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12 SMT Magazine • June 2017 by Stephen Las Marias I-Connect007 There is a critical need for inspection in the PCB assembly industry as the trend towards miniaturization of electronics systems and de- vices continue—on top of increasing require- ments for reliability and quality. For this month's issue of SMT Magazine, we spoke with Mark McMeen, vice president of engineering at STI Electronics, to know more about the inspection challenges and require- ments from an EMS provider's standpoint. We also talked with Jean-Marc Peallat, vice presi- dent of global sales at Vi TECHNOLOGY, to find out, from a supplier's perspective, how they are looking at these challenges and addressing them through their product development efforts. According to McMeen, the real challenge is being able to verify the solder fillets on very fine pitch QFNs and LGA parts. He said that's both done by utilizing the co-planarity of the part as well as being able to get a 3D viewing of the sol- der fillet on the side of the QFN and LGA. "One of the challenges in inspection is the miniaturization of the devices and compo- 3D: Towards Better Inspection Capability nents," said Peallat. "Joints are getting small- er, fine pitch are getting denser; this trend be- came a challenge for all our inspection types. Embedding 3D technologies in inspection sys- tems, and lately for the components inspection, is a solution to improve the quality and reliabil- ity of the tests." Peallat explained that most of the 3D sys- tems are using a top-down camera with projec- tors from the side. "I would say that that covers probably 95–98% of the vendors. In that case, systems are dependent on the top-down view from the camera. Some are using angled cam- eras, and one of the challenges is the calibra- tion of the optics. Combining top-down cam- eras and angled cameras is a real challenge with no simple solution when PCB warpage is impor- tant." According to Peallat, all these are common problems for all automated inspection vendors. "The other way to approach these process chal- lenges is to use a global approach of inspection in your line. If you look at the QFN joint qual- ity, it's a combination of what you have done at the print process and what you have done at component placement, not only individual, FEATU RE

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