Master Bond's thermally conductive adhesives offer superior heat dissipation for a wide range of electronic applications. Both one and two component systems are available for use. They include epoxies, silicones and other elastomeric products. Special formulations designed for unusual service conditions are also available.
Formulating Thermally Conductive Compounds
Thermal conductivity of a typical unfilled epoxy system has a very low value of 0.14/(m•K). This key property can be increased by adding metallic or ceramic fillers to the adhesive formulation. The type of filler, concentration of particles, their size and shape will determine the thermal conductivity of the product. They can be either electrically conductive or electrically insulative, as illustrated in the diagram below.
The chart below illustrates thermal conductivity values that can be achieved for select grades of systems with different fillers:
|System Type||Product||Filler||Thermal Conductivity|
|One part epoxy||Supreme 12AOHT-LO||Aluminum Oxide||1.30-1.44 W/(m•K)|
|Two part epoxy||EP30TC||Aluminum Nitride||2.60-2.88 W/(m•K)|
|One part epoxy||EP3HTS-LO||Silver||2.45-2.60 W/(m•K)|
|Two part epoxy||EP75-1||Graphite||1.87-2.02 W/(m•K)|
Key factors influencing heat dissipation effectiveness
Master Bond thermal interface materials (TIMs) are often applied between heat generating electronic components and cooling devices such as heat sinks. These systems are compounded to fill in thermally insulative air gaps, maximize heat transfer efficiency, improve device reliability and extend longevity. The following factors minimize the thermal resistance:
- High thermal conductivity
- Minimal bond line thickness
- Complete polymerization
- Elimination of voids
Thin Bonds Maximize Heat Transfer Properties
The lower the thermal resistance, the better the heat transfer. In this regard, Master Bond utilizes the principles based on the formula:
(where “R” is the thermal resistance; “t”, the thickness and “K” the thermal conductivity of the material). Master Bond epoxy thermal interface materials feature ultra thin bond lines to improve heat transfer characteristics. Thicknesses as small as 10-15 microns can be achievable using some compounds.
Common Applications Featuring Thermally Conductive Adhesives
Thermally conductive formulations are used for bonding, potting and encapsulation applications in a wide variety of industries. Some specific applications include:
- Heat sink bonding
- Potting/encapsulating sensors
- BGA die heat spreader interface
- Chip scale packages
- Power semiconductors
Master Bond thermally conductive adhesives offer convenient room temperature or heat cure schedules in controlled production environments. Many systems withstand 1,000 hours at 85°C/85% RH. They can be serviceable in a wide range of temperatures from 4K to over 500°F. Specific systems are designed to offer superior dimensional stability, adhere well to substrates with dissimilar coefficients of thermal expansion and resist vibration, impact, shock. They can be dispensed manually or automatically. Select two component grades are available for use in premixed and frozen syringes.
Our Most Popular Thermally Conductive Adhesive Formulations
B-staged film adhesive/sealant. Outstanding thermal cycling capabilities and structural properties. Offers superior toughness and flexibility. Excellent strength retention at elevated temperatures. Thermally conductive/electrically insulative. Provides uniform bond line thickness. Serviceable from -100°F to +500°F. Preforms are available.
Super Gel 9
Two part, room temperature curing, epoxy gel compound for sealing and encapsulation. Optically clear, soft and dimensionally stable. Ideal for retrievability. Two to one mix ratio by weight or volume. Low exotherm. Long working life. Low viscosity system. Unsurpassed thermal cycling and mechanical shock resistance. Used in conjunction with sensitive electronic and optical components. Serviceable from -100°F to +200°F.
Thermal conductive/electrically insulative epoxy cures at room temperature. Outstanding heat dissipative properties. Serviceable from -60°F to +250°F. Low viscosity. Suitable for potting/encapsulation. NASA approved for low outgassing.
Flexible, low viscosity, thermally conductive epoxy. Meets NASA low outgassing specifications. Superb electrical insulator. Good physical strength. Chemical resistant. Long working life. Withstands 1,000 hours 85°C/85% RH. Guards against mechanical shock and vibration. Excellent flowability. Ideal for potting and casting.
Features exceptional thermal conductivity. High dielectric strength. Idea for joining dissimilar substrates. Serviceable from -100°F to +400°F. Superior durability. Will cure at room temperature.
Two part, room temperature curable epoxy system with high thermal conductivity. Serviceable from cryogenic temperatures up to +400°F. Electrically isolating. Meets NASA low outgassing specifications. Halogen free. Paste consistency. Formulated to cure at ambient temperatures. Withstands 1,000 hours 85°C/85% RH.
One part, oven cured epoxy system with excellent thermal conductivity and superb resistance to thermal cycling. Primarily used for bonding of heat sinks and sensors where heat transfer is desirable. Halogen free. Serviceable from 4k to +400°F. Convenient processing.