Applied Science - Technology (2B)
Lab 

   
OBJECTIVES:
  • Investigating computer technology.
  • Observing computer chips.

VOCABULARY:

  • chip
  • computers
  • silicon
  • technology
MATERIALS:

Students look at a microchip under the microscope.

BACKGROUND:

Children are very familiar with the computer, but many do not know how computers operate. In this lab, we want the students to look at one of the basic components of a computer, the computer chip.
   
The manufacture of silicon that is used to make chips is a threefold process. The first phase uses crushed quartzite (SiO2) and coke. It is heated until a commercial grade of silicon is made. The second phase is when commercial grade silicon is mixed with methyl chloride to create different types of silicones. The third phase takes the silicones and hydrogen which then produces 99.9% pure silicon. It is this silicon that is used in the chip making industry.

When hot, silicon becomes liquidized, it can be poured into molds. Usually long cylinders are made of pure silicon, then cut into thin wafers. The wafer is then "fitted" with a plastic template and submerged into a vat of acid. This etches the exposed part of the template, which then acts as tiny electrical circuits.

PROCEDURE:
  1. Ask students to list people or things that use a computer:

    a.  secretaries - word processing
    b.  scientists - data
    c.  airplane pilots - navigate
    d.  check-out stand - read price of food
    e.  bankers - read money reports
    f.   teachers - education
      
  2. Hopefully there is a computer that you can show your students. Point out the parts of the computer. Ask students what kind of energy is needed to make a computer work? "Electricity." Can computers work without electricity? "No!"
      
  3. Show them a piece of silicon which is a human-made element derived from quartz. Microchips are made mainly from purified silicon. If you have a piece of quartz, show it to students.  Quartz is made out of silicon plus oxygen.  It is used to make pure silicon.   The students do not need to know the entire process, but just so students can see and feel a piece of the material that makes computer is the important part.
      
  4. Instruct students to take the chip out of its container. Put it carefully under the Swift GH microscope and have them observe the microchip. On the chip, students are looking at the etchings. The lines are really a miniature circuit board. Students should sketch what they see on the lab sheet.
      
  5. Show students a circuit board that you may have gotten from a broken computer or appliance. The circuit board has many chips that are laid in what is called "caterpillars." The caterpillars are the black rectangular objects that have "legs" that are hooked to the circuit board. The chips are in between the black layers.
       
    Hopefully now, students will know how "Silicon Valley" in California gets its name!

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