Sciencemadness Discussion Board

electrostatic " Chucks "

moose sniffer - 4-9-2005 at 13:15

I have been told that there are electrostatic " Chucks " that are used to affix silicon wafers without
face contact in semiconductor manufacturing.

It has two parallel serpetine conductors embedded in a silicone or other insulaters
that is charged with high voltage which acts like an electrostatic analog of a
megnet.

Thus these two fields act to attract things that are even electricaly conductive,
but are not magnetic.

I feel like a retards, because i dont get how this works. can somebody enlighten me?:(

12AX7 - 4-9-2005 at 17:27

Opposites attract, simple as that. The insulator keeps the charges from countering.

To do it, you have to prevent induction so you can't just place the disc on the platten and charge it, or charge it then bring the disc near; you need to ground the plate while charging. So it's not hands free...

Any dielectric will work, higher breakdown voltage the better (more electric field, proportional to force!).

Twospoons - 5-9-2005 at 16:02

The same trick was used on the old pen plotters, to hold the paper in place.

Lambda - 5-9-2005 at 19:03

A Laser printer or Photo copier, uses this principle to attract toner powder to the drum, before it is rolled out onto the paper sheet. The part of this static electricity charged drum that is hit by the copied objects recoiled laser beam, loses all, or part of it's charge. The dark or grey spots remain fully or partly charged, and thus attract the toner powder. The heater (oven) then bakes/melts (fixation process) this resin powder onto the paper sheet.

praseodym - 6-9-2005 at 22:35

If i am not wrong, some car companies also make use of this method to spray paint on their cars...

12AX7 - 7-9-2005 at 07:27

See powder coating.

Tim