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Original Publication Date: 1999-Sep-01
Included in the Prior Art Database: 2002-Sep-04
Document File: 1 page(s) / 70K

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Peter Yu: AUTHOR [+3]


The non-contact roller is a new modified struc- ture of a wafer load roller. The conventional roller is to be changed to avoid the scratching dies during semi-conductor production. This non-contact roller significantly reduces the occurrence of scratches on dies and increases output.

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Developments Technical 0 M MOTOROLA


by Peter Yu, L. J. Zhang and Qun Zhang

spring. When they are rolling, the rollers move a wafer frame in or out between them. Because the upper roller is cylindrical with a consistent diameter throughout its length, any particulate with a diame- ter which is larger than the gap between the up roller and the surface of the wafer, will be pressed onto the surface of the wafer and this causes scratches on the wafer. Consequently, dies that make up the wafer have scratches.

  Figure 2 shows a new non-contact roller where the upper roller is a step roller with different diame- ters along its length. The middle part has a smaller diameter relative to the two side parts which have the same diameter as the conventional roller. There is a bevel between the smaller parts and the middle part to insure that the wafer frame is moved smooth- ly. The axial length of the smaller part is longer than the diameter of the wafer on the wafer frame. When a wafer frame is moved between the upper and lower rollers, the front part of the wafer frame will be pressed and then moved forward by the mid- dle part of the upper roller. As the wafer frame is transported between the upper and lower rollers, the two side parts of the upper roller will continue to transport the wafer frame.

   Advantageously, there is now a bigger gap between the upper roller and the surface of the wafer than with the conventional roller,...