Presentation on theme: "BASIC HAND SOLDERING MULTICORE SOLDER"— Presentation transcript:
1BASIC HAND SOLDERINGMULTICORE SOLDERmost common type for hand soldering has a composition of Tin (Sn60) and Lead (Pb40), with a diameter of 0.71 mmcontains internal core of non-corrosive Rosin Mildly Activated (RMA) fluxhas a ‘plastic’ stage between the melting and solidifying stages
2BASIC HAND SOLDERING ‘Dry joints’ are caused through: movement of joint during ‘plastic’ stagethermal stressPCB contaminationoxidisationBASIC HAND SOLDERING
3TIPS BASIC HAND SOLDERING appropriate size and width is determined by the size of the connection to be madeideally 2/3 to equal the diameter of the padtips should be correctly 'tinned’ at all times, by adding a small amount of solder to the hot tip
4BASIC 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 methodswithout 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
5BASIC HAND SOLDERING COMPONENT MOUNTING Radial leaded loaded slightly off the PCB ( mm)Axial-leaded loaded with the body of the component very close to the PCB ( mm)
6BASIC HAND SOLDERING BENDING AND MOUNTING OF COMPONENTS mounted centrally between the holesresistors mounted so colour code orientated in the same directionpolarised components should be orientated so that polarity symbols (+ or - ) and component value are visible
7BASIC HAND SOLDERING LEAD TERMINATIONS TYPE 1 FULLY CLINCHED – bend the lead flat against the padtrim the lead to a length of between 1-2 lead diametersUsed in High Quality/High Reliability military or life support applicationsdifficult to reworkTYPE 2 SEMI-CLINCHED –bend the lead to an angle of approx. 45Cut to a minimum of 0.5mm and a max. of 1.5mm, or between 1-2 lead diametersUsed for commercial applicationsease of de-solderingTYPE 3 RIGID LEAD TERMINATION –straight through terminationCut to a length of min. 0.5mm and max. of 1.5mm, or between 1-2 lead diameters
8BASIC 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.
9BASIC HAND SOLDERING CLEANING a process of removing contaminates before and after solderingensures good mechanical/electrical connectionThree different methods:Mechanical - scourer or bristle brushChemical - solvents eg. Isopropyl AlcoholThermal - solder pot
10BASIC HAND SOLDERING BASIC SOLDERING PROCEDURE iron temperature is set at approx. 350soldering iron tip size is suitablesolder sponge is damptip is clean and shiny (wipe & tin)Apply flux (RMA) to help ‘wetting’ if necessarysoldering iron at a 45 angle
11BASIC HAND SOLDERING BASIC SOLDERING PROCEDURE heat the lead and the pad simultaneouslyflowing solder around the joint forms a heat bridgeremove soldering iron and solder simultaneously (prevents ‘spiking’)clean the PCB with Isopropyl Alcohol and a bristle brushwipe or pat dry with a lint free tissue to remove traces of residue.
12Use appropriate safety equipment fume extractors hand cleaners goggles BASIC HAND SOLDERINGUse appropriate safety equipmentfume extractorshand cleanersgogglesREADY TO SOLDER