Die Cast
Die Cast Heat Sinks are manufactured from aluminium alloy’s, such as ADC10 or ADC12, for a porosity free product. The big advantage of Die Casting is it is an effective method for forming complex shapes with little need for machining, as mounting holes, slots, pins and assembly clues, such as arrows, can be added with little cost penalty.
When used with forced air cooing, aerofoil shapes can be produced to direct airflow as required. This can greatly reduce back pressure by creating turbulence only where needed.
The thermal conductivity, of the Die Cast material, is not as good as that used in Extruded Heat Sinks (although it is possible to Die Cast Copper) and Die Casting tooling is generally more expensive.
Typical applications for Die Cast Heat Sinks are Laptop Computers, In Car Entertainment and Portable Instrumentation.
Many heat transfer problems can be solved using conventional Aluminium Extruded Heat Sinks. Due to a proven and reliable manufacturing process, this type of Heat Sink can be the ideal solution for both small and large quantities.
The manufacturing process is the most cost effective method of forming fins for Heat Sinks in production quantities, as tooling is relatively cheap, although there are limitations to the complexity of profile with a minimum fin thickness typically 1mm.
Extruding is most effective for creating linear shapes and is favoured by manufacturers of Sound Amplifiers and other electronic devices where a linear airflow is required.
Mounting and attachment points require machining and the improved thermal benefits of using copper cannot be employed as this material cannot be extruded.
Skived Fin Heat Sinks are manufactured from a single block of material that is machined to produce a profile with a dense population of uniformly shaped and distributed fins. The benefit is an ability to deliver maximum heat dissipation compared to other technologies greater dimension.
Skived Fin Heat Sinks can be manufactured from either Aluminium or Copper and are perfect for applications that require high airflow within a small space envelope.
The disadvantage is the manufacturing cycle time, which is longer than extrusion and hence, unit price is higher.
Stacked Fin Heat Sinks are composed of fins that interlock together to form a stacked fin array. This manufacturing process allows engineers to design heat sinks with very high aspect ratios, providing high performing thermal solutions.
They can incorporate a combination of Aluminium and Copper material to tailor the performance of the Heat Sink to a particular application. If heat needs to be spread over a large area, a Copper base can be used for its high conductivity, yet the heat sink fins can be produced from Aluminium, reducing the overall weight and cost. On the other hand, copper heat sink fins may be advantageous, due to its higher fin efficiency, and aluminium may be used in the base. Heat pipes may also ne integrated into the design.
Stacked Fin Heat Sinks are quite common in the PC industry, where volume out-ways the tooling cost which is more expensive than extrusion.