BASIC HAND SOLDERING MULTICORE SOLDER most common type for hand soldering has a composition of Tin (Sn60) and Lead (Pb40), with a diameter of 0.71 mm contains internal core of non-corrosive Rosin Mildly Activated (RMA) flux has a ‘plastic’ stage between the melting and solidifying stages

BASIC HAND SOLDERING ‘Dry joints’ are caused through: movement of joint during ‘plastic’ stage thermal stress PCB contamination oxidisation BASIC HAND SOLDERING

TIPS BASIC HAND SOLDERING appropriate size and width is determined by the size of the connection to be made ideally 2/3 to equal the diameter of the pad tips should be correctly 'tinned’ at all times, by adding a small amount of solder to the hot tip

BASIC HAND SOLDERING LEAD FORMING minimum distance from the end of the component body to the start of the lead bend is usually 2 lead diameters or 1.5mm for hand bending methods without undue pressure hold the component lead with the pliers and bend the lead protruding beyond the pliers with a finger until a 90 degree angle is formed. if damaged discard component

BASIC HAND SOLDERING COMPONENT MOUNTING Radial leaded loaded slightly off the PCB (0.3 - 3.0mm) Axial-leaded loaded with the body of the component very close to the PCB (0.3 - 3.0mm)

BASIC HAND SOLDERING BENDING AND MOUNTING OF COMPONENTS mounted centrally between the holes resistors mounted so colour code orientated in the same direction polarised components should be orientated so that polarity symbols (+ or - ) and component value are visible

BASIC HAND SOLDERING LEAD TERMINATIONS TYPE 1 FULLY CLINCHED – bend the lead flat against the pad trim the lead to a length of between 1-2 lead diameters Used in High Quality/High Reliability military or life support applications difficult to rework TYPE 2 SEMI-CLINCHED – bend the lead to an angle of approx. 45 Cut to a minimum of 0.5mm and a max. of 1.5mm, or between 1-2 lead diameters Used for commercial applications ease of de-soldering TYPE 3 RIGID LEAD TERMINATION – straight through termination Cut to a length of min. 0.5mm and max. of 1.5mm, or between 1-2 lead diameters

BASIC HAND SOLDERING CONSTRUCTING A GOOD SOLDER JOINT Figure a) the amount of solder applied is minimal and may result in a poor electrical connection over time. Figure b) shows the optimal solder joint that has good wetting between component lead and PCB pad. Figure c) indicates an excessive amount of solder has been applied to the connection.

BASIC HAND SOLDERING CLEANING a process of removing contaminates before and after soldering ensures good mechanical/electrical connection Three different methods: Mechanical - scourer or bristle brush Chemical - solvents eg. Isopropyl Alcohol Thermal - solder pot

BASIC HAND SOLDERING BASIC SOLDERING PROCEDURE iron temperature is set at approx. 350 soldering iron tip size is suitable solder sponge is damp tip is clean and shiny (wipe & tin) Apply flux (RMA) to help ‘wetting’ if necessary soldering iron at a 45 angle

BASIC HAND SOLDERING BASIC SOLDERING PROCEDURE heat the lead and the pad simultaneously flowing solder around the joint forms a heat bridge remove soldering iron and solder simultaneously (prevents ‘spiking’) clean the PCB with Isopropyl Alcohol and a bristle brush wipe or pat dry with a lint free tissue to remove traces of residue.

Use appropriate safety equipment fume extractors hand cleaners goggles BASIC HAND SOLDERING Use appropriate safety equipment fume extractors hand cleaners goggles READY TO SOLDER