Calumet is Bullish on Additive and Semi-Additive

Estimated reading time: 3 minutes

Calumet Electronics has been a domestic pioneer with additive and semi-additive electronics manufacturing processes. We recently asked Calumet’s Todd Brassard and Meredith LaBeau to discuss the state of this technology, which traditional processes that they might replace, and some of the challenges facing OEMs or PCB shops that are considering these options.

Barry Matties: We’re seeing more additive and semi-additive. Let’s start with what these technologies represent to Calumet.

Todd Brassard: I’m sure some of your readers will go a little crazy at our use of the word “additive.” In my mind, pure “additive” manufacturing is 3D-printed or deposition-based processes while “semi-additive,” in the context of circuit board substrates, involves a seed layer of copper (A-SAP™) or a very thin layer of copper foil (mSAP) with plated copper traces and features.

We understand the distinctions between terms additive and semi-additive; we do not use “additive” to necessarily describe a process, but rather as a proper noun to name the thing and contrast it against “subtractive” processes. For example, when working with Averatek’s A-SAP™ technology, the seed layer is so thin that it is removed with a simple micro-etch. To me, the process is so close to being purely additive, I name it an additive process. 

Matties: Is it going to be a mandatory offering for most fabricators in the coming years? Or is this something that will still be limited in scope?

Meredith LaBeau: What is driving the need for additive manufacturing—and I use this term “additive” as Todd just described—is design size and complexity. Next generation electronics will be much smaller. This is easy to see just following the mobile device industry. An electronic interconnect manufacturer in the U.S. can only go so small with traditional subtractive manufacturing processes. 

Another piece of this push toward additive technology is environmental. There will be many more conversations about the environmental impact of manufacturing processes, and these considerations will factor more heavily into contract awards. With traditional subtractive processes you’re removing copper, but with additive processes you’re mostly adding copper. I believe there's going to be a shift in design to reduce waste streams regardless of technology, as part of the wider ESG movement.

Todd Brassard: Yes, ESG: environmental and social governance.

Matties: Is that becoming more prevalent?

LaBeau: We are just starting to see environmental considerations seep into conversations and design considerations at our level.

Todd Brassard: We are seeing more environmental considerations flowing down from the DoD. The DoD wants to see transition to greener solutions. Calumet is learning the ropes of federal funding and we believe environmental considerations must be included in any submitted proposal. We’ve been seeing these types of requirements added to RFPs in the last few years. Personally, I believe this is a good thing. We should be paying attention to what we are doing to the planet; this is just common sense.

LaBeau: The additive and semi-additive movements are not just about miniaturization, but also system performance and integrity. Additive and semi-additive technologies provide for better copper trace and feature formation which improves signal integrity and shortens transmission lines, allowing faster bit rates and higher frequencies. For example, radar and communications systems achieve higher performance when trace walls are square and smooth. Combine the potential for feature formation with advanced materials and chemical processes and a wide array of possibilities emerge. As an example, Calumet can plate copper on transparent substrates; just imagine the applications, for example, in the augmented reality space.