Aavid Thermalloy offers 42 different base profiles to which fins with heights from 25mm to 140mm (1.0 inch to 5.5 inches) can be attached. Performance datasheets can be generated for any combination of base profile, fin height, and length.

Can bonded fin parts be black anodized?
No, it is not technically possible to black anodize bonded fin parts. Even if it were possible, the black finish would not contribute to heat removal in forced convection but it would increase costs substantially. Economical gold chromate is available as a finish to help protect against corrosion.

Will the fins fall out?
Proper materials, surface preparation, strict process control, and exceptional quality standards ensure error-free products. Aavid Thermalloy has refined the fin-to-base attachment process to the point that failures do not occur. Thousands of defect-free parts per year attest to the success of this process.

Does the epoxy joint restrict the flow of heat into the fins?
The design of the joint and the conductivity of the epoxy combine to hold the overall temperature rise to an immeasurable level. (Average >1.0 °C rise at 25 watt heat per fin)

Why not dip braze the assembly instead of using epoxy bond?
Cost — fixturing and processing a dip-brazed heat sink would add substantially to cost while adding very little to performance.

Do the tops of the long thin fins really increase the bonded fin heat sink's ability to remove heat?
YES. In many cases, the overall fin efficiency for bonded fin heat sinks is between 60% and 75%. While fin efficiency of conventional extrusions may be high as 85%, bonded fin heat sink's 200% to 300% increase in surface area more than compensates for lower fin efficiency.

How closely can the fins be spaced?
This depends on the width of the base. On bases up to 8.0" wide, 0.032" thick fins can be spaced 0.125" on center. For bases between 8.0" and 16.0", 0.05" thick fins can be spaced 0.20" center to center. Base widths above 16.0" must be examined on an individual basis.

Can the part be made of copper for increased conductivity?
Yes, but both the fins and base must be made of copper. Also, the part will be brazed, not epoxy bonded. The cost of a copper part is typically three times that of the comparable part in aluminum.

What materials are typically used?
Base material is 6063-T5 aluminum with fins made of 1100-H14 aluminum. This fin material is 15% more conductive than the fin material of conventional heat sinks, increasing the overall performance of the bonded fin part and compensating for any minor conductivity loss from the epoxy joint.