And do you truly know the source of the material? Occasionally my column topics are tied to discussions that flow through my email inbox. I had one such inquiry last month from a super-savvy signal-integrity consultant that I believe is of interest to a wider audience. I was reading your DesignCon paper on fiber-weave effect.…
Read MoreHow to develop a standard methodology, including electrical and mechanical parameters and – yes! – cost. Au: This article is a comprehensive follow-up to the April 2019 Material Matters column in PCD&F. They may be read together or independently. In April’s column, we discussed how total board thickness can be used to drive decisions on the appropriate glass-transition temperature…
Read MoreThe stack-up and materials are the backbone of a board design. I’ve been searching for a reasonably solid, fairly-simple approach to selecting laminates for a good part of the last eight years. (This was a background task to marketing laminates and designing software for stack-up design and material selection.) I’m writing about this now because…
Read MorePart three of our series on Dk and Df characterization looks at stripline methods. This is part three in a series that examines how the industry at-large characterizes laminates. It’s true such things are of little interest below 1GHz, but I suspect the relative comfort of the sub-GHz world has slipped into the distant past…
Read MoreThe background of the measurement specs and tests. Last month’s column asked, “Whose idea was it to have a dozen different IPC material-measurement standards (for relative permittivity and loss tangent of PCB laminate materials)? Which ones are appropriate or accurate, and in what situations?” An engineering manager said, “I am still at a loss as…
Read MoreDetermining tradeoffs among various laminates. If not for my parents’ objection, I would have been held back in kindergarten. Mrs. Steinbaugh said I just didn’t understand what school was all about. I remember other kids going to play while I tried to figure out how to connect the monkeys by drawing a line between the…
Read MoreShould you use wider trace widths? And how will you know? An engineer recently asked me about the relationship between trace width and insertion loss, while adjusting dielectric height to maintain a 50Ω single-ended impedance. At a high level, five variables are at work here, including trace width, copper weight, dielectric height, Dk and Df.…
Read MoreThe genesis of a new column, and how the author came to write it. As I type this, I’m still considering about five column names. I have a lot to say about printed circuit materials, which I find super interesting, and all the candidates have the word “material” in them. Whatever appears at the top…
Read MoreThe relative permittivity for FR-4 is just that: relative. Ed.: This is Part 3 of a three-part series on preparing for next-generation loss requirements. LAST MONTH, IN Part 2 of this series, I outlined the means by which insertion-loss requirements are determined. Here, I’ll suggest a better method for obtaining accurate Df numbers without having…
Read MoreCan signal-integrity test vehicle results be accurately simulated? Ed.: This is Part 2 of a three-part series on preparing for next-generation loss requirements. Here in Part 2 of the series, I’ll outline the means by which insertion-loss requirements are determined. In Part 3, I’ll suggest a better method for obtaining more accurate Df numbers without…
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Z-zero, based in
Redmond, Washington, develops
PCB stackup planning and
material-selection software
for electronic-system design.
