Technical Article

Focusing on SiC Technology With WeEn Semi’s CEO

July 10, 2022 by Holger Moscheik

Founded in Aug 2015, WeEn Semiconductors is committed to improving power conversion efficiency and providing superior power products for home appliances, renewable energy, automobiles, telecom and more.

When PCIM Europe returned as a live face-to-face event and WeEn Semi showcased its latest products and technology to the industry, we had the chance to talk with WeEn Semi’s CEO, Markus Mosen, for his insightful views on the industry.

Holger Moscheik: What new technologies and products are WeEn Semi showcasing at PCIM Europe? Please tell us about it.

Markus Mosen: Thank you for having us here and having a chance to talk. I’m very happy to see that after three years we are physically back at PCIM! A lot of things happened in these last three years with respect to technology for WeEn Semi product development, as well as internal staff development. We might talk about that later and about the size of the company in terms of revenue, which has almost doubled. In Europe, the number one topic is Wide Bandgap Technology, SiC and GaN. I can see plenty of companies exhibiting these technologies.


Markus Mosen. Image used courtesy of Bodo’s Power Systems


This year at PCIM, we are presenting our 6th generation SiC diodes and for the first time SiC MOSFETs, which we released in Q4 of 2021. We are showing our first platform for IGBTs, which has 650V  and 1200 V products. Also, we are exhibiting our new TVS (Transient Voltage Suppressor) and ESD (Electrostatic Discharge) portfolios for the first time.

As you can see, there are many things happening in our new portfolio, but we have also invested in our existing and well-running product portfolio, such as Fast Recovery Diodes, Schottky Diodes, Standard Diodes, Bridge Diodes and, last but not least T&T (Thyristors & Triacs), which still represent our major product families.

We have more to come in the pipeline and new technologies to be released by the end of this year, like IGBT 8-inch Trench Gate/Field Stop Technology from a new foundry and SiC, where we are using foundries in the US, Taiwan & China (4-inch and 6-inch wafers). Basically, we are offering the same level of performance as other market players and we are sure that our performance is on par with the top companies in the segment.

Moscheik: I see a lot of things are going on like Silicon Carbide. What is your view on the trends? And as I see technology and its applications, what products can WeEn Semi offer in this area?

Mosen: Starting with applications, we believe that electrical vehicles will take off. They are taking off for sure already in some countries. For example, in the EU, in Germany, with the promotional support and tax incentives of the German government, we are experiencing a huge increase in sales and demand for electric vehicles. Unfortunately, there’s some shortage in terms of semiconductor supply. But I don’t believe it is really the SiC products, rather it's other products like ICs, SENSORs and MOSFETs that have shortages. For SiC, there is no shortage but, of course, we know that presently substrates are in a supply shortage. In the foreseeable future, the SiC market will be driven mainly by automotive, primarily for inverters with the use of ten or more SiC MOSFET devices but also for onboard chargers and charger stations which will integrate SiC in the solution as well.

So, in the automotive area, these will be significant applications for the growth of the market. However, we are also selling a lot of non-automotive certified SiC devices into the PV Market (mainly photovoltaic inverters), but also into UPS, industrial power supply and even the aircon markets.

Moscheik: And speaking of electric vehicles, does WeEn Semi offer automotive-related products already?

Mosen: Yes, we do have qualified automotive products for Si-Diodes, SCRs and SiC Diodes but not yet for the SiC-MOSFETs. We are working to qualify SiC-MOSFETs for automotive-grade and should have the first releases towards the end of 2022.

So, by end of the year, we will open our Module Plant, to focus on advanced Module products including Bipolar Modules (SCR & Diodes module), IGBT Modules and SiC Modules and this Fab will be Automotive Certified.

The foundries we are using now for SiC are Automotive Certified, the Module Plant will also be automotive qualified, adding to our in-house qualified Reliability Lab and Failure Analysis Center. This will enable us to introduce more Automotive Certified products.


WeEn Semi’s Team at PCIM Europe 2022. Image used courtesy of Bodo’s Power Systems


Moscheik: As to manufacturing, what are the current wafer sizes WeEn Semi is using?

Mosen: Our current wafer sizes are 4 to 8-inch. We still have 4-inch for SiC, but we are moving to 6-inch and by the middle of this year it will be all 6-inch. Although, we still have a 5-inch Fab in northern China, mainly for Thyristors and Diodes, with doubled capacity since 2019. We are also using 8-inch in foundries that are qualified for IGBT, Schottky Diodes and others.

Moscheik: Great. Regarding the current tight capacity situation, what measures does WeEn Semi have to ensure customer delivery?

Mosen: Logistics is a big challenge; the shipping cost is up almost 50% and we bear the cost. Also, we have increased our own front-end capacity by 50%, which is essentially a doubling within the last year. Furthermore, we doubled the capacity in foundries and of course, in addition, the back end/subcon manufacturing capacity has been increased accordingly. However, we all know this did not fully satisfy the demand of our customers. Logistics not only depend on us but of course on our logistic partner as well. We have our sales team to serve our customers, work together with the distributors and make sure there’s sufficient supply for everyone.

Moscheik: What is the revenue percentage of WeEn Semi’s Chinese business and oversee business respectively?

Mosen: We have three regions. One we call GC - Greater China, which means China, Hong Kong and Taiwan. This is about 60% of total business. Then we have what we call the West Region and Asia Pacific region, representing around 20% each. We expect all regions will maintain their respective market shares.

On the product portfolio, looking at the single families we have, then the majority of products, for example, Diodes, (like Schottky Diode, Standard Diodes, Fast Recovery Diodes - all that are needed for power supply and computing) are mainly sourced in AP and China, via EMS companies. This is the major portion, but we do see a good share increase in the EU in recent 2-3 years.

If you look at the newer technologies we’re offering, SiC is already up to 10% of our total revenue. The majority is still T&T (Thyristors & Triacs), which has increased significantly in the last year. I can say we have at least now around 30% market share worldwide.

This is mainly because of some shortages from our competitors and due to our timely capacity increase so we could gain some share in the market. And of course, the CoVid-19 pandemic with the shift to “home offices” supported the demand increase for small and major household appliances.

Moscheik: Speaking of Asia, at the beginning of this year, WeEn Semi launched a global operation center in Shanghai. Can you tell us a little bit about that?

Mosen: Basically, we have set up a new HQ. In this office we have established a new R&D center and a new Operations Center. Why? Because before that, our main operation center was in North China, where just one of our factories is located. We have set up in Shanghai because of the capacity increase in our own Fab as well as in other foundries and sub-cons, not only in mainland China but also in other areas. Consequently, “Logistics” has really become important for us as we are shipping 1.5 billion pieces. So, we needed to have a more focused approach on operations.

As I mentioned before, we are also going to build a new factory near Shanghai. This factory will not only be for modules but also packages used by SiC. This will be done in-house, with our own people to assure quality and obtain automotive certification. This is also a big reason why we have our new HQ and call it the “Global Operations Center.”

Moscheik: That answers all my questions, do you want to add anything?

Mosen: For us, as a Chinese company, we understand ourselves as being active globally as well. We have staff all over the world, and we have sales offices or use sales reps all over the world. Indeed, logistics is a real challenge, but we have our professional supply chain people managing the situation. So far, our overall supply chain situation is still stable and any impact on customers has been minimized.


Featured image used courtesy of WeEn Semiconductors

This article originally appeared in Bodo’s Power Systems magazine.