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

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Figure 2-14.—Stereoscopic zoom microscope.TOOL CHESTThe tool chest (not shown), provides storage space for the electronic repair hand tools, dental tools,abrasive wheels, solder and solder wicks, eyelets, abrasive disks, ball mills, various burrs, and otherconsumables used with the repair procedures. The chest is portable, lockable, and has variously sizeddrawers for convenience.REPLACEMENT PARTSReplacement parts are provided with the 2M repair set to ensure the technician has the capability tomaintain the equipment properly. Actual preventive and corrective maintenance procedures, as well asdata on additional spare parts and ordering information, are found in the technical manual for the 2Mrepair set equipment.REPAIR STATION FACILITIESTo be effective, 2M electronic component repair must be performed under proper environmentalconditions. Repair facility requirements, whether afloat or ashore, include adequate lighting, ventilation,noise considerations, work surface area, ESD (electrostatic discharge) protection, and adequate poweravailability. The recommended environmental conditions are discussed below. With the exception ofrequirements imposed by the Naval Environmental Health Center and other authorities for ship and shorework conditions, each activity tailors the requirements to meet local needs.LIGHTINGThe recommended lighting for a work surface is 100 footcandles from a direct lighting source. Lightcoloredoverheads and bulkheads and off-white or pastel workbench tops are used to complement thelighting provided.VENTILATIONFumes from burning flux, coating materials, grinding dust, and cleaning solvents require adequateventilation. The use of toxic, flammable substances, solvents, and coating compounds requires a ductsystem that vents gasses and vapors. This type of system must be used to prevent contamination often2-18
found in closed ventilation systems. This need is particularly important aboard ship. Vented hoods, ducts,or installations that are vented outside generally meet the minimum standards set by the NavalEnvironmental Health Center.NOISE CONSIDERATIONSNoise in the work area during normal work periods must be no greater than the acceptable levelapproved for each activity involved. Because the work is tedious and tiring, noise levels should be as lowas possible. Ear protectors are required to be worn when a noise level exceeds 85 dB. Ear protectorsshould also be worn anytime the technician feels distracted by, or uncomfortable with, the noise level.WORK SURFACE AREAWork stations should have a minimum work surface of at least 60-inches wide and 30-inches deep.Standard Navy desks are excellent for this purpose. Standard shipboard workbenches are acceptable;however, off-white or pastel-colored heat-resistant tops should be installed on the workbenches. Chairsshould be the type with backs and without arms. They should be comfortably padded and of the properheight to match the work surface height. Drawers or other suitable tool storage areas are usually provided.ELECTROSTATIC DISCHARGE SENSITIVE DEVICE (ESDS) CAPABILITYA 2M work station should be capable of becoming a static-free work station. This is specified in theDepartment of Defense Standard, Electrostatic DISCHARGE Control Program for Protection of Electricaland Electronic Parts, Assemblies, and Equipment. ESD will be discussed in greater detail in topic 3.POWER REQUIREMENTSNo special power source or equipment mounting is required. The 2M repair equipment operates on115-volt, 60-hertz power. A 15-ampere circuit is sufficient and six individual power receptacles should beavailable.HIGH-RELIABILITY SOLDERINGThe most common types of miniature and microminiature repair involve the removal andreplacement of circuit components. The key to these repairs is a firm knowledge of solder and highreliabilitysoldering techniques.Solder is a metal alloy used to join two or more metals with a metallic bond. The bonding occurswhen molten solder dissolves a small amount of the metals and then cools to form a solid connection. Thesolder most commonly used in electronic assemblies is an alloy of tin and lead. Tin-lead alloys areidentified by their percentage in the solder; the tin content is given first. Solder marked 60/40 is an alloyof 60 percent tin and 40 percent lead. The two most common alloys used in electronics are 60/40 and63/37.The melting temperature of tin-lead solder varies depending on the percentage of each metal. Leadmelts at a temperature of 621 degrees Fahrenheit, and tin melts at 450 degrees Fahrenheit. Combinationsof the two metals melt into a liquid at different temperatures. The 63/37 combination melts into a liquid at361 degrees Fahrenheit. At this temperature, the alloy changes from a solid directly to a liquid with noplastic or semiliquid state. An alloy with such a sharp changing point is called a EUTECTIC ALLOY.As the percentages of tin and lead are varied, the melting temperature increases. Alloy of 60/40 meltsat 370 degrees Fahrenheit, and alloy of 70/30 melts at approximately 380 degrees Fahrenheit. Alloys,2-19
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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-
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 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
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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
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
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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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