Applications

EV Charger Thermal Pads & Power Module Insulation

High-conductivity thermal pads and electrical insulation for AC and DC EV chargers — 3 to 6 W/m·K silicone pads for IGBT, MOSFET and SiC power modules, flame-retardant sealing foam for the enclosure, and aramid magnetics insulation, die-cut to your drawing for OEM production.

3–6 W/m·K conductivity range0.5–3 mm thicknessISO 9001:2015 certifiedMOQ 10 sheets
The Problem

Why EV charger cooling is a steady-state problem

An EV charger is thermally closer to industrial power conversion than to consumer electronics, because the defining condition is duration. A charger runs near its rated output for the length of a charging session, so the design case is sustained steady-state dissipation, not a short peak the enclosure can absorb. The losses land in the PFC stage, the IGBT or SiC switching modules, and the magnetics — and they keep landing there for as long as the vehicle stays connected.

Outdoor and wall-box units then remove the easiest cooling option. To keep water and dust out they are sealed, so there is no through-airflow and effectively all heat leaves by conduction into the casting or heatsink. That puts unusual weight on the interface layer, since it is in series with every watt on its way out — a pad that bridges the gap badly raises module temperature for the whole session, every session.

Magnetics bring a second, separate requirement: winding and layer insulation rated for the temperature class the transformer actually reaches. That is a paper and film problem rather than a thermal pad one, and we supply aramid paper die-cut to the bobbin or core geometry alongside the pads. We supply EV charger thermal pads and magnetics insulation converted and die-cut to your drawings for OEM production.

The Path

The thermal path in a sealed EV charger

Every watt the power stage loses has to travel the same road. The module temperature is whatever the ambient air is, plus the sum of every thermal resistance along that road.

Every watt lost in the PFC stage, the switching modules and the magnetics has to reach ambient air through the same chain: out of the module baseplate, across the interface, into the heatsink or sealed casting, and away. In an outdoor or wall-box unit the enclosure is sealed against water and dust, so there is no through-airflow to help — conduction is the whole story.

That makes the interface pad a genuine design component rather than an assembly afterthought. Its thermal resistance sits in series with everything else in the path, and at 6 W/m·K the pad's share of the total budget stays small even as module power climbs. Specify it against the measured case temperature and the real gap, not the headline number.

Thermal path in a sealed EV charger: from the power module through the baseplate and thermal pad into the heatsink or sealed casting, out to ambient airIGBT / SiCmoduleModulebaseplateThermal padHeatsink /castingAmbient
The interface pad is in series with every watt leaving the module — in a sealed charger there is no airflow path around it.
Selection Guide

Selecting a grade by location in the charger

The four locations below cover the charger end to end — the power module interface, the control electronics, the enclosure seal and the magnetics. Each takes a different material family, and specifying them together at quotation is cheaper than buying them one at a time.

LocationGradeConductivityCommon thickness
IGBT / MOSFET / SiC module interfaceCP6006.0 W/m·K0.5–3 mm
Control and driver boardsCP3003.0 W/m·K0.5–3 mm
Enclosure sealing, vibrationMCF-PUNot a TIM — UL94 HF-1 / HBF0.5–5 mm, custom
Magnetics — winding & layer insulationNOMEX-CUSTAramid, Class HTo drawing

A sealed charger has no airflow margin to fall back on, so fill the gap properly before reaching for a higher-conductivity grade. Match the pad to the measured case temperature and the real stack-up, not to the largest number on the datasheet.

Specifications

Grade specifications

Both silicone grades are supplied as sheet with or without adhesive backing, and every part on this page can be die-cut to your drawing. Technical datasheets are linked per grade.

GradeConductivityDielectric strengthThickness optionsAdhesiveDatasheet
CP6006.0 W/m·K6.0 kV/mm0.5 / 1 / 2 / 3 mmAdhesive or plain TDS
CP3003.0 W/m·K6.0 kV/mm0.5 / 1 / 2 / 3 mmAdhesive or plain TDS

Sealing and magnetics insulation

PartMaterialKey specificationsThicknessDatasheet
MCF-PUMicro-cellular PU foamUL94 HF-1 / HBF · −40 °C to +100 °C · ≥50 % set recovery0.5 / 1 / 2 / 3 / 5 mm + custom
NOMEX-CUSTAramid insulation paperClass H · die-cut to bobbin or core geometryTo drawing Datasheet

MOQ 10 sheets · typically dispatched in 7 days.

Catalogue

Related products

Grades most often specified for EV charger assemblies, drawn from the live catalogue.

Why Perfect Insulations

Built for charger OEM production

EV charger focus

Materials aligned to charger power stages — module interfaces, control boards, enclosure sealing and magnetics.

High-voltage insulation

Electrically insulating silicone pads and aramid papers for live module tabs and Class H magnetics.

OEM conversion

Custom die-cut parts for enclosures, module stack-ups and gasket profiles, quoted to your drawing.

Supply Terms

Supply terms

Supply terms. Standard sheet grades start at 10 sheets; die-cut TO-package shapes start at 50 pieces. Catalogue grades are typically dispatched within 7 days. Parts to a new drawing are quoted per job — send a DXF or PDF with the grade and thickness, and note that die cost is one-time, so the per-part price falls sharply with volume. Adhesive and non-adhesive options are available across the silicone grades. ISO 9001:2015, supplied to OEMs and contract manufacturers across India from Bengaluru.

FAQ

Frequently asked questions

What conductivity does an EV charger power module need?

6 W/m·K (CP600) is the usual choice at the IGBT, MOSFET or SiC module interface, because the module runs at high duty for the whole session. Control and driver boards are normally fine at 3 W/m·K.

Why does a sealed outdoor charger need a better interface material?

Sealing the enclosure against water and dust removes airflow, so conduction is the only path out. The interface layer is in series with every watt leaving the module, which makes it a much larger share of the total thermal resistance than in a ventilated box.

What insulation do charger magnetics need?

Aramid paper for Class H service and aramid–polyester–aramid laminate for Class F, both die-cut to the bobbin or core geometry. That is a separate material family from the thermal pads and is quoted from the insulation paper catalog.

Do these materials handle outdoor temperature cycling?

The micro-cellular PU foam we supply for sealing is specified from −40 °C to +100 °C with high set recovery, which is what matters for a gasket that must keep sealing after repeated cycles. For the silicone pads, confirm the expected case temperature with us and we will advise the grade.

Can you supply to our enclosure drawing?

Yes — send a DXF or PDF with the grade and thickness. Charger enclosures usually need several different die-cut parts, and quoting them together is cheaper than quoting them one at a time.

Applications

Related applications

Bulk & Custom Supply

Send your specification — grade, thickness, size or die-cut drawing, and quantity — and our team will quote to your requirement.

Custom Inquiry