In this interview from SMTA International 2018, Jason Fullerton of Alpha Assembly Solutions discusses the benefits and challenges of low-temperature soldering. He also highlights the biggest concerns he’s currently seeing in the industry, including young engineers lacking hands-on manufacturing experience and training, voiding and head-in-pillow issues, and low-temperature soldering demands. Barry Matties and Happy Holden also spoke with Jason about the difficulties surrounding each of these trends and how Alpha is helping their customer base to best combat these issues.
Barry Matties: Jason, can you tell us a little about Alpha Assembly Solutions for our readers?
Jason Fullerton: We're one of the market’s leading providers of metals, chemicals, and materials for soldering and assembly. We specialize in metallurgy and alloys, solder pastes, fluxes, solder preforms, and core wires. We also have an advanced materials division that works more on semiconductor fabrication and solder alloys for those applications as well.
My title is a Customer Technical Support Engineer. I'm basically a field service engineer for Alpha and a soldering process engineer by trade. I spent 15 years working in factories using products from Alpha and other companies as an engineer running the assembly processes. Our role at Alpha is to help our customers use our products by providing a resource that's walked a mile in their shoes and can advocate for them within the organization. We understand the challenges they face because we used to meet the same challenges back when we were in engineers working for a living.
Matties: That's a great background to have in this particular role because as you said, you've been in their shoes. What are the most common issues that your customers come to you with that they need to be solved?
Fullerton: The biggest issue I see in the industry right now is an influx of younger engineers that don't have the background and training in techniques and technology that we use in electronics today. There's a large training issue now, especially with startup and smaller companies that don't have the budget to hire experienced engineers. They bring engineers in and expect them to learn on the job, and they make basic mistakes along the way. Then, people like me come in with their supply base to help them prevent those kinds of mistakes.
One of the things we like to do is provide training to our customers. I do a “solder paste 101” training on the very basics of the solder materials. There are other sessions on advanced printing, wave solder troubleshooting, and the importance of reflow technology. The lack of training and education in the United States to teach people how to solder and be process engineers in this industry is a big issue.
Matties: Is there a large interest for people to be in this role, or is it something that they stumble into?
Fullerton: A little bit of both. The people who have an interest in it gravitate towards universities that have programs for this.
Matties: That's what I was thinking, so you're dealing with people who stumbled into this career.
Fullerton: A lot of times, yes. I'm a manufacturing engineer by degree but I stumbled into electronics assembly at the start of my career. All throughout my career, I've worked with people who have a degree in electrical or mechanical engineering, and then one day they’re told to be a process engineer—"That's your new job. You're going to learn how to solder, coat, or use adhesives, and apply them in an advanced production process.” However, their educational background doesn't prepare them adequately for that, and so they have to learn on the job as they go. This lack of background knowledge usually leads to a lot of mistakes.
Matties: When you say you're shifting your effort around education, are training sessions offered online or do you visit in person?
Fullerton: Typically, in person because we want to observe their processes and ensure the training is relevant to their specific needs. Part of my methodology is to do what I call the “book learning” to start. We go in with a PowerPoint, talk about the technology, and then take the group out to the production line and apply that hands-on experiential learning so we can reinforce what we address in training.
Matties: Is this something that you're formalizing or is it more on a case-by-case basis?
Fullerton: It's semi-formalized. We have standard PowerPoint presentations and programs we offer to our customers. Many times, these meet their needs, but if a customer—especially a key customer—comes to us with a specific need for education, we'll develop new materials around that particular question or set of topics that they're interested in.
Matties: This is a value-add that you bring to your customers.
Fullerton: You took the words out my mouth. Our role in the company is not to charge our customers to do new things; our customers get access to this level of support and expertise for being an Alpha customer.
Matties: Aside from the training, what other sorts of problems does your team encounter most frequently?
Fullerton: One of the most popular ones we see nowadays is voiding. If you walk around this show, you'll see every soldering company has a voiding display, panel, or marketing representation because that's a big challenge in the industry—both how to prevent and mitigate the effects of voiding solder joints, and how to better understand the impact of those voids on the reliability of the solder joints themselves.
Matties: It's an ongoing issue with no solution?
Fullerton: There are solutions, but they are not easy or obvious. The answer isn’t to simply change your solder paste or modify your reflow profile; it's more complicated than that. Thus, voiding solutions aren't just a single product. As a company, we offer a service to our customers called “Void Reduction Solutions” where we essentially form a cross-functional engineering consulting team within our organization to assess the current efforts that the customer has made toward their voiding problems—where they have gotten to at this point, their objectives, and holistically looking at the entire system from stencil design, to the interaction of board surface finish materials, solder pastes, and the actual solder paste application process. These are the kinds of things we will take and try to identify what can be improved in their operation to reduce the impact of voiding on the solder paste they need.
Matties: Densities also increase, of course. How does that complicate the process?
Fullerton: We want smaller chips to do more and dissipate more heat. Heat is one of the times when voiding can be a reliability concern. Many devices use a thermal plane on the bottom as their thermal interface material between the chip and the heat sink, which is the board. Voids in the material will undoubtedly reduce the thermal conductivity, but there is not a good understanding of what is the critical level. Is 10% or 20% good enough? How about 50%? No one knows the real number, so since we can measure it and we know that more must be bad, we strive towards less, but no one knows where that finish line is. We want to see increasingly less, even though continually driving down that number may not provide as many benefits as people think it does.
Matties: It becomes a diminishing return.
Happy Holden: It's interesting because when you're telling us about companies hiring new engineers and expecting them to know all these practical elements, the same is true for printed circuit design and fabrication. Electrical engineers don't know how to design a PCB. They know all about Maxwell's equation and signal integrity but without any kind of hands-on experience. Do we need to rethink four-year degree programs and start focusing on offering four-year technology degrees where you don't have theoretical math and science classes, but more hands-on design and assembly so engineering graduates can start knowing a lot more about the real world in practical electronics? It costs your company money to train these people, and somebody has to pay for that. It probably comes out of your profits or your prices. A company that offers no training but offers lower prices versus a company that has all the training and gets the business is not a good financial model.
Fullerton: We follow a philosophy that our success is tied to our customers’ successes, so the things we can do to make our customers more successful will lead them to buy and use more solder materials in the long run. You’re right that there are certain situations where a low-cost competitor can undercut us, but that's not really where we play. We play in the value selling market and make sure that the total package that Alpha offers to our customers meets and exceeds their needs and expectations.
As far as the education levels and how to improve that at the university level, there are two things that I see as beneficial. One is something I took advantage of as an undergraduate—I went to a school that offered co-op. There are a number of co-op universities around the country, and I'm going to make a shameless plug for Kettering University in Michigan, which is where I earned my degree back when it was still called GMI Engineering & Management Institute. At Kettering University, completing a series of co-op experiences is a requirement. All students leave the school with a bachelor’s degree and two to three years of hands-on experience in the field that they work in as a requirement to graduate.
Drexel University in Pennsylvania is another good example where co-ops are an integral part of the requirements for their degree program. Other schools have optional programs that they offer their students that some take advantage of, so I sought out and chose a co-op school when I looked at my undergraduate education. I wanted to get both book learning and the hands-on part of the overall package.
Ford Electronics near Philadelphia where I grew up hired me when I was a student. I started as an 18-year-old that knew very little about engineering but learned as I went in that factory about how electronics were being manufactured, different processes, how a factory works, and who's responsible for what. When I graduated, I had practical real-world experience to accompany the piece of paper that said I had a degree in manufacturing engineering. This is a big piece of advice that I always encourage young people to look at when they are considering education opportunities—find ones that package hands-on learning along with classroom education.
The other side is schools like Rochester Institute Technology or Auburn University that have manufacturing labs and programs built around electronics and SMT-type manufacturing, but there are very few of those. There's a lot of investment and equipment and know-how that they need put into that. Manufacturing is not exactly a glamorous industry that is easy to recruit young people into as far as a degree program goes. There is a limitation on how many people are willing to put out that expenditure into building this kind of program and take a risk on a relatively limited field as far as they see.
Holden: I graduated with a lot of my friends because they worked for 14 months between their junior and senior year, so they graduated one year later, but they had over a year of hands-on experience.
Fullerton: There is no value you can put on hands-on experience, especially at that age when you're just learning and forming your understanding of the engineering field. Having hands-on experience where you’re around people that have been doing it for 10–30 years and seeing how they do things is priceless. Plus, you can make the mistakes that don't hurt anybody when you’re young, so you can learn from those mistakes and not repeat them later when it really matters—when you’re in charge of things.
Holden: What do you think was the most valuable class that you took at your university?
Fullerton: I would probably say my design for manufacturing (DFM) class because it forced me to look at the world from a designer’s point of view, integrate how the designer views the assembly of a product, and identify opportunities for efficiencies to be gained by designing the part properly for the manufacturer. In my role, I am typically the recipient of that work from designers, especially when I'm working for OEMs and manufacturers. Many times, their biggest problems were caused by designers that weren't aware of how the choices they made at a design level impact the ability or inability of assembly of that part. At one of my jobs, I was infamous for taking boards on first prototype runs, walking them back to the design rooms, pointing out the things that were difficult for us that they caused, and showing them that there are other ways to solve the problems we encountered that could make my life easier—"We can all win in this.”
Holden: I haven't heard of too many DFM courses. How was that structured, and did they use Dewhurst and Boothroyd?
Fullerton: Yes, exactly. They taught us B&D DFMA. I still remember giving my final presentation on that luggage cart to Prof. Tuttle.
Holden: I never took a class like that, but that's one of my definitions of what design for manufacturing is—doing it right the first time and not design rule checking to find your errors. I’m glad to meet somebody that had a class like that in their education.
Matties: And considers it valuable.
Holden: Exactly—considers it one of the most valuable. It validates my opinion of that particular piece of knowledge. I never took a DFM class, but similar to that, the most valuable course I took was engineering statistics. It was not boring university statistics out of a book; instead, it included experiments on how to optimize black boxes. As a chemical engineer, they kept teaching me, "Don't worry what happens inside the box. Your job is to take A and B and make C for a profit." The big thing was to make a profit. “Let the scientists worry about what happens inside of the black box.” That was a design of experiments (DOE) approach, which is a form of DFM in a sense because your output is divided by input.
Fullerton: My second most important class was on probability and statistics, which was when I first realized I was in the right field of engineering. Calculus was hard and challenging, and I did well enough in it, but I didn't have to put much effort into my probability and statistics class, and I got an A because it came to me easily. Statistics and probability is the math of manufacturing. Calculus is the math of electrical and mechanical engineering, but randomness and variation in the world around us is the math you use in the manufacturing field. When I had such an easy time in that class, I confirmed that I had chosen the right path in my degree program.
Holden: I think I'll take this recording to my visit to Michigan Tech next week where they're putting together a PCB laboratory for undergraduates to get some hands-on experience.
Fullerton: Michigan Tech is an excellent school. The freshmen that are there will know what Kettering University is as well because it’s down in the under-the-bridge part of Michigan.
Matties: In addition to training and education, we recently published Alpha’s low-temperature soldering book. Tell me a little bit about the demands for low-temperature soldering and what people should know.
Fullerton: Low-temperature soldering has a number of significant advantages over standard tin-silver-copper (SnAgCu, or SAC) alloys and lead-free soldering temperatures, including the reduction in the stress on components and substrates on boards. Another benefit is the effect on warpage on thin substrates. Thus, the development of our newest material was driven by Intel and their need to develop thinner, larger, more powerful chips. The problem is that when we soldered them at 240°C at SAC temperatures, the warpage and integrity of the solder joint was a huge problem and head-in-pillow risks were much higher.
Thus, Intel approached us with this challenge and said, "How do we solve this through material development?" Our response was to look at lower soldering temperatures and low-temperature solders. The challenge of low-temperature soldering has always been that they are typically very high in bismuth. Bismuth tends to be brittle and doesn't stand up to the thermal cycling as well as Sn63 or SAC305 does. The challenge our metallurgists took on was to develop a tin-bismuth alloy that had low-temperature soldering properties but met or exceeded the reliability performance of the SAC305 solder joint in those system. Now, we have a successful customer that's currently using these in a low-temperature soldering system in a commercial product that’s in the field; people are using all the time, and they don't even realize it was formed with a low-temperature soldering process.
Matties: Is there a natural demand for this or is this something that people need to be educated on?
Fullerton: A little bit of both. Some challenges can't be met when we are soldering with the same SAC305 alloys; part warpage is a big one. There are other advantages that people can take advantage of, such as the reduction of the energy you consume or the elimination of wave solder by using a pin and paste on components that couldn't tolerate 240°C but could maybe tolerate reflow of 190°C. Suddenly, these parts are back in play and reducing an entire process out of your process flow is highly advantageous for operations.
Matties: Is there an approval process that OEMs would require or request to go through for this?
Fullerton: Typically, our strategy is to approach OEMs, especially if they are using EMS companies as their service provider because EMS companies do not have the authority to change something as significant as an alloy on their own. We have partnered with people like Intel and their customer, and we’re working with other OEMs to help them qualify this material at an OEM level; then, they can flow down the requirement as we take the material to their subcontractors.
Matties: What's the greatest challenge in convincing an OEM to go in this direction?
Fullerton: There is always a challenge to convince somebody to do something different. What I say a lot is that doing nothing is easy but doing something is hard. There is some effort required, and reliability testing needs to be done to gain the confidence in the performance of that alloy in the system to determine if it’s going to be what they expect when they need to deliver to the customer base. There is an investment in time, effort, materials, and money that occurs at the initial stage. There is also the challenge of convincing customers that the advantages down the road will be more than they are going to have to invest to get to that same level.
Matties: When OEMs look at the advantages, what do they most often hope for or what should they expect?
Fullerton: The reduction of defects, especially if you're using devices prone to head-in-pillow defects, is a big advantage. There are some benefits in the voiding realm too. Running a low-temperature process has inherent benefits when it comes to the formation of voids due to the flux, so there are some advantages there. Again, the reduction of the overall manufacturing cost is one that the EMS will achieve, and they can pass that on to their customers as a cost-save down the road or over time. These are benefits they can gain, but the trick is to quantify the benefits and make sure that the investment in achieving them has a payback with the benefits that you produce.
Matties: Is there a dedicated line at an EMS company that they have to install or how does this process integrate with a current flow?
Fullerton: Usually, there will be some offline prototyping that's done initially to do some general testing of the materials. Eventually, a robust and reliable engineering program will involve taking materials out of the standard manufacturing process and testing those as well to ensure that any variables that are encountered going from low-volume prototyping to high-volume production are considered when they run these tests.
Matties: One last question we always ask is what advice would you give to a young person entering this industry?
Fullerton: Get some hands-on as part of your education—don't just learn it out of the book. I've seen many engineers come out of college thinking they knew everything about everything because it was all in the book, and the day they entered the real world, they realized nobody uses their books anymore, so make sure you get some good real-world experience. Having a co-op helped me choose the right electives that I knew would support the areas I was interested in as well. I saw what the engineers used around me and then chose the classes to help me learn about the techniques and topics that they used.
Matties: Thank you so much for your time today, Jason.
Fullerton: Sure thing. Thanks for having me.
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The Printed Circuit Assembler’s Guide to… Low-Temperature Soldering