2D X-Ray Inspection With Materials and Thickness Identification
A technology has been developed that, instead of simply measuring the total absorption of the X-ray beam, enables changes in the beam energy to be resolved.
Analysis Lab programs cover topics including:
Corrosion, Contamination, Data Acquisition, ESD and EOS, Inspection, Measurement, Profiling, Reliability, R&D, RFID, Solder Defects, Test, Tombstoning, X-ray and more.
Paul D. Scott, Ph.D.
Sedgefield, County Durham, UK
Evstatin Krastev, Ph.D., P.E.
Aylesbury, Buckinghamshire, UK
X-ray inspection systems are key tools for quality control, yield enhancement, and failure analysis of PCBs and semiconductor devices. In many cases, these capable tools provide the only non-destructive techniques for inspection of electronic components. There have been significant improvements in the X-ray inspection capabilities (both 2D and 3D) in the last several years. In this paper we report a new development that permits material and thickness information to be obtained via 2D X-ray inspection. While absorption contrast X-ray imaging is a very powerful inspection technique, it does not exploit all of the information present within the X-ray beam transmitted through a sample.
A new technology has been recently developed that, instead of simply measuring the total absorption of the X-ray beam, also enables changes in the beam energy to be resolved. This allows the effects of thickness and density to be decoupled, enabling both to be determined. This quantitative composition and thickness information can then be used to provide new levels of insight in PCB and semiconductor inspection, potentially leading the way to a new generation of X-ray inspection technology.
It is quite straightforward to accommodate this technology in an existing 2D X-ray (2DX) inspection system. Advanced software algorithms need to be incorporated and an intuitive user interface is provided. We present an overview of this new technology and give examples of other industries where this technology is being adopted, as well as example applications for the PCB and semiconductor industries. Key words: X-ray inspection, 2DX, 3D CT, AXI, Multi Absorption Plate, MAP, PCB inspection, material identification, thickness identification, profilometry, automated X-ray inspection, X-ray technology, PCT, CT without cutting, Large Board CT, non-destructive
We have presented a newly-developed technology that enhances the capabilities of 2D X-ray inspection for the
electronic industry. It provides additional material type and thickness information that has not been available to date in 2DX inspection.
The key to the technology is a physical structure known as the Multi Absorption Plate or MAP. This is coupled with sophisticated machine learning algorithms and training methodologies. Several cases were discussed to demonstrate applications in the electronics, security and food safety industries.
Below are key enhancements gained through MAP technology:
Enables users to visualise samples in a new way by looking at a materials image as well as a standard grey-scale absorption contrast image.
Detection of defects and impurities that are invisible in the regular 2DX grey-scale image.
Quantitative thickness and material information returned to the user.
Can be fitted to most flat panel detectors.
Near real-time operation.
Ability to adapt algorithms for automated inspection applications.
The authors are very interested in discussions, ideas and collaborations within the electronics industry in order to focus the developments and take full advantage of this new, exciting technology.
Initially Published in the SMTA Proceedings
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