As electronic assemblies become more compact and performance demands rise, wire bonding has grown increasingly complex. Industries such as automotive electronics and 5G communications now rely on ultrathin wires, finer pitches, and higher power capacities. These advances place new pressure on inspection processes to ensure absolute reliability and detect defects that could compromise safety or performance.
Traditional inspection approaches are no longer adequate. Electrical testing, for example, cannot verify whether multiple bonds are fully intact or determine the integrity of adhesive contact surfaces. Likewise, conventional 2D optical inspection systems lack height information, making it impossible to assess critical dimensions such as loop height, wedge elevation, wire clearance, or exact wire length.
Some manufacturers have attempted to adapt 3D inspection technologies used in SMT, but these are limited. Reflective, rounded bond wires, especially those under 300 µm, do not reflect sufficient usable data with systems originally designed for flat SMD components. As a result, key defects and dimensional inaccuracies often go undetected.
Recognising this gap, Viscom has developed a new 3D wire bond inspection solution tailored specifically to the unique challenges of wire bonding. The system incorporates a custom lighting concept, a proprietary camera setup, and a high-speed 3D imaging method.
At the core is a dome-style illumination system that combines reflected-light and dark-field techniques. This enables accurate imaging of shiny, slender wires, including those as thin as 15-20 µm. The custom camera provides 25-megapixel resolution and a high data transfer rate, which improves image quality and reduces false alarms. For 3D reconstruction, the system rapidly captures a stack of high-resolution 2D images and calculates the height profile using both CPU and GPU processing. This parallel processing enables full 3D inspection in-line without slowing production.
The platform accommodates various materials such as aluminium, copper, gold, silver, and ribbon or thick wire formats. Inspection covers bond positions, wire routing, dies, and component placement, while inspection programs can be created offline to avoid production interruptions.
A built-in classification and statistical process control station adds another layer of value. Defect candidates can be reviewed and categorised, and trend analysis tools help identify recurring issues. Typical findings include misaligned die attachments, missing or malformed balls or wedges, wire breaks, pinched routes, and incorrect spacing or loop shapes. The system can also detect changes caused by tool wear, contamination, or parameter shifts after maintenance.
One of the major breakthroughs is the ability to measure true wire and wedge heights. Minimum clearances, loop elevations, and precise wire lengths can now be verified, which is especially beneficial in tightly packed assemblies. Even wafer indentation depth in ribbon bonds can be fully assessed – something that was previously impossible to perform in-line.
By combining high-resolution 2D imagery with accurate 3D data, the system significantly reduces false calls, while improving inspection speed. This hybrid approach ensures that complex assemblies can be inspected thoroughly and efficiently, supporting better quality control and more stable production processes.
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