Browse Prior Art Database

Wafer Orienting Bernoulli Head

IP.com Disclosure Number: IPCOM000080373D
Original Publication Date: 1973-Dec-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Ananthakrishnan, RB: AUTHOR [+2]

Abstract

This Bernoulli head lifts a silicon wafer from above without touching the wafer surface and carries the wafer to a measurement station. During the carry mode, the wafer is rotated to a desired position.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Wafer Orienting Bernoulli Head

This Bernoulli head lifts a silicon wafer from above without touching the wafer surface and carries the wafer to a measurement station. During the carry mode, the wafer is rotated to a desired position.

The head 10 operates on the Bernoulli principle. Basically, jets of air are directed onto the wafer 12 at relatively high velocity to create a low-pressure region. This pressure being lower than atmospheric pressure, will cause the wafer 12 to lift towards the high-velocity source. The angled jets of air from the head 10 have a two-component force vector. One component is the lift component and the other is the directional component. The air passages 14 supplying the air jets are symmetrically balanced in six equal 60 degrees sections.

One position contains a smaller air passage 16 perpendicular to the radius of the wafer 12, which produces the tangential force component of the system. The reduced size of this opening upsets the directional components, with the equilibrium of directional forces being directed towards the orienting pin 20. The rotation jet 16 provides pulsed air to prevent acceleration of the wafer 12. The head 10 includes a lower plate 22 which contains the air passages 14 and 16. A pin 20 to which the notch 24 of the wafer is to hook is provided, and a guide pad 26 is provided to prevent the wafer 12 from spinning off the head 10.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]