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SiC Power Module:DENSO (Equipped in SUBARU SOLTERRA) Module Structure Analysis Report


SUBARU SOLTERA https://www.subaru.jp/solterra/	Inverter core module	Power Module

Report Overview

In November 2025, the updated model of the SUBARU SOLTERRA was released. The vehicle is equipped with a new eAxle manufactured by BluE Nexus, which features DENSO’s new inverter core module. In this module, the arrangement of the power modules has been changed from a vertical layout to a flat horizontal layout, and a new double-sided cooling module with a built-in insulated substrate (SiC MOSFET) has been adopted. Focusing on this new DENSO module and the integrated SiC MOSFET, this reports aim to clarify their technical details.

Product Features

Product numbe: unknown, Inverter system voltage : 400V, Vehicle Release date: 2025

eAxle (FRONT) Motor Output: 165 ㎾
Torque: 268 Nm,
Estimated Maximum Operating Voltage (Vdss): 700–750 Ⅴ

Analysis result summary

⑴ Module Structure Analysis Report (47 pages)

⑵ SiC MOSFET Overview Analysis Report (12 pages)

⑶ SiC MOSFET Structure Analysis Report (63 pages)

⑷ SiC MOSFET Electrical Characteristics Evaluation Report (20 pages)

Please refer to the next page for further details.

Analysis result summary

⑴ Module Structure Analysis Report (47 pages) : 25G-0772-4
- A double-sided cooling module that uses resin insulated substrates on both sides.
- A heat-dissipating insulating sheet containing BN filler is used for the insulation layer of the resin insulated substrate, resulting in an extremely thin insulation layer compared to standard ones.

⑵ SiC MOSFET Overview Analysis Report (12 pages) : 25G-0772-5
- Die image, saize, confirmation of basic cell structures, and a simplified structural comparison with the company’s conventional products have been conducted.

⑶ SiC MOSFET Structure Analysis Report (63 pages) : 25G-0772-6
- A trench gate structure is adopted for the cell structure. Additionally, a P-shield is formed at the bottom of the trench, resulting in a design that differs from conventional DENSO SiC MOSFETs.
- Junction Termination Extension (JTE) and guard rings are utilized for the edge termination structure.
- A temperature-sensing diode is integrated within the die.

⑷ SiC MOSFET Electrical Characteristics Evaluation Report (20 pages) : 25G-0772-7
- BVdss, C-Vds, Idss-Vds-T, Igss-Vgs.
- Based on the correlation between electrical characteristics and device structure, the components of on-resistance (Ron) are analyzed, and the impurity profile of the epitaxial (Epi) layer is extracted.