A thermal interface grease at a heat sink joint has to solve the same basic problem every time — eliminate the air gap between two mating surfaces so heat actually transfers instead of stalling at the interface — but whether that joint also needs to carry electrical current or ground a connection changes which filler metal actually belongs in the grease. Incure’s Epo-Weld™ thermally conductive grease line covers both cases across three grades, unbonded and reworkable rather than curing into a permanent joint the way an adhesive does.
TCG-10 Moves Heat While Staying Electrically Insulating
Epo-Weld™ TCG-10 is an alumina-filled grease built specifically to conduct heat while remaining electrically insulating — a combination that matters directly for mounting transistors and rectifiers, where the thermal interface sits close to live circuitry and can’t become a path for current leakage or signal interference. It maintains stable, non-drying performance up to 550°F, holding its consistency at the heat sink interface rather than separating or hardening over sustained thermal cycling the way a lower-grade grease would. That non-drying behavior matters specifically because a grease that hardens or crumbles over time reintroduces the same air-gap problem the grease was applied to eliminate in the first place — an interface that looks fine at initial assembly can quietly lose most of its thermal performance months later if the filler system doesn’t hold up under repeated heating and cooling.
TCG-30 and TCG-40 Both Conduct Heat and Current, Split by Filler Metal
Epo-Weld™ TCG-30 and TCG-40 take the opposite approach from TCG-10, both formulated to conduct heat and electricity simultaneously through the same interface — the property TCG-10 is specifically built to avoid. TCG-30 uses aluminum filler for grounding connections and high-power electrical contacts, providing a low-resistance path for both current and heat at a moderate cost. TCG-40 steps up to copper filler, delivering genuinely lower contact resistance and better electrical conductivity than aluminum, positioned for high-current switches and grounding lugs where minimizing voltage drop across the interface is the primary requirement rather than a secondary benefit. That’s the same cost-versus-performance trade-off found in Incure’s thermally and electrically conductive adhesive line, just applied to a non-curing grease interface rather than a permanent structural bond — aluminum for cost-effective general-purpose conductivity, copper where contact resistance genuinely needs to be minimized. Both also resist moisture and oxidation, keeping their conductivity stable rather than degrading as the metal filler itself corrodes over years of service — a genuine concern on any grease relying on a bare metal filler for its conductive path, since an oxide layer forming on the filler particles would raise contact resistance right at the interface the grease exists to protect.
Email Us with your interface’s electrical requirement — insulating or conductive — and whether cost or minimum contact resistance matters more, and Incure’s engineers can confirm which Epo-Weld™ thermally conductive grease grade actually fits.
Same Mechanical Profile Across All Three, Filler Chemistry Is the Only Real Variable
All three grades share the same thixotropic paste consistency and 2-hour, 200°F cure schedule, with nearly identical flexural strength around 1,100 PSI. Tensile shear runs slightly lower on TCG-30 at 200 PSI against TCG-10 and TCG-40’s 300 PSI, a modest difference that reflects filler-particle characteristics more than any deliberate mechanical trade-off — none of the three grades are chosen for their tensile figures the way a structural epoxy would be. That consistency across the mechanical spec means the actual selection decision comes down entirely to the electrical property the interface needs, not to comparing hardness or bond strength between grades the way a reader might on one of Incure’s structural adhesive lines. Because none of the three grades cure into a rigid bond, they’re also inherently reworkable — a heat sink or contact using any of these greases can be disassembled and cleaned without the joint-preparation work a cured adhesive bond would require, a practical advantage on any assembly that needs periodic service access rather than a one-time permanent joint.
Where the Line Fits
Power electronics and heat sink mounting on sensitive circuitry favors TCG-10 wherever the thermal interface has to stay electrically isolated from nearby components. Grounding connections and general power-electronics thermal management favor TCG-30’s aluminum-filled conductivity as the cost-effective default. High-current switches, grounding lugs, and any interface where voltage drop across the joint is a real design concern favor TCG-40’s copper filler specifically. Facilities already running Incure’s thermally conductive epoxy line for permanent, structurally bonded thermal joints can add this grease line wherever the assembly needs a reworkable, non-permanent thermal interface instead — a heat sink that gets removed for service, for example, rather than one that stays bonded for the life of the assembly.
Contact Our Team to confirm the Epo-Weld™ thermally conductive grease grade for your interface.
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