Subaru is among the first automakers evaluating the platform for future EVs
(Image courtesy of onsemi)
onsemi has introduced the Embedded Power Platform, a wafer-level packaging architecture that embeds power semiconductors directly into silicon rather than mounting them on a separate substrate. Subaru is among the first automakers evaluating it for future electrified vehicle architectures. onsemi expects qualification in the first quarter of 2027, and the company’s early EV engagements are targeting 400-volt and 800-volt battery architectures, according to Allyson Fairchild, onsemi’s strategic project lead for the platform.
How the embedded power platform changes power system design
Conventional power modules mount semiconductor die onto a ceramic substrate, connect them with wire bonds, then encase the assembly in mould compound. onsemi’s Embedded Power Platform instead uses a standard 12-inch silicon wafer as the package itself, cutting a cavity into the wafer and building copper redistribution layers around the embedded die to form the connections.
Silicon, silicon carbide and gallium nitride die can share a single package this way, co-optimised for electrical, thermal and mechanical performance. onsemi states the approach can deliver three to five times higher power density than current solutions and shorten development cycles to as little as four months. onsemi is developing the platform across automotive, industrial and AI data centre markets at once, a reflection of power density becoming a shared constraint as AI infrastructure and vehicle electrification both compete for the same finite power budget. An early solid-state circuit breaker design built on the platform came out roughly 50% smaller and 20% cooler than existing designs, according to the company.
For EV traction inverters specifically, onsemi reports up to four times higher power density and 15% lower power losses compared with conventional approaches. Silicon’s higher thermal conductivity relative to the mould compound and ceramic substrates used in standard power modules is part of the reason, allowing better thermal management and heat to move more efficiently through the package.
Subaru’s early evaluation of the EV powertrain platform
Subaru Corporation is one of onsemi’s first automotive partners, gaining early access to engineering samples, simulation models and technical expertise as it evaluates the platform for future electrified vehicle architectures. Tamotsu Inui, Subaru’s Managing Executive Officer and Chief General Manager of its Engineering Division, said the engagement lets Subaru assess the platform’s integrated approach to power system design while drawing on onsemi’s modelling and simulation work.
Dinesh Ramanathan, onsemi’s senior vice president of corporate strategy, said the shift toward more sophisticated vehicle architectures is pushing automakers to simplify development and improve efficiency. He added that Subaru’s engagement brings practical customer insight to the platform’s continued development. onsemi describes the current phase as early engineering evaluation and technical learning, exploring how power semiconductor integration can translate into scalable system-level solutions.
Timeline and procurement implications
onsemi is sampling the platform with strategic customers through 2026 across automotive and AI infrastructure applications. Ramanathan has said the company expects qualification in the first quarter of 2027, followed by general availability to customers beyond its initial partners. Fairchild has said the company’s initial EV engagements are targeting 400-volt and 800-volt battery architectures, alongside 800-volt and low-voltage applications in AI data centres.
Because the platform scales across power levels and device types on one architecture, onsemi says automakers could reuse a single inverter design across multiple vehicle programmes. That reduces the number of components requiring separate qualification, which onsemi frames as a route to lower engineering costs and faster development cycles across a model range, supporting broader drivetrain electrification and powertrain integration plans.
onsemi has kept its exact method for inserting die into the wafer cavity proprietary, disclosing only the broad architecture. The current phase, both companies say, is about engineering evaluation and technical learning, building the groundwork for whatever comes next in Subaru’s electrified vehicle plans. onsemi is targeting qualification in the first quarter of 2027, after which the platform moves to general availability for customers beyond the partners named so far.
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