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

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Figure 3-10.—Solder wicking.This method should be used to remove surface joints only, such as those found on single-sided anddouble-sided boards without plated-through holes or eyelets. It can also remove excessive solder from flatsurfaces and terminals. The reason is that the capillary action of the wicking is not strong enough toovercome the surface tension of the molten solder or the capillary action of the hole.MANUALLY CONTROLLED VACUUM PLUNGER.—The second method of removing solderinvolves a manually controlled and operated, one-shot vacuum source. This vacuum source uses a plungermechanism with a heat resistant orifice. The vacuum is applied through this orifice. Figure 3-11 shows thelatest approved, manual-type desoldering tool. This technique involves melting the solder joint andinserting the solder-extractor tip into the molten solder over the soldering iron tip. The plunger is thenreleased, creating a short pulse of vacuum to remove the molten solder. Although this method offers apositive vacuum rather than the capillary force of the wicking method, it still has limited application. Thismethod will not remove 100 percent of the solder and may cause circuit pad lifting because of theextremely high vacuum generated and the jarring caused by the plunger action.Figure 3-11.—Manual desoldering tool.3-16
Because 100 percent of the solder cannot be removed, the extraction method is not usually successfulwith the plated-through solder joint. The component lead in a plated-through hole joint usually restsagainst the side wall of the hole. Even though most of the molten solder is removed by a vacuum, thesmall amount of solder left between the lead and side walls causes a SWEAT JOINT to form. A sweatjoint is a paper-thin solder joint formed by a minute amount of solder remaining on the conductor leadsurfaces.MOTORIZED VACUUM/PRESSURE METHOD.—The most effective method for solder jointremoval is motorized vacuum extraction. The solder extractor unit, described in topic 2, is used for thistype of extraction. This method provides controlled combinations of heat and pressure or vacuum forsolder removal. The motorized vacuum is controlled by a foot switch and differs from the manual vacuumin that it provides a continuous vacuum. The solder extraction device is a coaxial, in-line instrumentsimilar to a small soldering iron. The device consists of a hollow-tipped heating element, transfer tube,and collecting chamber (in the handle) that collects and solidifies the waste solder. This unit is easilymaneuvered, fully controllable, and provides three modes of operation (figure 3-12): (1) heat and vacuum(2) heat and pressure, and (3) hot-air jet. Some power source models provide variable control for pressureand vacuum levels as well as temperature control for the heated tubular tip. The extraction tip and heatsource are combined in one tool. Continuous vacuum allows solder removal with a single heatapplication. Since the slim heating element allows access to confined areas, the technician is protectedfrom contact with the hot, glass, solder-trap chamber. Continuous vacuum extraction is the onlyconsistent method for overcoming the resweat problem for either dual or multilead devices terminating inthrough-hole solder joints.Figure 3-12A.—Motorized vacuum/pressure solder removal. VACUUM MODE.3-17
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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
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wafer, as shown in figure 1-27. Thi
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Figure 1-29.—J-K flip-flop discre
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Figure 1-31.—Lead numbering for a
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Figure 1-34.—Manufacturer's Data
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comparison to the distance between
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LEVEL III.—Drawers or pull-out ch
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Conductors located several layers b
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Figure 1-43A.—Evolution of modula
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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 90 and 91: other than eutectic, go through a p
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 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
Page 140 and 141: A GOOD SOLDER JOINT is bright and s
Page 142 and 143: ANSWERS TO QUESTIONS Q1. THROUGH Q3
Page 145 and 146: APPENDIX IGLOSSARYALLOWANCE PARTS L
Page 147 and 148: MODULAR PACKAGING—Circuit assembl
Page 149: APPENDIX IIREFERENCE LISTCHAPTER ON
Page 152 and 153: Microelectronics—Continuedpackagi
Page 155: 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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