These days, refinements in the manufacturing processes mean that heat sink extrusions manufacturers can extrude a heat sink and accomplish ratios of about 23:1. This is in stark contrast to previous extrusion ratios, which were anywhere from 8:1 to 10:1, depending on the size of the diameter tool. These heat sinks were comparatively inefficient and some lacked the cooling ability to keep up with today’s power semiconductors at a safe operating level. Heat sink extrusions manufacturers that offer a high ratio shape are more efficient, have better cooling capability and do it at a smaller volume than those without the new technology.
Getting the High Ratio Equation
By measuring the height of the air gap between fins and dividing that with its width, you can find the ratio for heat sink extrusion. Any extruded aluminum heat sink is applicable to this ratio and only the tools for extrusion dies limit it.
Because extrusion presses force at an extraordinary pressure (more than 1000 tons) against them, these circular dies must hold underneath rising temperature during the process. High fin ratios allow a thermal management solutions company to increase cooling at a reasonable cost.
Improving the techniques used to manufacture these newer extrusion heat sinks has meant doing a computer analysis of the pressing process for each shape. Then, improving the hydraulic ram controls used for the extrusion, as well the tool steel for dies, took some the “black magic” out of the equation.
A high ratio is a ratio of 23:1 for 5-inch, and 20:1 for 8-inch diameter tools. This results in lighter weight and thin fins (with a 1.0″ height, thickness is in at 0.040″).
Advantages for the New Heat Sink Extrusions
The advantages of these new heat sink extrusions are many. As previously mentioned, the fin thickness has been brought down, so they can also easily replace bonded-fin sinks. Their weight reduction translates into lower costs, both for shipping and purchase. This is brought on by the single-piece aluminum alloy construction using highly conductive aluminum.
For an aluminum extrusion heat sink turnkey services company, ultra-high ratio types provide more cooling in a smaller volume. At Getec, we have more than 30 years of experience and can extrude tubing to the smallest specifications.