Bonding a power semiconductor to a grounded heat sink asks two things of the adhesive at once: pull heat out of the device, and keep it electrically isolated from the sink. Most metal-filled thermal epoxies fail the second test. Incure Epo-Weld™ TC-9051 is formulated to pass both. What TC-9051 is Epo-Weld™ TC-9051 is a two-part thermally conductive epoxy filled with aluminum nitride rather than a metal powder. Aluminum nitride has high thermal conductivity but is an electrical insulator, so the cured adhesive conducts heat across the joint while maintaining dielectric separation between the component and the substrate. That combination is what makes TC-9051 suited to power electronics, where a metal-filled epoxy would short the device to the chassis. Its service range runs from roughly -65°C to 205°C (-85°F to 400°F), covering cold-soak startup and sustained operating temperature in most power-conversion hardware. Key properties and why they matter Thermally conductive and electrically insulating. You get a low-thermal-resistance path and a dielectric barrier from a single material, removing the need for a separate insulating pad or film with its own contact resistances. Wide temperature range. The adhesive holds properties from deep cold to 205°C, matching the operating envelope of most drives, converters, and LED modules. Strong structural bond. Unlike a thermal grease or a clip-held pad, TC-9051 mechanically fixes the component, which improves vibration resistance and simplifies assembly. Environmental protection. As a potting compound it also shields the encapsulated electronics from moisture and contamination. Where TC-9051 fits Power electronics: bonding IGBTs, MOSFETs, rectifiers, and power modules to heat sinks and cold plates while keeping them isolated. LED lighting and displays: attaching LED arrays and drivers so heat leaves the junction without a separate insulator. Automotive and aerospace: thermal management for onboard power conversion exposed to vibration and thermal cycling. Renewable energy: bonding and potting inverter and charge-controller electronics in solar and wind systems. Industrial motor drives: heat-coupling and isolating switching devices in variable-frequency drives. Designing the isolated thermal joint Control the bond line. Thermal resistance rises with thickness, but so does dielectric strength. There is an optimum: thick enough to guarantee isolation with no filler particles bridging the gap, thin enough to keep thermal resistance low. The datasheet gives a recommended range. Keep it void-free. A void is both a hot spot and a weak point in the dielectric. Apply the adhesive so air is pushed out as the parts close. Manage expansion mismatch. A rigid joint between a semiconductor and a metal sink is stressed on every power cycle. Reducing bond area and controlling the gap spreads that load; the mechanism is covered in how CTE mismatch causes adhesive bond failure. If you need to confirm that a given bond line will hold off your working voltage, Email Us with the voltage, the gap, and the substrates. Surface preparation, mixing, and cure Degrease and lightly abrade metal surfaces, then wipe clean and dry. Meter the two components accurately and mix until completely uniform; the ceramic filler hides streaking, so extend the…

A heat sink only works if heat can actually reach it. An air gap or a low-conductivity adhesive at the interface throttles the whole thermal path. Incure Epo-Weld™ TC-9042 is a two-part epoxy that moves heat across the joint while surviving temperatures that defeat most thermal adhesives. What TC-9042 is Epo-Weld™ TC-9042 is an aluminum-filled, two-component thermally conductive epoxy for bonding and potting. The metal filler raises the bulk thermal conductivity of the cured matrix so the adhesive conducts heat from a component into a sink or chassis instead of insulating it. Its service range extends to roughly -60°C to 300°C (-76°F to 572°F), which is wider than typical thermal epoxies and lets it work in exhaust-adjacent, downhole, and furnace-adjacent locations. TC-9042 is thermally conductive but is not formulated as an electrical insulator; where a component must be both heat-coupled and electrically isolated, use the aluminum-nitride-filled TC-9051 instead. Key properties and why they matter Thermal conductivity across the bond line. The relevant figure is the conductivity of the adhesive multiplied by the contact area and divided by the bond line thickness. A thinner, void-free joint of conductive epoxy dramatically lowers thermal resistance. Wide temperature range. Holding properties to about 300°C means TC-9042 does not become the weak link in equipment that already runs hot. Chemical resistance. The cured matrix resists solvents, fuels, and dilute acids and bases. Bonding and potting in one product. You can attach a heat sink and encapsulate the surrounding electronics with the same qualified material. Where TC-9042 fits Aerospace and defense: bonding heat sinks and cold plates on avionics that see wide thermal swings. Automotive and transportation: attaching power electronics and sensors in engine-bay and exhaust-adjacent locations. Industrial power conversion: potting and bonding rectifiers, drives, and controllers that dissipate significant heat. Oil and gas: thermal management for downhole and surface electronics exposed to high ambient temperatures. Furnace and oven instrumentation: bonding sensor packages that must shed self-heating while sitting in a hot enclosure. Getting the thermal path right Keep the bond line thin. Thermal resistance is proportional to thickness. Use just enough adhesive to fill the gap and wet both surfaces; excess adhesive squeezed into a thick layer defeats the purpose. Eliminate voids. An air pocket is a local hot spot. Apply the adhesive in a pattern that pushes air out as the parts close, rather than trapping it in the center. Flatten and clean the mating faces. High points carry all the load and leave the rest of the interface starved. Plan for expansion. A rigid conductive joint between a silicon device and a metal sink is loaded every thermal cycle. This guide to how CTE mismatch causes adhesive bond failure explains how to manage that stress. If you want help estimating the thermal resistance of a proposed joint, Email Us with the die size, power dissipation, and sink details. Surface preparation, mixing, and cure Degrease and abrade metal surfaces, then wipe clean and dry. Meter the two parts at the specified ratio and mix…