HDI Design Education: Is Anyone Interested?


Reading time ( words)

I first became aware of high-density interconnection (HDI) design methodology in 1997 when a co-worker of mine came back from a training class that was taught by Happy Holden. “Little Dave” (since our department had two employees named David W.) came back excited to try this new design knowledge on a multilayer board stackup that only used blind and buried vias, with no through-hole vias. His excitement and dedication paid off, as he completed the design with an autorouter exactly as he planned. Through Dave’s success, our department then started to create other designs using HDI stackups that were taught in Happy’s class and our autorouter tool.

I did a few complex designs that fit into the IPC Type III category. One of the more complex designs I attempted could only autoroute up to 98% completion after trying many setup files (with great assistance from “Big Dave”) and our most powerful computer available within our group. I finished the design manually, and the board was fabricated and worked as designed.

About six months later, when we upgraded our department’s autorouter computer, I restored the design from archive, and re-ran the last autorouter configuration file on that 98% completed design. This time, the design was now 100% completely autorouted, and took about a third less time than on the previous “most powerful” computer. This one little re-investigation became the catalyst for my full immersion into HDI design research, reviewing the existing designs and now trying newer autorouting approaches with a variety of more challenging stackups, via spans, and via sizes. Each new redesign attempt created more curiosity to push autorouters and stackup methodologies to their absolute limits.

Over the next few years, any article written on HDI that crossed my path became assimilated into my mental database. I met Mike Fitts lecturing on HDI at a design conference, and I asked him to clarify my repository of HDI re-design questions. When Mike and I met at another design conference, he introduced me to the very person who inspired Little Dave: Happy Holden.

Read the full column here.


Editor's Note: This column originally appeared in the May 2014 issue of The PCB Design Magazine.

I first became aware of high-density interconnection (HDI) design methodology in 1997 when a co-worker of mine came back from a training class that was taught by Happy Holden. “Little Dave” (since our department had two employees named David W.) came back excited to try this new design knowledge on a multilayer board stackup that only used blind and buried vias, with no through-hole vias. His excitement and dedication paid off, as he completed the design with an autorouter exactly as he planned. Through Dave’s success, our department then started to create other designs using HDI stackups that were taught in Happy’s class and our autorouter tool.

I did a few complex designs that fit into the IPC Type III category. One of the more complex designs I attempted could only autoroute up to 98% completion after trying many setup files (with great assistance from “Big Dave”) and our most powerful computer available within our group. I finished the design manually, and the board was fabricated and worked as designed.

About six months later, when we upgraded our department’s autorouter computer, I restored the design from archive, and re-ran the last autorouter configuration file on that 98% completed design. This time, the design was now 100% completely autorouted, and took about a third less time than on the previous “most powerful” computer. This one little re-investigation became the catalyst for my full immersion into HDI design research, reviewing the existing designs and now trying newer autorouting approaches with a variety of more challenging stackups, via spans, and via sizes. Each new redesign attempt created more curiosity to push autorouters and stackup methodologies to their absolute limits.

Over the next few years, any article written on HDI that crossed my path became assimilated into my mental database. I met Mike Fitts lecturing on HDI at a design conference, and I asked him to clarify my repository of HDI re-design questions. When Mike and I met at another design conference, he introduced me to the very person who inspired Little Dave: Happy Holden.

Read the full column here.


Editor's Note: This column originally appeared in the May 2014 issue of The PCB Design Magazine.

Share


Suggested Items

Fadi Deek Discusses Mentor’s New Power Integrity eBook

04/17/2018 | Andy Shaughnessy, Design007 Magazine
At DesignCon 2018, I ran into Mentor’s Fadi Deek, the author of both of Mentor’s I-Connect007 eBooks: the newest, "The Printed Circuit Designer’s Guide to Power Integrity by Example," and their first book, "The Printed Circuit Designer’s Guide to Signal Integrity by Example." We sat down and discussed how the idea for the books came about, as well as some of the power integrity challenges facing PCB designers and engineers.

Mentor’s HyperLynx Automates SERDES Channel Design

04/09/2018 | Andy Shaughnessy, Design007 Magazine
Mentor recently released the newest version of its HyperLynx signal integrity software. This version may be the first SI tool in the industry to fully automate SERDES design channel validation. I spoke recently with Chuck Ferry, product marketing manager with Mentor, about the new HyperLynx and some of the new serial link design capabilities that customers have been demanding.

Julie Ellis: TTM’s Interface Between Designer and Fabricator

04/04/2018 | Barry Matties, Publisher, I-Connect007
As a field application engineer for TTM, Julie Ellis sees the problems that can occur between circuit board designers and manufacturers. Barry Matties spoke with Julie at the AltiumLive event in Munich about the age-old problem of throwing designs “over the wall,” the trend towards HDI, and what advice she would give new designers.



Copyright © 2018 I-Connect007. All rights reserved.