Tim’s Takeaways: Thermal Management for PCB Designers—Staying Out of the Fire

The Life of a PCB
If there’s one thing in life that really feels the pressure of being in the hot seat, it’s the PCBs that we design. After putting up with the trauma of having copper added and then etched away through exposure to ultraviolet light and various chemical baths, you would think that the PCB would deserve a little break. Instead, the board goes from the frying pan into the fire, so to speak, as the different layers get laminated together. This involves a great deal of heat and pressure, as the epoxy in the prepreg is melted to fuse the PCB layers together. Next comes drilling and plating, which is also no picnic, and by this point, the heat and pressure should finally be over for this little guy, right? But now the board needs to be assembled.

Our plucky hero has gone through all kinds of processes to complete its fabrication, including some intense scrutiny by both automated equipment and human inspection. Now, it’s back into the oven again—literally—for PCB assembly. Once the board has had its components pasted down onto it, it will be subjected to temperatures in the solder reflow oven that can get up to 255°C. That is almost 500°F for those of you who are thinking that perhaps it really isn’t so bad. Let me just say this; there isn’t a sunblock in the world with an SPF-value high enough to help with this kind of heat.

Not every PCB that is manufactured will go through the solder reflow oven—you’re right. But if they don’t go through reflow, they’re most likely go through wave solder instead. If you’re thinking that going through a wave sounds a little more pleasant than going through an oven, think again. We’re talking about a molten wave of solder, which can get up to 270°C if lead-free solders are used. How would you like to dip your toes into that kind of a wave?

As you can see, the PCB deserves our admiration for all the heat and pressure it has to deal with during manufacturing, but that is just the beginning. Next comes the regular day in and day out thermal stress of the board’s normal operating environment. All those electronic components can generate a lot of heat in themselves, and life for the board can get pretty toasty. That is what PCBs are created for, though, and why PCB designers like you put so much effort into designing them to survive and flourish in all that heat.

A PCB Designer’s Job
We start by designing boards with symmetrical layers of precisely-controlled copper evenly spread out to help with the fabrication process. We also take care in the placement and routing of PCB components to ensure there aren’t any problems with soldering during assembly. Additionally, we design the boards with their operating temperatures in mind by giving hot parts the space they need, as well as placing them where they can leverage the airflow across the board for cooling. We also use thermal vias to distribute heat throughout the board and incorporate heat sinks, fans, and other thermal management tools and devices, as necessary.

As PCB designers, we are accustomed to using a variety of procedures to manage the heat on our PCBs. However, the question is, “Do we give the same level of attention to managing the heat in our jobs as PCB designers?” Many designers tell me that they often find themselves under a lot of pressure while doing their work, which puts them squarely in the hot seat, looking for a fresh breeze of relief. 

Four Techniques
We are already good at PCB design thermal management, so let’s consider four techniques in thermal management for PCB designers that might help.
 
1. Plan a Schedule
A lot of folks will ride the wave of the day in the performance of their jobs without any sort of planning at all. While this works for repetitive tasks, it can create a lot of stress for those who have schedule obligations that must be met. Certainly, we have our meetings and other company events planned in advance, so why not put a schedule around our design work too? The goal here is to prevent everything from piling up at the last moment and creating a catastrophic train-wreck with your deliverables. By planning regular milestones as you work, you can better manage the project’s long-range delivery dates and give yourself plenty of room to make schedule adjustments along the way, if necessary.

2. Manage Interruptions
When working in an environment where there are continual interruptions, it can be easy to get frustrated as each new interruption raises our temperature another notch. For PCB designers, this can be especially troublesome as the design process involves keeping several sequential tasks going all at the same time. “This via can move over as soon as this resistor is rotated, which I can do as soon as these traces are re-routed, which can only happen after I slide the capacitor a little down and to the left…” You can almost see the tasks floating around a designer’s head like little bubbles until an interruption causes all the bubbles to simultaneously pop, taking all those ideas crashing to the floor with them. To avoid this, try scheduling times when you shut down electronic interruptions and go dark to the outside world for a while. Of course, this requires planning so that other team members (and your boss) know what you are doing, but carving out blocks of uninterrupted time in your schedule can be a real game changer.

3. Document the Process
The temperature in the design room often gets elevated through poor communication. People may not know what they are supposed to be doing, or they may not know what you are doing. The best way to remedy this is through documentation. Make sure that everyone knows who the stakeholders are and who is calling the shots. It is also helpful if everyone has access to project schedules and timelines. Also, take the time to take some notes. I’m not talking about writing a novel here; just keep up with some simple entries in the project log. This makes it much easier for people to pick up where you left off, or for you to demonstrate why or why not certain tasks have or have not been completed.

4. Relax a Little
When the heat is on us, it is easy to get really wrapped up in our work. I’m sure that all of us have found ourselves working through the night on more than one occasion to get an important project out the door. The concern, though, is that having such a tight hold on what we are doing may make it difficult to let go when we need to. Sometimes, board designs change in mid-stream or even get canceled, and that can be really tough to deal with if we are hanging on too tight. What’s worse is to find out that we’ve made a mistake somewhere along the way and now we have to go back and correct it. Relax. We’re all human, and mistakes happen, so let it go. The important thing is to learn from any errors we have created so that we don’t make those same ones again. Take a deep breath and forgive yourself, and then get back into the game again.

Conclusion
There is one thing in life for certain: when an object gets too hot, it will change. In PCB design, we know this better than most, which is why we design our boards to manage an excess of heat. Objects that overheat tend to get crispy, inflexible or even melt away, which is the last thing we should allow to happen to us as PCB designers. The world of electronics design is constantly changing, and we must remain flexible to stay ahead of the rapidly changing curve and avoid the pressure that could lead to a melt-down.
What do you think? Has this helped to turn the thermostat down in the old design room yet? Remember, you already know how to manage the heat in your design to protect it; now, take the time to do the same for yourself. Until next time everyone, keep on designing.  
 
This column originally appeared in the September 2020 issue of Design007 Magazine.

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2020

Tim’s Takeaways: Thermal Management for PCB Designers—Staying Out of the Fire

09-09-2020

If there’s one thing in life that really feels the pressure of being in the hot seat, it’s the PCBs that we design. But PCB designers often feel a lot of pressure while doing their work, which puts them squarely in the hot seat. Tim Haag shares four techniques in thermal management for PCB designers.

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Tim's Takeaways: Navigating Industry Expectations

05-29-2020

While some expectations are normal—and, well, expected—in the workplace, there are also those that do more harm than good. Tim Haag unpacks negative expectations and shares suggestions for improving communication in the workplace, as well as positive expectations that you can set for yourself.

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Tim’s Takeaways: Working From Home—5 Tips for Newbies

03-24-2020

Due to the COVID-19 outbreak, many people who have worked in an office environment for their entire career have suddenly found themselves shifted to working remotely. At first, this may seem like it isn’t that big of a change, but it may be a bigger deal than you realize. Tim Haag, who has worked from home for over 17 years, shares five tips for making the most of this situation and working successfully from home.

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Tim’s Takeaways: Clearing Up the Buzz

02-14-2020

My first “real” job in the world of electronics was working at a Radio Shack store back in the late ‘70s. It was a step up from flipping burgers, but it didn’t last long. However, there was one notable aspect of that job; I was there during the time that Radio Shack introduced its first personal computer—the TRS-80. Although it is practically unimaginable now, in those days, there wasn’t much in the way of personal computing available for the general consumer.

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2019

Tim's Takeaways: Realizing a Higher Standard for PCB Design

10-09-2019

To the untrained eye, one circuit board may look pretty much like any other, but as we know, there are major differences between them. Not only are they different in purpose and design but also in how they are manufactured for specific industries. If you are designing medical equipment, for instance, you will have to meet many different regulatory requirements from organizations, such as the Food and Drug Administration (FDA), World Health Organization (WHO), and International Electrotechnical Commission (IEC), among others.

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Tim's Takeaways: Clear Communication Takes the Cake

07-10-2019

Whether baking a cake or building a circuit board, it’s all about clear communication. If the person writing the recipe had not made the choice to clearly communicate what their intentions were for baking that cake, I would have been lost. A missing ingredient here or an incorrect oven temperature there and my birthday surprise would have ended up in the garbage in the same way a successfully built circuit board starts with clear communication from the designer. Circuit board manufacturers want to create a perfect PCB for you, but they can only do so to the extent of the instructions that you give them.

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Tim's Takeaways: Rules Keep You from Crossing the Line

06-20-2019

Driving rules are designed to keep drivers between the lines of traffic instead of crossing over those lines into dangerous situations. Similarly, design rules are also intended to keep PCB trace routing between the lines instead of crossing over them as well. But you might be surprised how many people refuse to use the full potential of their DRCs to protect themselves, and in some cases, refuse to use them at all.

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Tim's Takeaways: I Think I’ll Go for a Walk

04-08-2019

Many years ago, my boss at a PCB design service bureau had his own unique way of encouraging us to take a break. He would come through the design bay and call out in his deep baritone voice, “DARTS!” and we would all follow him into the break area for a quick game. In addition to the benefits of taking a break, forcing our eyes to focus in and out as we threw a dart was a great way to relieve us all from the eye strain of older CRT monitors.

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Tim's Takeaways: A Job Worth Doing

02-28-2019

I get it. We PCB designers are made of the kind of tough stuff where we will work ourselves to death if given the chance. But in our all of our efforts, are we really doing it right, or could we somehow be doing it better? Let’s take a moment to consider some other ways that we might help ourselves to improve.

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2018

Tim's Takeaways: Contract Positions—Go the Extra Mile

10-10-2018

For newbies just entering the industry or experienced designers who have always worked for a corporation, the transition to contractor can be a real culture shock. The allure of working from home and setting your own hours can quickly be replaced by the realities of chasing jobs and wondering where your next payday will come from. However, there are some wonderful aspects of working as a contractor that can make it very worthwhile.

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Tim's Takeaways: Where Have All the Designers Gone (and Who Will be Taking Their Place)?

08-17-2018

We have a lot to pass on to the new designers. We must stress the importance of understanding of the roots of our industry and why this design knowledge is important. I have worked with many designers who don’t understand anything about the output of their design files. They go through a procedure, hit a series of commands, and presto: The design files are all wrapped up in a neat little zip file ready to go out to the manufacturer. That’s all well and good, until something breaks or a manufacturer has a specific question. It would be a great thing to make sure that the designers of tomorrow understand what a Gerber file and an aperture list really is.

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Tim's Takeaways: Hiring the Right PCB Designer

06-04-2018

Like the rest of you, I’ve had times of unemployment, when your daily job is looking for work. You find yourself writing and then rewriting your resume, searching online forums and job search sites, and applying to every job that you can find. I’ve also hired people, and I know what hiring managers face. But hiring managers may be hurting their companies by drawing up a list of expectations so tight that highly qualified people may be slipping between the cracks.

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Will Cool Technology Attract the Next Generation of PCB Designers?

04-17-2018

If I had the opportunity to design some boards that went into medical detection equipment like my new blood pressure cuff, I would be extremely motivated to do that. Maybe what we should be focusing on is not just playing with the new toys, but showing the younger generation different ways to think about how they can improve upon these new toys.

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Customer Support: What do PCB Designers Really Want?

03-19-2018

First, let’s throw a leash around the elephant in the room. That’s my way of saying, “Here are some things that designers want, but we in the support business just can’t give it to them.” The first one that comes to mind: Customers have asked, manipulated, and even tricked me in their attempts to get free software.

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Tim's Takeaways: Good Support Isn’t Just for Customers

03-06-2018

I have been working in PCB CAD tools customer support for years and years, and it isn’t that often that the tables are turned and I have someone who is supporting me. I’ve got to say, it was a pleasure being the recipient of some quality support.

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2017

True Design Efficiency: Think Before You Click

10-09-2017

At the captive shops that I’ve worked with, where the designers were more involved in the entire design cycle and had better access to the corporate libraries, staff engineers, etc., the story was often the same. Some designers would jump into the deep end of the pool of design without any thought to drowning while others would be so busy lacing up their life preservers of preparation that they would take too long getting out of the shallows and into the depth of their design. So, what’s the best approach here?

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Tim's Takeaways: It Really Wasn’t My Fault

09-07-2017

I once received verbal instructions from an engineer who directed me to make a certain change. I didn’t think anything of it. Many months later, this same engineer told me that there were troubles with the board and all its successive versions because of the change that I had made. He ended up making it right in the end. But in hindsight, what could I have done to save myself a couple of months of suspense and worry?

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Tim's Takeaways: Stepping into the Great Unknown

08-16-2017

Many years ago, I was given the opportunity to switch my career path from senior circuit board designer to CAD systems administrator. I wasn’t certain that I wanted to give up the comfort of being a designer; after all, I had been one for a long time. But I knew that this transition would help my overall knowledge base of everything CAD-related, as well as better position me in my quest for a management position. So, I pulled the trigger and accepted the new job even though the idea of stepping into the great unknown like that was very intimidating.

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Tim's Takeaways: Design Tools of Tomorrow--A Real 'Marvel'

04-05-2017

Imagine if you could interact with your design as a hologram floating in front of you the way Tony Stark did in the movie "Iron Man." Wouldn’t it be amazing if you could pick a section on your holographic design with your hands and expand it to the point where you could peer into it, spin it around, and manipulate it as you desired? Want to push a trace down to a different layer? Just give it a nudge in the right direction and the holographic display changes it to the next layer. Don’t like the way a certain area fill looks? Then just grab it with your fingers and pull it out and throw it into the virtual garbage can.

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Tim's Takeaways: 'Sparks' to the Rescue in RF Design

01-03-2017

Just like the early days of radio where Sparks the radio specialist was in demand to get the job done, we now need RF specialists to work together with electrical engineers to create the intricate designs required for RF circuits. You are now Sparks, the go-to specialist who will take care of RF design business.

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2016

The Basics of Hybrid Design, Part 3

06-16-2016

The world of hybrid design is growing, and we have lots of hybrid-specific functionality built into our software that helps designers meet and conquer the unique hybrid design requirements that they are faced with. And yet many designers out there (and I used to be one of them) have no idea what is meant when people start talking about hybrid design.

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The Basics of Hybrid Design, Part 2

05-16-2016

In the first part of this series, we discussed the basics of hybrid design from the PCB designer’s perspective, and here we will continue that discussion.

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The Principles of Hybrid Design, Part 1

04-25-2016

What exactly is a hybrid design? We are seeing more and more of our customers exploring the world of hybrid design, and we are getting new customers for whom hybrid design is their sole focus. The world of hybrid design is growing and we have lots of hybrid-specific functionality built into our software that helps designers conquer the unique hybrid design requirements.

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2015

Tim's Takeaways: The Utility Belt

05-12-2015

The utility belt is a great thing to have. Batman would be long dead without his, and Tim “The Tool Man” Taylor would be useless without his. But for a circuit board designer, a utility belt is equally important. All of us at one time or another will have questions about the CAD system we use, and one essential tool to have in your utility belt is a list of people you can go to for help. At the top of this list should be your CAD system’s friendly customer support staff (like me).

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DFM: The PCB Designer as Arbitrator

04-08-2015

Design engineering is usually a combination of electrical and mechanical engineers. Although these two groups can have their own dramatic conflicts between each other, they will usually end up working together because they ultimately serve each other’s needs. But the manufacturing engineering requirements usually come from a completely different department or from an outside manufacturing vendor.

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2014

Like it or Not, You're a Role Model

12-24-2014

"During the years that I built my skills as a circuit board designer, many people helped shape my character. Some were impulsively brilliant at laying out a board, while others were steady and consistent in their approach to work, dotting every 'i' and crossing every 't.' But they were all patient with me, answering my questions, showing me the ropes, and setting good examples for me to follow," says Columnist Tim Haag.

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Blink and You Will Miss It

11-05-2014

Tim Haag writes, "Friedrich Nietzsche said, 'That which does not kill us makes us stronger.' Well, that adage certainly proved to be true in my situation. If I hadn't been ripped from my secure position and forced to contract for a short season, who knows how my future would have eventually unfolded. And if it hadn't been for that brief season of hardship, would I have had the strength and flexibility to succeed later on?"

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Tim's Takeaways: Blink and You Will Miss It

11-05-2014

Tim Haag writes, "Friedrich Nietzsche said, 'That which does not kill us makes us stronger.' Well, that adage certainly proved to be true in my situation. If I hadn't been ripped from my secure position and forced to contract for a short season, who knows how my future would have eventually unfolded. And if it hadn't been for that brief season of hardship, would I have had the strength and flexibility to succeed later on?"

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There Are No Stupid Questions

09-10-2014

Many of us who have been designing boards for years have had to deal with annoying questions from "the kids." You know who I mean: The rookies, newbies, greenhorns, or puppies just starting out in their design careers. We've all had to answer questions like, "Why is library development so important?" or "Why is solder mask green?"

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Tim's Takeaways: There Are No Stupid Questions

09-10-2014

Many of us who have been designing boards for years have had to deal with annoying questions from "the kids." You know who I mean: The rookies, newbies, greenhorns, or puppies just starting out in their design careers. We've all had to answer questions like, "Why is library development so important?" or "Why is solder mask green?"

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Design Rule Checks - For Your Protection

07-09-2014

Columnist Tim Haag writes, "I have designed multitudes of PCBs over the years, but I have a confession to make: It can be hard for me to run that final design rule check. I know that it is important, but at the end of a long design cycle, I just want to be done. I don't want to redo anything, and I sure don't want to look at my own errors. Do any of you feel that way?"

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Tim's Takeaways: Design Rule Checks - For Your Protection

07-09-2014

Columnist Tim Haag writes, "I have designed multitudes of PCBs over the years, but I have a confession to make: It can be hard for me to run that final design rule check. I know that it is important, but at the end of a long design cycle, I just want to be done. I don't want to redo anything, and I sure don't want to look at my own errors. Do any of you feel that way?"

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Customer Support: Not Just for Customers Anymore

06-04-2014

Columnist Tim Haag writes, "In my role as the customer support manager, I have seen plenty of examples of customer support. But my point here is not to focus on customer support as a function of a support technician. Instead, I want to explore the concept of how we should all strive to provide the best level of customer support in our jobs, no matter what we do."

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