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

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other than eutectic, go through a plastic or semiliquid state in their heating and cooling stages. Solderjoints that are disturbed (moved) during the plastic state will result in damaged connections. For thisreason, 63/37 solder is the best alloy for electronic work. Solder with 60/40 alloy is also acceptable, but itgoes into a plastic state between 361 and 370 degrees Fahrenheit. When soldering joints with 60/40 alloy,you must exercise extreme care to prevent movement of the component during cooling.USE OF FLUX IN SOLDER BONDINGReliable solder connections can only be accomplished with clean surfaces. Using solvents andabrasives to clean the surfaces to be soldered is essential if you are to achieve good solder connections. Inalmost all cases, however, this cleaning process is insufficient because oxides form rapidly on heatedmetal surfaces. The rapid formation of oxides creates a nonmetallic film that prevents solder fromcontacting the metal. Good metal-to-metal contact must be obtained before good soldering joints maytake place. Flux removes these surface oxides from metals to be soldered and keeps them removed duringthe soldering operation. Flux chemically breaks down surface oxides and causes the oxide film to loosenand break free from the metals being soldered.Soldering fluxes are divided into three classifications or groups: CHLORIDE FLUX (commonlycalled ACID), ORGANIC FLUX, and ROSIN FLUX. Each flux has characteristics specific to its owngroup. Chloride fluxes are the most active of the three groups. They are effective on all common metalsexcept aluminum and magnesium. Chloride fluxes, however, are NOT suitable for electronic solderingbecause they are highly corrosive, electrically conductive, and are difficult to remove from the solderedjoint.Organic fluxes are nearly as active as chloride fluxes, yet are less corrosive and easier to removethan chloride fluxes. Also, these fluxes are NOT satisfactory for electronic soldering because they mustbe removed completely to prevent corrosion.Rosin fluxes ARE ideally suited to electronic soldering because of their molecular structure. Themost common flux used in electronic soldering is a solution of pure rosin dissolved in suitable solvent.This solution works well with the tin- or solder-dipped metals commonly used for wires, lugs, andconnectors. While inert at normal temperatures, rosin fluxes break down and become highly active atsoldering temperatures. In addition, rosin is nonconductive.Most electronic solder, in wire form, is made with one or more cores of rosin flux. When the joint orconnection is heated and the wire solder is applied to the joint (not the iron), the flux flows onto thesurface of the joint and removes the oxide. This process aids the wetting action of the solder. With enoughheat the solder flows and replaces the flux. Insufficient heat results in a poor connection because thesolder does not replace the flux.Q10. Stereoscopic-zoom microscopes and precision drill presses are normally associated with whattype of repair station?Q11. Solder used in electronic repair is normally an alloy of what two elements?Q12. In soldering, what alloy changes directly from a solid state to a liquid state?Q13. Flux aids in soldering by removing what from surfaces to be soldered?Q14. What type(s) of flux should never be used on electronic equipment?2-20
SUMMARYThis topic has presented information on the Miniature and Microminiature 2M Repair Program andhigh-reliability soldering. The information that follows summarizes the important points of this topic.The MINIATURE/MICROMINIATURE (2M) REPAIR PROGRAM provides training, toolsand equipment, and certification for 2M repair personnel.CERTIFICATION of technicians ensures the capability of high-quality, high-reliability repairs.The three SM&R codes for maintenance of electronic devices are: DEPOT (D),INTERMEDIATE (I), and ORGANIZATIONAL (O).SM&R CODE D MAINTENANCE is characterized by extensive facilities and highly trainedpersonnel. Code D activities are capable of the most complex type repairs.CODE I activities provide direct support for user activities. This includes calibration, repair, andemergency manufacture of nonavailable parts.CODE O maintenance is the responsibility of the user activity. It includes preventive maintenanceand minor repairs.ON-LINE TEST EQUIPMENT continuously monitors system performance and isolates faults toremovable assemblies.OFF-LINE TEST EQUIPMENT evaluates removable assemblies outside of the equipment andisolates faults to the component level.FAULT ISOLATION USING GENERAL-PURPOSE ELECTRONIC TEST EQUIPMENT(GPETE) should only be attempted by experienced technicians.2M REPAIR STATIONS are equipped according to the level of repairs to be accomplished.ALLOYS, such as solder, which change directly from a solid state to a liquid are called eutecticalloys.SOLDER with a tin/lead ratio of 63/37 is preferred for electronic work. A ratio of 60/40 is alsoacceptable.ROSIN or RESIN FLUXES are the only fluxes to be used in electronic work.2-21
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NONRESIDENTTRAININGCOURSESEPTEMBER
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PREFACEBy enrolling in this self-st
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TABLE OF CONTENTSCHAPTERPAGE1. Micr
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Module 11, Microwave Principles, ex
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INSTRUCTIONS FOR TAKING THE COURSEA
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THIS PAGE LEFT BLANK INTENTIONALLY.
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CHAPTER 1MICROELECTRONICSLEARNING O
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VACUUM-TUBE EQUIPMENTVacuum tubes w
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SOLID-STATE DEVICESNow would be a g
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FILM INTEGRATED CIRCUITS are broken
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Development of a microelectronic de
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Figure 1-9.—Crystal furnace.The c
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Figure 1-12.—Planar-diffused tran
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Figure 1-14.—Vacuum evaporation o
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Figure 1-17.—Cathode-sputtering m
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Q23. How do the two types of monoli
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Figure 1-21A.—TO-5 mounting PLUG-
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Dual Inline PackageThe dual inline
Page 39 and 40: wafer, as shown in figure 1-27. Thi
Page 41 and 42: Figure 1-29.—J-K flip-flop discre
Page 43 and 44: Figure 1-31.—Lead numbering for a
Page 45 and 46: Figure 1-34.—Manufacturer's Data
Page 47: comparison to the distance between
Page 50 and 51: LEVEL III.—Drawers or pull-out ch
Page 52 and 53: Conductors located several layers b
Page 54 and 55: Figure 1-43A.—Evolution of modula
Page 56 and 57: ENVIRONMENTAL CONSIDERATIONSThe env
Page 58 and 59: SUMMARYThis topic has presented inf
Page 60 and 61: Rapid development has resulted in i
Page 62 and 63: Large DIPs are being used to packag
Page 64 and 65: MINIATURE ELECTRONICS are card asse
Page 66 and 67: Three methods of interconnecting ci
Page 68 and 69: ANSWERS TO QUESTIONS Q1. THROUGH Q5
Page 70 and 71: A43. Conventional printed circuit b
Page 72 and 73: Upon satisfactory completion of a 2
Page 74 and 75: One such improvement in system test
Page 76 and 77: those that should be observed when
Page 78 and 79: Figure 2-2.—Low voltage Handpiece
Page 80 and 81: Figure 2-6.—Rotary-drive machine
Page 82 and 83: Figure 2-9.—Pana Vise.HAND TOOLSF
Page 84 and 85: Figure 2-10a.—Pliers.TweezersView
Page 86 and 87: Even though all the items are not u
Page 88 and 89: Figure 2-14.—Stereoscopic zoom mi
Page 92 and 93: A1. Chief of Naval Operations (CNO)
Page 94 and 95: CAUTIONTHIS SECTION IS NOT, IN ANY
Page 96 and 97: The coating material can best be id
Page 98 and 99: Figure 3-3.—Rotary tool conformal
Page 100 and 101: Figure 3-4A.—Eyelets (interfacial
Page 102 and 103: Figure 3-5B.—Clinched leads. SEMI
Page 104 and 105: Figure 3-8A.—Terminals. PIN AND T
Page 106 and 107: Figure 3-8E.—Terminals. SOLDER CU
Page 108 and 109: Figure 3-10.—Solder wicking.This
Page 110 and 111: Figure 3-12B.—Motorized vacuum/pr
Page 112 and 113: INSTALLATION AND SOLDERING OF PRINT
Page 114 and 115: Figure 3-15.—Component arrangemen
Page 116 and 117: Figure 3-16.—Thermal shunt.APPLIC
Page 118 and 119: Removal of Plug-In DIPsTo remove pl
Page 120 and 121: Figure 3-19.—TO mounting techniqu
Page 122 and 123: Figure 3-21.—Flat pack in protect
Page 124 and 125: Figure 3-23.—Pcb conductor damage
Page 126 and 127: REPAIRING DELAMINATED CONDUCTORS.
Page 128 and 129: 5. The repair is completed using th
Page 130 and 131: SAFETYSafety is a subject of utmost
Page 132 and 133: OBJECT OR PROCESSWORK SURFACESFLOOR
Page 134 and 135: 8. When moving an ESDS device or as
Page 136 and 137: Power ToolsHazards associated with
Page 138 and 139: dispensers will prevent many accide
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A GOOD SOLDER JOINT is bright and s
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ANSWERS TO QUESTIONS Q1. THROUGH Q3
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APPENDIX IGLOSSARYALLOWANCE PARTS L
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MODULAR PACKAGING—Circuit assembl
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APPENDIX IIREFERENCE LISTCHAPTER ON
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Microelectronics—Continuedpackagi
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Assignment QuestionsInformation: Th
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1-7. Which of the following charact
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1-24. Vacuum evaporation and cathod
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___________________________________
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1-49. Ground planes and shielding a
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1-65. Which of the following types
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ASSIGNMENT 2Textbook assignment: Ch
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2-20. Turret, fork, and hook termin
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2-39. Component leads may be clippe
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2-52. To ensure a good mechanical b
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