SABIC's New PPS Compounds Take On the Insulation Problem Inside 800 V Inverters

The race to 800 V is, at its core, a materials problem. Doubling the bus voltage from 400 V doesn't just change the semiconductor spec sheet - it rewrites the requirements for everything that surrounds the switching device: the base plate, the housing, the busbar bracket, the sealant interface. Shifting from 400 V to 800 V greatly increases the electrical stress on insulation materials throughout the EV powertrain, with components like inverters, junction boxes, and cables facing partial discharges, electrical tracking, and thermal runaway risk. The semiconductor gets most of the press. The polymer enclosing it rarely does.

SABIC is trying to change that. The company has introduced two new grades of polyphenylene sulfide (PPS) compounds - LNP THERMOCOMP OFM76XXP and OFM76EXP - engineered specifically for the insulation demands of high-voltage power modules. The announcement, dated July 14, 2026, is narrow in scope but pointed in its intent: give power electronics designers a material that can hold its shape, hold its insulation, and hold its flame rating as inverters get smaller, hotter, and more voltage-stressed.

Why the Insulation Problem Is Getting Harder

The inverter is where the grid-side or battery-side DC becomes the AC that drives the motor - and in a fast-charging context, it's also where the charger's power conversion happens. The 800 V inverter modules market is expected to grow from USD 4.28 billion in 2025 to USD 24.41 billion in 2034, at a CAGR of 21.3%. That growth is compressing design timelines and pushing power density upward simultaneously.

Higher power density means more heat per unit volume. Most power inverter failure mechanisms are directly traceable to excessive semiconductor junction temperatures. And at 800 V, the electrical stress on insulating surfaces is qualitatively different from what 400 V designs contend with. Surface tracking - the gradual formation of conductive carbonized paths across an insulator - becomes a live failure mode rather than a theoretical one. At 800 V, surfaces are more prone to arcing and surface tracking, especially in humid environments.

The insulated-gate bipolar transistor (IGBT) sits at the center of this. Despite the industry's well-documented move toward silicon carbide MOSFETs in premium 800 V platforms, IGBTs remain relevant: IGBT manufacturing is mature, cost is predictable, and field reliability is well established across fault conditions, thermal cycling, and long service lives. For OEMs managing cost-sensitive programs or applications where the aggressive dV/dt of SiC switching creates its own insulation headaches, IGBTs aren't going away. That means the insulation base plate beneath them still needs to perform.

What SABIC Is Claiming

The two OFM76 grades share a core set of electrical and thermal credentials:

• CTI-PLC 0 - the highest class on the comparative tracking index, meaning the material resists surface conduction even under sustained high-voltage stress
• Dielectric strength sufficient for effective electrical insulation at 800 V operating conditions
• UL94 V0 flame retardancy down to a 0.4 mm wall thickness - relevant as designs push toward thinner, lighter parts
• Heat resistance: the compounds retain 90% of their strength and insulation capability after 1,000 hours of heat aging at 200°C

That last figure matters for charging infrastructure as much as for traction inverters. A DC fast charger running at 350 kW is not a benign thermal environment. The power conversion hardware inside it cycles hard, and the insulating materials around the switching devices need to survive years of that without creeping, cracking, or losing dielectric performance.

Compared with polybutylene terephthalate (PBT) and polyphthalamide (PPA) - the materials these grades are positioned to displace - SABIC says the OFM76 compounds offer better dimensional stability and resistance to thermal shock. That translates directly to thinner and lighter parts: a meaningful benefit when every gram and millimeter counts in a densely packaged power module.

Photo: Bermix Studio / Unsplash

The Two Grades, Differentiated

The OFM76XXP is the baseline grade - strong CTI, dimensional stability, heat aging performance, thin-wall flame retardancy. It covers the core insulation base plate application.

The OFM76EXP is the more capable variant. It adds:

• Enhanced laser-marking contrast - important because IGBTs carry QR codes that must remain readable after assembly; the grade can be molded in white or light colors to preserve code visibility
• Adhesion to silicone-based sealants - relevant for module sealing and encapsulation processes
• Crack resistance and the highest impact strength among comparable materials in this class

Beyond the Traction Inverter

SABIC is careful to frame these grades as broadly applicable, and that framing is worth taking seriously from an infrastructure standpoint. The listed applications extend well past the vehicle:

• DC power transmission systems
• High-voltage inverters and breakers
• Integrated busbar brackets
• Renewable energy infrastructure

For charging network operators and equipment manufacturers, the relevant question is whether the same material constraints that are tightening inside traction inverters are also tightening inside the power conversion hardware at the charger itself. The answer is yes. 800 V SiC vehicles can charge at up to 350 kW, effectively increasing the throughput of existing charging stations. But that throughput depends on charger hardware that can handle the same voltage stress, thermal cycling, and insulation demands as the vehicle-side inverter. A 350 kW charger is not a passive piece of infrastructure.

The industry is also already looking past 800 V. Experts predict that lessons learned from the 800 V SiC rollout will accelerate the development of 1,200 V and even 1,700 V systems, potentially enabling electric long-haul trucking by the end of the decade. Materials qualified at 800 V today will need to be re-evaluated - or replaced - as those voltage levels arrive. SABIC's decision to spec these grades for "800 V and higher" is a deliberate hedge against that trajectory.

The Infrastructure Angle

For anyone designing or procuring power conversion hardware for charging networks, the practical takeaway here is about component reliability over time, not just initial performance. Insulation degradation in a power module is not a sudden failure - it's a gradual process that shortens service life, increases maintenance frequency, and ultimately affects station utilization. A material that retains 90% of its insulation capability after 1,000 hours at 200°C is a material that reduces the probability of unplanned downtime in a high-cycle charging environment.

SABIC's Sergi Monros, Vice President of the Specialties Business, framed the driver plainly: "Higher voltages, greater power densities and miniaturization are driving manufacturers of critical power electronic devices like IGBT switches to choose materials that help enhance stability and power."

Both OFM76XXP and OFM76EXP are available globally now. The material spec is solved. The harder question - how quickly power module manufacturers qualify and integrate new compounds into production designs - is the one that will determine how fast these grades actually show up inside the chargers and inverters being deployed on the network.