Extruded Heatsink

An extruded heatsink uses the extrusion manufacturing process where material (either hot or cold) is pushed through a die of the desired cross-section at high pressure. A good video of the extrusion process can be found at this link. An extruded heatsink can have very complex cross-sections, and due to the high force and elevated temperature used to create the extrusion, facilitates the use of materials with otherwise brittle properties. The extrusion process forms parts with an excellent surface finish, is ideal for additional surface treatments such as Anodizing, or Plating. Radian utilises its experience using the “gummy” and difficult to work aluminum alloy A6063 to manufacture highly thermal conductive (200 W/(mK)) heatsinks. Extruded heatsinks are suitable for high volume production with a relatively low NRE. The molds are typically made with an EDM wire machine, and the Tooling lead time is typically 4-6 weeks. The extrusion process is most cost effective when post machining is not required, as additional CNC machining may induce stress in the part causing misshape. The effects of post machining can be minimised by special thermal treatment to limit failures due to stress. Extruded heatsinks can be manufactured as high fin density, thin fined heatsinks for forced air applications or thicker fin, low fin density for natural convection environments.