Alpha on New Technologies to Tackle Voiding

Estimated reading time: 5 minutes

In an interview with SMT Magazine, Tom Hunsinger, vice president of marketing at Alpha Assembly Solutions, discusses how their company is addressing voiding—one of the greatest challenges in soldering.

Stephen Las Marias: From a soldering standpoint, what are the greatest challenges that your customers face?

Tom Hunsinger: Voiding continues to be a critical issue for our customers in both BGA and in bottom terminated components, where you’re using that termination as a heat sink, or LED packages where the device is being used to drain heat away from the LED. That becomes more challenging because the solder is being used as a thermal interface material and so the presence of voids means you are lowering your thermal conductivity.

Understanding what causes the void formation during the assembly process is paramount and usually is where customers need some assistance. Flux, for instance, plays a big role in controlling void creation particularly during the pre-heat phase of a reflow process so optimizing your profile can significantly reduce voiding. It is also important to use soldering materials that match the application, so at the onset of a project, we take the time to discuss the design parameters with the customer so that both parties have the right information to decide on which alloy is best.

Las Marias: How is Alpha helping customers address voiding?

Hunsinger: In terms of voiding, Alpha is in the process of developing several products that will help prevent void formation. One is a solder paste material that was developed to meet the high reliability needs of both the automotive and lighting markets, while also delivering low levels of voiding. We also have a new solder preform coming soon that is designed specifically for large area power components that require consistent low-voiding solder joints from normal SMT processes.

The new solder paste Alpha is developing has a modified flux chemistry that enables us 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. This will be particularly helpful to the automotive market because we’ve had several discussions with key customers during the year on the impact voiding has on reliability. The solder preforms in development contain an ultra-low voiding flux formulation that is deposited very accurately from preform to preform ensuring repeatable performance every time. They will be available in tape and reel for easy assembly in SMT reflow applications and, upon request, can contain various coating levels, customized shapes and thicknesses to address a specific application.

Las Marias: What market development trends are shaping product innovation strategies at Alpha?

Hunsinger: We are seeing a great deal of material innovation for the flexible, formable and printed electronics sector and Alpha is developing a robust portfolio of new products and technologies to specifically meet the demanding performance and reliability requirements of flexible and printed electronic circuits. This is one of the fastest growing technologies in the world and is allowing electronics to be used in places it never has before, so we are quickly learning how to make materials that are adequate for this new environment. Our product development falls within two broad categories. First, with flexible PCBs which involves assembly of conventional components, such as ICs or processors, onto circuited flexible substrates. The second would be printed electronics/circuits on flexible polymer films in which the flexible circuits are additively printed on a polymer base film, typically through a continuous roll-to-roll process or through a high throughput sheet-to-sheet process which is then followed by other subsequent processes.

Las Marias: What other solder solutions should we expect from Alpha this year?

Hunsinger: In addition to what was already mentioned, Alpha will be introducing a new solder paste, a cleanable, no-clean material with fine feature printing capabilities that is derived from the SAC family of alloys. We also have our latest VOC-free, halide-free flux coming out soon that is designed to meet current REACH and RoHS legislation. And we also have a few other preform technologies coming to market, one that is geared toward power module assembly and the other focused on bond line control to prevent die tilt and help fix your bond line thickness.

Las Marias: How does Alpha provide value to your customers?

Hunsinger: One of Alpha’s key differentiators is the strength of our technical service, both from an R&D standpoint where we are designing materials that meet today’s challenges and future challenges as well, and from our customer technical support group in the field. This team is solely dedicated to working with customers to troubleshoot application problems, identifying key factors in their process and helping them select the right materials for their application. This is how we understand our customers’ challenges, how we help resolve the challenges and ultimately, how we help them meet the challenges of their own customer base.

Las Marias: What is your outlook for the soldering market this year?

Hunsinger: I think the outlook is promising for the solder market given the upward demand from EMS companies. We anticipate growth with the LED and automotive electronics industries, we see new opportunities to work with our customers in the consumer electronics space and the newer flexible, formable and printed electronics market that is taking off. I’d say 2017 has the potential to see the release of several solder material innovations. And, in addition to the work we are doing to develop new materials and assembly solutions, we are also continuing our work on improving the sustainability of materials used in electronics assembly through our metal reclaim programs and our participation in other industry led working groups.

Las Marias: Any final comments?

Hunsinger: Alpha Assembly Solutions is committed to be the industry’s preferred supplier of high performance materials and chemistry by delivering leading technology represented by our innovative products, processes and people.

Las Marias: Thank you, Tom.

Hunsinger: Thank you.