Process
100%
INSPECTION
High-Speed Non-Destructive Ultrasonic Scanning Identifies Minute Defects in Specialty Metals and Alloys
H
igh purity metals and alloys such as aluminum, zinc, cobalt, copper, titanium, zirconium, molybdenum, magnesium, and stainless steel are the backbone of many industries, from electronics to aerospace, and medical devices. Due to the critical nature of many of the components made from these materials, high purity alloys should be highly consistent, with extremely low levels of impurities and contaminations. This is driving non-destructive inspection using Scanning Acoustic Microscopy (SAM) to identify small inclusions and other defects as small as 50-microns. Scanning Acoustic Microscopy (SAM) is widely accepted in the semiconductor industry as a failure analysis and reliability detection metrology technology. Now the same technology, with variations in instrumentation and adaption for different use cases, is being applied to high purity metals and alloys. The challenge, however, is performing 100% inspection at sufficient throughput speeds to remove materials with defects that do not meet strict quality requirements. As with other inspection systems, increasing scanning speed traditionally meant sacrificing scanning image resolution. Fortunately, recent advancements in SAM technology have significantly improved throughput speeds and defect detectability. “While a conventional 5 MHz sensor could take up to 45 minutes to inspect an 8–10-inch square or disc alloy, an advanced phased array with 64-128 sensors and innovative software to render the images reduces inspection time to five minutes with more granular detection of small impurities or defects,” says Hari Polu, President of OKOS,
34 | IMD
MARCH 2022
a Virginia-based manufacturer of SAM and industrial ultrasonic non-destructive (NDT) systems. OKOS is a wholly owned subsidiary of PVA TePla AG, Germany and offers both manual and automated inspection systems for flat panels, thin plates, circular discs, sputtering targets, and special alloys. By dramatically increasing inspection speed, Polu says the specialty metals industry is no longer limited to selective
