
CEO interview: WeEn Semiconductors
WeEn Semiconductors is a power spinout of Philips and NXP that perhaps is overshadowed by Nexperia. It is a Chinese company with European management, with a focus on diodes, IGBTs and superfunction MOSFETs as well as SIC power devices.
“We have a long heritage, starting as a bipolar supplier in Hazel Grove for Philips,” said Markus Mosen, CEO of WeEn Semiconductors tells eeNews Europe.
“WeEn was spun off from NXP in 2016 in a joint venture, and NXP stepped out in 2019 and since then we have been 100% owned by private equity. Now we are 600 people and we have an R&D centre in Stockport, part of the Hazel Grove group and three sites in China. The company is looking to set up another design centre in Europe as it expands its intelligent power module business.
“We need another design cente in Europe, and for power semiconductor a lot of the expertise is in Europe,” he said.
“We started with thyristors for white goods where we are number two after ST, then Schottky diodes and HV transistors and we have been adding adding SiC, IGBT, modules and now superjunction MOSFETs. We opened a module plant last summer in Shanghai and are ramping up with modules with thyristors in our WeEnPack packaging and we are working on new modules for EVs with IGBTs and SiC.”
The first fab in JiIling used equipment from Hazzel Grove for thyristors on 5in wafers, and is capable of 6in (150mm) wafers. The company is also developing a 150mm fab in Beijing that will open in 2025 with a capacity of 120,000 wafers.
“We are moving to planar technology in Beijing for diodes then deep trench for SJ MOSFETs, opening at the start of 2025,” he said.
The choice of 150mm is driven by investment. “One reason is we were trying to move to an IPO in 2018 but that failed and we had to do investments for the module plant and the fab, and 150mm is lower cost than a 200mm fab. Yes the challenge is to go to the latest technology,” he said.
“We will not do SiC there, we use foundry at X-fab in the US, GTA, a former ASMC company in Shanghai and Episil in Taiwan – we are planning to do it in another fab as well which is not yet announced.”
“We started SiC in 2011/12, even before WeEn was created as we saw that was a market you would need to go into with higher power. With Episil we are on 150mm and we are working on 200mm with the foundry and with a university lab.”
“We released the first MOSFETs last year and now we have derivatives and are doing AECQ qualification for automotive. The investment into SiC is huge in recent years, there are some 30 projects in China and there is all the investment from ST, Wolfspeed, Infineon and Rohm.”
“A few years we had discussion with customers about shortages in epi and that has not materialised, but we invested in an epi provider and in a substrate house, both in China,” he said.
The key focus at the moment is the TSPAK packaging format developed by Tesla for its electric vehicle. Tesla opened up the patents to simulate suppliers
“The interesting part is that this has top cooling, AECQ qualification is done, and we developed this in Shanghai,” he said. “We are working on a new package which will allow more than one MOSFET inside with up to 4 MOSFETs. We are starting with a TO package and as the MOSFETs get smaller on 200mm.”
For example, an inverter for an electric car uses 48 TPAK MOSFETS and each of those has a 10% greater range than IGBT.
“A small city car is happy with a lower kW solution with IGBT and recovery diode but we are starting to see more demand for SIC diodes,” he said
“We are starting working on 1700V in the TSPAK and we will use that for the fast charging systems and for solar inverters.”
It plans to launch a 2000V SiC with an on resistance of 12 to 100mO in 2025. “We have started the project with the two foundries. Episil is a little bit of ahead in our opinion,” he said.
The next step will be integrated and intelligent power modules. “We have a company in Silicon Valley that would do the design of the logic the ICs for us based on our requirements on a TSMC process. I don’t think you can do that from scratch, you have to buy in the competence,” he said.
