Vapor Chambers Made Into Any Shape

Most manufacturers of vapor chambers use a traditional two piece design. While studies show that performance of heatsinks using vapor chambers can be enhanced by 20-30% over their heat pipe counterparts, a two piece design has cost implications of roughly the same magnitude. Consequently, their use has historically been limited to high power densities and/or those applications where other benefits outweigh the cost.

Manufacturing this type of vapor chamber requires the use of an upper and lower plate which are usually stamped but sometimes forged or machined. A wicking structure is attached to the upper and lower inside plates. Wick type and porosity can be optimized depending on the application but could involve sintered copper powder, mesh, or a grooved internal surface. Numerous solid copper columns are added to reduce deformation from either higher clamping pressures of the module to the heat source or from high internal VC temperatures.

Finally the two pieces are diffusion bonded on all sides, a working liquid is injected, and the device is vacuum sealed. The device is now ready to have a fin stack(s) and the appropriate connecting hardware added. Specialty piece vapor chambers are also available.The image below shows a 20mm thick T-shaped vapor chamber which provides an isothermal surface for the mounting of multiple heat generating components. Despite the added production time and cost, two piece vapor chamber designs have advantages over one piece and heat pipe designs.

Vapor Chambers Made Into Any Shape

  • Complex shapes in the X and Y direction can be stamped prior to the sintering process.
  • Changes to wick type along with porosity within a single vapor chamber are more easily manufactured.

Advantages of Two Piece Vapor Chambers vs.Heat Pipes

  • Ability to make direct contact with the entire heat source, reducing thermal resistance.
  • Multi-directional heat spreading versus linear heat transport. This enables more uniform heat distribution into the heat sink and reduces hot spots on the heat source (Tcase temp)
  • The surface area can be embossed to reach a recessed heat source.
  • Able to be made wider – feasibly up to ~300mm.
  • 3 to 4 times the maximum heat transport capacity.
Heat Pipe One Piece VC Two Piece VC
Min/Max Thickness ~2.0mm if flattened >1.0mm >2.0mm
Sizes Diameter: 2-35mm
Length: 100-1,000mm
Width: 10-100mm
Length: 50-500mm
Width:50-150mm
Length: 50-300mm
Flatness NA 0.001”/” 0.001”/”
Maximum Bending Angle 3x diameter R~10 (inner circle base) No
Shapes: X and Y Direction</td> Yes – Post Production
Factory Bending
No: Square or Rectangle
shape only
Yes: Pre-Production
Stamping
Max Heat Transport Capacity 5 watts @ 2mm
1kw @ 25mm
10watts @ 1mm
500 watts @ 4mm
10watts @ 1mm
500 watts @ 4mm
Allowable Operating Temp. 10 to 150 C 10 to 125 C 10 to 125 C
Storage Temperature -40 to 100 C -40 to 100 C -40 to 100 C
Storage Humidity (%RH) 5~90%RH 5~90%RH 5~90%RH
Life >100,000 hours >100,000 hours >100,000 hours
Through Holes Not Applicable No Yes