In Part I of this article, we asked test and inspection equipment providers for their perspectives on equipment evolution and contemporary challenges. In Part II, we ask what test and inspection customers want from their equipment, and look at examples of difficult test/inspection problems and how to solve them.
What’s most important to your customers?
“Getting value for their money; i.e. maximizing their testing dollars so they can demonstrate to their own management that detecting failures upstream at the board test stage reduces the cost of quality by reducing the incidence of failures downstream (system and the subsystem stage),” said Robert Boguski, president of test service provider Datest.
Programming software can also reduce costs by eliminating highly skilled/trained programmers. Omron’s EzTS easy teaching software simplifies initial programming generation to the point that line operators can create and fine-tune inspection programs.
“Manufacturers are relying on automated inspection equipment to streamline the manufacturing process and provide real-time root cause analysis of manufacturing defects,” said Brian D'Amico, president, Mirtec Corporation. The objective is to increase profitability by improving production yields and reducing costly rework.
Tobias Neubrand, Ph.D., product manager, 2D inspection at GE, Sensing & Inspecting Technologies, phoenix | x-ray, added that customers want easy-to-use X-ray equipment to ensure that quality standards are met. Defects must be clearly visible. Filters and automated image processing are often wanted as help for the operator. Fast set-up of inspection programs and results traceability are important for security-relevant applications. Read Neubrand's article on zero defects here: Can AXI Meet Zero Defect Quality Standards?
Paul Vere, managing director, Dage Precision Industries, a Nordson company, said that customers want a capable machine with user-friendly features and nanometer feature recognition in X-ray inspection. The return on investment (ROI) for such a piece of equipment is substantial, considering the full range of faults it can detect. Parito Lee, global marketing manager of CyberOptics Corporation added that good cost of ownership (COO) is about getting high-performance inspection at a lower cost, important to today’s customer regardless of manufacturing capacity or business nature. Equipment price erosion averages between 4 and 7% annually,
Steve Glass, RMD, said that XRF as a technology application for the electronics industry was very new back in July 2006, when the European Union’s RoHS directive was first implemented. By now, most end users have embraced XRF technology with open arms for detection of lead and other analysis. “Accuracy, precision, ease-of-use, COO, and safety are our key features/benefits. RMD has helped the pioneering effort for the advancement of XRF technologies that are applied to RoHS component screening in electronics. We are in the development stages for additional XRF technologies that go beyond just incoming RoHS inspection.”
“The most important thing to our customers,” said Bill Sinclair, CEO, Aries Electronics, “is delivery of a completed, custom
How were you able to solve a difficult problem for a customer?
“One board manufacturer suffered a high rate of functional test (FT) failures of high-end instrument boards manufactured in a high-mix/low-volume (HMLV) environment,” said Boguski. These boards were not designed for in-circuit testing, thus precluding ICT as a viable testing option. Datest engineers combined flying probe testing with 5DX inspection to maximize coverage and fault detection in a cost-effective manner. The combination of 5DX with flying probe raised fault coverage as a percentage of total nets on board to the 90+ percentile, solving the problem.
Speck of Omron gave this example: Automotive tier 1 suppliers have strict requirements to deliver zero defect goods to the next tier of operations. With up to 50 PCBs in most 2009 model year cars, board manufacturers support the auto industry’s need to find root causes of production problems to stay profitable. Omron helped automotive suppliers implement lean production improvement programs using Q-upNavi data mining software to analyze the raw data collected by AOI systems for guidance to correct machine performance and identify out-of-spec components. Typical results come from a line using AOI at three locations in the assembly process (post-paste-print, post-placement, and post-solder), where the inspection systems feed data to Q-upNavi. Faults are identified before a board moves to the next stage. With the use of AOI alone, the defect rate remained high but was reduced by 9 ppm over the course of a month. The next month, data collected from the various inspection systems was integrated and analyzed by Omron’s Q-upNavi software. Faults identified by the software in various aspects of the solder application and placement processes were corrected. By the end of that month, quality improved greatly, from 79 ppm down to 15 ppm. Read Omron's article on inspection for the automotive sector here: Zero Mistakes: Inspecting Complex Automotive Electronics.
Mirtec worked with Milford, NH-based Cirtronics Corporation, a full-service EMS provider offering prototype through end-product builds of electronic and electro-mechanical assemblies with a special emphasis on
Neubrand at phoenix|x-ray said that, because their equipment offers highly flexible image processing in a fully programmable machine, all kinds of defects become visible in the X-ray image. Examples of uses for this type of inspection are geometric measurements in small sensors, filling height check for THT solder joints of position checks of microvias.
“One customer was experiencing problems with their current AOI machine owing to a high number of false calls,” related Lee of CyberOptics. Their AOI system was designed to primarily achieve quick programming and a perceived good-enough performance. However, the high volume of false calls increased the operator’s workload and resulted in the operators becoming more likely to overlook genuine calls.” CyberOptics installed their AOI machine on-site for a performance comparison. Once set up, it provided accurate and reliable results continually, reducing overall COO and operator workload while ensuring precise measurement results.
Dage has worked with leading authorities to develop a software routine that automatically identifies head-in-pillow (HIP) failures. Advances in real problem detection are what
RMD’s Glass said, “One of our defense contractor customers was about to apply 11 BGA components to an instrument panel assembly. Each BGA was tested with RMD’s LeadTracer and it was determined that these were not lead-rich components, but were RoHS-compliant (lead-free) instead. This could present a major solderability problem, if the process had been completed with lead-free parts.” The LeadTracer improves quality processes on three fronts: RoHS component inspection, daily solder pot analysis capability; and counterfeit component identification.
Aries cited an example of a customer who had four different chips with the same size and pitch, but with different thicknesses. The customer wanted one socket to accommodate all four thicknesses. Aries’ solution was to provide an innovative adjustable pressure pad with a fine-pitch screw (100 threads per inch) that allowed for finite adjustment. The screw was incorporated into a standard molded package, allowing one socket to accommodate all four devices.
Certain themes have emerged in the test and inspection sector. Cost of ownership (COO) is a critical concern of users. Test speeds are increasing. Components and pads are shrinking. Accuracy, traceability, ease of use, and capability can make all the difference when choosing equipment. Most importantly, producing quality boards with low ppm failures requires modern test equipment.