​​Probe Mark Inspection and Classification​

In semiconductor manufacturing, before a wafer is sent to die preparation, each integrated circuit (IC) is tested for electrical continuity and functional defects using a probe card equipped with many microscopic electrical probes. These probes make contact with the wafer, leaving small marks on the die to indicate successful contact. While the presence of a probe mark confirms contact, manufacturers need to do more analysis to make sure that the pressure and alignment were correct. 

Probe marks must be clearly visible, centered, and consistent to verify accurate testing. Probes are delicate and costly; excessive pressure can lead to damage and degrade their performance over time, making probe mark inspection a critical step in wafer testing. 

For manufacturers, maintaining accurate probe marks is essential—not only to ensure test integrity, but also to extend the lifespan of expensive probe tools. Powered by Cognex AI, our advanced solutions analyze probe marks with precision, ensuring only valid marks pass inspection. This safeguards product quality and enhances operational efficiency. 

Traditional inspection systems are challenged by the complexity of probe mark testing. The small size, subtle contrast, and variable shape and placement of probe marks make them difficult to detect with rule-based vision systems. Marks affected by misalignment, excessive pressure, tool wear, or double hits can lead to misclassifications, false test results, and potential equipment damage.

​At the same time, ICs must be inspected for cosmetic molding defects – surface flaws like scratches, voids, flashes, or other surface defects that may compromise long-term chip reliability. These defects are often low contrast or faint, making them easy to miss during human inspection or with conventional tools.

​Cognex's high-resolution vision tools and classification software are specifically designed for high-speed, small-part inspection environments, delivering precise results with high magnification.​ 

​​AI-enabled Cognex In-Sight vision systems simplify and accelerate probe mark inspection by letting manufacturers effectively distinguish acceptable marks from true defects, while also identifying root causes such as pressure inconsistencies and misalignment.

​Trained on a diverse dataset of images, Cognex software leverages deep learning to classify probe marks with exceptional accuracy. It reliably differentiates between minor anomalies within tolerance and critical issues requiring attention, ensuring consistent and dependable results.

​With advanced high-resolution imaging, Cognex vision systems detect even the most challenging defects, including low-contrast, microscopic probe marks and subtle cosmetic flaws on molded surfaces. Real-time classification lets production teams quickly find problem areas and make immediate adjustments, reducing false rejects, minimizing rework, improving die yield and overall device reliability.

​Supported by a global network of Cognex experts and on-demand self-service resources, you gain the tools and assistance needed to ensure accurate and reliable semiconductor testing—ensuring only high-quality chips progress through the manufacturing process.