http://www.pcbdesign007.com/ PCB fabricator news from around the world: PCBDESIGN007 - articles Today's video equpment operates at gigabit rates, necessitating the use of large coaxial BNC connectors. Non-optimized BNC footrpints can cause impedance mismatches, reflections and signal loss. In this paper, Tsun-kit Chin of National Semiconductor discusses some common issues with BNC footprints, such as problems with the connector-to-board transition, and offers techniques for transparent footprint designs. http://www.pcbdesign007.com/pages/zone.cgi?a=70992 Wed, 01 Sep 2010 21:06:00 GMT I've been busier than a one-armed paper-hanger lately, and I wanted to give you all an update: Great books, cool electronic projects and more Grammar 4 Engineers. Can you think of a better way to lead into Labor Day? I certainly can't! Then again, I am an engineer ... regardless, read on! http://www.pcbdesign007.com/pages/zone.cgi?a=70991 Wed, 01 Sep 2010 19:11:00 GMT Designing differential pairs is challenging enough, and the "alphabet soup" of high-speed serial links such as SATA, SAS and XAUI create more problems as you move from 1 Gbps to 10 Gbps and beyond. Eric Bogatin discusses some of the cutting-edge design techniques he'll be teaching at his "Differential Pair Boot Camp" in Santa Clara on October 4. http://www.pcbdesign007.com/pages/zone.cgi?a=70671 Thu, 26 Aug 2010 19:49:00 GMT What is "rheology" and why does "everything flow?" Chet Guiles examines the science of rheology and how understanding the rheology of the prepregs you use, during the time they melt and flow, can help a process engineer manage and control the lamination process. http://www.pcbdesign007.com/pages/zone.cgi?a=70535 Mon, 23 Aug 2010 12:20:00 GMT Flexible circuit cables offer some significant advantages for facilitating the movement of data between elements of a system that must also be moved or flexed. However, there is a balancing act involved and there is more than one master to be served to create a system that is robust, reliable and easily manufacturable. http://www.pcbdesign007.com/pages/zone.cgi?a=70261 Sun, 22 Aug 2010 13:29:00 GMT If a customer asks you to build a PCB that can withstand 20,000 volts, would you know how to build such a board? First things first: You cannot just say, "Well, I think FR-4 will work." It won't, and the board will fail. Boom! Here's how to avoid arc-overs, coronas and, most importantly, any booms. http://www.pcbdesign007.com/pages/zone.cgi?a=70699 Thu, 19 Aug 2010 15:33:00 GMT Interconnect separation is usually expressed as a crack that propagates at the internal interconnection. This failure mode produces a crack that is wedge-shaped, with the large end on the side of the foil closest to the middle of the PWB. An interconnect failure frequently develops slowly over time, accumulating damage at a constant rate after onset. http://www.pcbdesign007.com/pages/zone.cgi?a=70391 Wed, 18 Aug 2010 21:42:00 GMT In Part III of a series, we'll take a look at loop or mounted inductance. Loop inductance is important, for instance, when we need a reasonably accurate estimate for the Series Resonance Frequency (SRF), or for the anti-resonance peaking between two different-valued capacitors or between the capacitor's inductance and the static capacitance of the power/ground planes it connects to. http://www.pcbdesign007.com/pages/zone.cgi?a=70672 Wed, 18 Aug 2010 20:44:00 GMT Traditionally, we've understood that a good, quiet power delivery system is one with lots of bypass capacitors. And it was easy to extend the understanding to the concept that more (bypass capacitors) is better. But there is another, better way to look at this whole issue. The concept of an "ideal" PDS impedance curve can be useful to keep in mind. http://www.pcbdesign007.com/pages/zone.cgi?a=70670 Wed, 18 Aug 2010 18:03:00 GMT Nothing like a bit of Nietzsche to get one's brain going! In this edition of my series "Writing 4 Engineers" we look at the use of "that" and "which," which can get many of you in trouble. Or is it "that" can get many of you in trouble? http://www.pcbdesign007.com/pages/zone.cgi?a=70666 Wed, 18 Aug 2010 16:04:00 GMT Developers of mil/aero and other high-rel applications depend on solid failure analysis. Paul Reid discusses how thermal cycling will cause a robust plated through-hole to crack slowly over time. Plotting a resistance graph of damage accumulation allows technologists to determine onset, rate of accumulation and whether the damage is accelerating linearly or exponentially. http://www.pcbdesign007.com/pages/zone.cgi?a=58530 Wed, 18 Aug 2010 12:39:00 GMT The characteristic impedance of a microstrip line is a complex function of frequency. Impedance changes are usually measured with time TDR, but does the observed impedance value depend upon rise time? What impedance value is actually visible in TDR of a line segment? Yuriy Shlepnev investigates in this app note. http://www.pcbdesign007.com/pages/zone.cgi?a=70420 Wed, 11 Aug 2010 14:15:00 GMT Differential signaling is now the norm for carrying fast signals. Differential signal transmission, using tightly coupled parallel PCB tracks, is more reliable than the single-ended variety. John Berrie explains how to design multi-gig boards using built-in analysis tools. http://www.pcbdesign007.com/pages/zone.cgi?a=70390 Wed, 11 Aug 2010 07:30:00 GMT This paper examines the thermal properties of various halogen-free laminates used in handheld electronic products and correlates these properties with manufacturing requirements. Thermal properties investigated include z-axis CTE, time to delamination at 260°C and 288°C and temperature to decomposition. http://www.pcbdesign007.com/pages/zone.cgi?a=70439 Tue, 10 Aug 2010 12:06:00 GMT Guest Editors Mark Thompson and Kelly Dack discuss techniques and materials for improving heat dissipation on PCBs, as well as the challenges designers face in trying to accurately calculate heat dissipation. http://www.pcbdesign007.com/pages/zone.cgi?a=70310 Mon, 09 Aug 2010 12:54:00 GMT Lou De Rose asks: With so many notions of value, how do we avoid the danger of oversimplifying its attributes, even its reality? How do we reduce the risk of acting on the assumption that decisions will have desired outcomes, when in fact they're invitations to disaster? http://www.pcbdesign007.com/pages/zone.cgi?a=70106 Sat, 07 Aug 2010 13:12:00 GMT What? You don't know what "Nescio Quid Dicas" means? I'm shocked and horrified. I thought everyone knew that this is Latin for "I don't know what you're talking about." In "Writing 4 Engineers," you never know what you might learn! http://www.pcbdesign007.com/pages/zone.cgi?a=70330 Wed, 04 Aug 2010 20:24:00 GMT To often, OEMs push PCB design projects onto their electrical engineers, computer technicians -- basically, anyone but the PCB designer. But it usually winds up costing the company time and money. That's what happens when companies try to trivialize our profession! http://www.pcbdesign007.com/pages/zone.cgi?a=70328 Wed, 04 Aug 2010 19:24:00 GMT We all know the buzz words: impedance, 50 ohms, 10%, balanced lines, CTE, dielectric constant and loss and countless more. In this new series, PCB 101, I will break down some of these buzz words in layman's terms in the hopes that more people will understand what's happening inside the circuit. http://www.pcbdesign007.com/pages/zone.cgi?a=70133 Mon, 02 Aug 2010 12:26:00 GMT If you're on software maintenance, you're really paying for your software vendor to be your team partner, 24/7/365. But if your support call gets lost in a black hole, you're left wondering, "What's the point of paying maintenance anyway?" Let me walk you through maintenance, from a product manager's point of view. http://www.pcbdesign007.com/pages/zone.cgi?a=70132 Wed, 28 Jul 2010 18:09:00 GMT The industry has been reluctant to use embedded capacitance materials due to a lack of understanding of its design benefits. J. Lee Parker of JLP Consultants explains the advantages of buried capacitance, including EMI suppression, decoupling and the chance to move capacitors from the top of the board into the less expensive inner layers. http://www.pcbdesign007.com/pages/zone.cgi?a=58877 Wed, 28 Jul 2010 13:23:00 GMT Solder-free and 3-D assembly will help bridge the performance and density gaps needed to extend Moore's Law, as lithography on silicon runs out of steam. It will offer America the chance to restore her electronic manufacturing mojo and provide for her security. Please, America, don't miss this chance to leap-frog the rest of the world! http://www.pcbdesign007.com/pages/zone.cgi?a=69967 Sun, 25 Jul 2010 12:46:00 GMT I recently converted a pair of 75-year-old headphones into some absolutely mega-cool retro iPod headphones. I'll show you how you can create these amazing headphones yourself, at very little cost, and be the envy of everyone you meet. Or at least you'll be the envy of anyone interested in old electronics, and who isn't? http://www.pcbdesign007.com/pages/zone.cgi?a=69963 Wed, 21 Jul 2010 19:06:00 GMT We finished the last Quiet Power column with a few questions about the inductance of bypass capacitors: Why do different vendors sometimes report different inductance values for nominally the same capacitor? Start by asking the vendors how they obtained these inductance values. http://www.pcbdesign007.com/pages/zone.cgi?a=69962 Wed, 21 Jul 2010 17:50:00 GMT According to Mark Thompson, timing can make or break your controlled impedance board. With many jobs going through turnkey environments, late communication about impedance issues takes valuable time out of the fabrication process and can delay delivery of product, leaving the end-user and the turnkey assembler unhappy. http://www.pcbdesign007.com/pages/zone.cgi?a=69913 Wed, 21 Jul 2010 13:51:00 GMT With proper planning, stiffeners can be designed to aid assembly through the designed manufacture of a flex circuit that can be handled as if it were a rigid circuit board. Such constructions can be accomplished by using any one of several methods. http://www.pcbdesign007.com/pages/zone.cgi?a=69814 Wed, 21 Jul 2010 12:37:00 GMT Engineers can now work concurrently--on the same database--entering schematics and constraints. As they are working, they can even see edits from other project engineers in real-time, set protection barriers, reduce wasted communication efforts and coordinate efforts to maximize productivity. http://www.pcbdesign007.com/pages/zone.cgi?a=69875 Wed, 21 Jul 2010 12:30:00 GMT Many Internet sources provide education and training in our respective fields. You just have to know where to look. It's not quite like attending a live training event, but you can improve your skill set through the Internet, and you can often do so free of charge. http://www.pcbdesign007.com/pages/zone.cgi?a=69780 Thu, 15 Jul 2010 12:20:00 GMT Polar Instruments CEO Martyn Gaudion will be exploring a number of themes. A major SI topic that is set to grow is the emergence of new silicon families designed to push traditional materials into the multi-gigahertz arena. These new chipsets lift transmission speeds up to a point where signal losses rather than reflections become the predominant concern from an SI perspective. http://www.pcbdesign007.com/pages/zone.cgi?a=69779 Wed, 14 Jul 2010 15:26:00 GMT John Ritchie, Product Manager for Rogers Corporation, reviews his company's new high-frequency laminate product, RO4360, which features a Dk of 6.15. The new product can address issues concerning what Ritchie sees as three mega-trends in the industry: The drive toward mass transit, sustainable energy and Internet growth. http://www.pcbdesign007.com/pages/zone.cgi?a=59079 Wed, 14 Jul 2010 14:26:00 GMT Corner cracks are observed less often than barrel cracks, but with high-rel boards, we can't be too careful. Unlike barrel cracks, which can fail catastrophically, knee cracks tend to propagate over time. The damaged pad actually resembles a funnel and the warp and weft of the glass give the funnel an uneven, puckered shape. http://www.pcbdesign007.com/pages/zone.cgi?a=69569 Sat, 10 Jul 2010 12:07:00 GMT