One-part toughened epoxy for dam-and-fill encapsulation

Master Bond Supreme 3DM-85 is a no-mix, non-solvent-based, one-component epoxy. This thixotropic paste material was formulated as the damming compound in dam-and-fill encapsulation applications. It can also be employed for bonding and sealing, particularly where no flow is required since the material cures in place and will not run or slump. The compound needs a relatively low heat cure of 85C for two to three hours and is thermally conductive and electrically non-conductive.

“Supreme 3DM-85 is designed for heat-sensitive components that cannot withstand high temperatures for curing. The fact that it is not premixed and frozen gives it an advantage in production situations where freezer storage may not be practical. Also, there are no special shipping requirements,” says senior product engineer Rohit Ramnath. As a toughened system, Supreme 3DM-85 resists rigorous thermal cycling. It is a reliable electrical insulator and offers a thermal conductivity of 5-10BTU•in/ft2•hr•F [0.72-1.44W/(m·K)]. It is important to facilitate heat dissipation and prevent overheating, especially in densely packed electronic assemblies. The epoxy maintains a Shore D hardness of 75-85, offers excellent damp heat resistance and has a good physical strength profile.

The epoxy forms strong bonds with an extensive range of substrates commonly found in electronics and semiconductors. Substrates include metals, composites, ceramics, silicon, and many plastics. It is easy to handle as a single-part system and offers unlimited working life at room temperature. It is opaque black in colour and can be applied manually or automatically. Serviceable from -100F to +350F [-73C to +177C], it is available in syringes and jars.

The epoxy is a toughened, one-part system developed as a damming compound for dam-and-fill encapsulation. It is also useful for bonding and sealing purposes, where heat curing above 200F is not possible.