Living Up to Their Name at Alpha Assembly Solutions

Estimated reading time: 11 minutes

Fullerton: There’s always a problem of the day.

Warner: And what's your prevailing problem du jour?

Fullerton: The one that's floating to the top now is voiding. Voiding in solder joints has become a very critical characteristic. We've been looking at voids in solder joints for 10–15 years, ever since we adopted lead free. But 10 or 15 years ago when lead free was brand new, it was primarily on the area array packages where voids were relatively straight forward. There is not as much of a relationship between voids and reliability in BGA or area array applications. Now there are types of packages that are out, bottom terminated components, where you’re using that termination as a heat sink, or LED packages where you're actually using that to drain the heat away from the LED. Especially with LEDs, it’s been an extremely difficult challenge to meet, because they're using that solder as a thermal interface material. The more voids you have in that solder joint, the lower your thermal conductivity. There's a very strong drive right now to develop products and processes that can minimize the amount of voids especially in the lighting and power device market.

Right now we are developing material and we have released a material for the lighting market that is designed to be ultra-low voiding. We did this by modifying the flux chemistry to minimize the reactions between the flux and other materials in the solder and on the surface finishes to minimize the amount of voids forming in the first place. That's something we pushed heavily into LED markets because that's where the biggest impact is on voiding and the biggest direct correlation.

Warner: Sounds like you need to write a new article for us, Jason. Hint, hint.

Fullerton: That's certainly something we've been talking about. It's relatively new to the market so there isn't a lot of field history with it yet.  We have some customers that are currently using it in production. As we develop more experience with that, we'll have a stronger data suite of the material used in the field. We have strong data from our R&D source, of course, but what works in the lab can be different than how it works out in the world. There are variables you can't control in the real world that you can control in the lab. As we get more and more field service, that's where I tend to be stronger with bringing information to the table because I'm involved in the application base. So the combination of the R&D chemistry on the front end and then supporting of our customers in troubleshooting and learning how the material works in real-world applications helps strengthen our ability to provide that solution to customers.

Warner: Okay, we're going to stay tuned for that. Sounds like as you get some case studies and get some data and long-term efficacy reports, we would love to hear about that. Jason, I understand you are presenting a paper this week. What can you tell me about that?

Fullerton: The paper I’m presenting tomorrow is a comparison of two engineered lead-free, silver-free alloys in a selective soldering application. It's a very specific application, that's for sure.

Warner: I would say so.

Fullerton: There's a widely known material that's been out since the advent of lead free that's very commonly used. In the last two years, we have released a product that competes directly with that. However, we struggle because there's a large install base with our competition, and we don't have that large field history of use to fall back on yet where our competition does. The initial intent of this project was to demonstrate to a selective soldering equipment manufacturer that our alloy was as good as another alloy they were very familiar with.

But what happened was as we developed this experiment, we actually realized that not only was it as good as it, but it showed some significant improvements in the ability to meet the challenges on certain difficult applications. I'm presenting data tomorrow that shows the comparison of the settings that are required from the process inputs, like pre-temperatures, solder temperature, and contact time during the solder process. This shows that you have a wider range of settings that can provide suitable quality and meet or exceed the requirements for through-hole selective soldering compared to our competition. This is going to be used, of course, to show that we have a competitive material. We're non-commercial here at the conference, however my field sales are also going to use that to demonstrate to customers currently using our competition’s material that there may be a better material out there for them to use.

Warner: Will that white paper be posted on your website for folks to grab or you going to have that posted on SMTAI’s website site?

Fullerton: It will be part of proceedings in the conference when they are released. We do publish the white papers we present and have them available for our customers on our website.

Warner: Well, it sounds like you're a busy guy. Thanks so much for coming by.

Fullerton: That is for sure. There is a lot to do at the SMTA International Conference and I try to get as much benefit from these events as I can.

Warner: It was great to talk to you. We look forward to seeing you again. Good luck with the show.

Fullerton: It's always a pleasure.

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