and hot water, about 130☏ will completely remove the flux residues. The spray cleaner can be either a batch type or an in-line type. The best results are achieved by removing the residues in an aqueous spray cleaner. Suggestions of how to remove the residues from no-clean fluxes: To remove the residues of no-clean fluxes most solvents will work. Metallographic Preparation of Lead Free Solderįlux Residue Removal Removing No-Clean Flux Residues This paper was published in the proceedings of SMTA International 2016 and can be found here. Download paper here. Microstructural Evolution and Mechanical Behavior of High Temperature Solders: Effects of High Temperature AgingĮffect of Ge addition on wettability, copper dissolution, microstructural and mechanical behavior of SnCu–Ge solder alloyĪ Study of Overcoming Solder Icicling and Copper Wire Dissolution in an Automated Lead-Free Soldering Kester offers the #5744 Dross eliminator for this purpose. The discoloration is a cosmetic defect and in no way degrades the reliability of the solder. This is normal and can only be prevented by using an anti-oxidant powder or pellet. When the surface of the molten solder is exposed to air it oxidizes and turns gold sometimes the tin oxide is a purple-blue color. Generally it flows better than the Sn60 and is the preferred alloy for wave soldering and surface mount applications.Īssemblers are often concerned when they see a gold color on the surface of a solder pot. Sn63Pb37 is eutectic and as such has no plastic range. Sn60 is often preferred for lead tinning and other solder coating applications. When is the use of one of these two alloys more appropriate than the other? The Sn60Pb40 has a plastic range and puts down a slightly thicker coating of solder. Follow the instructions on the Product Data Sheet when using chemical reducing agents. These chemical compounds react with the tin and lead oxides reducing them back to the base metal and releasing the oxygen to the air. There are also chemical dross reducing agents such as the Kester #5744 Dross Eliminator. A nitrogen blanket will prevent oxygen from reaching the surface of the solder and the dross generation will be greatly diminished or eliminated. Also, the more agitation the solder sees, the more dross will be formed. The hotter the solder pot is, the faster the dross is generated. Dross is generated by a combination of heat and agitation. What is dross? Dross is an oxide that is formed of the tin and lead in the solder. The small percent of silver in the solder prevents the silver on the leads from migrating into the solder resulting in a weak or brittle solder connection. The 2% silver is required when soldering to silver or silver plated components/leads. Additional alloy properties including information on conductivity, brinell, hardness, elastic modulus, surface tension. Shear strength, tensile strength and density values for some of the common alloys. Strength properties of some of the more common alloys.
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