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

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those that should be observed when troubleshooting equipment containing semiconductor or other voltageand current-sensitive devices.Voltage and resistance tests of resistors, transistors, inductors, and so forth, are usually effective inlocating complete failures or defects that exhibit large changes from normal circuit characteristics;however, these methods are time-consuming and sometimes unsuccessful. The suspect device often mustbe desoldered, removed from the circuit, and then retested to verify the fault. If the defect is not verified,the device must be resoldered to the board again. If this procedure has to be repeated several times, or ifthe board is conformally coated, the defect may never be located. In fact, the circuit may be furtherdamaged by the attempt to locate the fault. For these reasons, the device should never be desoldered untilall possible in-circuit tests are performed and the defect verified.Q7. List the three groups of test equipment used for fault isolation in 2M repair.Q8. What test equipment continuously monitors electronic systems?Q9. NELAT and VAST are examples of what type of test equipment?REPAIR STATIONSIn addition to the requirements for special skills, the repair of 2M electronic circuits also requiresspecial tools. Because these tools are delicate and expensive, they are distributed only to trained andcertified 2M repair technicians.2M repair stations are equipped with electrical and mechanical units, tools, and general repairmaterials. Such equipments are needed to make reliable repairs to miniature and microminiaturecomponent circuit boards.Although most of the tools and equipments are common to both miniature and microminiature repairstations, several pieces of equipment are used solely with microminiature repair. Precision drill pressesand stereoscopic-zoom microscopes are examples of microminiature repair equipment normally not foundin a miniature repair station. A brief description of some of the tools and equipments and their uses willbroaden your knowledge and understanding of 2M repair.The 2M repair set consists of special electrical units, tools, and materials necessary to make highreliabilityrepairs to component circuitry. The basic repair set is made up of a repair station power unit,magnifier/light system, card holder, a high-intensity light, a Pana Vise, and a tool chest with specializedtools and materials. As mentioned previously, stations that have microminiature repair capabilities willinclude a stereoscopic-zoom microscope and precision drill press.REPAIR STATION POWER UNITThe repair station power unit is a standardized system that provides controlled soldering anddesoldering of all types of solder joint configurations. The unit is shown in figure 2-1. Included in thecontrol unit's capabilities are:2-6
Figure 2-1.—Repair station power unit.• "Spike free" power switching for attached electrical hand tools to eliminate damage toelectrostatic discharge components.• Abrading, milling, drilling, grinding, and cutting using a flexible shaft, rotary-drive machine.This allows the technician to remove conformal coatings, oxides, eyelets, rivets, damaged boardmaterial, and damaged platings from assemblies.• Lap flow solder connections and thermal removal of conformal coatings.• Resistive and conductive tweezer heating for connector soldering applications.• Thermal wire stripping for removing polyvinyl chloride (PVC) and other synethetic wirecoverings.Power SourceThe basic unit houses the power supply, power level indicator, motor control switch, hand tooltemperature controls, air pressure and vacuum controls with quick connect fittings, positive groundterminal, the mechanical power-drive for the rotary-drive machine, and a vacuum/pressure pump. A twopositionfoot pedal, to the left of the power unit in the illustration, allows hand-free operation for allancillary (additional) handpieces. The first detent on the pedal provides power to the voltage heatingoutputs. The second detent activates the motor drive or vacuum/pressure pump.HandpiecesThe handpieces used with the power unit are shown in figures 2-2 and 2-3. The lap flow handpiece,view (A) of figure 2-2, is used with the variable low-voltage power source. This handpiece allowsremoval of conformal coatings, release of sweat joints, and lap flow soldering capability. (Lap flowsoldering will be discussed in topic 3.) The thermal wire stripper in view (B) is used to remove insulationfrom various sizes of wire easily and cleanly.2-7
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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
Page 25 and 26: Figure 1-9.—Crystal furnace.The c
Page 27 and 28: Figure 1-12.—Planar-diffused tran
Page 29 and 30: Figure 1-14.—Vacuum evaporation o
Page 31 and 32: Figure 1-17.—Cathode-sputtering m
Page 33 and 34: Q23. How do the two types of monoli
Page 35 and 36: Figure 1-21A.—TO-5 mounting PLUG-
Page 37 and 38: 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 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 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
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REPAIRING DELAMINATED CONDUCTORS.
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5. The repair is completed using th
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SAFETYSafety is a subject of utmost
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OBJECT OR PROCESSWORK SURFACESFLOOR
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8. When moving an ESDS device or as
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Power ToolsHazards associated with
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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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Navy Electricity and Electronics Training Series - Historic Naval ...

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