Warren's Home Page
The Job
Making microprocessors demands that the people who
make them are as clean as the environment in which they
work. This is because a microprocessor - itself about the
size of a dime - contains millions of microscopic
transistors. The tiniest speck of dust to a chip would be like
a Godzilla - sized footprint to us, and it could ruin
thousands of transistors.
HOW CLEAN IS CLEAN?
The ultra - clean environment where microprocessors are
made is called a cleanroom. Class one cleanrooms are the
cleanest of all with no more than one speck of dust per
cubic foot.
HOW SMALL IS SMALL?
Imagine a boulder large enough to cause traffic jams all
over a big city. If one fell on Times Square in New York, it
could stop traffic on many streets around it, and eventually
stop traffic on adjacent streets through a ripple effect. The
same is true of a speck of dust landing in the middle of a
microprocessor. Just one microscopic particle can obstruct
the chip's pathways, ultimately rendering it unusable.
How clean is a room containing only one speck of dust per cubic foot?
Cleanrooms are 10,000 times cleaner than a hospital operating room. It
takes an incredible amount of technology to achieve and maintain such
cleanliness. Huge air filtration systems completely change the air in
cleanrooms about ten times per minute, reducing the chance that there
are airborne particles that might harm the chips.
Suiting up is a rather involved process, not to mention that every time
you enter and leave a cleanroom you have to repeat the steps below:
1.Store personal items.
If you´ve never done it before,
putting on a bunny suit can
take 30 to 40 minutes. The Nortel
pros can do it in five.
At Nortel the suits come in any colour as long as its white.....
Getting into the lab is the first problem, troubleshooting the equipment inside is another story.
This enlarged image
of a grain of salt on a
piece of a
microprocessor
should give you an
idea of how small
and complex a
microprocessor really
is. 
Keeping the environment clean, however, is only half of the story. What
about the people who work in the cleanrooms? Each of the thousands
of people who work in Nortel cleanrooms wear special uniforms called
"bunny suits" to protect the chips from human particles such as skin
flakes or hairs. A bunny suit is made from a unique non-linting,
anti-static fabric and is worn over street clothes.
2.Discard any gum, candy,
etc.
3.Remove any makeup with
cleanroom soap and water.
4.Take a drink of water to
wash away throat particles.
5.Cover any facial hair with a
surgical mask or
beard/mustache lint-free
cover.
6.Put on a lint-free head
cover.
7.Clean shoes with shoe
cleaners.
8.Put shoe cover on over
shoes.
9.Clean any small,
pre-approved items to be
taken inside.
10.Pick up booties.
11.Sit on "dirty" side of bench.
12.Put on one bootie (over
plastic shoe cover).
13.Swing bootied foot to
"clean" side of bench.
14.Put on other bootie on
"dirty" side.
15.Swing bootied foot to
"clean" side.
16.Enter main gowning room.
17.Set aside badge, pager, and
any other items to be taken
inside.
18.Put on nylon gowning
gloves.
19.Obtain bunny suit and belt
from hanger.
20.Put on bunny suit without
letting it touch the floor.
21.Put on belt.
22.Tuck bunny suit pant legs
into booties.
23.Fasten snaps at top of
booties.
24.Attach filter unit to belt.
25.Attach battery pack to belt.
26.Plug filter unit into battery
pack.
27.Obtain helmet, safety
glasses, and ID badge from
rack.
28.Put on helmet.
29.Tuck helmet skirt into
bunny suit.
30.Zip up bunny suit at
shoulders.
31.Attach helmet hose to filter
unit.
32.Tighten knob at back of
helmet.
33.Put on ID badge.
34.Put on pager.
35.Put on safety glasses.
36.Obtain disposable scope
shield.
37.Remove protective covering
from both sides of scope
shield.
38.Undo front helmet snaps.
39.Attach face shield to
helmet.
40.Re-snap front helmet snaps.
41.Examine attire in mirror.
42.Put on latex gloves.
43.Enter the cleanroom.