Beyond Design: High-speed Rules of Thumb
Global PCB Connections: A Technical Overview of Long-flex Printed Circuit Boards
The Shaughnessy Report: A Handy Look at Rules of Thumb
This Month in Design007 Magazine: HDI Design, Landless Vias, VeCS, and More
November 9, 2020 | I-Connect007 Editorial TeamEstimated reading time: 2 minutes
Andy Shaughnessy, Happy Holden, and Dan Feinberg recently met with James Hofer, general manager of Accurate Circuit Engineering, to discuss via design techniques and via reliability from the fabricator’s viewpoint. As Hofer explained, even with open lines of communication between the designer and the board shop, there are plenty of variables to contend with regarding proper via design, especially when working with PTFE materials.
Andy Shaughnessy: James, start by telling us some of the problems that you see with failures in vias and microvias.
James Hofer: I face a couple of challenges. Designers tend to want to do HDI designs with laser-drilled vias with aspect ratios of 1.5:1 or 1.8:1, or they want to do laser-drilled vias through multiple layers without removing pads. I don’t yet have a reliable copper-fill process that gives me as flat a surface fill as I want. As you know, most of our product is PTFE. Stacking laser vias on PTFE and copper-filled vias presents a couple of challenges. I see more and more customers want a PTFE dielectric, and they want to put a 4- or a 6-mil via in it. That presents issues both in the drilling of the via and with the plating of the via. I see a lot of that, so I find myself trying to redo designs after the fact with most customers.
Shaughnessy: They’re trying to use HDI when they don’t necessarily need it.
Hofer: And when they don’t necessarily understand some of the give and take that goes with it. They don’t want to abide by some basic principles and rules that we manufacturers have to live by.
Happy Holden: Why would they get into HDI but not do any basic investigation on how to optimize drills or design with it?
Hofer: I agree. That’s exactly what we face.
Holden: Or they read about it or heard about it, and they’re going to use it, even though they don’t know anything about it.
Hofer: That sums it up right there. The majority read something about it. Perhaps they read the first couple of paragraphs of one of Happy’s articles and think, “Great, I can do this,” and then off they go. It is far more appropriate to discuss with the manufacturer before you implement the technology.
Holden: The HDI Handbook is free. It goes into reliability and plating and metallization, materials, aspect ratio, and cycle integrity.
Dan Feinberg: Why wouldn’t they read it and use some of those recommendations? That’s a good investment.
Holden: Or just type HDI into Google or Yahoo.
Shaughnessy: Don’t designers communicate with you beforehand? I know they say they’re going to talk to their fabricator, but do they really?
Hofer: No. We face that problem pretty much on a daily basis.
To read this entire interview, which appeared in the November 2020 issue of Design007 Magazine, click here.
Share on:
Suggested Items
Unlocking Advanced Circuitry Through Liquid Metal Ink
10/31/2024 | I-Connect007 Editorial TeamPCB UHDI technologist John Johnson of American Standard Circuits discusses the evolving landscape of electronics manufacturing and the critical role of innovation, specifically liquid metal ink technology, as an alternate process to traditional metallization in PCB fabrication to achieve ever finer features and tighter tolerances. The discussion highlights the benefits of reliability, efficiency, and yields as a tradeoff to any increased cost to run the process. As this technology becomes better understood and accepted, even sought out by customers and designers, John says there is a move toward mainstream incorporation.
Fresh PCB Concepts: The Critical Nature of Copper Thickness on PCBs
10/31/2024 | Team NCAB -- Column: Fresh PCB ConceptsPCBs are the backbone of modern electronics and the copper layers within these boards serve as the primary pathways for electrical signals. When designing and manufacturing PCBs, copper thickness is one of the most critical factors and significantly affects the board’s performance and durability. The IPC-6012F specification, the industry standard for the performance and qualification of rigid PCBs, sets clear guidelines on copper thickness to ensure reliability in different environments and applications.
Book Excerpt: The Printed Circuit Designer’s Guide to... DFM Essentials, Ch. 1
10/25/2024 | I-Connect007The guidelines offered in this book are based on both ASC recommendations and IPC standards with the understanding that some may require adjustment based on the material set, fabricator processes, and other design constraints. This chapter details high-frequency materials, copper foil types, metal core PCBs, and the benefits of embedded capacitance and resistor materials in multilayer PCBs.
The Cost-Benefit Analysis of Direct Metallization
10/21/2024 | Carmichael Gugliotti, MacDermid AlphaCarmichael Gugliotti of MacDermid Alpha discusses the innovative realm of direct metallization technology, its numerous applications, and significant advantages over traditional processes. Carmichael offers an in-depth look at how direct metallization, through developments such as Blackhole and Shadow, is revolutionizing PCB manufacturing by enhancing efficiency, sustainability, and cost-effectiveness. From its origins in the 1980s to its application in cutting-edge, high-density interconnects and its pivotal role in sustainability, this discussion sheds light on how direct metallization shapes the future of PCB manufacturing across various industries, including automotive, consumer electronics, and beyond.
Connect the Dots: Designing for Reality—Pattern Plating
10/16/2024 | Matt Stevenson -- Column: Connect the DotsIn the previous episode of I-Connect007’s On the Line with… podcast, we painted the picture of the outer layer imaging process. Now we are ready for pattern plating, where fabrication can get tricky. The board is now ready to receive the copper traces, pads, and other elements specified in the original CAD design. This article will lay out the pattern plating process and discuss constraints in the chemistries that must be properly managed to meet the customer's exacting manufacturing tolerances.