-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueRules of Thumb
This month, we delve into rules of thumb—which ones work, which ones should be avoided. Rules of thumb are everywhere, but there may be hundreds of rules of thumb for PCB design. How do we separate the wheat from the chaff, so to speak?
Partial HDI
Our expert contributors provide a complete, detailed view of partial HDI this month. Most experienced PCB designers can start using this approach right away, but you need to know these tips, tricks and techniques first.
Silicon to Systems: From Soup to Nuts
This month, we asked our expert contributors to weigh in on silicon to systems—what it means to PCB designers and design engineers, EDA companies, and the rest of the PCB supply chain... from soup to nuts.
- Articles
- Columns
Search Console
- Links
- Media kit
||| MENU - design007 Magazine
Cherie Litson on ECAD/MCAD and Training the Next Generation
March 7, 2019 | Andy Shaughnessy, Design007 MagazineEstimated reading time: 6 minutes
Cherie Litson, CID+, was one of the instructors at AltiumLive Munich. I asked her to discuss some of the topics she covered in her class, and what the future of PCB design will look like. How are we going to pass down all of this design knowledge to the next generation?
Andy Shaughnessy: Good to see you, Cherie. What is your title anyway?
Cherie Litson: That’s a good question. It keeps changing (laughs). I don’t know what to call myself. I’m a master circuit board designer and instructor. How’s that? That’s the closest title I can think of.
Shaughnessy: Great. So, you taught a class yesterday. What are some of the topics you covered?
Litson: One of the things Altium asked me to do was work with David Haboud to add a designer perspective to the multiboard design capabilities within Altium. And I thought, “Well, I’ve only tinkered with that a little bit, but I’ll check it out more, and we’ll see what it looks like.” And then it dawned on me. This is a great tool, but if nobody knows why they need it, then it doesn’t go anywhere. Then, what are you going to do with it? I looked at it and thought, “Why would I need this tool for my designs?”
I started to think about different designs I’ve done over the years and various companies I’ve worked with and how they would structure things. A lot of people start a project in the middle and then work down a little. “Let’s design this and that circuitry,” but nobody has a top-down view of things. They’re not looking at it from the point of view of, “Let’s start with what I need to do for all of my interconnects to make sure that I have the right interconnect for the right time.”
Both mechanical and electrical engineers didn’t think it was their job. The electrical engineers were creating everything as J1 and P1 on every single circuit and not defining what was connecting. When I looked at that, I thought, “You have to start with a scheme,” which is why I decided to start with this presentation. What’s the important thing when you’re doing multiple boards in a system? Having system design. Start there. And what does that mean in terms of individual projects? It means looking at how we interconnect these together and having a scheme for that, whatever that scheme becomes.
Also, you should know the practical applications as well as what the existing standards are. Most people don’t know the existing standards for those interconnections, but they exist. MIL specifications have had them for years for wiring and cabling. Then, people get to a circuit board and forget. They think, “That’s just the end of a cable I’m plugging into,” and it goes to that next extent. That’s what I talked about.
Shaughnessy: Did you get any interesting questions from the attendees?
Litson: Yes. People asked about the details of the interface, which is a good thing. There were two other interesting questions. One was about the ECAD/MCAD interface, and I think it still has a way to go. There are still some bugs we need to work out with that, but I think that Altium is open to making it work, which makes a difference too. They listen to the feedback, and we can come up with some good solutions that way. I appreciate that. A lot of companies don’t work on the MCAD and the ECAD side. “No, it’s your problem,” is usually the attitude. I like that Altium goes, “Okay, it’s a problem. Let’s solve it.”
Cherie and Altium's David Haboud teamed up for a class at AltiumLive in Munich.
Another interesting question I had was about connectors. How do you do the schematic side of the connector? And how do you represent that if you just have pins as a connection? My answer was to use a multi-part (1-5 pins per part) in the schematic for most connectors—maybe not every one, but for most of them. Because then you can swap the pins, you can assign them appropriately, and do it quickly and easily without redrawing the entire schematic page. Many engineers don’t even think about that; they just draw a box, stick some pins on it, and try to put everything from the circuit to that box.
Shaughnessy: Let the designer figure it out.
Litson: Right. Or they’ll do an airline net and just change the net name, but then you can’t see the interconnections of what that’s going to. Maybe that’s not a good idea. It depends on your scale and whether you have swappable pins on your connector or not and how you want to set that up. But they don’t even think about getting good schematic flow.
Shaughnessy: What do you think are some of the biggest challenges for new designers joining the industry today?
Litson: We’re seeing more and more engineers take on the responsibility of doing layout instead of designers, which is what it always has been—people who learned by being on the job and getting it done. We have engineers coming in who think they know how to do something, but realize very quickly they don’t and don’t know where to go. I think that’s the biggest problem that I see currently. In our industry, we have electrical engineers. They might be brilliant electrical engineers, but they’re trying to translate down to a mechanical environment in a manufacturing environment with absolutely no training or aptitude. That’s another issue; not every electrical engineer should do a circuit board. Some love it, but others should not even touch one.
Shaughnessy: It makes you want to say, “Stay away from the CAD tool!”
Litson: Yes. Go think theoretically and I’ll make it work for you. And that’s important for a company to understand when they’re assigning tasks to different people. You want to make sure that you know who has the aptitude to do what, and then get the proper training for people in your company. I’m getting to a point where I would like to retire and do more trainings, even corporately. And while I love doing circuit boards, I think I’d rather just show people the best ways to go about doing it and let them do it.
Shaughnessy: Share the knowledge.
Litson: Absolutely. I mean, I’m not going to be around for very long.
Shaughnessy: Yes, a lot of us are heading up that way.
Litson: I just turned 68 in December, and 20 years ago, I survived cancer.
Shaughnessy: I didn’t know that. Wow. Congratulations! I’m glad you’re still around.
Litson: Me too! I’m really glad I survived those 20 years because I’ve learned so much, and I want to be able to pass that on to others. Because who knows how long we all have? It comes up and surprises you. I lost a brother—the youngest of our family—who was only 52. He died of a sudden heart attack, and that really jarred me too. We don’t know how long we have, and it doesn’t matter what your age is or anything. You can survive drastic stuff or have something hit you out of the blue. I think that the industry needs to look at those of us who have been here for a long time. There are a lot of really good people, and new designers need to start learning. We’ll keep passing that information on to the younger group.
Shaughnessy: To ensure that the new designers don’t wind up just getting tribal knowledge, right?
Litson: Yes, because otherwise, it’s gone and you’re going to have to relearn it all over again the hard way.
Shaughnessy: Well, here’s to you, sticking around and teaching for a few more years, Cherie! Thanks for talking to me.
Litson: That’s the plan! Thank you, Andy. Anytime.
Suggested Items
The Knowledge Base: The Impact of Harsh Environments on Residue Tolerance
11/26/2024 | Mike Konrad -- Column: The Knowledge BaseElectronic devices are ubiquitous, performing critical functions in a wide range of applications, from consumer electronics to aerospace, medical devices, automotive systems, and industrial control systems. Many of these devices operate in harsh environments characterized by extremes in temperature, humidity, pollution, and chemical exposure.
Flexible Thinking: Rules of Thumb—A Word to the Wise
11/20/2024 | Joe Fjelstad -- Column: Flexible ThinkingIn the early days of electronics manufacturing—especially with PCBs—there were no rules. Engineers, scientists, and technicians largely felt their way around in the dark, making things up as they went along. There was a great deal of innovation, guessing, and testing to make sure that early guidelines and estimates were correct by testing them. Still, they frequently made mistakes.
All Flex Solutions Adds Talent to Flexible Circuit Facilities
11/14/2024 | All Flex SolutionsAll Flex Solutions is excited to welcome John Letourneau as our Director of Facilities and Maintenance at our Flexible Circuit Centers of Excellence!
BOOK EXCERPT: The Printed Circuit Designer’s Guide to... DFM Essentials, Chapter 2
11/14/2024 | I-Connect007 Editorial TeamThe 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 discusses panelization, placing PCBs on manufacturing panels, highlighting features like coupons, borders, and scoring to maximize material utilization and reduce costs, and detailing preferred panel sizes and modifications.
Flexible Circuit Technologies Announces Major Expansion of Capabilities & Resources
11/13/2024 | CNWFlexible Circuit Technologies (FCT), a global design and value add manufacturer of flexible circuits, heaters, and membrane switches based in Minneapolis, MN, announces the opening of FCT-Huizhou.