Thursday, June 21, 2018
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Meeting Tomorrow's AOI Challenges Today
Ultra 850 heralds a new generation of AOI.

Market demand for new electronics products has been on a fast track with growing desire for slick features, mobility, and increased integrated functionality. Aggressive design requirements mandate smaller form factors forcing shrinkage in all three dimensions. Integrated functionality forces a higher mix of SMT components with smaller features and lower profiles.

This trend provides a significant challenge for product integration specifically in the area of packaging assembly.

Real-time inspection with right "hooks" in place to provide meaningful feedback and easy-to-digest output information can now enable complex assembly lines to become more efficient in managing upstream-downstream process in terms of line yield, utilization, overall productivity, and profitability.

Last year MVP introduced yet another innovative line of products targeted towards packaging applications. The new platform was designed to meet and exceed today's complex high volume manufacturing assembly requirements. The configurable nature of the platform makes it a perfect high speed AOI choice for many applications in complex and hybrid C4 + SMT assembly lines. A configurable platform, it uses different electro-optic and/or material handling systems combined to meet various processing requirements. However, the base platform is the same for all applications. The similarity between different configurations improves overall utilization of complex assembly lines. Once basic training has been provided, equipment operators can switch positions from one process to another with minimal training since the same operating system and interface are shared across all configurations. Other key advantages are spares management and equipment maintenance. A very large portion of the same components is shared among all configurations which ultimately helps with spares management by reducing the number of spare parts on the shelves, enhances troubleshooting, as well as periodic maintenance.

Solid Granite Stage
All configurations are equipped with a solid granite stage to enhance overall inspection precision. A high precision frame complements the granite stage, a single 4 megapixel color camera, and programmable LED lighting enables repeatable high-speed on-the-fly image acquisition with field of view resolution of 3- 25µm/pixel. The telecentric lens is an option that further increases inspection accuracy required for certain applications. Careful attention has been given to the material handling system to assure ultimate flexibility while meeting JEDEC tray standards, with metal carriers, providing bare PC board as well as thin strip processing. All of the platforms can be configured as single or dual lane. Support pedestals and auto board clamping are also optional for more precise board registration and handling. Upstream-downstream communications have been taken into account with flexible PLC control, SMEMA interface, and full automation capability to transfer tool performance and recipe specific data to line management servers.

The platform comes with a powerful integrated SPC package. A large stream of valuable inspection results is gathered continuously and can be plotted real time in different formats to assist troubleshooting and maintain a high yielding assembly line. Offline programming and debug is available to minimize production interruption. A CAD driven library based programming Software cuts new recipe creation and testing time.

Organic Packaging
With the ever growing evolution of packaging technology, specifically in the organic packaging, and thin package processing the need for AOI continues to increase. The MVP 850G platform was specifically designed to address all new and next generation packaging assembly needs. The tool can be configured to perform 3D Paste Inspection, 2D Flux Inspection(without fluorescent additives), C4 Die and SMT component Inspection(pre and post reflow simultaneously), C4 Epoxy Underfill (spread, quality, fillet, etc.), Surface Finish(scratch, damage, etc.), Wire bond, Glue and Sealant, traditional SMT (pre and post reflow), and many more applications. The tool can be placed in-line or off-line depending on assembly layout and process needs.

Die Placement Metrology
An important challenge came from a major customer who needed a solution for the accurate measurement and inspection of dies placed onto a substrate. As the placement of these dies are critical to the reliability of the products MVP engineering and management embarked on a project to develop a measurement and inspection tool. The tool was required to be a robust metrology-based system to be capable of a repeatability for translation in X and Y of 1.3µ reproducibility in X and Y of less than 2µ, die rotation repeatability and reproducibility not to exceed 0.007° and overall accuracy between different tools not to exceed 10µ total. With years of experience of a variety of different inspection approaches across many industry sectors a task force set about specifying a new inspection tool which would meet the requirements of the customer. Not only would the tool have to be capable of inspecting the die placement on the substrate, both post and pre-reflow. It would also have to be capable of inspecting the surface finish including scratches and irregularities on the surface of the die. Other capabilities would include the inspection of surface mount components such as 0204, 0201, 0603 IDC, 0402, resistor networks and even 12-mil-pitch QFPs.

In order to meet the variety of inspection requirements a proprietary electro-optics module was developed. Resolution studies showed that a 16µ pixel size is adequate for meeting the various requirements of speed and accuracy. The electro-optics module utilizes a telecentric lens, and a tri-color lighting source complemented by a white light source. This assures visibility of the surface mount defects and provides an improved signal-to-noise ratio for the edges.

The platform software is equipped with a range of existing inspection algorithms including sub-pixel edge detection, surface defect detection, post and pre-reflow SMT and metrology algorithms. Other significant challenges were to meet the number of units per hour to be inspected. The range of 3000-4000 UPH required the utilization of concurrent fiducial registration and inspection which allowed for significant time savings during the inspection cycle. The system had to be provided with a dual lane capability, effectively working in tandem with existing production equipment to maintain the inspection speed of the line. Additional challenges were the requirements to integrate SECS/GEM and Lot Code Traceability to the inspection tool.

Uptime Is Critical
Another critical parameter was the uptime of the system which had a base specification of greater than 98.5 percent production availability. Again the platform surpassed this requirement providing greater than 99 percent uptime. The initial tool implementation met and exceeded all of the customer's requirements, who has since purchased over 50 similar systems.

With the transition from traditional SMT inspection into micro-electronic inspection capabilities MVP have proven their strength lies with high performance, flexible and innovative inspection solutions. Innovative solutions, built-in quality, reliability, low maintenance, and state-of-the-art high speed inspection capabilities have proven the technology to several industry leaders and high volume assembly powerhouses around the world.

Contact: Machine Vision Products, Inc., 5940 Darwin Ct., Carlsbad, CA 92008 760-438-1138 fax: 760-438-0660 E-mail: Web:   \par

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