Alpha Talks Challenges of Solder Recycling
I had the opportunity to meet and chat with Jason Fullerton, a customer technical support engineer with Alpha. We talked about his presentation on recycling solder and why doing this in-house is not a good idea. We also talked about the new, smaller particle solder pastes and about Alpha’s recycling program that must really benefit their customers.
Patty Goldman: I understand you presented a paper here at SMTAI. Perhaps you want to start with a little bit about your company or yourself and give us a little overview here.
Jason Fullerton: Sure, Alpha is one of the world's leading manufacturers and distributors of electronics interconnect materials. We specialize in solder and solder alloys and other chemicals used in the interconnect field, fluxes, materials like that.
I am a customer tech support engineer. My territory is the United States and Canada. I work with our customers on the application side. I help them use their materials properly, help them optimize their processes for used materials, and help them select new materials for new products or to update the products they're currently using. My background is a manufacturing engineer in the industry, so I once actually did the jobs that my customers do.
Goldman: That's nice.
Fullerton: I have experience with their jobs so I can help them more by consulting to our entire customer base. We essentially have engineers that are there to help them use their materials and run their processes as efficiently as possible.
Goldman: Because if they do well, you do well.
Fullerton: Exactly. They do well, they buy more of our materials and we do well. Everybody's happy.
Goldman: Everybody's happy. So you presented a paper that had to do with recycling?
Fullerton: Yes. The paper was comparing the properties of commercially available solder—which is controlled by pretty stringent specifications on purity and content—versus materials that result from a user recovery process. There is equipment on the market that can take their waste product from a user’s wave solder equipment, process that through another piece of equipment and the result is some waste and some metal bar that these users will now put back into their solder machines, that they’ll remelt and use again.
Goldman: So they've reduced their waste.
Fullerton: Well, they do; but the material that they're putting back into the machine is not the same as commercially available solder. It doesn't have the same level of purity. It has more contaminants. Dross inclusion is the biggest one that we have found.
Dross and oxides are formed when metals react with the oxygen around it, and that's a waste product the user can't use anymore. They'll take this material off. They'll squeeze it under heat and pressure in this piece of equipment. Then they'll get a bar. Well, this bar has pretty high dross content. We did a benchmark study some years back and we found that even the worst commercially available solder had less than 1% dross inclusion by weight in tin-lead solder. The alloy that we studied, the product of this recycling process, had about 12.4% dross by weight. That's an order of magnitude higher. Dross is not solder, it's pure waste. For every eight pounds of bar that came out of this machine, only seven pounds of it was actually useful metal. The other pound was useless and a waste product that's a contaminant in the solder process.
Goldman: Now suppose somebody tries to use that bar. What kind of problems do they have?
Fullerton: That's one of things we covered in the paper. One of the biggest issues is that with that level of dross content being put back into the solder machine, which can manifest as dross pumped up through the solder weight and then contacts the board. That can cause bridging in certain areas. It can also build up inside the hardware and inside the machine. Every six months or so, wave solder users have to take hundreds of pounds of hardware out and scrape them off. It's almost like taking barnacles off of a ship, having to scrape off all this dross. If they're putting more dross in than the raw material, they're going to get more buildup more quickly on the equipment.
It can increase the effort in maintenance. It can increase the frequency of this maintenance being required. This maintenance is pretty arduous. It's a 4–8 hour task to do this kind of maintenance. You want to put it off as long as you can. Adding this material with this contaminant level in there may increase the frequency of those, and that can be a significant problem for users.
Goldman: What's the outcome of this?
Fullerton: We found that the dross was a pretty significant problem. We actually saw another issue where we looked at the actual metal content of the bar. There are pretty strict specifications on the purity of the solder we sell to our customers. The alloy that comes out of this process, in some cases meets the specification, but they're very close to the specification limits. This can cause the users to dilute the tin, for example, in their solder machines, which eventually could make the machine alloy go out of specification itself.
Goldman: So it's not quite right. The recycled bars are not at the optimum levels or they all have different metal contents.
Fullerton: Right, this bar and that bar are not the same thing but the user treats them like they are the same thing. That's what we want to raise the awareness of. Now the alternative is why we have the incentive to write a paper like this. The alternative is that major solder manufacturers already have recycling and reclamation services.
In fact, we actually have a booth here just for reclamation services, separate from our main corporate booth. We'll take the dross from the user and we'll pay them for that material. We'll process the material and break it down into the units of tin and lead and silver and copper. We’ll use those pure materials and make new alloy and sell that as a pure alloy again.
Goldman: That really cleans it up.
Fullerton: We provide our customers with certification that the material is recycled—not put in a landfill, for example. It helps ensure they can comply with their environmental regulations by tracking and reducing their waste output in their processes. We will pay the customers for what is essentially useless waste to them. Some companies take it for free. Some companies actually charge users to take this material away. We'll pay them for it and take it away and prove to their environmental regulators that we safely transferred it back into new product or back into another circuit board.
Goldman: That should be important to your customers.
Fullerton: Absolutely. It's important to our customers. It's important to us too, because it's a way we can prevent having to use ore. It's a way for us to insulate ourselves from conflict mineral issues by using recycled materials as part of our raw material set. We have to take less from the environment, and from the world. There’s less risk of damaging the environment through the mining of these minerals that we use.
Goldman: That conflict mineral thing is a big deal. This must be really important to your customers.
Fullerton: Absolutely. In fact, less than a month ago, I had a customer call me and request our most current version of the declarations for conflict minerals and the source of our materials. We have a pretty robust environmental compliance and health and safety group that are also involved in ensuring that we do take materials from safe areas—not from areas that would be illegal or immoral to take materials from. We have all of the declarations ready for our customers. They can go right online and download immediately if they want. They’ll get an instant email for the most current version. Once they register, they will automatically get a copy of any future revision as soon as it's released.
Goldman: That's got to be really good for them.
Fullerton: It's good for everyone. It's good for the world. We have to take care of the world that we live in, right?
Goldman: Yes we do. What else is going on with you and your part in Alpha?
Fullerton: It's a busy time in the industry because everything is getting really small. That tends to challenge the manufacturing processes. The smaller things get, the more difficult they are to manufacture. The more difficult things are to manufacture and process, the more our customers need involvement from tech support, like myself and my colleagues at Alpha.
It's one of the things we pride ourselves on is providing excellent research and development, and a high level of technical support to our customers. We're not just selling them materials. We're also selling them the ability to use those materials, perhaps even better than they understand how to. By hiring people that are from a very strong background in processing from the industry, it can unveil things to the customers.
Goldman: Now, you make solder paste, I've been reading some articles about nanoparticles and very fine solder paste, things for the very fine features, right?
Fullerton: Yes. The smaller the feature, generally the smaller the powder you want to use in the solder paste.
Goldman: How does that come about? Talk about that a little bit.
Fullerton: The manufacturing process for that is pretty interesting. I don't fully understand it because I'm not manufacturing the material, but we are making smaller powders now than ever before. We're putting more and more research into smaller and smaller particle size materials. Here's a good example. Ten years ago, we developed our first commercially available lead-free solder paste. It was developed with Type 3 materials. That was the most common materials.
Goldman: Type 3 means what? It has to do with the particle size?
Fullerton: The particle diameter of 80% of the particles is between 25 and 45 microns. There's a specification on what Type 3 can entail. Seven or eight years ago when we made the second generation materials, we developed that as a Type 4 material. Our research and development uses a Type 4 material for all the testing that goes on. Then we made a Type 3 version of that. It showed how the market could shift in that short amount of time.
Goldman: Type 4 is what particle size?
Fullerton: That's where 90% of the particles’ diameters are between 20 and 38 microns. It's a slight shift smaller, but it changed the way we design and develop materials. Our R&D focused on the Type 4 version of that product because we saw that was going to be the most common type that we sold. Nowadays, it really is one of the most common types that we sell for new applications, that new product that we at developed that time. We have another new product coming out shortly. It's been released in Asia. We're scaling up in North America. It is our first product that's developed using a Type 5 powder size, which is where 90% of particles are between 15—25 microns in diameter. You can see the development of the materials is working towards smaller and smaller particle sizes. Now this material will be available in the Type 4, but the smaller the particle size, the more challenging it is to develop a flux package that works really well with that.
Goldman: That was the other thing, because you need more flux that with the smaller particles?
Fullerton: In these, more activity. There's more for the flux to do. The flux has more work to do with smaller particle sizes. It has to do with the fact that for every unit of volume, there's more surface area of powder in the smaller particle size paste, as compared to the same volume of a larger particle size paste. That large of a surface area requires more protection and treatment from the flux during the soldering process. So there's more for it to do when you're actually soldering. It's more challenging. As we go down in particle size, it has also challenged our chemists to develop materials that are appropriate for those smaller particle sizes.
Goldman: They jet solder also?
Fullerton: Yes. There's equipment out there that can jet a small deposit of solder paste. For those pieces of equipment, the smaller the particle size, the smaller the minimum feature size they can jet. The dot size becomes small. They can use and work on smaller designs. That's one area where the market pressure to get smaller and smaller particles is coming from, the people who are jetting.
Goldman: Now, when you have solder paste, there is no dross?
Fullerton: Correct. There's no dross from that process.
Goldman: Your recycling is really for the wave solder applications?
Fullerton: Well, there is some waste out of the SMT process. There's always going to be a little bit of residue left in the container—the jar, the tube, etc. There are wipes and tools and things like that as well. As a service for the customers that engage us for recycling, we'll also recycle their scrap. We can reclaim very small amounts of metals from this. It's not really something we make a lot of money on. We offer it as a service for those currently engaging in our recycling services. We do it as a service for the user so we're kind of a one-stop shop. We can also certify that the scrap and the waste material and the wipes and those sorts of materials were also recycled properly so that none of the metal content goes back into the environment.
Goldman: Seems like a real win-win.
Fullerton: Especially for people still using tin-lead solders; those materials are generally considered hazardous. The way to dispose of them has to be treated much differently than a non-hazardous material. If you sell it to us or ship it to us, and we reclaim it, it's not being put back into environment. It's being put back into other solders. It's a much more environmentally friendly way of dealing with waste than to send it to a landfill.
Goldman: As an aside, is there much call for tin-lead solders anymore?
Fullerton: There is—the high reliability industries, aerospace and military. The medical industry is losing some of their exemptions soon, but right now they're still pretty much a tin-lead industry. For products that are sold only domestically there are still a number of customers that are making products that, if they were sold in the EU, would have to be lead-free. Because they only sell to the North America market, they're using old fashioned tin-lead solder paste. They're still out there.
Goldman: Because there's a lot of history on tin-lead reliability.
Fullerton: I joke that it's the evil that we know versus the evil we don't know. We have a very good handle on the life cycle of tin-lead solder based on research and historical usage. We have not even 10 years doing lead-free. We still don't have that 30, 40, 50-year life cycle product that has actually been in the field long enough to see how those react.
Goldman: Like those airplanes.
Fullerton: Right, exactly. Those segments still stay with tin-lead because they can quantify the reliability and they can plan around that. With the lead-frees, the long, long term reliability still hasn't been proven out, pro or con. Those industries are afraid of the unknown. They'd rather quantify it and plan around it, so that's where they still live.
Goldman: When you need the ultimate reliability, you stick with what you know that has the reliability.
Fullerton: Yep, I want the airplane that takes me home to Philadelphia tomorrow to have the most reliable solder possible.
Goldman: And I don't care about anything else.
Goldman: Wonderful. Well, thanks for stopping by Jason.
Fullerton: No problem. Thanks for having me.