Spinning plate for substrates

Details Spinning plate for substrates Spinning plate for substrates

1994-02-07

1995-09-26

Bishop, Steven C.

Chucks or sockets

Vacuum

269 21, 451289, 451388, B23Q 308, B25B 1100

Patent

active

054529050

DESCRIPTION:

BRIEF SUMMARY
The invention concerns a spinning plate for substrates.
Substrates have one or two facing active surfaces which frequently must not be touched and contaminated. The substrates are handled by their surrounding edges projecting from the active surfaces. For treating the active surfaces with flowable substances, such as resists, cleaning agents, or the like, the substrates are placed on spinning plates rotating at high speed so that the flowable substance is uniformly distributed on the active surface and excess substance is spun off.
There are essentially three types of substrate spinning devices. In the first type of device, the substrate is arranged on a turnstile with eight receiving pins at its ends. The second type of device comprises a spinning plate with a circular plate (disk) on the surface of which support blocks are positioned. The support blocks have a horizontal bearing surface, supporting the edge of the substrate, and a vertical support face which radially secures the substrate against the centrifugal forces occurring. Such a device is described, for example, in the Patent Abstracts of Japan, JP-A-57 121 227. The third type of device comprises a spinning plate with a disk having a milled recess for accommodating the substrate. The substrate is lowered into and lifted from this milled recess by means of pins.
With all of these known spinning plates, the substrate is loosely arranged thereon. On the spinning plate, the substrate is merely retained by gravity and radially secured against centrifugal forces. Therefore, it may happen during the spinning process that the substrate becomes detached from the spinning plate and is spun off by the high centrifugal forces. This leads to destruction of the substrate, which may be very expensive, for example, with ceramic substrates, and to damage of the equipment.
A special device for fixing the substrate on a spinning plate is known from the Patent Abstracts of Japan JP-A 63 258 667. With this device, the substrate is pressed against the spinning plate at reduced pressure and retained there during spinning.
It is the object of the invention to provide a spinning plate for substrates on which the substrates are automatically centered and reliably retained during spinning.
For a spinning plate of the previously described kind, this object is accomplished according to the invention by the features of the characterizing part of claim 1.
With the known spinning plates, the substrate is accommodated with a radial play necessary for its insertion and removal, without being accurately centered. According to the invention however the substrate is accurately centered by being forced against defined centering stops by means of a pressure element. As square, rectangular or multi-edge substrates and circular substrates are accurately aligned relative to the centering stops and thus to the rotational axis of the spinning plate by means of defined reference edges and defined reference points, respectively, they may be photooptically scanned and tested or otherwise treated on the spinning plate.
The substrate is preferably centered by the pressure element with the aid of the vacuum applied through the drive shaft, so that for actuating and controlling the pressure element no high mechanical forces have to be applied to the rotating plate. The pressure element is preferably actuated by a membrane to which a vacuum is applied and by an actuating means. A throttle means ensures that the vacuum applied through the vacuum bore of the drive shaft initially actuates the pressure element for centering the substrate and then, after a particular delay, causes the substrate to be sucked against the disk with high force.
With the spinning plate according to the invention, the substrate, say, a ceramic substrate, instead of being loosely arranged on the circular plate and supported only radially, is sucked against the circular plate by a vacuum so that it is retained by the support blocks and not spun off. To ensure that the substrate is reliably sucked against the circular plate, t

REFERENCES:
patent: 1130679 (1915-03-01), Staunton
patent: 1457247 (1923-05-01), Hreschede et al.
patent: 3389682 (1968-06-01), Gardner
patent: 4659094 (1987-04-01), Leonov
patent: 4784377 (1988-11-01), Woodward
patent: 5171031 (1992-12-01), Nishiyama
"Centering Chuck System", by H. A. Appenzeller et al., in IBM Technical Disclosure Bulletin, vol. 21, No. 7 (Dec. 1978), pp. 2770-2771.

Affiliated with

Also associated with

Rating

Spinning plate for substrates does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Spinning plate for substrates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spinning plate for substrates will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1548685