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

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The vacuum evaporation technique is most suitable for deposition of highly reactive materials, suchas aluminum, that are difficult to work with in air. The method is clean and allows a better contactbetween the layer of deposited material and the surface upon which it has been deposited. In addition,because evaporation beams travel in straight lines, very precise patterns may be produced.CATHODE-SPUTTERING.—A typical cathode-sputtering system is illustrated in figure 1-16.This process is also performed in a vacuum. A potential of 2 to 5 kilovolts is applied between the anodeand cathode (source material). This produces a GLOW DISCHARGE in the space between the electrodes.The rate at which atoms are SPUTTERED off the source material depends on the number of ions thatstrike it and the number of atoms ejected for each ion bombardment. The ejected atoms are depositeduniformly over all objects within the chamber. When the sputtering cycle is completed, the vacuum in thechamber is released and the wafers are removed. The masks are then removed from the wafers, leaving adeposit that forms the passive elements of the circuit, as shown in figure 1-17.Figure 1-16.—Cathode-sputtering system.1-16
Figure 1-17.—Cathode-sputtering mask.Finely polished glass, glazed ceramic, and oxidized silicon have been used as substrate materials forthin films. A number of materials, including nichrome, a compound of silicon oxide and chromiumcermets, tantalum, and titanium, have been used for thin-film resistors. Nichrome is the most widely used.The process for producing thin-film capacitors involves deposition of a bottom electrode, adielectric, and finally a top electrode. The most commonly used dielectric materials are silicon monoxideand silicon dioxide.Thick FilmThick films are produced by screening patterns of conducting and insulating materials on ceramicsubstrates. A thick film is a film of material with a thickness that is at least 10 times greater than the meanfree path of an electron in that material, or approximately 0.001 centimeter. The technique is used toproduce only passive elements, such as resistors and capacitors.PROCEDURES.—One procedure used in fabricating a thick film is to produce a series of stencilscalled SCREENS. The screens are placed on the substrate and appropriate conducting or insulatingmaterials are wiped across the screen. Once the conducting or insulating material has been applied, thescreens are removed and the formulations are fired at temperatures above 600 degrees Celsius. Thisprocess forms alloys that are permanently bonded to the insulating substrate. To a limited extent, thecharacteristics of the film can be controlled by the firing temperature and length of firing time.RESISTORS.—Thick-film resistance values can be held to a tolerance of ±10 percent. Closertolerances are obtained by trimming each resistor after fabrication. Hundreds of different cermetformulations are used to produce a wide range of component parameters. For example, the material usedfor a 10-ohm-per-square resistor is quite different from that used for a 100-kilohm-per-square resistor.CAPACITORS AND RESISTOR-CAPACITOR NETWORKS.—Capacitors are formed by asequence of screenings and firings. Capacitors in this case consist of a bottom plate, intraconnections, adielectric, and a top plate. For resistor-capacitor networks, the next step would be to deposit the resistormaterial through the screen. The final step is screening and firing of a glass enclosure to seal the unit.1-17
Page 1 and 2: NONRESIDENTTRAININGCOURSESEPTEMBER
Page 3 and 4: PREFACEBy enrolling in this self-st
Page 5: TABLE OF CONTENTSCHAPTERPAGE1. Micr
Page 8 and 9: Module 11, Microwave Principles, ex
Page 10 and 11: INSTRUCTIONS FOR TAKING THE COURSEA
Page 12 and 13: THIS PAGE LEFT BLANK INTENTIONALLY.
Page 15 and 16: CHAPTER 1MICROELECTRONICSLEARNING O
Page 17 and 18: VACUUM-TUBE EQUIPMENTVacuum tubes w
Page 19 and 20: SOLID-STATE DEVICESNow would be a g
Page 21 and 22: FILM INTEGRATED CIRCUITS are broken
Page 23 and 24: 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: Figure 1-14.—Vacuum evaporation o
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 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
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Figure 2-10a.—Pliers.TweezersView
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Even though all the items are not u
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Figure 2-14.—Stereoscopic zoom mi
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other than eutectic, go through a p
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A1. Chief of Naval Operations (CNO)
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CAUTIONTHIS SECTION IS NOT, IN ANY
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The coating material can best be id
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Figure 3-3.—Rotary tool conformal
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Figure 3-4A.—Eyelets (interfacial
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Figure 3-5B.—Clinched leads. SEMI
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Figure 3-8A.—Terminals. PIN AND T
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Figure 3-8E.—Terminals. SOLDER CU
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Figure 3-10.—Solder wicking.This
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Figure 3-12B.—Motorized vacuum/pr
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INSTALLATION AND SOLDERING OF PRINT
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Figure 3-15.—Component arrangemen
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Figure 3-16.—Thermal shunt.APPLIC
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Removal of Plug-In DIPsTo remove pl
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Figure 3-19.—TO mounting techniqu
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Figure 3-21.—Flat pack in protect
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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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