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Effects of Moisture Content on Permittivity and Loss Tangent of Printed Circuit Board Materials
Bhanu Sood, CALCE
Wednesday, August 18 • 10:00 am—11:00 am Central time
Printed circuit board laminate datasheets provide permittivity (dielectric constant, Dk) and loss tangent (dissipation factor, Df) values that are used for specification and board design. But past studies have shown that these properties vary with changes in the moisture content of the PCB laminate material. Major problems can arise when material substitutions are made using laminate datasheets as a guide, especially when the data is derived using dissimilar test conditions or methods. For example, initial impedance calculations on the basis of datasheet values may be acceptable, but actual board performance may be significantly different and may result in poorly functioning and unreliable boards.
What You Will Learn
This webinar will discuss the results of an experimental study to establish whether the preconditioning steps outlined in the IPC-TM-650 2.5.5.9 (Permittivity and Loss Tangent, Parallel Plate, 1MHz to 1.5 GHz) test standard account for varying moisture contents in PCB laminate test coupons. The moisture content in a PCB material may vary because of material constituents, board design or handling, processing, shipping and end use conditions. Results also shed light on the dependence of dielectric values on moisture content and type of flame retardant used. Commercially available PCB materials sourced from two manufacturers were tested in this study. Materials were classified on the basis of flame retardant type (halogenated or halogen-free) and glass transition temperature. Extent of variation in the dielectric properties is discussed as a function of material constituents and moisture content. Types of materials that are most affected—and reasons behind the variation—are also reviewed.
About the Instructor
Bhanu Sood is the director of the Test Services and Failure Analysis (TSFA) Laboratory at the University of Maryland's Center for Advanced Life Cycle Engineering (CALCE).
His research areas include electronic materials characterization, failure analysis of electronic components and assemblies, printed circuit board materials and conductive filament formation. Prior to joining CALCE in 2005, he worked at U.S. Naval Research Laboratory. His technical publications include papers on embedded electronics, energy storage systems and instrumentation for fatigue studies. He holds master's degrees in materials processing and materials science, and a bachelor's degree in mechanical engineering.
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Effective BGA Fanouts
Charles Pfeil, Mentor Graphics
Thursday, August 26 • 10:00 am—11:00 am Central time
Choosing the appropriate fanout patterns for routing large BGAs can enable fewer layers, better signal integrity and lower costs. When using HDI, there are many options available which sometimes make the task daunting. This session is intended for PCB designers who want to find effective fanout methods for large, dense BGAs — and for those who are testing the HDI waters due to increased pin density.
What You Will Learn
- The principles for effective fanouts, independent of particular PCB design software, will be explored
- Special software for this task in Expedition PCB will be demonstrated
About the Instructor
Charles Pfeil has more than 40 years in the PCB design industry as a designer, service bureau owner and as a marketing and/or engineering manager at software vendors. Since 1999, he has worked for Mentor Graphics, where he is currently an engineering director. The original product architect for Expedition PCB, Pfeil is one of the inventors of the XtremePCB technology and has authored a number of other patents. He is the author of BGA Breakouts and Routing (2008) which provides unique methods for fanout and routing of complex BGAs in the context of many different stackups. The book is available as a free download at http://iconnect007.com/ads/mentor/regform.php
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 All sessions will run from 10:00 am to 11:00 am Central time (Chicago).
Calculate your start time.
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Stretch your training budget:
Log in one time — with your whole team in the room — a great value at $75 for IPC members/$100 standard industry rate. Register now, and send out those meeting invitations!
Each session will run for one hour: slide presentation followed by question & answer session.
Register now for any session of the IPC Online Technical Education Series.
Questions?
Contact Laurie Delfosse, professional development coordinator, at +1 847-597-2877. |
