Interview with Aly Mashaly Rohm provides local support for Europe for Silicon Carbide

Mit Aly Mashaly, Manager Power Systems bei ROHM Semiconductor und Leiter des neuen Labors, sprach DESIGN&ELEKTRONIK-Redakteur Ralf Higgelke
Aly Mashaly (left), Manager Power Systems at ROHM Semiconductor and head of the new test facilities, was interviewed by DESIGN&ELEKTRONIK editor Ralf Higgelke.

Rohm Semiconductor has opened its Power Lab in Willich for analyzing power electronics. The semiconductor manufacturer wants to provide local support for Europe at application level. DESIGN&ELEKTRONIK learned more from Aly Mashaly, Power Systems Manager and head of the lab.

DESIGN&ELEKTRONIK: Mr. Mashaly, what was the basic idea for installing this 300 square meter Power Lab?

Aly Mashaly: Rohm Semiconductor wants to increase its European sales in the next few years considerably. By 2020, for example, half of global sales in power electronics are expected to come from Europe. Therefore, Europe is of great strategic relevance to us. Correspondingly, it is also essential for us to know what the customer requirements are and which applications our customers are working on, especially here in Europe. We want to provide our European customers' with the best technical support possible.

In this context I use the term usability; we are taking on the role of our customer. This helps us to better understand what the developer at our customers really needs. Subsequently, we can offer him the best solution.

Which applications do you concentrate on here in Europe?

In the photovoltaic market, these are the inverters, electromobility of course, power supply units for data centers and auxiliary power supplies for drives in general. These are the main applications of our customers here in Europe.

You mentioned you want to understand the customer better. What exactly do you mean by that?

Take silicon carbide MOSFETs as an example. Usually the question arises: "Why should I use them?" In academia there are a lot of papers, but currently still very few implementation examples. In order to achieve a breakthrough we as market leader in this business must convince the developer at the customer. And if they affirm: "But I have always done so. Why should I use this nice but expensive silicon carbide?", then we have to deliver convincing arguments. In my view, there are four: technical benefits, system costs, reliability and availability.

With my team here at the Power Lab we are concentrating on the advantages of silicon carbide and how our customer can fully use the benefits of this technology for their application. To understand the customer better means to reproduce his application and to examine it in detail in our Power Lab and not only by simulation. This allows us to help him to make the most out of silicon carbide in his application.

That means you're providing development support, don't you?

Exactly. In the concept phase, the developers concentrate on the key components of the system under development, because they eventually determine its performance. In power electronics, this of course includes MOSFETs and IGBTs. The developer checks which components are available, which information is available for these components and how they can be used. Once he has decided, more and more technical questions arise. Perhaps he is missing a parameter for his application which is not specified adequately or not at all in the data sheet. In cases like these, we can also support him during his development.

Which instrumentation capabilities and which test benches are currently available in your Power Lab?

We initially decided to focus on a few test scenarios so that we have enough space to add more test benches in the future. Currently we are able to operate continuously up to 8,000 volts and 750 amps. We currently have test benches for characterizing the components and monitoring the switching and short-circuit behavior. This often involves the interaction of MOSFET and gate-drivers. Additionally, we have the capability to test boards under real world conditions continuously.

We have test benches for DC and AC voltage both at input and output. By means of a so-called artificial mains network, we are able to apply very different AC mains voltages and, if necessary, harmonic overvoltages to the DUTs as well as DC. To emulate different loads such as batteries or electric drives at the output we have implemented various electronic loads for DC and AC.

Another highlight is our calorimetric test bench, because I know from my own experience as a former power electronics developer that the thermal design of a system is always critical during the development phase. And it was very important to us to have this expertise on site.

We think this is adequate at the moment for the market we are addressing in Europe, but as I said, we still have plenty of time to move on. In the characterization test bench we are not limited to 750 amperes, but can allow several thousand amps.

Which investments have been made so far for the Power Lab?

I do not want to disclose the precise numbers. However, our table tennis table used to stand in these spaces and the area was used as a warehouse in the past. We had to completely reconstruct this area before finally installing an ESD floor and high-current connections. Accordingly, there was a lot to do.

During the guided tour you said that such a Power Lab and the test benches were not available off the shelf. What do you mean by that?

The individual components of the test equipment can be purchased of course. But the requirements we have to fulfil in order to support the different applications are so special that we had to build the test benches ourselves.

How long did it take to establish the Power Lab?

A year and a half have passed since the decision was taken. It took so long, because we started with the detailed planning after the approval of course. At the start there was obviously much to be done in terms of safety standards, regulatory requirements and construction efforts. After that we were able to deal with the infrastructure and the test equipment. Basically, these were various sub-projects that eventually led to a single goal.

Mr. Mashaly, thank you very much for the interview.

The interview was conducted by Ralf Higgelke.