IF FL5821

Suitable for

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  Pre-tinning

  Pre-tinning is a soldering technolgy used for wires and cables and also for the leads of some electronic and mechanical components. Pre-tinning applies a layer of solder on the surface that will provide a good solderability for the following soldering processes. The solderability of this layer is maintained very well during storage. Pre-tinning is usually done by dipping the surface to be soldered in liquid solder, that usually is a lead-free Sn(Ag)Cu alloy. Some systems use a small wave of liquid solder or a nozzle that jets liquid solder to do the pre-tinning. The pre-tinning process can be done manually but in most cases is done in an automated process. Before soldering the lead or wire is dipped in a soldering flux. To avoid flux residues after soldering, the dipping depth in the flux is usually lower or just as deep as the dipping depth in the solder. Depending on the solderability of the surfaces to be pre-tinned, different fluxes can be used. For surfaces that are hard to solder, like Ni, Zn, brass, heavily oxidized Cu,...usually water soluble fluxes are being used. They provide excellent solderability but can be and must be cleaned in a water based washing process afterwards, as the residues of these fluxes might create problems (like e.g. corrosion). For surfaces with normal solderability, IF 2005C or PacIFic 2009M can be used. The temperature of the soldering alloy is usually higher than for wave and selective soldering because this speeds up the process and the risk on damaging components is very limited. It is also possible that the dipping process needs to remove/burn off the coating of the Cu-wire to be tinned, this also requires higher temperatures. In general soldering temperatures vary from 300-450°C. These temperatures will oxydise the surface of the solder bath quite strongly. The use of Anti-Oxydant pellets can compensate for this oxydation. Some solder baths mechanically remove the top layer of the solder bath with a scraper just before the component is dipped into the solder. Dipping times very much depend on the thermal mass of the component to be soldered and usually are from 0,5s to 3s.

Key advantages

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  High deoxidation power

  The main purpose of soldering chemistry is to deoxidise the surfaces (or surface finishes) to be soldered so that the liquid soldering alloy can penetrate those surfaces (or dissolve the surface finishes) and make an intermetallic. When the quality of the surfaces in electronics is normal, in general the lowest activation class L0 suffices to deoxidise those surfaces. When boards or components have been stored too long, or have seen too high temperatures in storage or in previous processes, it is possible that a flux with higher deoxidation power is needed. In general, the higher the activation class, the higher the deoxidation power. L0 is the lowest activation class and the standard, it should be suitable for all normal quality conventional surfaces used in electronics assembly. L1 is the lowest activation class but with a halogen content up to 0,5%. These halogens will in most cases provide a higher deoxidation power. However, it has to be noted that halogens do not only deoxidise, they will also react with the metal itself into metal salts that are quite hygroscopic and water soluble. The next activation classes are M0 and M1. M stands for Medium activation. 0 again stands for up to 500ppm of halogens and 1 in this case stands for up to 2% of halogens. It has to be noted that an M0 classified solder wire will not necessarily give higher deoxidation power than an L1 classified solder wire, it can also be the other way around. The next activation classes are H0 and H1. H stands for High activation. 0 again stands for up to 500ppm of halogens and 1 in this case stands for more than 2% of halogens. Also here an H0 classified solder wire will not necessiraly give higher deoxidation power than an M1 classified solder wire, it can also be the other way around. Soldering products of the H class are to be treated with care as they can be corrosive and need to be cleaned off, preferrably in a automatised cleaning process. For soldering electronic applications without cleaning after soldering, in general only products from the L0, L1 and M0 class are being used.
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  Increased wetting ability

  The wetting ability of a soldering product refers to how well the activation of the soldering product is able to clean off oxides from the surfaces to be soldered. These oxides need to be removed to enable the liquid soldering alloy to penetrate the surfaces to be soldered. When the quality of the surfaces to be soldered in electronics manufacturing is normal, it is possible to use a soldering product from the lowest activation class L0. In general, only when surfaces are degraded or when the base metal is hard to solder, then a product with a higher activity or increased wetting ability is used. Such surfaces can be for example chemical Sn that was applied too thin or stored too long before soldering, components or PCB boards that were stored too long in hot and humid conditions and are heaviliy oxidised, non protected Ni, brass,... Another possible reason for using a product with increase wetting ability is ease-of-use. For example a solder wire with increased wetting ability in general will provide faster soldering and is not so sensitive to the correct handling required to produce a good hand soldered solder joint. In high volume hand soldering operations for electronc units that have not so high requirements to the residues after soldering, solder wires with increase wetting ability are often used. Also for robot soldering and laser soldering solder wires with increase wetting ability are often used because in general they have better properties for these processes.
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  High activity

  High activity of a soldering product can be needed for surfaces with poor solderability like e.g. brass, unprotected Ni, Oxidised Ag, Cu that was not micro-etched,...or surfaces with degraded solderability like e.g. I-Sn that was stored too long or did see too much heat, Cu-OSP that passed a lead-free reflow profile too long ago,...An indication of the activity of a soldering product is their classification. The most popular and accepted classification for soldering products is the IPC. L0 is the lowest activation class and the standard, it should be suitable for all normal quality conventional surfaces used in electronics assembly. L1 is the lowest activation class but with a halogen content up to 0,5%. These halogens will in most cases already give a better result on many of the previously mentioned surfaces with poor or degraded solderability. The other activation classes are M0 and M1 and H0 and H1. M stands for Medium and H stands for High. 0 stands for up to 500ppm of halogens for both M0 and H0. 1 stands for up to 2% of halogens for the M1 class and for H1 more than 2% of halogens are allowed. Soldering products of the H class are to be treated with care as they can be corrosive and need to be cleaned off, preferrably in a automatised cleaning process.
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  Water based

  Water based soldering fluxes are liquid fluxes that have water (H2O) as their principal solvent. Water based fluxes have numerous advantages to alcohol based fluxes, like lower consumption, no VOC (Volatile Organic Compound)-emmissions, no fire hazard, no need for special transport and storage, lower smell in the production area,...However a lot of electronic manufacturers seem to prefer the larger process window of alcohol based fluxes to the advantages of water based fluxes. Alcohol based fluxes in general are less sensitive to the correct spray fluxer settings to get a good flux application on the surface and in the through holes. Furthermore they are more easily evaporated in the preheating and give less risk on remaining solvent drops creating solder balls, solder splashes or bridging upon wave contact.  However, some countries have already implemented legislation that limits the VOC-emission of factory chimneys or imposes taxes on VOC emissions. This appears to be an extra incentive to change to water based fluxes. A recent development forced a lot of manufacturers to look into water based fluxes. The COVID-pandemia in the beginning of 2020, suddenly increased the demand for alcohol based desinfectants to that extent that at a certain moment the availability of alcohols on the market was pretty much non existing. There is a good chance that this will increase the acceptance of water based fluxes on the market. Also the global ecological awareness has improved substantially lately which drives a lot of companies towards a more ecological and sustainable policy. This will also translate into a better acceptance of water based fluxes on the market.
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  RoHS compliant

  RoHS stands for Restriction of Hazard Substances. It is a European directive: Directive 2002/95/EC. It restricts the use of some substances that are considered Substances of Very High Concern (SHVC) in electrical and electronic equipment for the territory of the European Union. A listing of these substances can be found below: Please note that this info is subject to change. Always check the website of the European Union for most recent information: https://ec.europa.eu/environment/topics/waste-and-recycling/rohs-directive_nl https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32011L0065 1. Cadmium and cadmium compounds  2. Lead and lead compounds  3. Mercury and mercury compounds(Hg)  4. Hexavalent chromium compounds(Cr)  5. Polychlorinated biphenyls (PCB)  6. Polychlorinated naphthalenes (PCN)  7. Chlorinated paraffins (CP)  8. Other chlorinated organic compounds  9. Polybrominated biphenyls (PBB)  10. Polybrominated diphenylethers (PBDE) 11. Other brominated organic compounds  12. Organic tin compounds (Tributyl tin compounds, Triphenyl tin compounds)  13. Asbestos  14. Azo compounds  15. Formaldehyde  16. Polyvinyl chloride (PVC) and PVC blends  17. Decabrominated diphenyl ester (from 1/7/08)  18. PFOS : EU directive 76/769/EEC (not allowed in a concentration equal to or higher than 0.0005% by mass) 19. Bis(2-ethylhexyl) phthalate (DEHP)  20. Butyl benzyl phthalate (BBP)  21. Dibutyl phthalate (DBP)  22. Diisobutyl phthalate 23. Deca brominated diphenyl ester (in electrical and electronic equipment) Other countries outside of the European Union have introduced their own RoHS legislation, which is to a great extent very similar to the European RoHS.