The SiC (silicon carbide) home court is about to open, are you ready?

Article source: Electronic Engineering World

Author: Tang Honglin

While we are still enjoying the low-cost dividends brought by Si devices, many key applications have begun to embrace SiC.

Although SiC is still a little bit more expensive, it has its own unique advantages: compared with Si, SiC has a 10-fold higher dielectric breakdown field strength, a 2-fold higher electron saturation velocity, a 3-fold higher energy band gap, and a 3-fold higher thermal conductivity.

With the improvement of epitaxial process and the reduction of cost, SiC has become a hot material in the semiconductor field. It is known as one of the semiconductor materials with the brightest commercial prospects and can be called the new generation "golden track" in the semiconductor industry. Its application market is also expanding rapidly.

According to Wang Limin, product marketing manager of ON Semiconductor's power solutions division , the SiC market will have an average annual compound growth rate of 35% between 2017 and 2022, and its market capacity is expected to exceed US$1 billion by 2022.

Power factor correction (PFC), electric/hybrid vehicles, electric/hybrid vehicle infrastructure, photovoltaics, uninterruptible power supply (UPS), motor drives, railways, wind power and other fields are all application spaces where SiC can show its strength.

Wang Limin, Product Marketing Manager, Power Solutions Division, ON Semiconductor

So which market will be the first to take off for SiC? And which areas are the key focus of SiC devices? Let's follow the footsteps of ON Semiconductor to find out.

The devices will focus on four major application markets: electric vehicles (EV)/hybrid vehicles (HEV), 5G power supplies and switch mode power supplies (SMPS), EV chargers/piles, and solar inverters.

The development speed of electric vehicles is obvious to all. The use of SiC devices in applications such as automotive main drive inverters, on-board chargers (OBC) and DC-DC stages can greatly improve efficiency and increase endurance. Therefore, automotive applications have become one of the main driving forces for SiC devices, accounting for about 60% of the total SiC market capacity.

Whether from the perspective of user experience or from the perspective of car manufacturers' quotations based on driving range, improved energy efficiency and increased driving range will undoubtedly play an important role in the development of the electric vehicle market. Therefore, almost all manufacturers of main drive inverters are currently researching SiC as the main drive direction.

At the same time, in the field of on-board charging (OBC) and DC-DC applications, most manufacturers are also using SiC to achieve high efficiency, high voltage and high frequency applications.

This series of policies has promoted the substantial growth of electric vehicles, and the demand for high-voltage, high-frequency and high-efficiency devices in electric vehicles has also driven the substantial growth of the SiC market.

In the traditional switching power supply field, there has always been a persistent pursuit of power density in boost circuits and high-voltage power supply applications. From the earliest communication power supplies to the current 5G communication power supplies and cloud data center power supplies, there are very high requirements for energy efficiency.

SiC devices have an energy efficiency of up to 98%, which perfectly matches the development of the power supply and 5G power supply markets, and also performs well in this application field.

A series of strategies such as new infrastructure and internal circulation are rapidly driving the development of electric vehicle charging piles. There are many ways to implement charging piles. Consumers are most interested in DC fast charging. DC fast charging charging piles require very large charging power and very high charging efficiency, which all need to be achieved through high voltage.

Therefore, as power and speed requirements increase, more and more charging pile solutions will use SiC MOSFET. Naturally, electric vehicle charging piles are also one of the key markets for ON Semiconductor's SiC devices.

SiC is also widely used in the field of solar inverters, and the market is booming. Wang Limin introduced that currently 1% of the world's electricity comes from solar energy, and it is expected that 15% of the energy will come from solar energy in the next 10-15 years.

It is reported that China's National Energy Administration (NEA) has set a clean energy target to meet 20% of China's energy needs by 2030. At the same time, the European Union has also set a goal to improve energy efficiency by 20%, reduce carbon dioxide emissions by 20%, and reach 20% of renewable energy by 2020.

Policy-driven applications have led to an increasing number of SiC devices being used in solar inverter boost circuits. As the cost of solar inverters is optimized, more and more manufacturers will use SiC MOSFETs as the main inverter device to replace the original complex three-level inverter control circuits.

Faced with current market competition, the high efficiency, high energy efficiency, high power density and high voltage of SiC products are indeed very attractive, but cost is also an issue that customers have to consider.

Reliability is a prerequisite for device use. Wang Limin said that ON Semiconductor SiC devices have leading reliability and all devices meet automotive regulations .

In the semiconductor high temperature and high humidity reverse bias aging test (H3TRB), under the same test conditions, ON Semiconductor SiC diodes can pass the 1000-hour reliability test. In actual tests, ON Semiconductor will extend this test to 2000 hours, which is enough to show the high reliability of its SiC devices.

High cost performance is also one of the characteristics of ON Semiconductor's SiC devices. Its SiC MOSFET and diode are both near-ideal switching devices that can well combine Rds_on and low switching losses while supporting higher voltages (>600V).

In this regard, Wang Limin gave a set of theoretical comparative data: when the breakdown voltage reaches 1200V, the area required for each device to achieve the same efficiency is compared.

In addition, if the Si solution is replaced with SiC, its volume, power density and overall BOM cost will be optimized, as shown in the figure below.

At the same time, in order to help engineers quickly apply SiC devices to their designs, ON Semiconductor also provides complete solutions based on its application expertise , including single-tube solutions, module solutions, and various on-board charger solutions for electric and hybrid vehicles. It also provides a complete set of circuit drawings, BOMs, demos, and strong support from a team of solution experts.

Surge and avalanche are one of the main manifestations of the robustness of SiC diodes. Wang Limin introduced that while greatly improving efficiency, SiC diodes also have a design pain point, that is, whether in the Boost circuit or the PFC circuit, SiC diodes must withstand surge current.

In addition, ON Semiconductor's MOSFETs also cover almost all mainstream SiC MOSFETs on the market, including 20mΩ, 40mΩ, 80mΩ, and 160mΩ devices, with packages including TO-247 3-pin and D2PAK 7-pin packages, and all products provide industrial and automotive specifications. In addition, ON Semiconductor also has 900V SiC MOSFETs, and 20mΩ and 60mΩ are some of the most mainstream specifications on the market.

For all the current markets that are experiencing sustained growth, ON Semiconductor is developing relevant solutions to provide customers with a complete set of solution designs. At the same time, it has established close cooperative relationships with key customers in the industry, including joint laboratories and joint development.

In the future, ON Semiconductor will continue to invest significantly in the SiC field and operate its ecosystem.