US 8,553,968 B1 · Using optical character recognition augmented by an error correction code to detect serial numbers written on a wafer

Abstract

A serial number detector is disclosed for detecting an encoded serial number written on a wafer. A scanner scans the wafer to generate a raster image representing the encoded serial number, and an optical character recognition (OCR) system detects a detected serial number comprising a plurality of detected data characters and a plurality of detected redundancy characters. A character-to-binary converter converts the detected data characters and the detected redundancy characters into codeword symbols. A syndrome generator generates a plurality of error syndromes in response to the codeword symbols, and an error corrector, responsive to the error syndromes, detects and corrects errors in the codeword symbols.

Claims6

Dependent claims

A method of writing a serial number on a wafer, the serial number comprising a plurality of data characters and a plurality of redundancy characters, the method comprising:

during a first stage, writing a first subset of the data characters together with a first subset of the redundancy characters on the wafer;
and
during a second stage after the first stage, writing a second subset of the data characters together with a second subset of the redundancy characters on the wafer.

Dependencies are inferred from the claim text.

Using optical character recognition augmented by an error correction code to detect serial numbers written on a wafer

Life of this patent

Using optical character recognition augmented by an error correction code to detect serial numbers written on a wafer

Life of this patent

Abstract

Claims6