Die casting heatsink Benefits and Process introduction

     A die casting heatsink uses the cast process by forcing molten metal under high pressure into a molded cavity. The molded cavity  of the diecast heatsink is created using a hardened tool steel die which is carefully machined into a predesignated shape.  The casting equipment and the metal dies represent large capital cost which tend to limit the process to high volume production applications. 

     In the process to manufacture a diecast heatsink, two halves of a die are required in the die casting process. One half is called the “cover die half” and the other is called the “ejector die half”. A parting line is created on the part where the two die halves meet. The die is designed so that the finished casting will slide off the cover half of the die and remain in the ejector half as the die is opened. The ejector half contains ejector pins to push the casting out of the ejector die half.  In order to prevent damage to the casting, an ejector pin plate accurately drives all of the pins out of the ejector die at the same time and with the same force. The ejector pin plate also retracts the pins after ejecting the casting to prepare for the next shot.

   Excess material such as metal extension can be removed from the ejected die cast heatsink through a secondary machining operation. Casting metal extension removal cost can be reduced if the amount of metal extension to be removed and the removal method to be employed are considered in the early stages of the design. For Multi-slide casting machine allow very complex designs but adds additional costs. 

Diecast heatsink casting process：

The following are the typical steps in Radian’s die casting process:

• Create the Die mold
• Lubricate the Die
• Fill the die with molten metal
• Ejection from the cover die half
• Shakeout from the ejector die half
• Trimming and then grinding the excess material
• Powder coat, Paint, or Anodize the Diecast Heatsink

    A die casting  heatsink  is ideal for high volume applications that can support initial Non-recurring Engineering charge. Typically at around 5,000 pieces the initial NRE is covered by the reduced part cost. Once set up the manufacturing process time is shorter than other methods and saves money when producing heatsinks in higher volumes.  Another benefit is that die-casting  can support complex geometries that can be challenging to produce by other processes.  By casting parts that are near the final shape of the product, you can eliminate or reduce the final machining operation for the Die casting Heatsink.

   Using Aluminum with a high purity produces a good Die casting Heatsink that is efficient in removing heat from electronic components.  Aluminum can be difficult to die cast, so impurities are often added to aid in the die casting process. This does affects the thermal performance of the metal due to reduced thermal conductivity. Most aluminum diecast companies use A380 which hel[p the structural strength of the product.