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Electronic Materials are what you find inside
the components making up electronic products. They
consist of some stuff that you cannot easily exchange with something else - not even in principle - without losing the function.
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What you can change easily for example, is
the material for the box, the housing. Use Al instead of plastic or vice versa for your
video recorder - it would still work, needing at most some minor adjustments. |
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You also may change (in principle) the metal for real wires. Using Au,
Ag, or Al instead of - let's say - Cu,
makes little difference for the function. |
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But exchange any material in a "chip"
(i.e. in an integrated circuit) with something else (even allowing for minor adjustments)
- and that definitely will be the end of your product. |
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Let's look at some typical products or product groups that contain electronic
materials: |
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Electronics in general (Computer, TV, Radio, Radar, Microwave,
...). |
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Flat panel displays (FPD). |
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Micromechanics and Microsystems
(MEMS). |
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Solar cells. |
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Lasers (in particular semiconductor Lasers). |
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Batteries, Accumulators; energy storage
systems in general. |
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Sensors, in particular solid state sensors, that convert whatever they sense
directly into a current or a voltage. |
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Fuel Cells. |
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Magnetic Memories. |
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Looking at Components |
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Consider, e.g., a laptop or notebook
in more detail. If you take it apart, you find the "high tech" stuff: |
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Any number of chips, i.e. integrated circuits. |
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Some quartz oscillators. |
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A hard disc, i.e. a magnetic memory for the bulk memory. |
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A reading head for the hard disc that uses the "giant
magnetoresistance effect" |
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A CD
ROM, i.e. an optical
memory and a semiconductor Laser |
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A flat-panel display (FPD) using "liqiud crystals",
whichis pretty big as a single component, but cannot be subdivided in smaller pieces. |
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But there is also "low tech" - or so it seems: |
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Capacitors and inductors. |
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Switches, connectors, the keyboard as a unit. |
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Insulation. |
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Mechanical stuff like the disk drive, but also the housing. |
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Some components betray their key material in their name ("quartz"
oscillator) or by common knowledge (who, besides some so-called intellectuals, does not know that the word "chip"
is almost a synonym for Silicon?), but for most components we have to look deeper - we must open them up (which will almost
always destroy them). What do we find? |
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Electronic Materials |
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Lets open up a chip. We find |
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Packaging material - either some polymer
blend or ceramics. |
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A "chip" mostly consisting of Si, but interlaced in an intricate pattern with other materials
like P, B, As, SiO2, Si3N4, MoSi2,
W, TiN, Al, Cu.... |
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A lead frame - the little pins sticking out of the package - made of some
metal alloys. |
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Tiny wires connecting the leads to the chip or some pretty sophisticated stuff doing this job. |
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Now open up the FPD. You will find many materials, the most suspicious beyond what we
already found in chips are: |
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Liquid crystals, some strange liquid stuff. |
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Amorphous Si. |
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Indium tin oxide
ITO, a transparent
electrode. |
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Plastic foils acting as polarizers. |
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A plastic (or glass) front and end plate. |
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Now lets look at the Laser coming with the CD drive : |
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You find a complex mix of GaAs, GaAlAs, some other elements, as well as wires and packaging
materials. |
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And all of this is quite different from what you find in the Si chips! |
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Soon you would find GaN in your Laser diode - and the capacity of your CD memory will quadruple! |
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We could continue this, but by now you got the idea: |
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Progress in Electronic and Communication Technology is driven by
Progress in Material Science
(and almost nothing else) |
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© H. Föll (Electronic Materials - Script)
