X-ray inspection system – development of inspection software

Citation

(2005), "X-ray inspection system – development of inspection software", Aircraft Engineering and Aerospace Technology, Vol. 77 No. 2. https://doi.org/10.1108/aeat.2005.12777bab.012

X-ray inspection system – development of inspection software

X-ray inspection system – development of inspection software

Keywords: BAE Systems, Inspection, Software

International defence and aerospace giant, BAE Systems, has purchased a phoenix|X-ray pcbjanalyser from production automation specialist, Contax Ltd, to ensure the quality of their PCB production and work towards the IPC 7095 standard. This purchase has also led to the development of quality inspection software, Xe2, which provides automatic X-ray analysis of solder joints on surface mount devices.

BAE Systems produce high reliability products for civil avionics and defence applications. The PCBs manufactured are typically using Ball Grid Array devices for critical systems, such as control panels and head-up displays for military and civil aircraft. As the solder joints are not visible, an X-ray inspection system is required to verify that they conform to quality standards.

Previously, BAE Systems had outsourced the X-ray inspection, so it was not within the process lines. Following manufacture, the batch was inspected and verified. This has proven expensive and significantly increased the lead time in production. The Company was also looking towards the new, demanding, IPC 7095 standard.

“We wanted to take more control of our production, improve lead times and guarantee a very high quality build,” explained Paul Brockett, senior manufacturing engineer at BAE Systems. “We therefore decided to invest in our own X-ray system. This would enable us to verify the quality as we build, and make any corrections before a batch is produced.”

BAE Systems undertook a very thorough and detailed evaluation of six systems over a period of time. Its initial preference was for phoenix|X-ray, and after exhaustive testing, the pcbjanalyser continued to out-perform its rivals.

“The results from the test boards were consistently better from the phoenix|X-ray system, and we liked the fact that we could change the filaments quickly with no set up. It was basically plug and play,” commented Paul.

The phoenix|X-ray pcbjanalyser also had the potential for further enhancements. Paul continued, “We needed software that could automatically inspect the solder joints as we had experienced a level of voiding and needed to address this problem.”

Contax and phoenix|X-ray worked together to develop the Xe2 software. This automatically ascertains whether or not a physical joint is present, analyses the voiding, locates the voids and determines the level of wetting.

“The Xe2 software was exactly what we needed,” said Paul, “and we are now working with phoenix|X-ray to calibrate it further, so improving the base product.”

BAE Systems were impressed with a number of other features available with the phoenix|X-ray pcbjanalyser. For example, it offers a dual mode X-ray tube, with both microfocus X-ray down to 5 µm and nanofocus that measures to within one or 2 µm.

Continued Paul Brockett, “We have put together a technology road map and plan to work on smaller devices that will require higher resolution inspection. We also wanted to make sure that any images were of the highest quality, so we have opted for a digital image chain rather than the standard CRT, to provide us with better contrast and clarity”.

Other facilities include the oblique view high magnification (OVHM) module, which provides oblique views of up to 61° of any position of the solder joint. Whilst an anti-collision system using infrared technology automatically stops the machine if there is any danger of product damage during inspection.

“The phoenix|X-ray system has lived up to our very high expectations,” said Paul. “It will improve our process control, help drive our continuous improvement, which in turn will lead to the IPC standards. We also have a host of features – such as the Xe2software – that were previously unavailable”.

“Contax and phoenix|X-ray have worked very hard on this project, and it is to their credit that the installation has been so successful. We have worked with Contax for many years now, and it is an on-going partnership that has gone from strength to strength. We have always been able to rely on them, and they have become a tried and trusted supplier,” he concluded.

Details available from: Contax Ltd. Tel: +44 (0)1489 885808.