1. 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

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

3. TIPS  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

4. 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

5. 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

6. 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

7. 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

8. 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

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

10. 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

11. 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. BASIC HAND SOLDERING

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