(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51476;image) |
Figure 1. Mechanically bound conductor cross-sections that show: A) the effective contacts between bound only |
conductors, which manifest at the "points" illustrated across the arrows, versus B) the area of contact between |
bound and soldered conductors, which manifests as the solid conductive mass illustrated between the arrows. |
SOLDER ALLOY % RATIO | SOLDER FUSING TEMPERATURE | |
60 Sn/40 Pb | — | 361 - 374 °F (183 - 190 °C) |
63 Sn/37 Pb – eutectic alloy | — | 361 °F (183 °C) |
70 Sn/30 Pb | — | 361 - 377 °F (183 - 192 °C) |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51430;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51448;image) | |
Figure 2. Photomicrograph of a ductile fracture that propogates through a | Figure 3. Routine mechanical binding of component leads prior to soldering. | |
soldered joint, severing the connection. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51450;image) |
Figure 4. Four typical examples of ductile failures occurring in PCB through-hole soldered joints that would benefit from repair using silver-bearing solder. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51419;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51420;image) | |
Figure 5. Acceptable (left) versus dry (right) lead-free solder joints. | Figure 6. Very dry solder joint. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51462;image) |
Figure 7. Rosin soldering flux bulk paste. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51447;image) |
Figure 8. Five common types of heat source: A) pencil iron, B) rudimentary soldering station, C) gun, D) butane micro-torch, and E) propane torch. Many options exist |
within the first three types, A, B and C. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51590;image) |
Figure 9. Four examples of pencil style soldering iron tips: A) knife, B) conical, C) oval, and |
D) chisel. There are many variations of each basic design. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51551;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51449;image) | |
Figure 10. Three methods of attaching flexible wires to a rigid PCB: A) inserting the wire | Figure 11. The options available for binding wire and component leads to PCBs can be somewhat limited and | |
through the PCB and soldering it to the foil located on the opposite side of the board - the | problematic requiring simple creativity such as bending the leads that protrude through the PCB prior to | |
PREFERRED METHOD, B) soldering the wire directly against the foil side of the PCB without | soldering. Clip the free ends of the leads close to the board after the solder congeals. | |
passing the wire through the board from the opposite side - POOR, and C) inserting the wire | ||
through the PCB, but from the foil side and then soldering - POOR. The illadvised methods | ||
illustrated in B) and C) can subject the foils to tearing away from the PCB! |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51439;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51446;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51443;image) | ||
Figure 12. Preheat the iron to full operating temperature. | Figure 13. Generously 'tin' the tip of the iron. | Figure 14. Remove ash, contaminants and excess solder from | ||
the iron. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51441;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51442;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51444;image) | ||
Figure 15. Heat the joint. | Figure 16. Apply solder to the joint. | Figure 17. Upon fusing with good joint penetration, retract the | ||
solder and iron simultaneously. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51552;image) |
Figure 18. Prepping the gun for soldering. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51553;image) |
Figure 19. Heating and soldering the joint. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51445;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51418;image) | |
Figure 20. Characteristics of an ideal solder joint. | Figure 21. Good lead-based solder joint exhibiting a bright shiny | |
finish and smooth transitions. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51421;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51422;image) | |
Figure 22. Good versus cold solder joints. | Figure 23. Cold solder joint. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51428;image) |
Figure 24. Excess solder applied to a joint. Note the lack of consistency between the |
applications of solder to the three adjacent joints in the foreground reflecting an error |
in method. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51583;image) | (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51584;image) | |
Figure 25. One example of desoldering wick. | Figure 26. Desoldering wick inserted between the preheated iron and the joint. |
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=51585;image) |
Figure 27. Special purpose desoldering tools. A) low to moderate wattage desoldering iron with a nickel plated tip, B) spring loaded, button triggered, |
solder sucker with a Teflon tip, and C) standalone rubber bulb with a Teflon tip. All of the tool tips resist solder adhesion. |