OPTICAL MICROSCOPE KEEPS UP WITH PRODUCTION NEEDS KEEPS UP WITH PRODUCTION NEEDS Custom production interface helps solve a critical cavity depth process control metrology problem. As production manufacturing tolerances are pushed to tighter limits, accurate metrology becomes critical to product success. ON Semiconductor (Phoenix), a leading electronics manufacturer, has chosen the Bruker (Tucson, AZ) ContourGT-X3 3-D Optical Microscope to support its copper wire bond pad inspection and process control needs. The production-level speed of the ContourGT-X3 combined with the ease of use and custom production interface has enabled ON Semiconductor to solve a critical cavity depth process control metrology problem, according to Harold Anderson, principal staff engineer at ON Semiconductor. CAVITY DEPTH IN WIRE BONDING In the copper wire bonding process, high forces are used to bond the wire to bond pads. A cavity depth optimization problem results-too much or too little force means reduced reliability of the final wire bond. Therefore, an accurate and fast method for quantifying the cavity depth is necessary. The need for fast, automated inspection with excellent vertical resolution over a relatively large field of view makes 3-D microscopy based on white light interferometry an excellent choice for this application. To address this problem, ON Semiconductor chose the Bruker ContourGTX3 3-D Optical Microscope. Their selection was based on the need for a system that offered a combination of automated run-time metrology, robust analysis and ease of use of the operator interface for industrial applications. Additionally, automated logging of pass/fail criteria on hundreds of defined parameters of measurement can be set and stored to a part-specific database for sorting and part rejection, while eliminating operator bias and variance. A line engineer or manager can create specific material recipes which are automatically linked to material via operator ID, material ID, or lot/inspection ID. Compared to SEM inspection, sample preparation time is reduced from 15 to 20 minutes to approximately a minute set up and measure with the GT-X3, says Anderson. These software controls smooth the transition process control to production and allow for accurate identification and flagging of good and bad production output. The ContourGT-X3 system is ideal for keeping up with production environment needs with stable metrology and analysis for a multitude of applications. These key features make the GT-X3 an excellent choice where 24/7 shift operation is employed for production inspection and process control. BENEFITS " Sample preparation time is reduced from 15 to 20 minutes to approximately a minute with the GT-X3. " Automated logging of pass/ fail criteria on hundreds of defined parameters of measurement can be set and stored to a part-specific database for sorting and part rejection. " Software controls smooth the transition process control to production and allow for accurate identification and flagging of good and bad production output. CMM GETS NEWS LIFE Software allows old "dogs" to learn new tricks. In 2010, IKA Works Inc. celebrated 100 years of company history and 25 years in the United States. Based in Staufen, Germany, the company has gained a leading position in the world market with its wide range of innovative laboratory and process equipment for numerous industries, including the pharmaceutical, chemical, food and plastics industry. The company's product portfolio includes magnetic and overhead stirrers, calorimeters, rotary evaporators, heating or cooling technology as well as homogenizers, dryers and mixers. In 1994, with the establishment of a laboratory division and also significant growth, IKA USA headquarters relocated from Cincinnati to Wilmington, NC. Since their on-site machine shop and local vendors were now producing more parts, they needed a more efficient and more reliable inspection process. In 1998, IKA purchased a Zeiss Eclipse 550 CMM with Zeiss U-Soft metrology software. Before purchasing the CMM, IKA was using standard hand tools such as electronic bore micrometers and calipers. In 2010, IKA decided to upgrade their CMM with Calypso metrology software from Carl Zeiss."With a leaner inventory we have low quantities but frequent delivery of incoming parts, and our in-house machine shop produces small batch numbers of a large variety of parts that require a quick turnaround from quality inspection," says John Moncrief, senior QC inspector at IKA."We needed a software that would fit this transition and provide us with dependable results not only for inspection but to assist our R&D department with design projects and customer application issues. Calypso from Carl Zeiss is the standard and seemed to fulfill all of our expectations, so we decided to teach an old dog a new trick and upgraded our Eclipse." Calypso is a Windows-based software, designed for manual and CNC measurements, as well as online and offline measurements. The software is multisensor capable and compatible with all current Zeiss sensors. IKA chose to use the dual software option: they utilize their existing U-Soft and the new Calypso side by side. This is an operator friendly option since existing programs can be used while new ones are written. This dual software option is possible with Calypso and other non- Zeiss software as well. The benefits of choosing Calypso became evident immediately. Measurement plans can now be written from CAD models and all results are saved on our network. "For 13 years, we had to print out every result. With Calypso, this huge amount of paperwork has been eliminated which saves space and eliminates about 30 minutes of handling time per day," Moncrief explains."Results can be organized and recalled very easily." Furthermore, programming time was significantly reduced. "My program writing time with Calypso has been reduced from about 1.5 hours to 45 minutes," states Moncrief. "The time-consuming task of creating travel paths around the part has been eliminated. Every phase of program writing, editing and running is faster and easy to commit to memory. I can use this extra time to perform other tasks." Another advantage of Calypso is that measurement plans can be adapted to the needs of production. IKA custom designs process systems to meet customer application needs. Parts may require heat or hardening treatments that can alter the part dimensionally requiring re-inspection, thus quick turnaround with Calypso. Another beneficial result IKA has realized besides the faster programming, editing and runtime, is that all of their cylindrical and ring gages, as well as length standards can be now verified in-house instead of sending them out for calibration. "We use Calypso to verify approximately 20 ring gages and length standards per year, which saves us about $1,500 in calibration expenses," says Moncrief. The Calypso software upgrade has helped IKA with their measurement requirements and improved their response time with measurement needs. "I have always been most impressed by the reliability of our Zeiss CMM system. Since upgrading to Calypso, my only regret is that we waited so long," Moncrief states.
Published by QualityMagazine. View All Articles.
This page can be found at http://digital.bnpmedia.com/article/Case+Studies/897541/89761/article.html.