KEEP Kentucky Electronics Education Project

1
KEEP Kentucky Electronics Education Project

• Dr. Janet Lumpp - Electrical and Computer
  Engineering
• Dr. Kelly Bradley - Educational Policy Studies
  and Evaluation
• University of Kentucky
• July 2005

2
KEEP Objectives

• Educate teachers regarding
• Electronic assembly technologies
• Properties of electronic materials
• Develop curriculum materials
• Solicit industry partnerships
• Organize hands-on projects and fieldtrips
• Encourage young students to consider technical
  and engineering careers

3
KEEP Background

• Classroom activities
• Teacher workshops
• Independent implementations
• West Jessamine High School
• The Lexington School
• Lafayette High School
• Girls in Science - students and teachers
• KSTA PD Session - November 2005

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KET Partnership
CD-ROM Coming Soon

• Studio session
• Filmed cooking show circuit steps - Dec04
• Editing now
• SMC, Inc. - Electronic assembly process
• Filmed manufacturing equipment - June05
• Editing now
• NAVSEA Crane - PCB fabrication
• Filming to be scheduled after renovation

5
Electricity to Electronics

• Electricity and Magnetism
• Principles and definitions
• Circuit elements, symbols and diagrams
• Electronic Circuits
• Add semiconductor devices
• Physical size of components
• 2D and 3D locations and connections

6
Types of Components

• Through hole or Surface Mount
• Passive or Active

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Printed Circuit Boards

• PCB Printed Circuit Board
• Copper conductor
• Epoxy/Glass insulator
• Green coating solder mask
• Single or double sided copper
• Single or multiple layers
• Through holes vias
• Component leads
• Connect layers
• Plated with copper

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How to Solder

• Soldering iron heat source
• Heat copper ring and component lead
• Bring in solder wire
• Activate flux to clean oxides off of metal
  surfaces
• Solder alloy melts and wets clean metal surfaces
• Pull solder wire away from joint
• Remove soldering iron
• Coat soldering iron tip with solder to prevent
  oxidation between uses

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Project Steps

• Layout pattern drawn from schematic
• Print layout on Press-N-Peel paper
• Iron pattern on to clean copper PCB
• Soak off paper backing, repair lines
• Etch excess copper in sodium persulfate
• Remove remaining toner (etch resist)
• Drill through holes
• Insert components
• Hand solder

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Implementation Options

• Purchase or borrow tools
• Purchase circuit project kits
• Solder only
• Drill and Solder
• Full process
• On-going PD Workshops
• Science, math, technology teachers
• Core team in one school or district
• Develop instructional units

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Science Standards and KEEP

• SC-M-1.3.2 Heat energy moves in predictable ways,
  flowing from warmer objects to cooler ones, until
  both objects reach the same temperature.
• Soldering iron converts electrical energy to heat
  energy.
• Must make contact with cooler objects to transfer
  heat by conduction.
• The temperature of the iron is greater than the
  melting point of the solder.
• Solid-liquid-solid transformation at each solder
  joint.

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Science Standards and KEEP

• SC-M-1.3.1 Energy is a property of many
  substances and is associated with heat, light,
  electricity, and sound. Energy is transferred in
  many ways.
• SC-M-1.3.5 Electrical circuits provide a means of
  transferring electrical energy when heat, light,
  sound, and chemical changes are produced.
• Flashing LED Circuit - heat, light, electricity,
  chemical to electrical (battery) energy
  conversion
• Buzzer Circuit - heat, light, electricity, sound,
  chemical to electrical (battery) energy conversion

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Science Standards and KEEP

• SC-H-1.1.1 Matter is made of minute particles
  called atoms, and atoms are composed of even
  smaller components. The electric force between
  the nucleus and the electrons holds the atom
  together.
• SC-H-1.2.1 Atoms interact with each other by
  transferring or sharing outermost electrons.
  These outer electrons govern the chemical
  properties of the element.
• Electrons and chemical bonding determine which
  materials are conductors, insulators and
  semiconductors.
• All types of materials are needed in
  microelectronics.
• Different materials must bond without
  contamination.

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Science Standards and KEEP

• SC-H-1.3.1 Chemical reactions occur all around us
  and in every cell in our bodies. These reactions
  may release or consume energy. Rates of chemical
  reactions vary. Reaction rates depend on
  concentration, temperature, and properties of
  reactants. Catalysts speed up chemical reactions.
• Etching Copper - solution of sodium persulfate in
  water
• Solution is heated to increase the reaction rate.
• As copper is etched, the reaction rate slows
  (concentration).
• Catalyst can be added to increase the reaction
  rate again.

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Math Standards and KEEP

• MA-E-1.1.5 Multiple representations of numbers
  (e.g., drawings, manipulative, symbols)
• MA-M-1.1.6 Representation of numbers and
  operations in a variety of equivalent forms using
  models, diagrams, and symbols (e.g., number
  lines, 10 by 10 grids, rectangular arrays, number
  sentences)
• Resistor color code - colors represent numbers 0
  to 9
• Two digits and order of magnitude, 123 12 X 103
• Tolerance of ? 5 (gold) or 10 (silver)

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Resistor Color Codehttp//www.mechatronics.me.vt.
edu/VT84Construction/resistorcodes.html
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Science Standards and KEEP

• SC-H-3.5.5 Human beings live within the worlds
  ecosystems. Human activities can deliberately or
  inadvertently alter the dynamics in ecosystems.
  These activities can threaten current and future
  global stability and, if not addressed,
  ecosystems can be irreversibly affected.
• Science in Personal and Social Perspectives
  -describe the individuals roles and
  responsibilities in the following areas changes
  in populations, resources and environments
  including ecological crises and environmental
  issues, natural hazards, science and technology
  in society, and personal and societal issues
  about risks and benefits.
• Electronics manufacturing uses tremendous amounts
  of metals, acids, water, energy, etc.
• What are the safety issues for workers?
• What are the environmental issues?
• What are the economics of improving the
  manufacturing methods?

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Math, Science and KEEP

• Science as Inquiry
• Science and Technology
• Science in Personal and Social Perspective

• MA-E-1.1.4 Place value, expanded form, number
  magnitude (order, compare) to 100,000,000, and
  decimals through thousandths.

• Orders of magnitude in dimensions, memory,
  pixels, processor speed.
• Why is it that a new PC with 24 GB of RAM is
  not any bigger than an old PC with 24 MB of RAM,
  a 1000 times increase in memory?
• Why is it that a 10 MB hard drive used to be
  the size of a shoe box and now 40 GB fit in an
  iPod in your hand running on batteries?
• Why does the microprocessor in a new laptop PC
  run 5 times faster than an old laptop, but the
  batteries last longer in the new laptop?

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Math Standards and KEEP

• MA-H-2.1.1 Students will describe properties of
  and give examples of geometric transformations
  and apply geometric transformations
  (translations, rotations, reflections,
  dilations), with and without a coordinate plane,
  to both real-world and mathematical situations.
• MA-H-2.2.1 Students will perform transformations
  (reflections, translations, rotations, dilations)
  on figures.
• MA-H-2.2.2 Students will classify two-dimensional
  and three-dimensional geometric figures according
  to their characteristics such as lengths of
  sides angle measures and number of sides,
  faces, edges, and vertices. Students will
  describe the intersection of a plane with a
  three-dimensional geometric figure.
• Identify components by describing the three
  dimensional shapes of the packages and leads.
• Recognize components by their two dimensional
  projections as seen by visual alignment systems.
  Sophisticated vision systems see color and read
  labeling.
• XY Locations on a circuit board - placing
  components, dispensing dots of adhesive, wirebond
  pads around a chip

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Math Standards and KEEP

• MA-H-2.3.4 Students will understand how a change
  in one or more dimensions of a geometric shape
  affects perimeter, area, volume, or surface area.
• Area density percentage of board area occupied
  by components.
• Circuits are miniaturized by choosing smaller
  components and reducing the spacing between
  objects.
• Use layout software to compare alternative
  designs and calculate area density.

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Math Standards and KEEP

• MA-H-4.1.1 Students will understand the concept
  of a function and roles of independent and
  dependent variables.
• MA-H-4.1.4 Students will identify linear,
  quadratic, absolute value, and exponential
  functions from graphs and equations.
• MA-H-4.1.5 Students will apply direct and inverse
  variation to both real-world and mathematical
  problems.
• MA-H-4.3.2 Students will understand how formulas,
  tables, graphs, and equations of functions relate
  to each other.
• I-V (Current-Voltage) relationships for
  resistors, capacitors, inductors
• Series and parallel combinations of resistors,
  capacitors, inductors
• Current and voltage divider expressions for
  resistors
• 555 timer formulas

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I-V Relationships

• Resistors
• Ohms Law
• VIR

• Capacitors
• ic(t) dvc(t)/dt
• Inductors
• vL(t) diL(t)/dt

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Kirchoffs Laws

• Kirchoffs Voltage Law - KVL
• The sum of all voltages around a closed loop is
  zero.
• S Vn 0
• Kirchoffs Current Law - KCL
• The sum of all currents entering a node is zero.
• S In 0

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Series and Parallel

• Elements in series have the same current flowing
  through them.
• Elements in parallel have the same voltage across
  them.
• Series R, Series L, Parallel C
• Rs S Rn
• Parallel R, Parallel L, Series C
• 1/RP S 1/Rn
• Two R in parallel RP (R1R2)/(R1 R2)

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Current and Voltage Dividers

• Combine Ohms Law and Kirchoffs Laws to develop
  short cut formulas
• Voltage divider
• v1 v(R1/(R1R2))
• Current divider
• i1 i(R2/(R1R2))

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Capacitor Discharging and Charging

• DC (battery) sources
• Capacitor is initially charged to a voltage V0
• Discharging
• v(t) V0e-t/t
• t RC time constant
• Charging from V0 to Vs,
• Vs steady state
• v(t) Vs (V0-Vs) e-t/t
• If V0 0, v(t) Vs(1 - e-t/t)