Epoxy potting compound

Pick TIE280-AB epoxy potting when the assembly needs a rigid, high-modulus pour (mechanical reinforcement of the PCB, top-class moisture barrier, chemical resistance to fuels/solvents). Pick silicone potting (TIG680 / TIS680) when thermal cycling, vibration absorption, or reworkability matter — silicone is softer and more elastic but lets in more humidity and is harder to bond to over-mold steps. Operating range also differs: epoxy is rated to about 160 °C continuous, silicone goes to 200 °C and beyond.

Open the A and B containers (Part A is the resin + filler, Part B is the curing agent), weigh out 1:1 by weight, mix thoroughly under low shear for 3 – 5 minutes (a planetary centrifugal mixer is ideal — manual mixing risks air entrapment and uneven cure), degas under vacuum if the application is dielectric-critical, and pour into the cavity. Working life (pot life) is typically 30 – 60 minutes at 25 °C — see the per-grade datasheet. For high-volume lines, a meter-mix-dispense machine is recommended.

Rigid epoxy (Shore D 70+) does have a higher CTE mismatch with copper and aluminum than silicone, so deep pours over large copper planes can crack on −40 ↔ +130 °C cycling. Mitigations: keep pour depth ≤ 10 mm where possible, design stress-relief features into the housing, or step up to a silicone potting compound (TIG680 / TIS680) for cycle-heavy applications. The TIE280 family is best when the operating temperature is steady or has a narrow swing window (≤ 50 K typical).

Yes — TIE280-12AB and TIE280-15AB datasheets list a 70 °C / 3 h accelerated cure, and TIE280-25AB lists 80 °C / 1 h. Faster oven cures yield slightly higher cross-link density and a narrower modulus distribution. Confirm that none of the embedded components have a thermal limit below the cure temperature, and avoid cures above 100 °C as they can drive off un-reacted curing agent before full cross-linking is reached.

All three TIE280-AB grades are RoHS / REACH compliant. UL-94 ratings vary by grade and pour depth — TIE280-15AB and -25AB datasheets call out V-0 at sample thickness 3 mm. If your application requires UL-Yellow-Card listing on the finished assembly, contact engineering with the part geometry and we can arrange a sample-to-burn test report.

TIE380 (1K heat-cure) is for bonding two parts together — thin-bondline structural adhesive. TIE280-AB (2K room-temp-cure) is for filling a cavity around components — bulk encapsulation. Different paste viscosity, different application workflow, and different mechanical role. They share the same chemistry family but are not interchangeable.