heat sink
What is heat sink
Heat sink belongs to passive electronic components that helps transferring the heat. With its high thermal conductivity, light weight, and flexible matching possibility, heat sink is widely applied in different fields like power electronics, mechanical devices, personal computer and laptop, and LED lighting, etc.
To optimize heat dissipation, we can add heat pipes, apply thermal adhesive or thermal paste, even install fans on the heat sink to boost performance.
Manufacturing process of heat sinks
Heat sinks are often classified by manufacturing process. Aluminum, Copper are main materials for heat sinks, as well as bonded Aluminum / Copper (Al/Cu) heat sinks and Copper heat pipes. Zaward provides diversified heat sink processes, which include extruded, skived, cold forged, bonded, CNC machining, stamped, swaged, and die-casted. Each process has its advantages and challenges.
Extruded is a process forcing material rod into a die mold under high temperature, creating aluminum section material. Aluminum extrusion is widely used in various ranges due to aluminum’s unique physical characteristics; it provides the product with strength, ductility and conductivity
Cold Forged is a process which forms under high pressure and in room temperature. Forging heat sinks offer accurate dimension, strong surface and reliable structure and flexibility of a high aspect ratio for any fin type. Materials can be aluminium or copper
Die-Casted is a process that inserts molten metal under high pressure into a mold cavity. It produces high structural integrity, smooth cast surface without secondary machinery operation.
Stamped is the process of placing flat sheet metal into a desired form, producing light weighted heat sinks, various ranges of shape and sizes in high productivity. It is widely used in PCB due to its minimal size.
Bonded is adapted for high power thermal solutions, individual fins bonded to base with thermal conductive epoxy and owns maximal flexibility in fin dimension of width and length.
CNC Machining is a sophisticated process often deployed in high precision level of mechanical parts; it is used to form the raw material in the desired shape and size, improved surface finish/coating and design.
Skived is carved out of a single block of metal to make an array of fine fins in specific shapes and size. Integrated base and fin structure minimize thermal cost in-between and enhance thermal conductivity as well as a lower development.
Pros and cons of heat sinks
PROCESS | PRO | CON |
---|---|---|
Extruded | Cheap tooling cost | Limited shape |
Standard profile available | ||
Short lead time | ||
Skived | Low thermal lost | Restricted shape |
Aluminum and copper achievable | ||
Cold Forged | Round pin achievable | Higher MOQ |
Wide dimension | ||
Less secondary processes | ||
Bonded | Higher fins achievable | Higher thermal loss |
More space for heat dissipation | High tooling cost | |
CNC Machining | Sophisticated structure achievable | Higher unit price |
Longer lead time | ||
Stamped | Wide application | Higher MOQ |
Good for limited space | High tooling cost | |
Die-casted | Complex structure achievable | High tooling cost |
Less secondary processes |
How to choose an appropriate heat sink type for your design?
It can be rather tricky to navigate the suitable heat sink among various processes. The similarity and yet the differences can be complex to determine the right heat sink for your design. Hereby we show you few examples of process comparisons to help you choose and Zaward is always ready to help.
Cold Forged vs. Die-Casted Heat Sink
Cold forged tooling costs slightly more than die-casted because it needs to withstand tremendous force during production and generates high density and strength than die-casting.
Die- casted can be produced in more complex shapes than forging and in fast production rate and higher volume. However, if the part’s strength and durability are crucial, forging might be a better solution than die-casting. When debating between the strength and durability rather than shapes, forging would be a better option than die-casting.
Cold Forging Pros | Cold Forging Cons |
---|---|
|
|
Skived vs. Extruded Heat Sink
Extruded and skived are both an integral structure causes no thermal loss between the fins and the base. With extrusion, heat sinks can be made with aluminum only, while skiving heat sinks can be made with alumiunm or copper at a lower development cost. For small quantity orders, skived could be a better solution.
Skiving Pros | Skiving Cons |
---|---|
|
|
Bonded vs Extruded Heat Sink
Bonded heat sink can achieve up to aspect ratio of 45 in comparison to 22 of extruded heat sink, and with higher fins increase surface area and optimize heat dissipation, having more flexibility in material than extrusion. For higher power applications, bonded heat sink might be a good choice.
Bonded Pros | Bonded Cons |
---|---|
|
|