Terms - memorize these - IT 318it318.groups.et.byu.net/Lecture-2014.pdf · Terms - memorize these Term Units Unit ... Frequency Hertz Hz f Cycles/sec ... femto f 10-15 Peta P 1015

IT 318 LECTURE NOTES (Winter/2014) Page 1 Terms - memorize these

Term Units Unit Abbrev

Symbol Meaning

Voltage Volts V E ElectroMotive Force (EMF) Current Amperes A I Flow of electrons Resistance Ohms R Opposition to electron flow Power Watts W P Energy/unit time Joules/sec Frequency Hertz Hz f Cycles/sec

Capacitance Farads F C 1 F = 1 Coulomb (6.24 x 1018

electrons) at 1 Volt

Scientific Prefixes - memorize these (p. 5 of packet)

Prefix Name Symbol Multiplier Prefix Name Symbol Multiplier

milli m 10-3 kilo k 103

micro 10-6 Mega M 106

nano n 10-9 Giga G 109

pico p 10-12 Tera T 1012

femto f 10-15 Peta P 1015

atto a 10-18 Exa E 1018

zepto z 10-21 Zetta Z 1021

yocto y 10-24 Yotta Y 1024

These are used in engineering notation, and must be used throughout this class. Italicized are FYI only. Resistor Color Code:

0 = Black 5 = Green 1% = Black five stripes 1 = Brown 6 = Blue 2% = Red 2 = Red 7 = Violet 5% = Gold 3 = Orange 8 = Gray 10% = Silver four stripes 4 = Yellow 9 = White 20% = No stripe

Mnemonic: Better Boys Realize Our Young Girls Become Very Great Women Examples: 47k 5% = yellow, violet, orange, gold 100 10% = brown, black, brown, silver 10 20% = brown, black, black, (blank) 82M 5% = gray, red, blue, gold Orange, white, yellow, silver = 390k 10% Green, blue, green, gold = 5.6M 5% M1: DC Electric Circuits (Supplemental, Chapter 1) Ohm's Law: I = E/R and its derivatives

Discuss large and small loads * Analogy to water, pump and faucet (*Fig 3-9, p. 47)

Power formula: P = IE and its derivatives, as well as I2R and E2/R Go over some examples:

Power drawn by an 80% efficient, 2 HP electric motor 100 W incandescent light bulb

The Kilowatt-Hour

IT 318 LECTURE NOTES (Winter/2014) Page 2 kW hours, measurement, calculation of total Lab 1: Ohm's Law and Series Circuits Series Circuits Series

Voltage divider RT, IT Connected in series, each uses only a portion of the voltage (miniature Christmas lights)

Adding voltage sources (extra batteries): Connect them in series for extra voltage

Parallel Circuits Adding voltage sources (extra batteries):

Connect them in parallel, so they see the same voltage Schematic diagrams of simple circuits (lights in room, flashlight w/ multiple bulbs. Discuss analogy of load resistors to actual loads. Connect them in parallel for longer-lasting under higher current Example: car battery for 12 V, 1200 A

Car battery for 24 V, 600 A How can you make a flashlight brighter?

Does a voltage source also supply current? Why do we call them voltage sources? Formula for RT of parallel resistors; RT < smallest of resistors RT = 1/R1 + 1/R2 + ... + 1/RN Discuss why this is intuitively so (that the total amount of resistance is less than the smallest) Other useful relationships:

RT = (R1R2)/(R1 + R2) (Equation 6.5, p. 156) When adding resistors in parallel:

If R2 >> R1, then RT has not changed appreciably R1 = 1/10 R2, then RT = .909 R1 (10% decrease) R1 = 1/100 R2, then RT = .990 R1 (1% decrease)

If R1 = R2, then RT = 1/2 R1 Example: amplifier driving two 8Sspeakers.

If R1 = 1/2 R2, then RT = .667 R1 (33% decrease) If R1 = R2 = R3, then RT = 1/3 R1 If R1 = R2 = R3 = R4, then RT = 1/4 R1, Etc.!!

Lab 2: Parallel Circuits & the Power Formula Power in Electricity P=IE P=IR P=E/R

IT 318 LECTURE NOTES (Winter/2014) Page 3 M2: Electronic Measuring Equipment (Supplemental, Chap 2) Electronic Measuring Equipment (pp. 116 - 129) You cannot measure anything without disturbing that which you are measuring. This in turn means that any time you measure something, you are measuring only to some degree of accuracy. Accuracy: Degree of conformance to a known or given reference or standard. Precision: Degree of repeatability; gives same reading each time for identical stimulus. Resolution: The smallest increment that can be resolved. High resolution equals small increments. Example: True voltage = 3.00000000000 V

Reading 1 = 2.99 V---, Accuracy = (Avg Measured-Actual)/Actual=(2.997-3.0)/3.0=.1% Reading 2 = 2.99 V /)) Precision = (high reading-low reading)/average reading = Reading 3 = 3.01 V- (3.01 - 2.99)/2.997 = .667%

Resolution = 1 part of 1000 (0 to 999) = .1% Voltage measurement, parallel effects

1 M input impedance, circuit = 10 k, 10 k , 10 V. 1M input impedance, circuit = 10 M, 10 M, 10 V.

Current measurement, series effects 1 input impedance, circuit = 10 k, 10 k (parallel), 10 V. 1 input impedance, circuit = 1, 1, (parallel), 10 V.

Input impedance of various meters: DMM: 10 M (voltage, other parallel measurements)

.01 (current) Analog: 20 k /V (voltage, other parallel measurements)

.1 (current) Oscilloscope: 1 M (x1 probe), 10 M (x10 probe) - (voltage, other parallel measurements)

Special probe required to measure current. Note: Article on instrumentation loading: Electronic Design, Mar 17, 1997, pp. 155-162; by Howard Johnson. "Probing High-Speed Digital Designs"

Operation of oscilloscopes & Demo: Oscilloscope, function generator, power supply @ Four main sections of scope (@Handout: Setting the Controls)

Screen control: intensity, focus, astigmatism, scale illumination, beam finder Vertical amplifier

Cover various amounts of amplification Horizontal timebase

Cover variable time/div sweeps Triggering

Demonstrate need for and operation of triggering Scope ground lead is connected to earth ground; do not try to make it otherwise. Lab #3: Electronic Measuring Equipment M3: Resistance, Resistors & Potentiometers (Lunt Chap 3) Resistance opposes the flow of current and converts electrical flow (current) to heat. Everything has resistance, except for superconductors. Range of resistivities, division in to conductors, insulators, semi-conductors

IT 318 LECTURE NOTES (Winter/2014) Page 4

Lunt, CHAPTER 3: FIXED AND VARIABLE RESISTORS @3.1: Fixed Resistors (@take envelope)

If the transistor is the star of the show, the resistor is the warm-up group (lead show)

Desirable characteristics:

Low age drift Low cost

Can handle current surges Low parasitics

High reliability Small size

Low temperature drift Low (tight) tolerance

Wide range of values

IC resistors

*Carbon comp resistors (*Fig 3.1)

***Carbon and metal film resistors (***Figs 3.2, 3.3, 3.4)

**Network resistors (**Figs 3.5, 3.6)

**Wirewound resistors (**Figs 3.8 , 3.9)

*Chip resistors (*Fig 3.10)

*MELF resistors (*Fig 3.11)

*Summary (*Table 3.1)

@3.2: Variable Resistors (@take envelope)

Difference between pot and rheostat

Use of limiting resistor for rheostat applications

*Types: ceramic substrate (*Fig 3.15)

* Wirewound (*Fig 3.16)


M4: AC Electric Circuits (Supplemental, Chap 3) Alternating Voltage and Current AC waveforms:

Triangle Sawtooth Square Sinusoidal (the big one for analysis, & for power generation & distribution)

Why the sine wave is sinusoidal * Basic generator output voltage (*Figure 2-2, p. 38)

Analogy to pedaling a bicycle Basic equation: v = Vp sin Units of Measure for AC Voltages and Currents Vpeak, Vp-p, Vrms go over examples of each Go over relation between each, and why Vrms is used Calculating power consumption in AC circuits Frequency, Phasors, and Angular Velocity f = 1/t; t = 1/f --- Go over examples, especially in estimating

* Phasors (*Fig 2-5, p. 40) Vector addition and subtraction

Review of complex algebra Relating back to the Pythagorean Theorem, we know that z/ represents the hypotenuse of a

right triangle, and that from this information we can find the remaining two sides. Likewise, x + jy represents the two sides of a right triangle, and that from this information, we can find the length and angle of the hypotenuse.

z = (x2 + y2) x = z cos Vectors in electronics: = arctan (y/x) y = z sin 1+12; if: (1/90) + (1/-90) it = 0! Practice a few on your calculators, then learn how to use the shortcut your calculator has. A few sanity checks:

3 + j4 = 5; 6 + j8 = 10; 30 + j40 = 50; 60 + j80 = 100; etc.; all / 's = 53.13 1 + j1 = 1.414; 2+j2 = 22 = 2.828; 3+j3 = 23; all / 's = 45 Hypotenuse must be longer than either side; both sides must be shorter than hypotenuse. If j component > x component, / > 45 If j component < x component, / < 45

Inductance "Since every current flow produces a magnetic field, and the field strength depends on the current strength, this means that an alternating current produces a magnetic field that is constantly varying in strength, and therefore induces a voltage in the circuit. The polarity of the voltage thus induced always opposes the change in the current." (Packet, p. 42, first paragraph of section 2-4). This property is known as self-inductance, or just inductance. Thus, inductance opposes changes in the current. Therefore, in inductive circuits, the current

changes lag the voltage changes, or vice versa (ELI). This type of opposition to current flow is known as reactance, and its symbol is X; units are Ohms ().

XL is frequency dependent XL = 2fL (equation 2-7, p. 44)

Example: find the reactance of a 45H inductor at 10.7 MHz. (XL = 2 (10.7MHz)(45H) 3.025 k

Analogy: hanging a mass on a spring (I=mass); also inertia in a moving mass on a frictionless surface.

Inductors in series and in parallel Inductors


Capacitance Go over buildup of charge between two insulated, conductive plates; one electron at a time. Analogy to 2-ported reservoir with diaphragm separating ports. The current changes instantaneously, while the charge takes time to accumulate; thus the voltage

cannot change quickly, and therefore lags (ICE). Thus, capacitance opposes changes in the voltage. This type of opposition to current flow is also

known as reactance, but is capacitive (XC). Units are Ohms (). XC is also frequency dependent, but is inversely proportional:

XC = 1/2fC (equation 2-13, p. 46) Example

Capacitors in series and in parallel

Lunt, CHAPTER 4: FIXED AND VARIABLE CAPACITORS @4.1: Fixed Capacitors (@take envelope and supercapacitors)

Review of factors contributing to capacitance:

Ca

d

r

( )( )( ) 0

, which for a vacuum (r = 1.00), a = 1m2, and d = 1m:

Cx m

mx or pF

( . )( . )( . )

. , .8 85 10 1 00 1 0

18 85 10 8 85

12 2

12

Analogy of reservoir with diaphragm

Desirable characteristics:

Low leakage -------------------------------------------------------------------

High dielectric strength; discuss relationship to thickness and size

* Small size (*Table 4.1: dielectric strengths and constants)

Low dissipation factor

Wide value range

Tight tolerance

Wide useful frequency range Table 4.2

Wide value range

Low cost

Low parasitic inductance and resistance (ESR)

Excellent temperature stability

Low dielectric absorption ----------------------------------------------------

*Comparison of various capacitor types (*Table 4.2)

Note 5 basic families of capacitor types and their similar characteristics

Discuss the manufacturing of electrolytics and super lytics.

@4.2: Variable Capacitors (@take one) Both trimmer and user-variable


Transformers Close proximity of two coils, one driven (primary), the other loaded (secondary). ONLY works with AC; discuss why

* Symbol and construction (*Fig 2-15, p. 48) Significance of turns ratio:

Vs/Vp = Ns/Np Thus, I can step voltage up or down.

But: I can't get more power out than I put in (2nd law of thermodynamics, or law of entropy), so: Ip/Is = Ns/Np So, when I step voltage UP, the current gets stepped DOWN by the same amount;

AND vice versa. Series Circuits Containing Resistance and Reactance These are the real types of circuits; only imaginary circuits contain only one of these, although many times we can ignore one as insignificant.

Resistive loads: heaters, power-corrected power supplies Inductive loads: relays, solenoids, motors Capacitive loads: long-distance transmission lines

Combination of R & X = Z, which is the vector sum of R + X. Impedance Calculations for Series RX Circuits Add all the resistive elements, then all the reactive elements, then find the result.

Example (from packet): R1=1k ; XC1=3k ; R2=2k ; XC2=1.5k RT=3k ; XT=4.5k ; Z = 5.41k /56.3 Example 2: f = 455 kHz; C = 116.6 pF; R = 1.0k ; L = 1.224 mH; V = 10 Vrms ZT = 1.0 k +j500 = 1.118 k /26.56 IT = (10 V/0) / (1.118 k /26.57 = 8.945 mA/-26.57 vR = iR * R = 8.945 V/-26.57 vL = iL * XL = 31.3V/63.43 vC = iC * XC = 26.83V/-116.57

Series LCR Circuits Plot of XL and XC versus frequency Note that Z = R + j(XL - XC). Resonance

@ Note particularly what happens at XL = XC (@Handout of resonance plot) Reactive elements store energy from the source, then give it back. But work is required to store the energy first, so the source must supply this energy. Each cycle, this energy must be restored to the reactive elements; thus the source is required to provide this energy, even though it is given back. At resonance, with pure reactances, the energy is merely traded between C and L. At resonance:

Z = R Q = 1/R (LC) XL = XC = 0 fr = 1/2 (LC)

Importance in tuned circuits Circuit Q Q = quality of tuned resonant circuit; depends generally on L, and on RL specifically. Q = XL/R.

Thus there are two ways to raise the Q: lower the resistance, or increase XL, most easily by raising the frequency.

* BW = fr/Q; discuss the need for narrow bandwidths most of the time. (*Fig 2-31, p. 59)


M5: Motors (PowerPoint presentation; also Supplemental, Chap 4) Main point: understand motor types, their characteristics and their applications. M6: Connectors; Safety (Lunt, Chap 5; pp 7-9) CHAPTER 5: DISCRETE TRANSISTORS AND DIODES; CONNECTORS @5.2: Connectors (@take some)

*Fig 5.2 - Failures in electronic systems and their causes

Permanent, semi-permanent: chapter 11. This chapter: separable only

Specifications:

# of pins

Current

Voltage

Operating temperature range

# of mating cycles

Environmental conditions (dust, humidity, vibration)

Insertion force (per pin)

Physical size, weight

Problems in making a good connection: dirt, dust, oxide

Solutions:

*3-step operation of the actual connection part: contact, swage, swipe (*Fig 5.4)

Precious metals Hard contact metals for higher voltages

Note the many choices that exist for materials for the housing, pins, plating, wire, & insulation. Safety (pp. 109 - 115) - read: http://web.bsu.edu/tti/3_3/3_3h.htm @Video: Edit Electrocution (12 minutes) Indirect Dangers: Spark in combustible atmosphere Surprise reaction Direct Dangers: Fibrillation Burns * *Figure 3-1, Effects of 60 Hz Electric Shock, from "Student Reference Manual for Electronic

Instrumentation Laboratories. Discuss Ohm's Law in relation to your body.

Skin: about 5 kOhms - 100 kOhms, depending on many factors. At 120 Vrms, 5 kOhms = 24 mA; 100 kOhms = 1.2 mA (not noticeable).

Very wet skin .1 kOhms; at 50 Vrms = 50 mA. Try to keep the current from flowing through your heart (only use one hand) Difference between +12V on your hands and +9V on your tongue. Respect electricity; anything above 50 V can kill you directly; any electricity can kill you Indirectly Maximum safe voltage How GFIs work

http://web.bsu.edu/tti/3_3/3_3h.htm


M7: IC Manufacturing (Lunt, Chap 6) CHAPTER 6: HISTORY, SUBSTRATES AND PATTERNING 6.1: Introduction Level 0 only this chapter; levels 1-3 in later chapters. 6.2: IC Manufacturing (Level 0): Chips Complexity of making ICs: 500 steps, alignment to 5 nm; 6 months. Facilities incredibly expensive to

build, equip, operate, maintain. Average # of engineers/project = 50

Mask set = $3M; EUV photolithography tool=$60M (2010) Average project length = 12 months (Design costs = 50*1*$125,000 = $6.25M = 80% total cost) Annual loaded engineer cost = $125,000 Masks & wafers 8% Average re-spin cost = $192,000 Synthesis, place & route 4% Configuration errors = 15% Hardware validation 8% Expected revenue = $32,744,625 Development margin = 20% From Distributed Design Teams: Survival of the Best Connected, by Ron Schneiderman, Electronic Design, 11/24/03, pp 66-72 *Out of IC mfg came the AFM and STM, new microscopes that allow atomic-level probing. *IBM spelled with Xenon atoms on nickel substrate ICs are at the foundation of modern society; essentially all modern products depend directly or

indirectly on them. Moores law has held true for almost 40 years; presently we can put >100G transistors on a chip # of off-the-shelf choices number >100,000. Making the substrates: silicon mostly by the Czochralski method; results in monocrystalline growth of the highest-purity material in the world. (*Fig 6.1) *Sliced using an inside-diameter saw (a very thin band of diamond-coated metal stretched tight) @ (*Fig 6.2) @take 8" wafer and 3" wafers Main manufacturing processes: patterning; adding materials; removing materials Photoresists: Positive-acting (softened by exposure) = novolac resin w/ DNQ for Photo-Active Compound (PAC) (DNQ = diazonaphthoquinones Negative-acting (hardened by exposure) = cyclic synthetic rubber resin w/ bis-arylazide for PAC. **Photolithography is main tool for patterning (*Fig 6.4; Fig 6.5) Three main advantages of present photolithography: 1. Many chips can be done at the same time 2. Resolution limited mainly by , which can be quite small. 3. Can be highly automated. **Main tool for photolithography: stepper (*Fig 6.6, 6.7) Issues in photolithography: of process primarily limited by of light source, which is not small

enough. Problems: Light must be monochromatic Light must be collimated and in-phase helps even more. Must be able to focus and move light (using optics or something!) Presently we use deep UV (235 nm; moving to 150 nm), which requires calcium flourite optics Much research going on in e-beam and x-ray for this, but nothing practical yet. From Preserving Moores Law Pushes Lithography to its Limits, Marie Freebody, Photonics Spectra, May 2011, p. 45: Keeping up with Moores Law over the past four decades has seen lithography wavelengths drop from the 436 and 365 nm produced by mercury arc lamps to 248 nm by the krypton fluoride excimer laser. In 1998, a group at MITs Lincoln Laboratory developed a 193-nm source with the argon fluoride laser, which is used to produce todays 45- and 32-nm IC technologies. But the biggest question in the field today is this: What imaging method will be used to pattern

features that are 22 nm and below? Will shorter wavelengths such as the long-awaited extreme-

ultraviolet (EUV) be the answer, or can Moores Law be extended by other means?


Other approaches used to push lithography even further include phase-shift masks, improved the

chemistry of photoresists, fabricated lenses with high NAs, and developed immersion lithography. *IC dimensions (*Table 6.1) Clues for remembering: hair 2-3 mils diameter, or 50-75 m; radius of Si atom = 1.46 ; spacing between Si atoms = 4 . About 25 m in a mil; about 40 mils in a mm.

SEEING DOUBLE: Some day chips might be made with X-rays. Until then, double-

patterning lithography will be the only game in town. By Chris A. Mack; IEEE

Spectrum, Nov 2008, pp 46-51. 1971: Intel introduces the 4004, the worlds first microprocessor, with 2300 transistors; capable

of 60,000 instructions/second. Today: 820 million transistors on Intel Core2 Extreme,

capable of 72GIPS.

1963: transistor cost $10, automobile tire. Today $25/8 GB of flash memory (=64G

transistors, which = 390.6 p$/transistor)

Whats stopping further progress? Hard limits on photolithography.

X-ray lithography, ion-beam lithography, even electron-beam lithography all work, but

only at extremely low volumes (not viable for production volumes). Issue: cycle

time (about 10-100 times too slow)

Process node .5 (/NA). For todays limit of = 193 nm and NA = 1.35, this = 72 nm

(pitch; smallest dimension = 36 nm).

NA = 1.35 requires immersion lithography to get a refractive index >1, plus HUGE

lenses (HUGE = $$$).

Photolithography tools have increased in cost: doubling every 4.4 years.

Options: EUV (down to 13.5 nm) and double-patterning lithography.

Problems with EUV: everything absorbs it (air, lenses); lenses terribly difficult ($$$) to

make; sources far too weak for good cycle time; poor photoresists presently;

defects extremely hard to find and eliminate.

Problems with double-patterning: alignment (down to 2 nm); doubles lithography steps.

But EUV not available until 2011, 2012; until then, double-patterning lithography the only option.

From Moore or Less?, Kevin Lewis, ASEE Prism, March-April 2011, pp 38-39:

Looking farther out, carbon-based nanoelectronics using nanotubes and nanoribbons made

out of grapheme, a single-atomic-layer sheet of carbon is currently the leading candidate for a more

fundamental paradigm shift. According to the 2009 International Technology Roadmap for

Semiconductors (ITRS) report, carbon-based nanoelectronic exhibits high potential and is maturing

rapidly. At the moment, though, the technology is still largely in the hands of academic researchers.

And Jeff Welsers job is to make sure that research gets done. The thing thats interesting about

carbon right now is it can serve two different purposes: one, you can use it to make a FET [field-effect

transistor, the current standard], whether its a nanotube or graphene, that can potentially be a higher

performance FET than what you get with silicon; it also might be useful for interconnects between

silicon transistors; its an extremely good thermal conductor, so it might help you with getting rid of

some of the heat that youre trying to dissipate on these chips right now. The other aspect that I think

makes carbon even more attractive as an area to put your money into far-out research is its got very

different physics, particularly in the grapheme, in terms of the way electrons move in it that you could


use maybe to try to make totally different types of switches, maybe a switch based on spintronics,

where youre manipulating the spin of the electron, or one based on something called pseudo-

spintronics, where youre taking advantage of a quantum property of an electron in graphene thats

unique to the graphene structure.

From Photonic Techniques Spark Manufacturing Revolution, by Valerie C Coffey, Photonics Spectra, Jan 2013, pp 56-57.

EUV: 22 nm resolution with 13.5 nm source. ASML unit gives 30 W output for 18 wafers/hour (wph); its next target of 105 W gives 69 wph. Needed are 1018 photons/cm2/s. Air and glass greatly absorb these wavelengths, so it requires photolithography in a vacuum, and mirrors instead of lenses. These mirrors must each be coated with hundreds of layers, each 3 nm thick, to produce a reflective effect on these EUV rays. The optical surfaces of these mirrors must be uniform to within /30, or 0.45 nm (4.5 ), which is the equivalent of 1 hills (maximum) on a surface as wide as the continental United States.

IT 318 LECTURE NOTES (Winter/2014) Page 12 M8: IC Manufacturing Adding Materials (Lunt, Chap 7) CHAPTER 7: ADDING MATERIALS * Dispensing and spinning: used primarily for photoresist; not a selective addition method. (*Fig 7.1)

* Oxide growth (*Fig 7.2) for entire wafers or boats of wafers; again not done selectively. Oxide is the main material used for patterning wafers.

Sputtering (*Fig 7.3) - mostly for metals Evaporation (*Fig 7.4) - mostly for metals

* CVD (*Fig 7.6) - for SiO2, Si3N4, polySi, Al2O3, other insulative materials, SiGe, metals, etc. Very versatile, but uses many extremely dangerous feeder gases for the chemical reactions. Note: CVD also heavily used in manufacturing optical fiber preforms.

Photochemical vapor deposition - similar to CVD, but uses light as catalyst. Diffusion - occurs in ovens like for oxide growth; isotropic; inexpensive * Ion implanation - (*Fig 7.9); shoots ions of desired material into substrate (after patterning); very expensive, but highly controllable and anisotropic. Also requires annealing afterward * MBE (*Fig 7.10)

IT 318 LECTURE NOTES (Winter/2014) Page 13 M9: IC Manufacturing Removing Materials (Lunt, Chap 8) CHAPTER 8: REMOVING MATERIALS

Developing - used for photoresist; a chemical dissolving process for non-hardened photoresist, very similar to developing film.

Stripping - used to remove hardened photoresist; attacks interface between hardened photoresist and oxide beneath, causing liftoff but not dissolution. Must be filtered out of stripping chemical. Wet (chemical) etching - isotropic; requires chemical which dissolves exposed material to be * removed. (*Fig 8.1) * Dry (plasma) etching - anisotropic; uses chlorine or fluorine (highly reactive) (*Fig 8.2); can * be used to remove almost anything. Features created by this process: *Figs 8.3, 8.4 @Video: Creating an IC Chip failure mechanisms:

Metal migration. Analogy for current flow: swarm of gnats Localized line corrosion Manufacturing defects Bridging between adjacent conductive corrosion deposits

Each of the above failure mechanisms is accelerated by the presence of moisture, and other corrosive agents in the atmosphere, so the final step in chip processing is passivation. However, cracks may develop in this deposition

Metal migration is chiefly carried out by current densities. All the above failure mechanisms are exacerbated by heat and moisture

Future of electronic devices

Fundamental limits seem to continue to move out, but eventually WILL stop us. MOSFETs will probably not make it much beyond 2015 for cutting-edge ICs.

Other possibilities: Carbon nanotubes; molecular-level construction; quantum devices; bioelectronics. Also see above article, SEEING DOUBLE.

IT 318 LECTURE NOTES (Winter/2014) Page 14 M10: IC Packaging (Lunt, Chaps 9, 5) CHAPTER 9: INTEGRATED CIRCUIT PACKAGES: PROCESSES AND MATERIALS

(LEVEL 1) @Sometimes, the chip is the final packaging level for the IC manufacturer: @DCA, MCM, hybrids

Desirable characteristics for IC packages: (covered before in Chapter 2.2)

Provides large # of I/O pins

Allows for dissipation/removal of all the heat generated by the circuit

Structurally supports the circuit

Protects the circuit from the environment

Allows the circuit to be tested economically

Can be easily mass-produced

Very low cost

Occupies very little real estate

Very low weight

Adds no parasitic devices

Very high reliability

*Four basic parts of IC package (*Fig 9.1)

*Categories of packages: (*Fig 9.2)

SMT vs through-hole

Peripheral leads vs array beneath package

Chip connected to frame via C4, TAB, or wire bonds

Package material = plastic (novolac: epoxy + phenolic), ceramic, or metal

Material of connection substrate = polyimide (TAB), A42/copper, organic (FR4), ceramic

(Al2O3)

Lead frames and wirebonding

** *Fig 9.3: thermocompression (a) and ultrasonic (b); also *Fig 9.4

Chip bonded to paddle (center of lead frame) via epoxy

**Tape Automated Bonding (TAB): **Figs 9.5, 9.6

*C4 (*Fig 9.7)

Lead Pitch: major issue. Tradeoffs between array I/Os and peripheral I/Os

Package size Pitch Pin ruggedness Attachment process

Speed of attachment I/O bonding speed

Packaging materials: issues

Cost Weight Hermeticity Ruggedness Thermal conductivity

* Hermeticity (*Fig 9.8)

** Thermal conductivity (*Tables 9.1, 9.2)

CHAPTER 5: DISCRETE TRANSISTORS AND DIODES; CONNECTORS @5.1: Discrete Transistors and Diodes (@take examples of common ones) Discuss features of each of the main discrete package types

IT 318 LECTURE NOTES (Winter/2014) Page 15 M11: MCMs & Hybrids (Lunt, Chap 10) CHAPTER 10: HYBIRDS, MCMs, AND PWBs 10.1: Hybrid ICs and MCMs (Level 1)

**@ What they are: (**Figs 10.1, 10.2) (@take examples)

Advantages: greater density, less weight, lower cost @ high volumes, higher performance,

Disadvs: high NRE costs, unfamiliar technology, not flexible for changes, KGD

Hybrids have a mixture: IC dies, chip Rs & Cs, film Rs M12: PWB Manufacturing (Lunt, Chap 10) 10.2: Printed Wiring Boards: Fabrication

Old technology (about 1945); spawned some ideas for IC mfg.

@@*Process of making a core (*Fig 10.4) (@take sheet of FR4, @core)

*Multi-layer board (*Fig 10.5)

@video: Basic Multilayer Fabrication

Functions:

Mechanically fix components in place (solder depended upon, primarily)

Electrical connections formed (solder depended upon, primarily)

Electrically separate individual signals, voltages (dielectric)

Remove heat and spread it out

Provide testability

Desirable characteristics for conductive materials

Low-resistance Low cost Can be formed into thin sheets Low CTE

High thermal conductivity

* *Table 10.1

Desirable characteristics for substrate

Excellent insulator (high breakdown voltage, high electrical resistivity, low moisture absorption)

Chemically inert Physically tough Light weight Good thermal conductivity

Low CTE Low dielectric constant Low cost

*@ Properties of resin materials (*Table 10.2) @example of polyimide substrate in metal box

* Properties of fiber materials (*Table 10.3)

*PWB terms: via, blind via, buried via (*Fig 10.8)

PWB design: variables include shape, # of layers, thickness, width & thickness of lands, distance

between lands

* Width & thickness of lands (*Fig 10.9)

* Distance between lands (*Table 10.4)

Future needs & challenges:

Cost, especially multilayer PWBs Lower dielectric constant

Higher thermal conductivity Higher frequencies

Finer resolution for IC leads


M13: PWB Assembly (Lunt, Chap 11) CHAPTER 11: PWB ASSEMBLIES (LEVEL 2) PWB Assembly has become a 1 T$ industry!

@Take examples of each

Through-hole technology (old, very reliable, higher cost & size)

Insert components, clinch & trim leads

* Wave solder (*Fig 11.1)

Surface-mount technology

** Screen print solder paste (*Fig 11.3) for top side, or adhesive dot (*Fig 11.4) for top side

Place components

Reflow (for paste) or wave solder (for bottom side)

Mixed-mount technology:

Many combinations are possible and are being tried/used

Soldering

Very old, but terrific for our needs

Role of fluxes: clean oils, oxides (corrosive action); tradeoff between activity and need to

remove oxides, oils, dirt.

Role of thermal cycle in forming intermetallics

* A good joint: (*Fig 11.5)

Common alloy for today: SAC 305 (3% Ag, 0.5%Cu, remainder - 96.5% - Sn)

*Hand Soldering Procedures: (*Fig 11.6)

Make sure the iron tip is clean. If it is a new tip, then tin it correctly:

Clean tip with fine sandpaper or steel wool until copper is bright

Heat and apply solder generously as it begins to melt

Leave tip hot and covered with solder for about 1-2 minutes, then cool

After completely cooled, reheat and wipe off excess solder

Make sure the joint to be soldered is clean and mechanically stable

Wipe tip on damp (not soaked) sponge.

Apply tip to joint; use enough area to get the heat transferred

A small amount of solder on the tip will help the heat transfer

Rosin in the solder is key to cleaning the surfaces to be soldered; the joint should be made only of

freshly melted solder.

Apply the solder to the other side of the joint and add until all surfaces are wetted. Do not use

too much or too little solder. A taper is desirable.

Remove iron and let cool naturally; do not blow on it.

Clean off flux with warm soapy water and toothbrush; alcohol is helpful sometimes

Future Challenges and Needs

Better no-clean paste formulations

Better rheological agents

Finer solder spheres for lower cost

A replacement for lead


M14: Computers (Walters, Chap 1) Text: The Essential Guide to Computing: The Story of Information Technology, by E. Garrison Walters Chapter 1: The Core of Computing: How the Key Elements of Hardware Work Together (pp 3-37) Basically, what is a computer? - An electronic instruction executer @FDD, HDD *Pictures of: CPUs; Motherboard; SIMMs; power supply; glue logic; cache; BIOS Every morning when the CPU wakes up, it goes through a complete re-start:

Im a microprocessor unit that can do whatever Im told to do (this is hardware-designed into the PU). In this case, the PU is to be the CPU of a desktop computer.

First thing I always do is go to address 0000, which points me to the systems BIOS. BIOS does a self-test (test memory, drives, devices); if all is well, I give control to the OS (Windows, Apple, Linux, Unix)

OS: allows multiple programs to appear to run simultaneously on PU; keeps track of occupied memory, vacated memory and free memory; handles interaction with I/O devices. OSs are incredibly complex programs that have 4M ways they can go wrong; thus all the bugs.

*Organization of computer *Organization of CPU *Instruction cycle *Storage hierarchy. Note that 1 kB = 1024 bytes; 1MB=1024 kBytes *Memory allocation Interrupts - analogy of working in my office; doing each task quickly creates the appearance of true multi-tasking @A computer is always executing instructions; what does it do when theres nothing to do? @Demonstrate with Task Manager and Idle Process Whats the future? Moores Law; normal and more exotic research Carbon nanotubes; DNA research; quantum-level devices; other substrates


M15: Computers (Walters, Chap 2) Chapter 2: Memory, Storage and I/O Loading files from disk to memory - one byte at a time, or more depending on data bus width FAT tells where to find all the data Discuss disk fragmentation *Memory system of computer (*Fig 2.1, p. 43) Access time a function of:

random/burst access mode SRAM or DRAM Degree of fragmentation of file/data

Data rate a function of: Bus width, clock speed

*Role of each memory type (*Table 2.1, p. 44) *Ways to make it go faster (*Fig 2.2, p. 47) Need for proximity if you want speed *20 years of change in DRAM (*Table 2.2, p. 53) *Hard disk evolution (*Table 2.4, p. 56) Access time a function of:

Seek time, which is a function of: Latency, which is a function primarily of RPM Track access time (moving head to proper track)

Degree of fragmentation of file/data Density of data on drive

Data rate a function of: Data density Number of platters

The I/O Bus: a critical bottleneck Industry Standard Architecture (ISA bus): 32 Mbps; 1982 Extended ISA (EISA): 64 Mbps; 1988 Peripheral Component Interconnect (PCI bus): 132 Mbps; 1992 PCI-X: 266 Mbps; 1998 External I/O SCSI: 1984; 40 Mbps; SCSI2 = 80 Mbps (1995); SCSI3 (aka SCSI-160) = 160 Mbps (2000); SCSI-320 = 320 Mbps (2006); SCSI-640 = 640 Mbps (2009) Universal Serial Bus (USB): 1994: v. 1.0: 12 Mbps; 2000: v. 2.0: 480 Mbps; 2009: v. 3.0: 4.8 Gbps. Firewire (IEEE 1394): 1996: 400 Mbps; 2005: 800 Mbps; declining in popularity. Both USB and Firewire are hot-swappable Ethernet: 10 Mbps, 1984; 100 Mbps, 1995; 1 Gbps, 2000; 10 Gbps, 20081119


M16: Digital Communications (Walters, Chap 10) Chapter 10: Digital vs. Analog: Communications Basics *The electromagnetic spectrum (*The Electromagnetic Spectrum, my file) All of it travels at the speed of light (visible light is only one narrow portion of it); fast, but

sometimes not as fast as wed want. All of it can be used to transmit information, as demonstrated first by Heinrich Hertz, then by

Guglielmo Marconi (1901; first transmission across Atlantic Ocean) The need for modulation: * Things that can be modulated: amplitude, frequency, and phase (*Figs 10.3, 10.4, 10.5, pp 271, 272) Bandwidth: the amount of spectrum used to carry information; also note that BW capacity. The BW required by a signal is a function of how fast it changes and how much information it

contains. Examples: Telephone contains about 3.3kHz at the highest; BW 3kHz Audio contains about 20 kHz at the highest; BW 20kHz Video contains about 4.5 MHz at the highest, plus audio (to give TV), plus other 6MHz

Comparison of modulation characteristics:

Characteristics AM FM Phase M Digital Mod

Simplicity of circuitry

Simple Complex Very complex

Extremely complex

Required bandwidth Low Medium Medium High

Noise immunity Low High High Very high

Other advantages None None None EDC; compression; many others

Capacity of a carrier: (Shannons Law) Capacity = BW * log2(1+SNR)

Example: phone lines (as exemplified by phone usage): Capacity = 3.0 kHz * log2(1+4000) = 3.0 kHz * 11.966 = 35.898 kbps

Attenuation a complex function of frequency LF and RF penetrates walls, travels long distances; reflected by ionosphere Microwave, IR, visible light, etc, are line-of-sight only; also goes through ionosphere Microwave attenuated by dust, clouds, rain; IR and up is stopped by it. Water molecules absorb lots at certain frequencies High frequencies contain more energy per unit bandwidth, so harder to generate at high powers. Analog vs digital Analog: continuously varying; infinite number of levels.

Technologies built on analog: AM, FM radio; TV; phone system; faxes; records; cassette tapes

* Noise and amplifier distortion which enter the wave are inseparable (*Figs 10.6, 10.7, p. 276). Extremely difficult to compress; already about as BW efficient as possible Digital: varies in discrete increments; larger # of bits gives smaller steps (greater resolution)

Technologies built on digital: computers, floppies, CDs, DVDs, most cell phones, PDAs, watches, cameras, toys, video games, etc.

* Amplifiers (regenerator/amplifiers) can remove the distortion, noise, and even errors, up to a point. (*Fig 10.9, p. 277). Can be readily compressed Sampling:


Nyquist criterion says: 2x highest frequency, or you lose something and get artifacts. Example: audio has highest freq = 20 kHz; sampling rate used = 44.1 kHz

* Recovered wave smoothness proportional to sampling rate (*Figs 10.11, 10.12, 10.13, 10.14, pp 279, 280, 281). Resolution a direct function of #bits/sample:

4 bits = 16 steps; 8 bits = 256 steps; CDs use 16-bit samples. Most people cant hear the difference between 16 and 18 or 20 bits, but some claim it is audible.

So what does it take? Audio: 44.1 ksamples/sec * 16 bits/sample = 705.6 kbps (per channel); stereo = twice that.

Video (TV): 486 x 720 pixels for NTSC * 10 bits per pixel * 30 frames/sec = 104.98 Mbps. What capacity do we have in a 6MHz channel? - Comes out to about 19.3 Mbps HDTV: 720 x 1280 pixels * 10 bits/pixel * 30 frames/sec = 276.48 Mbps

So how do you put an elephant through a straw? Data Compression Content-based: Spatial compression: compresses the information in a single frame. Example with a picture.

Temporal compression: compresses the information between frames. Example with changes between frames for a picture

JPEG standards (Joint Photographic Experts Group): .jpg files MPEG standards: 1, 2, MP3, and 4 - adaptations of JPEG standards for moving pictures Lossless vs. lossy compression

Lossy can compress more, but cannot be counted on to produce the exact original info. Fine for video and audio if the stuff lost is imperceptible.

Lossless necessary with things like computer data, but cannot achieve great compression. Noncontent-based: (based on data patterns)

Codes or dictionaries to represent repeating patterns of bits. Can give significant amounts of compression on computer data, because it does not have random irregularities (noise) as does video and audio data.

Statistical or Huffman codes: some patterns of data repeat more often than others; short codes can be used to represent them, using longer codes for less-often repeating patterns. Morse code is an example of this.

End result: digital video needs 3 Mbps; we have room for 19.3 Mbps! Error Detection and Correction When errors occur in digital, they must be at least detected, and if possible, corrected. Error detection always relies on redundant information being added. Simplest form of error detection: parity checking.

Example: adding even or odd parity bit to byte. Will detect 1-bit errors. Next more complicated form: CRC, which adds a byte or more to the end of a packet or string.

Will detect most 1-bit errors, fewer 2-bit errors, fewer 3-bit errors, etc. Most complicated form: forward error detection/correction

Redundant information added directly into data pattern in a complex, calculated method. Example: FEC used at IBM for -inch tape, or at JPL for Voyager 1 & 2.


M17: Industrial Networking (Walters, Chaps 11) Chapter 11: Network Fundamentals Overview Mailroom analogy used in book; actually quite similar and useful. Files are broken up into packets, for purposes of standardizing the material transmitted. A packet is like a letter, in that it contains all necessary information to allow it to travel by whatever means, through whatever locations, to reach the end destination. Sending a File TCP/IP: Transmission Control Protocol/Internet Protocol - the big rules for sending packets over the Internet. * Internet: loosely connected group of computers, basically world wide, to which any computer may be connected. (*Fig 11.4, p. 312) Protocol: formal set of rules which must be followed for effective communication to occur. * Packet: contains letter info (sender addr, destination addr), plus wrapper to protect contents (error

detection/correction bits), plus sequence # (to know how to put it back together) (*Fig 11.1, p. 304)

Frame: higher-level envelope, using any of several protocols for its definition. Router: opens envelope, finds destination address for each packet, determines best path there,

wraps it back up, and sends it on its way. Big advantages of this system:

Allows use of any transmission medium Allows use of any transmission format or standard Allows transmission of all data types Can grow to any size Essentially infinitely flexible

The Importance of Packets Dial-up phone lines used previously; dedicated connection for the duration of the link. Wasted

BW, but only way at the time. Used modems (modulator/demodulator). Freeways are obviously much more efficient, because traffic may share each lane, instead of

needing a dedicated lane for each vehicle. 5 Issues with packets: (not issues with switched circuits)

Common addressing scheme for all packets Routing necessary; algorithms of cost, distance, congestion, etc. Sequencing must be recoverable Accuracy essential (data integrity) Latency and jitter must be within acceptable limits; primarily an issue with streaming audio,

video, phone service Packet loss rate or ratio: % of packets lost * Anatomy of a packet (*Fig 11.1, p. 304) Issues of packet size:

Fixed requires no overhead about packet size Fixed wastes packet bits, but only in last packet of each file Packet sizes are therefore usually a function of data type (more on this later)

Protocol Stacks ISO/OSI model uses 7 layers, 4 of which are most useful to us. Table 11.1 summarizes the function

of each layer. For our purposes, suffice it to say that each higher layer encapsulates the layers below it into another envelope for transmission and 5 packet issues above. This model allows for maximum flexibility in options for each layer, along with interoperability among different vendor products.


Getting from A to B: Circuits, Virtual Circuits, and Circuitless Approaches

Network Type How Switched? Persistence of Link Bandwidth

1 Circuit Permanent Highest; dedicated

2 Circuit Temporary Medium; dial-up

3 Packet None; no circuit Low-Medium

4 Packet Virtual circuit High

Above table a summary of information presented on pp. 310 319 @Media (@take samples) No such thing as perfect media; all have their respective advantages and disadvantages.

Media type Advantages Disadvantages

Wireless: RF Penetrates walls, rain, clouds,

dust; proven technology

Limited distance, BW; much inter-

ference; very crowded

Wireless:

Microwaves

Penetrates walls; proven technol-

ogy; BW greater than RF; greater

capacity

Limited distance; some interfer-

ence; some crowding; difficult and

expen$ive circuit design

Wireless: Infrared Massive capacity; nearly immune

to interference

Limited distance; cant penetrate

anything

Wired: Twisted-pair Cheap; Cat 5 up to 1 Gbps; Cat 6

up to 10 Gbps, short lengths (25)

Relatively difficult above 100 MHz

Wired: Coaxial cable Good to about 10 Ghz, 100 ft Much more expen$ive than twisted

pair

Wired: Fiber Optic Massive capacity; immune to

EMI; lighter; much greater

distance between repeaters

More expensive; very expensive

emitters, detectors; very difficult to

splice

Topologies, Multiplexing, and Synchronization * Types: Star, Point-to-Point, Bus, Ring, Tree *Figs 11.9, 11.10, 11.11, 11.12, 11.14, pp. 328-333 Multiplexing:

FDM (radio stations) TDM (packets, sharing) SDM (radio stations) CDM (cell phones; military)

The Plexes: Simplex: one-way only (broadcast) Half duplex: two-way, but only one direction at a time (2-way radios) Full duplex: two-way, both at same time (requires 2 channels)

The synchros: Synchronous: uses a time signal to control flow of information Asynchronous: uses control information between packets to control flow of information Synchronous is usually faster than asynchronous (no overhead; no wasted bit periods)


Network Connecting Points Hub: simply repeats and rebroadcasts packets or frames. Contains no intelligence. Repeater: simply amplifies and repeats the signal. Contains no intelligence. Bridges: connects 2 similar LANs and provides a filter so that only packets with appropriate

addresses cross the bridge. Routers: Special-purpose computers that decide where to send each packet, then re-encapsulate

them and send them on their way. Can connect different types of networks. Most of its work is done in software.

Switches: Lower-layer router; does most of its work in hardware, so it is faster. M18: Computers (Walters, Chaps 12, 14) Chapter 12: Types of Networks LANs Ethernet

The most common type; defined about 20 years ago; improved from original of about 10 Mbps to 100 Mbps about 5 years ago (Fast Ethernet). Currently working on a spec for a 1 Gbps Ethernet. *-see below

Uses Carrier Sense Multiple Access with Collision Detection (CSMA/CD). Sounds weird, but it works!

Each Ethernet card has a hard-coded address, 48 bits (281 T possibilities). Maximum length: 185 m for 100 Mbps; 200 m for 1 Gbps; about 50 m for 10 Gbps No guaranteed data rate or latency; great for bursty data, but not sustained data rates.

Token Ring - the only other significant option; about 10% of the market Originally 4 Mbps; upgraded to 16 Mbps. Now available in 10 Gbps. Guaranteed data rate and latency; great for short packets and high sustained data rates.

CANs Multiple LANs; greater distances, and a need for very high data rates to interconnect them FDDI: Fiber Distributed Data Interface

100 Mbps, then 1 Gbps, then 10 Gbps; token-passing Much more expensive than cable, twisted pair approaches

ATM: Asynchronous Transfer Mode Small cell (packet) sizes: 48 bytes data, 5 bytes header Great for streaming data applications - developed by phone companies. Not so good for

bursty data Standard is 155 Mbps over fiber Lengths to 80 km Can handle all types of data NOTE: ATM not used much any more

* Gigabit Ethernet IEEE 802.3z requires optical fiber CSMA/CD Length in the range of 4 km Cheaper than ATM Also over CAT 5; 10 Gbps also available now Lots of work going on to see if 100 Gbps over twisted pair can also be done.

Acess Networks T-1 : 24 digital phone lines, each @ 64 kbps; plus 8 kbps for signaling gives 1.544 Mbps. Can

also be allocated to other uses besides phone calls. Usually over twisted pair (two pairs for full duplex).

T-3 : 28 T-1s, or 45 Mbps. Usually over coax or microwave. Both T-1 and T-3 are leased lines, meaning they are dedicated 100% to the entity that leases


them. * xDSL: Digital Subscriber Loop. Uses unoccupied bandwidth of ordinary phone lines which are

within a specified distance from the local office. (*Fig 12.5, p. 368) Many flavors (which is what the x stands for). Several speeds, depending on distance and

flavor:

Chapter 12

DSL Flavor Maximum Distance Downstream Speed

ADSL (A=asymmetric) 18,000 ft (3.6 miles) 1.544 Mbps

ADSL 12,000 ft (2.4 miles) 6.312 Mbps

ADSL 9,000 ft (1.8 miles) 8.448 Mbps

VDSL (V=Very high data

rate)

4,500 ft (0.9 mile) 12.96 Mbps

VDSL 3,000 ft (0.6 mile) 25.82 Mbps

VDSL 1,000 ft (0.2 mile) 51.84 Mbps

Cable modems: take out 1 TV channel from cable service and devote it to computer data; has a

capacity of about 30 Mbps. Uses coaxial cable of the TV cable companies. Network services:

Dial-up analog phone lines, using modems ISDN (Integrated Services Digital Network) Switched 56 X.25 (used by ATMs and credit-card verification devices at POS terminals) Frame Relay Switched MultiMegabit Data Service (SMMDS)

WANs SONET (Synchronous Optical Network)

Self-healing, dual counter-rotating ring topology Very advanced technology, standardized world-wide.

* Note data rates in *OC- table, p. 382 WDM (Wave Division Multiplexing)

FDM in optical domain; huge potential, being heavily researched and implemented. Wireless WANs and Access Networks Satellite links serious possibilities, coupled with very serious challenges. Note failure of Iridium

project.


Chapter 14: The Internet and Network Security Origins of the Internet DARPA in 1969 (later ARPA). Expanded by many people working at many universities, most notably Berkely, Stanford, MIT, Carnegie-Mellon. Grew because TCP/IP was cheap, effective, and flexible (for different types of hardware, and for scalability). Todays backbone of the Internet is provided predominantly by the long-distance providers WorldCom, GTE, and Cable & Wireless; paid for initially by DARPA, later NSF. The interface to the Internet, for 24 years, was a command-line interface to a text-based program. NO GRAPHICS. Fascinating only to the nerds of the enterprises, and even then not many of them. Apps: bulletin boards; email (text only); ftp 1993: Software by Tim Berners-Lee of CERN, creating a way to exchange documents and have them look the same on any computer. This is HTTP, or Hyper-Text Transfer Protocol, and uses HTML (Hyper-Text Markup Language). Demo: View Source option after right-clicking on a Web page. This opened it up for everyone; WWW is the Internet, to most people. EXPLOSIVE growth. Metcalfes Law: the value of a network (# nodes); note the rapid growth in the value of the Internet. (Robert Metcalfe = originator of Ethernet, founder of 3COM). Note that in the discussion of the 4 levels, POP refers to Point of Presence, not Post Office Protocol. Levels:

4) ISP now mostly local carriers (old phone companies, new communication companies) 3) Regional backbone - networks of ISPs, interconnected typically by T-1s and T-3s. 2) The backbone - lots of regions, interconnected typically by ATM over SONET; examples

include MCI (now part of WorldCom), Sprint, GTE. 1) The network access point - interconnection points between backbones, since there are

now multiple backbones. Addresses: 32 bits, presently, which is 4.295 Gaddresses, which is a lot, but not enough. Looking ahead, IPv6 (currently we are at IPv4) plans 128-bit addresses, which is 340.3x1036, or enough for an address for every atom on the whole planet, including all life forms. XML: next generation of HTML. Making the Web Go Faster Faster links are the main step. Other steps: better compression; more intelligent software; caching

(which leads to cookies); ActiveX or Flash with Java beans Intranet: very common within companies; utilizes full TCP/IP protocols and web browsers, but is isolated from all other networks. Firewall: a server that sits between a LAN and a WAN to provide security and hide LAN computers from the WAN. VPN (Virtual Private Network): only appropriately encrypted packets leave or can enter; set up at the interfaces between corporate/company and the Internet. Provides significantly greater security. Network Security Plaintext and cipher: Mathematically operate (multiply or other more complex operation) on a plaintext

and you get the cipher; extremely hard to reverse without knowing the exact way it was encrypted. Very easy to do in hardware or software. Secret key: requires secure exchange of the key, but is very secure. DES (Data Encryption Standard) is the main one here. Public key/private key: public key that all can use to encrypt, but cannot be used to decrypt. Private key

needed for decrypting. Thus all who wish to send to you may encrypt for your eyes only, and the data thus encrypted can only be decrypted using your private key, which you do not release. Pioneers Rivest, Shamir and Adleman (RSA) started company now strongest in this market. PGP (Pretty Good Privacy) combines these to allow faster en/de cryption than public key allows. 128-bit encryption: @100 T possibilities/sec = 108 P years (x 1015).


Digital Signatures Combining a digital signature (using public key encryption to verify the identity of the sender) with a digital envelope and a digital certificate or ID allows terrific security. Biometrics are very helpful, but can also be captured and replicated. Conclusion: The Next Stages of Computing (pages 451-463) The State of the Foundation Hardware the great enabler Software major challenges, but also major progress. Windows 2000: 25M lines of code! Networks a connection for every home, store, kiosk, appliance, etc. Four Emerging Technologies 4G Cellular who needs 10 M bps for a phone call (actually only needs about 30k bps)? VOIP and video, TV over IP Wow! Digital TV, radio Piconets Seven Challenges to the Pervasive Future

1. Lithography 2. Portable power (battery limitations) 3. Software reliability 4. Network security 5. The last mile 6. Standards theyre both good and bad! 7. Human factors you know its been successful when the technology is no longer noticed, and its

use becomes widespread. Electricity is a great example here.

-END-

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Terms - memorize these - IT 318it318.groups.et.byu.net/Lecture-2014.pdf · Terms - memorize these Term Units Unit ... Frequency Hertz Hz f Cycles/sec ... femto f 10-15 Peta P 1015