Multicore Size 5 Tube Savbit Alloy Solder

Product Information

For small-scale soldering jobs, an iron of 40 W or less, with a tip of 6.3 mm or 5.0 mm is recommended. For larger-scale electrical soldering tasks and sheet metal working, 120 to 200 W irons with tips up to 20 mm wide are recommended. For service applications, cordless irons that are either battery- or gas-operated have proven to be very effective. Soldering in electronics production facilities is usually handled by automated ovens that process complete, populated PCBs as they pass through on a conveyor belt. Many PCBs today are populated mostly with surface-mount (SMT) devices and require ovens using reflow soldering. However there are usually a number of through-hole components also mounted on the PCB; these are typically installed using hand soldering stations in the production area. Conversely, PCBs containing only through-hole devices can be processed using wave-soldering ovens.

Below, we describe the soldering issues you should consider, whether you are a hobbyist or a technician working in a service or manufacturing environment. We discuss the constituents of solder and their impact on soldering; this includes lead-free solder, which must now be used on most applications. We then look at the techniques essential for successful soldering, and finish by discussing the soldering tools available – from simple soldering irons to small, manually-operated soldering ovens. Solders and fluxes A far more serious problem with tin/lead soldering alloys is their use of lead; this has high toxicity, coupled with a tendency to leach into the environment from PCB assemblies. As a result, lead-based solders are among the hazardous materials identified for restriction or banning by the European Union’s Restriction of Hazardous Substances Directive ( RoHS) and Waste Electrical and Electronic Equipment Directive (WEEE), which took effect in July 2006. These are required to be enforced and become law in each member state. We have seen how the right solder alloys and fluxes, and the right soldering techniques contribute to the quality of soldered joints. However solder joint quality depends also on using the most suitable and best-available soldering equipment; accordingly, we finish our look at soldering with a review of the soldering equipment currently on offer.By contrast, 63/37 alloys have no plastic range; they melt at 183°C. Alloys that have a single melting point like this, rather than a melting range, are known as eutectic. They are ideal for applications such as wave soldering that require a low melting point, while avoiding a plastic range that would give components an opportunity to become misaligned before the solder freezes. For other applications such as hand soldering, these considerations are not critical – so 60/40 alloys are favoured, as they are slightly lower cost. Under conditions of slow cooling, 60/40 may give duller joints than 63/37 but this is a purely cosmetic effect. Fig.1 shows how melting point temperatures vary with tin/lead ratios. Acceptability requirements for soldering are covered in the IPC Association's IPC-A-610D Section 5. This covers connections of all types, including SMT, through-hole and terminals. It also refers to three classes of equipment and environment, and their demands for soldering quality; Class 1 refers to general electronic products, Class 2 to dedicated service electronic products and Class 3 to high performance electronic products, such as life-support systems or other equipment where performance on demand is critical. Overall, fluxes are subject to the IPC Joint Industry Standard J-STD-004 or equivalent. Soldering techniques Never heat the solder wire directly. Instead, heat the wire or terminal to be soldered to the correct working temperature, then introduce the solder. This melts and flows into the joint. After finishing soldering, carefully remove the soldering iron to leave a clean, smooth soldered joint. This is particularly important when using soldering guns – keep the power triggered on until the soldering tip is well away from the joint, to avoid leaving solder residues on the tip. To extend a solder tip’s life for as long as possible, tin it before returning to storage.

Soldering success in all these environments depends on three factors - the solder and flux used, the soldering techniques, and the soldering tools or equipment utilised for the operation.The flux should be specifically designed for lead-free applications and therefore able to withstand higher soldering tip temperatures without charring, spattering and decomposition. Some fluxes may smoke more when using hotter tip temperatures. Removal and replacement of Ball Grid Array (BGA) and SMT components in a rework or service environment must be done manually; this is a demanding operation with scope for many types of error if not performed correctly. For example if an IC is heated excessively, the IC itself, the PCB or neighbouring components can be damaged. Alternatively, if an IC is not sufficiently heated, and the solder fully melted before removal, pulling the IC up may tear some of the pads from the PCB, causing possibly irreparable damage. For this reason, rework stations need accurate heating profiles to allow successful BGA/SMT removal and replacement. These profiles approximate to those used in reflow ovens. Soldering using lead-free soldering wire presents some special challenges, as previously mentioned, because of the higher melting temperature of lead-free soldering alloys such as Sn/Cu/Ag and Sn/Cu, which are 30 to 40°C higher than leaded solder. As a result, lead free hand soldering requires stable dynamic temperatures. To achieve this, soldering irons must have more power and an efficient method of transferring thermal energy to the soldering iron tip. Attempting to overcome the heating problems by running lower-power soldering irons at higher temperatures to increase the heat energy in the tip are unsatisfactory.