The soldering tip’s job is to transfer heat from the heating element to the work. At its simplest form, it consists of a metal tip, a heating element that brings the tip up to soldering temperature, an insulated handle to allow safe holding of the soldering iron, and a plug for either a wall outlet or the soldering station. Flux, if the wire solder does not include a flux core or if additional flux is needed.Ī soldering iron is a hand tool used to solder two metal surfaces together.Wire solder, with or without a flux core.A soldering iron capable of reaching the melting point of the solder.When soldering an electronic connector to a contact point (often called a “pad”), you generally need the following: Hand soldering is the process of soldering one connection (called “solder joint”) at a time, as opposed to more automated soldering processes such as wave soldering (for thru-hole components) or reflow soldering (for SMT components). Flux is used to clean and prep the surfaces, which allows the melted solder to flow (or “wet”) and bond with the metal surfaces. The solder is melted using a soldering iron. It also provides electrical continuity, so that the electronic signal can travel through the connection without interruption. Solder secures the connection so it doesn’t break loose due to vibration or other mechanical forces. To obtain higher quality and reliability of solder joints, reflow time-temperature curve has to be reset so that SAC solder balls can be completely melted and lead in SnPb solder paste can be absolutely mixed with melted SAC solder balls.Soldering is the joining of two metal surfaces mechanically and electrically, with the use of metal called solder. As a result, the solder joints are uneven and unstable. How far lead can be dissipated in SAC solder balls depends on how high reflow temperature is set and how soon SnPb solder will be melted in solder paste. Lead will be dissipated to the boundary of solder ball crystal particles that are not totally melted. Solder paste (SnPb) coated on pad is melted but SAC solder balls are still not melted. When lead-free solder needs to be cooperated with lead solder paste, backward compatibility will happen.
As a result, vacancies and internal non-metal slag inclusions will be generated due to difficult expelling of flux solvent and contaminant in solder paste, which are not allowed. In this situation, BGA solder joints are melted first and covered on solder paste whose alloy isn't melted, leading to massive collapse and oxidation of lead solder balls. As a result, soldering defects tend to be caused in this transient process.įor example, when lead-free SAC solder paste is used to solder lead BGA (ball grid array) solder joints, forward compatibility will take place, which derives from the fact that component distributors' lead-free schedule is later than that of PCB manufacturers'. That's because different apartments in electronics manufacturing industries fail to keep synchronization on lead-free schedule and technology preparation. A transient process must be available with lead and lead-free elements coexisting. Total transition can never be achieved just by one step from complete SnPb soldering system to totally lead-free soldering system. As a result, all the soldering tools manufactured by industrial manufacturers, soldering equipment and supporting materials used for soldering have to be designed and selected based on heat resistance of 260☌. Peak temperature in lead-free reflow soldering can be as high as 250☌, so the lowest heat resistance of MVCs has to be set to be at least 260☌. Lead and lead-free components differ from each other in terms of their capability to withstand reflow soldering.īecause the peak temperature in lead reflow soldering won't exceed 230☌, heat resistance of MVCs should be set to be at 240☌, including all the soldering tools manufactured by industrial manufacturers, soldering equipment and supporting materials used for soldering all of which are designed and selected based on heat resistance of 240☌. MVCs refer to the most vulnerable components (MVCs) during reflow soldering such as liquid dielectric aluminum electrolytic capacitors, connectors, DIP switches, LEDs, transformers, PCB (Printed Circuit Board) substrate material etc.