Consistently decode wafer ID marks for reliable tracking of wafers prior to the dicing process
Wafers have laser-marked ID numbers that are placed onto a small area of the silicon disk. These codes are either alphanumeric characters or Data Matrix codes and are used to trace wafers through front-end processes until they are diced. A wafer ID may degrade during various masking, etching, and photolithographic processes, becoming difficult to decode due to the reflective background of the wafer.
Cognex In-Sight 1740 series wafer readers feature advanced algorithms developed specifically for wafer identification, providing both optical character recognition (OCR) and two-dimensional barcode capabilities before dicing the wafer. These wafer readers use integrated, adaptable lighting and image processing to provide optimal image formation for a variety of marking methods, including alphanumeric and SEMI-T7 Data Matrix codes. The In-Sight 1740 automatically adapts to changes in the mark’s appearance caused by various process steps, thereby reducing no-reads, minimizing the need for machine assists, and maximizing machine uptime. The In-Sight 1740 ensures codes are read quickly and accurately enabling accurate wafer traceability.