Preparing for strong growth in mild hybrid vehicles

In view of the expected increase in demand, Infineon has set up a new manufacturing process to now produce the chips on its line for 300mm thin-wafers in Dresden, Germany.

"In this decade, we will reach the point where the majority of all newly produced cars worldwide have a partially or fully electric powertrain," said Stephan Zizala, Vice President and General Manager Automotive High Power at Infineon.

"According to market research, production of models with 48V power supply and a mild hybrid drive is likely to increase more than tenfold between 2020 and 2030. In addition to our portfolio for high voltage systems in battery-electric drives as well as full and plug-in hybrids, we therefore also strengthen our offering for 48V systems with new devices and expanded supply capacities.”

Portfolio expansion at both ends of the power spectrum

Infineon offers a variety of 80V and 100V MOSFETs in OptiMOS 5 technology with very low, scalable on-state resistances down to 1.2mΩ. For the core applications of a mild hybrid, for example starter generators, battery switches and DC-DC converters, where high power densities are required, Infineon is expanding its TOLx package family. This is based on the established TOLL (TO-Leadless, 10 mm x 12 mm) product for standard copper substrate PCBs and currents up to 300A.

In addition, the family comprises the TOLG (TO Leads Gullwing Design) package with identical footprint for Insulated Metal Substrates (IMS) with aluminium core. Since the thermal expansion coefficients of copper and aluminium differ, the use of IMS boards under high thermo-mechanical stress leads to increased stress on the soldered connections between package and PCB. In order to mitigate this stress, the TOLG package is equipped with gullwing leads.

New package for top-side cooling

In the next step, Infineon will expand the TOLx family with a third member that is unique among the competition: the TOLT (TO Leads Top-Side Cooling) package. It enables heat dissipation through top-side cooling via the top of the package instead of via the PCB. This allows an increase in power of more than 20% and reduces the necessary cooling effort on the board. The start of volume production of TOLT products is planned for 2021.

Next to the TOLx family, Infineon also expands the package portfolio addressing less power-hungry auxiliaries such as fans and pumps that are also increasingly being transferred to the 48V supply. Completely new are versions in the small S3O8 package (3.3x3.3mm) for lower currents up to 40A. They complement products with the slightly larger SSO8 package (5x6mm) for currents up to 100A that were added to the portfolio recently.

Mild hybrid drives based on a 48V supply are a fast and cost effective way for car manufacturers to achieve lower CO₂ fleet emissions. Among other things, they allow a higher recuperation energy compared to a 12V system and use the energy gained for electrical support of the combustion engine.

In addition, a 48V supply offers performance and efficiency advantages for safety and comfort functions with high current loads, such as stability control or air-conditioning compressors. Depending on the configuration of the drive system and the number of auxiliary units, a mild hybrid can reduce CO₂ emissions by up to 15% compared to a pure combustion engine.

Products in TOLL, TOLG, SSO8 and S3O8 packages are now available. The start of volume production of TOLT products is planned for early 2021.