EC Vacuum Chucks - O-Ring Design

These vacuum chucks are used with the PWM32 Spinner Series and the EC101/PM101 Spinner Series. The o-ring surface holds glass, quartz, ceramic and metal substrates. O-ring chucks seal to the substrate better than flat surface chucks, and give greater resistance to torque slippage. Typically O-ring chucks are not recommended for thin fragile substrates, such as silicon wafers. The O-ring seal projects above the chuck surface and the powerful vacuum will pull the substrate inside the O-ring area with sufficient force to significantly deform the substrate, and perhaps break it if it is brittle or has flaws around the edge. Flat surface chucks should be used for such substrates. For extremely thin or flexible substrates, special chucks and other techniques may be required. The shaft size is 3/8".

When using flat-surface, or o-ring type chucks, the substrate should overhang the chuck by 1/4" or more, to prevent fluid reaching the surface of the chuck. If fluid reaches the substrate/chuck interface, capillary forces will wick the fluid between the substrate and chuck, thereby fouling the backside of the substrate and the surface of the chuck. The flat-surface and o-ring chucks are usually provided with a plastic disc mounted below the surface of the chuck, with a larger diameter than the substrate. This disc provides a visual alignment aid to help center the substrate on the chuck. The disc also helps protect the backside overhang of the substrate from aerosol particle contamination during the spinning operation. Some flat surface and o-ring chucks are designed as "raised center" chucks, meaning the alignment disc is a machined part of the chuck. See the section on "raised center" vacuum chucks for this type.

The recommended vacuum is 23 "/Hg or more. HRI spinner interlocks are typically set at the factory to operate at about 17 "/Hg, and drop out approximately 1-1/2 "/Hg below the operate point. 23"/Hg or more provides for quickly passing through the operate point, and therefore provides a quick consistent response. The interlock set-point is adjustable, and can be adjusted to a much lower level if necessary, for thin fragile substrates. An accessory vacuum regulator may be required to operate at a consistent vacuum, lower than the source.

Features:

• O-Ring Substrate-to-Chuck Seal
• O-Ring Chuck-to-Shaft Seal
• Maximum Vacuum Holding Capacity

The chart below shows a variety of o-ring chuck sizes and materials. We have or can custom design chucks of many other sizes and possibly other materials upon request.

Select Below for Information on All Chucks