Printed Circuit Design & Fab - October 2008 - (Page 37)

Table 1. PlatinG ances, mechanical properties and erodibility of the 10 electrodeposited copper samples were observed. While differences in the erosion rates of copper from different suppliers varied by up to a factor of 1.7, no strong correlations were identified between erosion rate, grain structure or tensile properties. Different chemistries and processing parameters may have resulted in variations in the copper structure other than the UTS and elongation that was measured. Industry experts suggests factors including grain structure, hardness or organic contamination may also influence dissolution. The work on this project will continue until the correlation factor can be identified. pCd&f chryS ShEa is founder of Shea Engineering; chrys@sheaengineering.com. JiM kEnny and JEan raSMuSSEn are with Cookson Electronics; jkenny@cooksonelectronics.com and jrasmussen@cooksonelectronics.com. kEith SwEatMan is did not submit foils. with Nihon Superior; ksweatman@aol.com GiriSh wablE and QuyEn chu are with Jabil, St. Petersburg, FL; Girish_ Wable@Jabil.com and Quyen_Chu@Jabil.com. ShianG tEnG is at San Jose State university. kaZuhiro noGita, Ph.D. is at university of Queensland, Australia. tablE 1. tensile test results, suppliers C and E did not submit foils. Table 1. Tensile test results, suppliers C and E SAC305’s erosion rates of 0.625 μm/sec to 1.038 μm/sec. As a benchmark for comparison, Sample G was processed in eutectic tin-lead solder, and the erosion rate was 0.325 μm/ sec, less than half that of SAC 305 and roughly the same as Alloys 2 and 3. Differences in the erosion rates of the electrodeposited copper varied by a factor of 1.4 to 1.7, depending on the alloy used in the tests. Considerable differences in the grain structures, appear- Ed. Note: The experimental work contained in this article along with previously published work is part of an ongoing investigation. The complete report on current work was presented in August at SMTAI 2008 in Orlando, Proceedings. GerberStasis Film To Software Archiving Services GerberStasis services were designed to provide flexible cost options to companies seeking to develop a comprehensive back up plan for their legacy film libraries. While scanning films to TIF or JPEG files creates a software image, it also increases the cost to convert that image to a usable Gerber file for future production. Precision Images, LLC offers a strategic approach to legacy archiving that allows the customer to select the backup version based on the probability of the PCB being manufactured in the future. For as little as $5.00 per layer you can achieve the following benefits: • • • • • • Dimensional and feature size accuracy. PCB industry’s standard data format. Photoplot images for continued reverse engineering on any scanning system. Import to Gerber CAD/CAM systems as reference layers. Import to many PCB design programs as reference layers. Convert to DXF for import into AutoCAD as reference. Precision Images, LLC • 727 544-0201 • www.precision-images.biz OCTOBER 2008 printEd CirCuit dESign & fAB 37 http://www.precision-images.biz http://www.precision-images.biz

Table of Contents Feed for the Digital Edition of Printed Circuit Design & Fab - October 2008

Printed Circuit Design & Fab - October 2008 Contents Our Line Market Watch Around the World Happenings Test and Inspection ROI Tip Jar Interconnect Strategies Final Finish Forum The New Wave in High-Speed Modeling The PCB Design Library Mixed Signal Design Considerations Modeling Conductor Surface Roughness Copper Erosion: The Influence of Metallurgy on Copper Dissolution The Wave of the Future Ad Index Building a Profitable Niche Marketplace Off the Shelf BGA Bulletin

Printed Circuit Design & Fab - October 2008

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