Posts

– Tesla Model 3 production is ramping up, together with the production of Silicon Carbide MOSFETs used in its inverter.
– We investigated ST Microelectronics production capacity and compared it to Tesla’s production objectives.
– It look likes a shortage is slowly growing in the SiC MOSFET market, and it’s here to last.


To follow the EV market, follow Tesla

Tesla has been a subject on this website and in the Power Electronics community since the first release of the Roadster and the Model S. The interest is growing as it seems the company is holding a large part of the Electric Vehicle market. They drive innovation and participate, if not define the trends. Tracking Tesla’s technology choices is tracking a big part of Electric Vehicle market technology.

The Model S was a first and very interesting Electric Vehicle. We already pointed out the special strategy of Tesla, that highly participated in the company’s success. They are not making Electric Cars for ecologic reasons, but rather make EV because it gives awesome performances to a car. They just happened to be an alternative to fossil fuel. Model S is a great example. With an almost 600 hp and a 0 to 100 km/h in 4,4 s for the “slowest” model, down to 2,4 s for the best one, It accelerates faster than Lamborghinis (yes, all of them!). But still, the Tesla Model S has 5 more seats than Lamborghinis…

The Leap: From Si IGBT Discrete to SiC MOSFET Custom Module

This first mass produced EV from Tesla has been well analyzed on our side: It uses discrete IGBTs, produced by Infineon, and we wrote a long article on the technology choices. They are using discrete components to drive the motor with a car that requires up to 1500 Amps peak. Then came Model X, the luxury SUV from Tesla. It used similar components and topologies compared to Model S, at least on the power conversion side. Tesla’s management decided to stick to what was working. It was probably a safe move to release quickly a second mass market car, and be sure to reduce production issues.

Model 3, on the other side, is expected to be the first accessible EV car with long range. It has been presented as the first “ICE” killer car (ICE: Internal Combustion Engine). For the later, Tesla’s technical team went for a completely new design. Our analysis article detailed very well the power modules, and components used (SiC MOSFET from ST Microelectronics). Tesla is already ramping up production, with more or less success. We believe they had to put some innovations on the table, and bet on the production price to drop with volume. That’s what drove them into custom made power modules with Silicon Carbide MOSFETs. No one, in the EV market, took the risk to integrate SiC at motor drive level, before Tesla and its Model 3.

Boschmann AG sintered modules - Similar to ST Microelectronics SiC modules for Tesla
Example of a AG sintered module
Similar to ST Microelectronics SiC modules for Tesla Model 3
Source: Boschmann

Investors, early buyers, competitors, suppliers and market analysts are all watching closely the Model 3 production numbers every week. PntPower is no exception to this rule. We have made our homework of analyzing Tesla’s production numbers. But one thing stroke us: How can the SiC MOSFET production follow Tesla’s needs? They reached their target of 5,000 cars produced every week by Q4-2018, each using 24 modules of 2 SiC MOSFETs. We had to compare it to ST Microelectronics production capacity.

Tesla is eating all ST Microelectronics SiC MOSFET production capacity

Following Tesla’s production is actually easy, as many investors watch closely any moves from the manufacturer (together with the SEC…). Bloomberg has a full page, auto-updated, dedicated to Tesla model 3 production status. According to that page, Model 3 is currently produced at a peak rate of about 4,500 units/week (as of Q4 2018).

Tesla Model 3 inverter, showing the SiC MOSFET power modules from ST Microelectronics

A Model 3 has one main inverter that requires 24 power modules, each of which based on two Silicon Carbide MOSFET dies. These MOSFETs are made by ST Microelectronics fab in Catania, Italy, but we will come back to it later. It is a total of 48 SiC MOSFET dies in each car.

This means Tesla need 3 Million SiC MOSFET dies every quarter to keep its production rate of Model 3, as of early January.

Now, ST Microelectronics is producing 650V/100A Silicon Carbide MOSFET from it’s fab in Catania, Italy. We took the hypothesis of a 4 mm x 4 mm die size. This matches a current density of 6.25 A/mm². They are produced on 6 inches wafers (150 mm), which is a recent fab improvement from ST Microelectronics. We believe this improvement date matches the production start for the Gen. 2 SiC MOSFET that equip Tesla electric cars. Thanks to a marvelous tool (Die Per Wafer Calculator) that every semiconductor market analyst knows very well, we can estimate the number of dies per wafer at 702. These dies are not all good, as nobody has a 100% yield, especially in manufacturing SiC MOSFET. We have to insert a bit of hypothesis here. Let say that 75% of these dies are good dies. This is already quite an optimistic figure. We based our estimation on the production capacity of ST Micro Catania: 30,000 wafers/week, including 6 in. and 8 in. production lines. The SiC line is on 6 in. wafers only. According to our sources, it’s 800 wafers/week until Q3-2018 and will ramp-up at 1000 wafers/week by Q4-2018. We estimate that 85% of this production was dedicated to Tesla in Q2 2016, in order to stock MOSFETs for Elon Musks optimistic production ramp-up back then. We known ST Microelectronics has to make some devices for other customers time to time…

Based on these numbers:

  • ST Microelectronics produced 3,420,000 SiC MOSFET modules thanks to their ramp-up
  • Tesla Model 3 production consumed 2,950,000 SiC MOSFET modules

We can easily see that, without a stock of power modules, Tesla would be quite a tight supply-chain. But mostly, Tesla’s ramp-up relies mainly on ST Microelectronics’ ramp-up, and Catania fab better be efficient, and quickly, in order to extend the reach of ST Microelectronics to other potential automotive customers

We expect ST Microelectronics and Tesla to have signed a contract during the first Model 3 design phases. They most certainly started stocking dies from the first day they knew they would need it. A main objective for them must have been to secure as much as possible. This buffer stock became their comfort mattress for any slow down in production or breach in the supply-chain. We also expect Tesla to rely partially on a second source (with a contract that might be less advantageous) to ramp-up production. This second source appears to be Infineon. But these are assumptions and even if Infineon say they are second source, we still find it difficult to integrate a different SiC MOSFET die, knowing the technology is new. A different supplier would mean driving and design tweaks.

Tesla drives the SiC MOSFET market

Summarizing all this, we do not see how Tesla’s current need for SiC MOSFET does not affect the market. There is no other way than a growing tension in supplying SiC MOSFETs to customers, and we expect it to benefit to every manufacturer in the field. Customers unable to get a SiC MOSFET from ST Microelectronics or Infineon will go to their second or third choice. It will help everyone fill their lines, and invest in larger capacity. Don’t be surprise if SiC MOSFET manufacturers smiles look more authentic than before: The power is on their side now (so to speak…).

Don’t be surprise if SiC MOSFET manufacturers smiles look more authentic than before: The power is on their side now (so to speak…).

Searching for clues

The market analysis consulting job is not only about throwing forecast about sun, rain and wind, based on assumptions from looking at the sky… We also need to evaluate the confidence we have in our estimations or hypothesis. Here we used large estimations of yield and needs, to thicken the confidence in the conclusion.

But there are other signs or clues we can follow here. A first one, is to go to a distributor website (Mouser.com, Digikey.com, Arrow.com, FutureElectronics.com). You can check for yourself, and see what is the status. At the date of publication, only one SiC MOSFET from ST Microelectronics was listed as available: 1200V/12A SCT10N120. It’s a Generation MOSFET among the first MOSFETs to be produced. We believe these stocks dates from before the Tesla-ST Microelectronics deal.

ST Microelectronics is to take a majority stake in Norstel. This acquisition is thought to secure the SiC supply for ST Microelectronics, not long after a SiC wafer supply agreement was signed between ST Microelectronics and Wolfspeed of Cree group.

ST Microelectronics is to take a majority stake in the Sweden based SiC wafer maker Norstel. ST Microelectronics already announced early January this year that they signed an agreement with Cree. This agreement guaranteed a several years long supply of SiC wafers for ST Microelectronics. It is now a new strategic move for ST Microelectronics.

The French-Italian chip maker will acquire 55% of Norstel now, and signed an agreement for a future acquisition of the 45% left.

ST Microelectronics can ben seen as a large leader of the SiC MOSFET market thanks to its second generation MOSFET used in Tesla Model 3 cars. They recently increased the production of their main Silicon Carbide devices production line from 800 wafers per week to 1000 wafers per week during Q4 2018 (source PntPower). Production volume should keep growing thanks to the need of devices for Tesla Model 3 and expected other Electric Vehicles in the future. ST Microelectronics’ strategy is to become a main leader in automotive power electronics thanks to their SiC MOSFETs product line.

Source and PntPower market analysis.

GT Advanced Technologies opened and filled a new facility in Hudson with crystal furnaces from their former location in Merrimack. The objective? Start production of SiC wafers and target the growing Silicon Carbide devices market driven by new Power Electronics applications.

GT Advanced Technologies is well known to have been driven close to bankruptcy after a dangerous deal with Apple on Sapphire supply in 2015. The company is now reborn. The CEO, Greg Knight, announced its almost a completely new structure, that kept the former name. The engineering and finance team stayed, and found a new site for SiC production. According to M. Knight, they have the experience from the past, of installing, ramping up and running thousands of furnaces, so they will ramp up very quickly.

The objective is to be ready as a leading supplier for the Silicon Carbide market boom to come in 2021 or 2022. The process is based on GT Advanced Technologies ‘SiClone’ sublimation furnace and SiC seeds.

They also want to reduce cost, with six inch wafers at 1000$ in a near future.

Source

 

[Update 02/07/2018: We know the packaging manufacturer and added the name to the article. Devices used are  650V SiC MOSFETs and not 1200V, as stated at first. Update 09/07/2018: Packaging supply chain has been further described.]

Tesla Model 3 is using Silicon Carbide MOSFETs for its main inverter. It is now confirmed from reverse engineering analyses from different expert companies (Munro Associates and System Plus Consulting).

From Si IGBT in TO-247 to SiC MOSFETs in molded package

PntPower missed an analyst publication from August 2017 stating that ST Microelectronics was selected as a main supplier for Tesla Model 3 thanks to its SiC MOSFET at 650V. ST Microelectronics, at the time, was among the most advanced companies in SiC MOSFETs with a 1200V device already available, but nothing confirmed that SiC MOSFETs would be used as main devices for Model 3 inverter. As a reminder we extensively searched and commented the use of IGBTs in TO-247 packages in Tesla’s previous cars: Roadster, Model S and Model X. This also confirms the technological jump and the serious willingness of Tesla to become a major manufacturer of electric cars. This kind of specific design and packaging in a car is similar to the evolution of Toyota in the Prius, in a quest to improve design, density and efficiency of the HEV’s best seller, year after year.

Plastic molding and Cu ribbon-bonding: The high standard for power devices packaging

It is now confirmed that Tesla has been integrating SiC MOSFET based power modules from ST Microelectronics in Model 3 inverter. The modules are molded modules using copper ribbon-bonding for MOSFET connection. The SiC devices seems to be a 650V MOSFET at 100A made in Catania Fab (Italy), though no Automotive grade device is listed on ST Microelectronics website. The module is also very close to the most advanced technologies used today in Power Electronics packaging for automotive industry. It is to be compared with Mitsubishi electric J series TPM modules, with a cooling pad at the bottom and connections pin on the top. Packaging design has been made by a packaging expert company, based in the Netherlands, and called Advanced Packaging Center. Packaging production should be done by ST Microelectronics and/or their usual subcontractors for packaging.

Model 3 Main Inverter – Featuring 24 SiC MOSFET modules from ST Microelectronics (Source: Munro Assoc.)

1 000 000 SiC MOSFETs on the road

Tesla Model 3 manufacturing prediction from Bloomberg reach 38000 units as we speak (end of June 2018). 24 SiC MOSFET modules are used in each Model 3 inverter, this represents almost 1 Million ST Micro’s SiC MOSFETs on our roads. We will let the reader calculate the market it represents by putting its own price estimation on ST Micro’s modules.

Infineon will probably catch-up and quickly become a second source for Model 3 production in order to secure the supply-chain and follow the production ramp-up roadmap announced by Elon Musk.

Tesla made a technological jump between Model S and Model 3. It seems that Model S Power Electronic’s design objective was to quickly fulfill the power and performance requirements with off-the-shelf and available technology. On the other side, Model 3 designers might be more looking at mass-production and design and density optimization. It’s a clear sign that the Electric Vehicles market is starting to take the lead in Power Electronics innovation.

Kyoto based semiconductor manufacturer ROHM, plans a new production building at its Apollo plant in Chikugo, Japan. The expanded production capacity is intended to meet the growing demand for silicon carbide (SiC) power devices.

The global SiC market is forecasted to exceed $1bn by 2021. The largest share comprises power supply applications, such as PV inverters, EV fast chargers and on-board chargers among other main power electronics applications.

Rohm started mass production of SiC power devices:  Schottky diodes and MOSFETs, in 2010. It’s the first supplier to produce complete SiC power modules and SiC trench MOSFETs. Rohm is considered as a Silicon Carbide leader in the Power Electronics world, where it was not a Silicon power devices (IGBT & MOSFET) leader.

Rohm SiC fab Apollo new builidng

The new three levels building at Apollo will increase production area by about 11,000m². Construction work is scheduled to begin in February 2019 and be completed by the end of 2020.

Source

Rohm semiconductor is part of the first manufacturers to have developed and release SiC MOSFET in volume production. In order to demonstrate the performance of their devices, they sponsor the Venturi racing team: A team involved electric race car championship Formula E.

They presented last week the latest improvements added to the Venturi race car. After 3 seasons, Rohm and Venturi managed to reduce the size and weight of the main inverter, step by step. The 220 kW inverter is the main power piece of the official FIA (Fédération International de L’Automobile) electric-powered race championship.

The 4th version of the inverter, to be used in 2018, is now 4 kg lighter and 30% smaller compared to the one used in 2017. It’s now weighting 9 kg.

Rohm step by step improvement of the main inverter for Venturi team electric car

Littelfuse is in the news again. The former protection system manufacturer is now more and more in the Power semiconductor manufacturing business. Last week it was about its acquisition of IXYS Corporation. Today, Littelfuse announced the release of their first Silicon Carbide based MOSFET.

LittelFuse Silicon Carbide SiC MOSFET

Courtesy of Littelfuse

This transistor is the first one born from the investments in Monolith Semiconductor (read here and here) that happened all along the last two years. This device is a 1200V and 25A MOSFET with an 80 mΩ On-Resistance. It’s beautifully named LSIC1MO120E0080 and will be available in TO-247-3L. Samples orders can already be placed at Littelfuse sales offices.

As for any other SiC MOSFET, it’s a major performance leap compared with Silicon, especially if it’s to be used for high frequency of switching applications.

Infineon Technologies AG has released the sixth and latest generation of its Silicon Carbide Schottky Diode. The first CoolSiC diodes (CoolSiC being Infineon Silicon Carbide product line name) was released in 2001. It was followed by 2nd generation in 2006, and so on until the 6th generation.

This CoolSiC G6 Diodes have a new layout, a new cell structure and a new metal contact design. Infineon does not provide more information about the design, apart this results in a claimed 17% lower figure of merit (Qc x Vf ).

They are available in 650V and from 4A to 20, in T0-220 real2pin packages.

Source: Infineon Technologies AG

Mitsubishi Electric was present during ICSCRM 2017 (International Conference on Silicon Carbide and Related Materials). They seized the opportunity to present one of their latest developments. In its SiC MOSFET, MELCO (Mitsubishi Electric Corporation) R&D team developed a new structure for the Source. Instead of a single region, there are now two region of different doping to better control the source series resistance. This structure reduces the current flow during short circuits.

MELCO claims that the On-Resistance is reduced by 40% at room temperature and power loss by 20%. These numbers are based on a comparison with conventional SiC MOSFET at 1200V.

Mitsubishi Electric SiC MOSFET source structure

Source: Mitsubishi Electric

This new device design also allows circuit simplification. Designers can now use Si short-circuit protection circuits and apply it to Silicon Carbide devices, without making any modifications. The Silicon Carbide MOSFET is dedicated to Power Modules.

Mitsubishi Electric’s development teams will further refine the new device, aiming to make it available commercially from the year 2020.

Source: Mitsubishi Electric

Ascatron is now a SiC devices company

Ascatron has announced the availability of Silicon Carbide (SiC) components using its in-house technology. The Swedish company raised founds last year in order to pivot. The business model is evolving from SiC epitaxy material manufacturing to a SiC device making. Their strategy to become an innovative SiC supplier is now on rails.

The spin-out from Acreo research center developed their own 3DSiC® technology in order to reach higher quality and performance, as they claimed. They have a semi-fabless business model, where SiC epitaxy is made in-house, in Sweden, and chip fabrication and packaging is outsourced.

Ascatron Diode SiC devices

Source: Ascatron

Available products

The first samples available are:

  • Diodes:
    • Schottky: 1200V – 15 A & 20 A
    • Schottky: 1700V – 20 A
    • PiN: 10kV – 2A

MOSFET devices are under development and will be available in 2018.

3DSiC® technology, based on Ascatron expertise in advanced SiC epitaxy material, has the potential to lower losses up to 30% compared to conventional solutions, says Ascatron.

Source: Press Release

Littelfuse keep going with its entry in the power semiconductor business. The company, which formerly was mainly involved in protection and passive components, is now about to acquire IXYS Corporation. The deal is estimated at $ 750 million in cash and actions.

This comes after an investment to take a majority stake in Monolith Semi, a leading Silicon Carbide power devices start-up, and the acquisition of a division of ON Semiconductor.

The most important acquisition in Littelfuse’s history:

IXYS Corporation is a pioneer of the power device manufacturer’s landscape. They focus on medium and high voltage components, producing IGBTs, Diodes, Thyristors, but also IGBT and MOSFET drivers, among other components in power, RF, power control and protection.

IXYS Corporation was created in 1983, and grew in different fields through acquisitions worldwide. The IXYS brand is recognized and declined worldwide according to each division and application: IXYS Power, IXYS RF, IXYS UK Westcode…

Littelfuse ixys acquisition strategy alignement applications

Extract from Littelfuse investor presentation.

Conquering the Power Electronics World:

This acquisition will help Littelfuse’s in a growth strategy:

  • Extend its footprint in the power semiconductor manufacturing business
  • Access to manufacturing capacity through IXYS fabs
  • Access to many new customers to propose Littelfuse next generation SiC devices (issue of a previous investment in Monolith Semi)

The final entity will realize annual sales of approximately $ 1,5 billion. Littelfuse can now be considered as a main player in the Power Semiconductor Field.

Littelfuse announced new 1200V Silicon Carbide diodes during PCIM 2017 last week, called GEN2. Littelfuse, which first focus was protection systems, is now fully entered in the power semiconductor world. This news adds to the recent additional investment in Monolith Semiconductor, a Silicon Carbide power devices start-up.

The diodes are the first to be produced using the Monolith Semiconductor partnership. According to Littelfuse, they offer enhanced surge capabilities, with a low leakage. These characteristics add to the usual performances of SiC diodes: higher junction temperature, higher efficiency and power density for boost converters.

Typical applications for these devices are power supplies with a PFC and freewheeling diodes in inverters. The main markets as of now are PV inverters, DC/DC converters, switch mode power supplies, some high-end UPS systems and motor drives.

GEN2 SiC diodes are available at 1200V and at 5 to 10A, in discrete packages.

SiC MOSFETs at 1200V should follow quickly, according to Littelfuse timeline.