CP alignment (Characteristic point alignment) is the function which recognizes the target based on its profile and conducts matching. This is effective when alignment is difficult by the conventional method which recognizes the target based on the contrast.

Examples

Example 1 : Workpiece in which sufficient contrast cannot be obtained by light level adjustment

(Reference photographs: Si 300 µm thick + Si 300 µm thick bonded wafer)

• Currently

  

• CP alignment

  

Example 2 : Workpiece with many scratches and foreign matter on the target

(Reference photographs: Terminal on a package substrate)

• Currently

  

• CP alignment

  

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<Caution>
As shown below, depending on the condition of the scratches and foreign matter, there is a case where alignment may be unstable.

• Target can be recognized

  

• There is a scratch/foreign matter on the target profile

  

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