High Voltage Transparent 5:1 Epoxy Potting Compound for IGBT SiC Power Module Encapsulation

HN-5508AB is a two-component, high transparency epoxy potting compound with a 5:1 mix ratio by weight, developed for high voltage power module encapsulation. The cured compound delivers 25 kV/mm dielectric strength, a volume resistivity of 4.3 * 10¹⁵ Ω·cm, Tg above 90°C and a coefficient of linear expansion below 6.1 * 10⁻⁵ cm/K over a -60 to 135°C service range, so IGBT and SiC modules, DC-link capacitor banks and busbar assemblies keep their insulation and mechanical integrity through power cycling. Because the resin stays transparent, die attach, solder joints and busbar connections remain inspectable and incomplete filling is visible before the module is potted into its housing.

• 25 kV/mm dielectric strength for high DC bus voltage modules
• Volume resistivity 4.3 * 10¹⁵ Ω·cm with low leakage current
• Tg above 90°C and CTE below 6.1 * 10⁻⁵ cm/K for power cycling reliability
• -60 to 135°C service range, compatible with liquid-cooled assemblies
• High transparency for inspection of die attach, solder joints and busbars
• Shore D 80 hardness with strong adhesion to copper, aluminium, ceramic and PCB
• Void-free encapsulation that helps suppress partial discharge
• Fast cure options: 25°C in 12-16 hours or 80°C in 1 hour; EU RoHS compliant

For potting, encapsulation protection and high voltage insulation of power electronics, including:

• IGBT power modules
• SiC power modules
• GaN power stages
• DC-link capacitors
• capacitor banks
• busbar assemblies
• traction inverters
• EV powertrain modules
• energy storage PCS
• BESS racks
• string inverters
• wind power converters
• fast charging power stacks
• liquid-cooled power modules
• motor inverters
• servo drives
• UPS modules
• power shelves
• induction heating power units
• welding power sources
• X-ray generator tanks
• high voltage power supplies
• medium voltage sensors
• partial-discharge-sensitive assemblies
• fuel cell converters
• electrolyzer power supplies
• solar micro-inverters
• class-D amplifier modules
• high voltage relays
• LED driver power stages
• power supply modules
• AC capacitors
• miniature transformers
• ignition coils
• sensors and transducers

Typical values measured at 25°C / 60% RH; refer to the current TDS for the ordered grade.

1. Pre-mix Component A gently and preheat to 40-50°C for stable flow in cold workshops.
2. Weigh A and B at exactly 5:1 by weight, never by volume.
3. Mix slowly with a flat-bladed tool or planetary mixer, scraping the walls 2-3 times.
4. Vacuum degas the blend; residual voids reduce dielectric strength in high voltage parts.
5. Preheat the module and housing to 60-80°C for 1-2 hours to remove moisture before potting.
6. Cure for 6-8 hours initial and 12-16 hours full at 25°C, or 1 hour at 80°C, without stressing terminals.

• Factory-direct supply from Guangdong, China, 50 tons per month capacity
• High voltage, low CTE formulations for IGBT, SiC and DC-link encapsulation
• TDS and MSDS for every grade with batch traceability and consistent clarity
• OEM / ODM: custom colour, hardness, viscosity, packing and private label
• Free samples, MOQ from 1 kg, export-grade leak-proof packaging

Shenzhen Hanast New Material Co., Ltd. is a premier high-tech enterprise and leading source manufacturer specializing in the R&D, manufacturing, and global supply of industrial silicone materials. As a strategic branch of the renowned Shenzhen Kanglibang Technology Co., Ltd., Hanast integrates over a decade of chemical adhesive expertise with a cutting-edge 40,000-square-meter modern production base (including our newly expanding Jiangmen facility) to deliver high-capacity, reliable material solutions worldwide.

We serve as a vital tier-one supplier and OEM/ODM partner for global factories, procurement managers, and engineering teams across diverse sectors, including electric vehicles (EV), battery energy storage systems (BESS), solar inverters, LED lighting, and industrial automation.

Q: What voltage class is HN-5508AB designed for?
A: The cured compound provides 25 kV/mm dielectric strength and a volume resistivity of 4.3 x 10^15 ohm.cm, so it is used to encapsulate IGBT and SiC power modules, DC-link capacitor banks and busbar assemblies operating at high DC bus voltages where tracking and leakage current must stay low.

Q: How does the resin behave under thermal cycling?
A: Tg is above 90 degrees C, the coefficient of linear expansion is below 6.1 x 10^-5 cm/K and the service range is -60 to 135 degrees C, so the potted module keeps its insulation and mechanical integrity through power cycling, cold starts and liquid-cooled operation.

Q: Why does transparency matter for power module potting?
A: A transparent encapsulation lets you inspect die attach, solder voids, busbar joints and gate driver components after potting, and it makes incomplete filling or entrapped air immediately visible - which is critical because voids can trigger partial discharge in high voltage modules.

Q: What cure schedule should I use?
A: At 25 degrees C the compound reaches an initial cure in 6-8 hours and full cure in 12-16 hours; at 80 degrees C one hour is sufficient. Mix A and B at 5:1 by weight, degas under vacuum before dispensing and keep the assembly dry during cure.

Q: What are the MOQ, packing and OEM options?
A: MOQ starts at 1 kg. Standard packing is a 30 kg set of 25 kg Component A plus 5 kg Component B, with 25 kg barrels and 200 kg drums available. OEM and private-label supply with custom colour, hardness and viscosity is produced factory direct in Guangdong, China; TDS, MSDS and free samples are available.

Potting IGBT, SiC or DC-link assemblies? Send your module drawing, bus voltage and annual demand - our engineers will confirm the grade, packing and sample plan within 12 hours.