PROPERTIES OF SOLDERS properties tend to fall off with the reduced tin content. This data sheet lists the most popular solders supplied as solid or flux-cored wire, bar, stick or cream. We are always pleased to receive enquiries As far as obtaining a low melting point is for alternative specifications. concerned, there is no advantage in using a higher tin content than 63/37, since the higher tin content alloys have higher melting points and cost more. From the following diagram, it can be seen that most tin/lead solders have a plastic range, i.e. on heating they are pasty between the solid and liquid l SAVES Copper and Iron-plated Soldering states. The solders are solid at 183C (361F). Iron Bits According to the alloy composition they have l SAVES failure of soldered joints as Savbit different plastic ranges. 60/40 tin/lead alloy for prevents erosion of copper wires and copper example becomes liquid at 188C (370F) and therefore has a plastic range of 5C (9F), 40/60 l SAVES costs and improves reliability tin/lead has a plastic range of 51C (92F). Ersin Multicore Savbit Solder is produced especially to overcome the problem of ordinary tin/lead solders dissolving copper. It is an alloy to which a precise amount of copper has been added so that no further copper absorption should take place during soldering. The breakage time of 0.067mm copper wire in various solders as a function of temperature is shown below . For applications such as wave soldering of electronic assemblies, the requirement for a solder with a relatively low melting point in conjunction with a short freezing range leads to the choice of 63/37 or 60/40 Sn/Pb alloy. Although 63/37 is the eutectic alloy, 60/40 is often used in practice as the slightly higher 5C freezing range of 60/40 is of no practical significance and 60/40 is a little cheaper Savbit solder has been used by leading electronics than 63/37. Under conditions of slow cooling, manufacturers throughout the world for over forty 60/40 may give duller joints than 63/37 but this is a years. Savbit was originally used to increase the purely cosmetic effect. life of copper soldering iron bits. Soldering speed Lowering the tin content increases the pasty and efficiency are increased by keeping the iron in range and raises the liquidus temperature whilst of good condition. Iron-plated bits having a longer life course reducing the cost of the alloy. Wetting plating ERSIN MULTICORE SAVBIT ALLOY TIN/LEAD ALLOYSthan plain copper tips are now commonly used but they also fail eventually (usually by cracking of the Creep strength of HMP alloy: From information plating) and then erode rapidly unless Savbit solder supplied, it is clear that an outstanding feature is its is used. very great improvement in resistance to creep by It has also been proved that the use of Savbit comparison with the tin/lead solders, both at alloy can improve the strength and reliability of normal and at elevated temperatures. At 150C for soldered joints very considerably. This is because example, a 50/50 tin/lead solder will fail under a ordinary tin/lead alloys can erode thin copper wires load of 0.7 N mm-2 in approximately 10 hours. The (as used for leads of electronic components) and following results were obtained with HMP alloy at thin copper films (as used on printed circuit the same temperature. boards.) This erosion is between 50 and 100 times slower at normal soldering temperatures when Savbit alloy is used. Load (N mm-2) Time to failure Savbit solder with Ersin 362 flux has special 150 hours M.O.D. approval DTD 900/4535. At high soldering about 1 year temperatures (above 350C) Multicore HMP alloy no creep gives the best strength. Multicore 96S alloy is the pure tin/silver eutectic The presence of 1.5% silver substantially improves alloy like pure tin, it is bright, hardly tarnishes, is strength and wetting power compared to 5/95 lead-free and non-toxic, but unlike pure tin it is Sn/Pb solder. relatively strong. It has higher electrical conductivity than other soft solders and a melting point approximately 40C higher than either 60/40, 63/37 or LMP alloys. For Making nearby soldered joints: A useful one or more of these reasons it finds uses, despite application of a high melting point alloy is the its higher cost, in the form of ERSIN Multicore soldering of joints close to each other in such a Solder Wire usually in Electronics applications. The way that the first joint is not re-melted while the alloy itself is however used more extensively for later joint, or joints, are being made. The first joint non-electrical applications in the form of Multicore is made with HMP alloy (296-301C) and the ARAX Acid-cored Solder, particularly for soldering further joints are made with successively lower stainless steel. melting point alloys, for example - 60/40 tin/lead 96S has better wetting power on stainless steel alloy (183-188C) and good control of soldering than other solders. Note the silver in 96S does not temperatures. suppress absorption of silver from silver plated surfaces or metallisations into the solder, so 96S is Service at high temperatures: The maximum not suitable for soldering to such surfaces. safe service temperature for any solder alloy subjected to stress is about 40C below the solidus melting temperature, HMP alloy can therefore be relied upon in service up to about 255C compared with about 145C for the common tin/lead alloys. HMP alloy is consequently particularly suitable for Soldering silver-plated surfaces: The presence soldering electric motors, car radiators, high of the 2% silver in Sn62 alloys suppresses temperature lamps and other products which are absorption of silver from silver-plated surfaces into likely to meet relatively high temperatures during the solder. A good joint is thus obtained. If an their working life. ordinary tin/lead alloy is used on silver-plated If HMP is used to solder tin/lead coated surfaces, the silver can be lifted from the surface components, the resulting soldered joint will be a and dissolved into the solder so that a good joint is new alloy with a lower melting point than HMP unlikely. The attachment of terminations in the alloy. This will depend on the thickness and manufacture of silver ceramic capacitors is a composition of the coating. The coating itself could typical application. therefore be HMP alloy if necessary. Service at very low temperatures: Tin/Lead alloys containing more than 20% of tin become brittle at temperatures below about -70C. The HMP alloy containing 5% of tin remains ductile Lead-free plumbing solders: 97Cu and 99C are (non-brittle) down to below -200C. Multicore HMP lead-free (non toxic) plumbing solders with superior alloy is also recommended therefore for service in wetting and capillary filling characteristics. extremely cold conditions. Lead-free high temperature solder: 95A is a high melting point solder suitable for general purpose soldering where a lead-free alloy is require Applications 95A, 97Cu AND 99C SOLDERS Applications Sn62 SOLDERS Applications HMP SOLDER 96S TIN/SILVER SOLDER 0.7 1.7 3.4