Optical Character Verification on Wafers (OCV)

Task position:

Marking products with plain writing is widely used in industry. But partly it is not possible for the human eye to read the scriptures. Be it a reflective surface, poor marking systems or simply the size of the font. Especially in the semiconductor industry it is difficult to do justice to the human eye and to provide small components with large characters. The biggest problem is if all these circumstances apply. For this situation, an image processing system is to be created that replaces the human eye and reads plain text on wafers so that consistent quality can be guaranteed.


With the help of a PC-supported image processing system, a solution was integrated at the customer’s site that makes this possible. The software tools of Activ Vision Tools served as a basis to solve this problem. By using a special illumination a homogeneous surface on the wafer is created. This surface is recorded with a CCD camera. The software reads the plain text on the wafer and compares the character string with an existing database (Optical Character Verification -> OCV). This leads to the timely sorting out of missing parts that would otherwise have been further refined.

Customer benefits:

The built-in solution allows the customer to save important resources and use them at other workstations. The time required for shift changes is eliminated and production time is improved.