• Image: I am on the left, receiving the Committee Leadership Award.

How did you get into electronics/engineering and when did you start?

After my junior year of college I accepted an opportunity as an intern with Hughes Aircraft Company in Tucson, Arizona, in 1982.

How did you get involved with IPC and the 1-10b task group?

I was trying to find out how the PCB conductor current carrying capacity charts were derived back in 1999. Mil-Std-275E and IPC-D-275 were the documents that had the PCB conductor current carrying capacity charts. I called IPC and asked for the origin of the conductor current carrying capacity charts. They were not sure at the time, and led me to an IPC technical paper, IPC-TP-117 by Dr. Jennings at Sandia Labs. Long story short, that was not the origin of the data, but after chasing that question for another year I found a gentleman, Jim Yohe, that knew of a document that dated back to 1955 that actually had the original data, which is referenced in IPC-2152.

What happened from there?

During the year before finding the original data, I started doing PCB conductor current carrying capacity testing for the company I was working for at the time. I came up with results that were significantly different than the original current carrying capacity charts. There was more testing that needed to be performed. The company didn’t want to continue the testing, so I left that company and teamed with the University of Colorado, Denver to write a National Science Foundation grant proposal in an effort to get funding to continue the research. The funding was not approved, although we had already setup a lab. Without the funding we were not able to continue. So I formed a company and purchased the test equipment from the university, setup my own lab and continued the work.

What are your favorite hardware tools that you use?

Agilent data acquisition system in my home lab.

What are your favorite software tools that you use?

Thermal Man Calculator, Harvard Thermal; Thermal Analysis System (TAS), Harvard Thermal; TASPCB, C&R Thermal Desktop.

What is the hardest/trickiest bug you have ever fixed?

Current carrying capacity in printed circuits through the creation of IPC-2152. I am only one of many that participated, although I like to think that I had a significant role.

What is on your bookshelf?

On my work shelf, I have Clyde Coombs Jr., Printed Circuits Handbook, Dave S. Steinberg’s Cooling Techniques for Electronics Equipment and Vibration Analysis for Electronics Equipment, Principles of Heat Transfer by Frank Kreith, and Fundamentals of Heat and Mass Transfer by Theodore L. Bergman, Adrienne S. Lavine, Frank P. Incopera and David P. Dewitt.

Do you have any tricks up your sleeve?

Current carrying capacity in flex circuits, current carrying capacity in odd shaped geometries, high current pulses in conductors and current carrying capacity in wires and wire bundles.

All the data and references collected over the years on current carrying capacity provide a wealth of information on these topics. Periodically, workshops are given that share in a few hours information that took years to accumulate.

There are a handful of companies now that have tools to solve some of these problems. Ten years ago, Harvard Thermal Inc. was the only company with analysis tools that could solve current carrying capacity problems involving odd shaped geometries.

What has been your favorite project?

Phoenix, the Mars lander, allowed an opportunity to compare natural convection coefficients calculated for a CO2 environment with data we were getting back from Mars.

Do you have any note-worthy engineering experiences?

On my way to work one day in Huntsville, Alabama, listening to National Public Radio, there was a discussion that focused on the need for professionals to work with schools and students. That same week there was a call for papers for a local conference. In addition, there was a cookbook circulating around work that had the favorite recipes from a group of engineers and scientists. The requirement for writing and the acceptance of the recipes, by the engineers and scientists, was that they had to write their recipe in a scientific procedural style. It was an entertaining book and inspired me to write an abstract for a paper, which I entered for the upcoming conference.

Surprisingly, the abstract was accepted; it was titled, “An Experimental and Numerical Investigation into the Thermal Properties of an Egg.” I then went to a local high school, spoke to the principal and told her my story and that I was looking for students to work with me to collect data, make a thermal model, correlate the model to the data and write the paper. I ended up with eight students that worked with me after they got out of school on Fridays, and on Saturday mornings for the next couple of months. We went to the University of Alabama, Huntsville, talked to the head of the Mechanical Engineering department, told him our story and he gave us keys to their thermal laboratory and told us we could use any of their equipment that we needed.

We mounted thermocouples in eggs, using ceramic rods, and collected time temperature data for various egg parts as the eggs hard boiled. We also took egg parts, the white, yolk, and shell, and measured their density, specific heat and thermal conductivity. Using that data we made a thermal model and compared the time temperature response of the egg during the process of being hardboiled.

The students and I presented the paper. It was well received and mentioned by the keynote speaker as one of the papers he wanted to see.

Separately, the latest project I’ve been involved with is the thermal vacuum testing of the spacecraft JUNO, correlation of the spacecraft model, flight predictions and launch.

What are you currently working on?

Thermal analysis of electronics and their cold plates for the MPCV, or Multi-Purpose Crew Vehicle. I’m using a software product by C&R Technologies, Thermal Desktop to model fluid flow and perform thermal analysis of the cold plates. Electronics boxes get mounted to these cold plates, which are designed to maintain the box temperatures within design limits.

Can you tell us more about JUNO?

I am a thermal analyst. I was a part of the thermal team. My job involved deriving boundary conditions for science payloads, working on the thermal model of the spacecraft, modeling the test environment, correlating the model, creating flight predictions and documenting the results.

The biggest problem that I noticed was the level of funding and the time frame for the project. I started in the engineering field in 1982, and from my perspective, companies have continually been forced to reduce the amount of money and resources they put into their projects.

JUNO is a spectacular spacecraft that just started on a journey to collect information about Jupiter. A Web search on NASA JUNO will show some interesting links.

Without funding how did you continue to do the work?

I consulted doing thermal analysis to fund doing the work. There were two students at the University that worked with me to setup the lab and I was able to hire them to work with me to do the conductor current carrying capacity data collection. We were able to collect trace heating data on multiple boards, create thermal models of the boards and correlate the models to the data.

Over the next several years we worked with the Navy and a private lab to help them perform the same testing, which we used for comparison. Their results agreed with ours with variations resulting from altitude and relative humidity. 10 years after we started, and coincidentally at the end of our 10 year plan, the IPC 1-10b task group published IPC-2152, Standard for Determining Current Carrying Capacity in Printed Board Design.

What direction do you see your business heading in the next few years?

The company that I work for will likely be getting contracts for smaller satellites and shorter schedules.

My own company, Thermal Man Inc., will be focused on bridging young people interested in the sciences with industry.

An interesting outcome to the egg experiments and investigation, aside from the great experience of getting a paper published before these kids graduated high school, was a discussion that came after the presentation. A scientist that had recently gone on an expedition to the Galapagos Islands to recover rare turtle eggs had a question. Could our model be used to predict the temperature response of these rare turtle eggs? There was no reason that the models could not be modified to make predictions for the turtle eggs.

The expedition, upon their return found that the eggs did not survive. That was the reason that the scientist was asking the questions. He suggested that we submit a proposal to the National Science Foundation to investigate how we could help in future efforts. We did not write any proposals on the topic, but the thought has been with me for a long time. That project, and many other ways, can be used to bridge young minds with the professional world to help students pick a path for their future. Those are the type of projects that my company will be focused on.

What challenges do you foresee in our industry?

The challenge will continue to be doing more with less. There are some exciting transformations in software tools that have been slow in coming up through the industry. The transformation is directly associated with computer advancements. I see the area of multi-physics tools being at the edge of a significant breakthrough. It will be a little painful at first, as most changes are, but I think the benefits will be significant.