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Navy Electricity and Electronics Training Series - Historic Naval ...

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Figure 3-17.—Preferred solder joint.When a solder joint is completed, solvent must be used to remove all flux residue. The two mosthighly recommended solvents, in the order of their effectiveness, are 99.5 percent pure ethyl alcohol <strong>and</strong>99.5 percent pure isopropyl alcohol.Q19. What is solderability?Q20. What is the most common source of heat in electronic soldering?Q21. What determines the shape <strong>and</strong> size of a soldering iron tip?Q22. What term describes a device used to conduct heat away from a component?Q23. What is the appearance of a properly soldered joint?REMOVAL AND REPLACEMENT OF DIPSIn topic 1 you learned the advantages of DIPs. They are easily inserted by h<strong>and</strong> or machine <strong>and</strong>require no special spreaders, spacers, insulators, or lead-forming tools. St<strong>and</strong>ard h<strong>and</strong> tools <strong>and</strong> solderingequipment can be used to remove <strong>and</strong> replace DIPS.DIPs may be mounted on a board in two ways: (1) They may be mounted by plugging them into DIPmounting sockets that are soldered to the printed circuit boards or (2) they are soldered in place <strong>and</strong> mayor may not be conformally coated. Although plug-ins are very easy to service, they lack the reliability ofsoldered-in units, do not meet MILSPECS, <strong>and</strong> are seldom used in military designed equipment. They aresusceptible to loosening because of vibration <strong>and</strong> to poor electrical contact because of dust <strong>and</strong> dirt <strong>and</strong>corrosion.3-25

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