What is cold plates (water- cooled heat sink)?

High-end applications, such as electronic components used in high temperature environments, require an efficient cooling system that does not interfere with operation.

Cold plates (also known as water-cooled heat sinks) are used , as the most efficient cooling method, in vacuum chambers of vapor deposition equipment in the display manufacturing process and  protect electronic components from temperature environments of hundreds of degrees Celsius and thus provide a high level of performance and reliability to the equipment accordingly.

The cold plate with a water-cooled jacket structure heated in the vacuum chamber comes into contact with the cooling water circulating inside through a tube or passage (groove), which results in the entire cold plate being cooled, reducing the heat load by dissipating excess heat.

Cold plate of Kyoyu -SEISAKUSHO

Kyoyu Seisakusho’s cold plate has a water-cooled jacket structure made of aluminum, stainless steel and copper.

The method of joining the plate body and the water-cooled lid in the water-cooled jacket is specialised in Tig welding for stainless steel and friction stirring welding (FSW) for copper and aluminum. In addition, with advanced distortion technology, the ground contact with the heat source realises the optimal flatness and contributes to the improvement of cooling efficiency.

Production range

Material Aluminum, Stainless steel, Copper
Joining methods Tig welding, Vacuum brazing, Electron beam welding (EBW), Friction stirring welding (FSW)
Maximum size that can be manufactured Circular form:φ800mm
Rectangular form:Width 1,000 mm、Length 2,000 mm
Structure The jacket structure having grooves covering the lid from the above is main.
Shape Compatible with various external shapes and complex waterway shapes
Specifications All manufactured parts are custom-made with customer specifications

Product examples

Aluminum Cold Plate

This case is a prototype development product that has been requested through the homepage. The water-cooled groove is processed into the main body, the lid is attached from the top, and then joined by FSW After joining with frictional stirring welding, the surface in contact with the heat source provides plane accuracy by machining The ...

Round Stainless Cold Plate

After Tig welding with a water-cooled lid to the main body, distortion correction and machine finishing are performed.  After that, the distortion correction is done again to get flatness. Material SUS304 , SUS316 Size Diameter 400mm~900mm Industry Vacuum Industry Processing details Machining Center, Tig Welding

Copper Cold Plate

Pure copper is a difficult material, and warping occurs after cutting or joining. Therefore, in order to ensure the thickness of the water-cooled lid, distortion correction is necessary each time.It is also easy to scratch, so you need to pay close attention Material Pure Copper C1020 Size W300mm~400mm x L1000mm~1500mm Industry Vacuum Industry Processing details ...

Square Stainless Cold Plate

After Tig welding with a water-cooled lid on the main body, the distortion correction is performed to get flatness. Material SUS304、SUS316 Size W200mm~400mm x L500mm~1500mm Industry Vacuum Industry Processing details Machining Center, Tig Welding

Production process examples

Example 1: Copper Cold Plate

Product Customized Liquid Cold plate
Material Copper
Processing method Friction stir welding (FSW), Machining center

Process❶ Before welding (Preparation)

  1. On the main plate, the groove where the cooling water flows and the fitting part of the same depth as the thickness of the lid are machined.
  2. Cover the joint groove with a lid (tapping so that there is no step on the bonding surface)
Before welding (Preparation)

Process❷ FSW processing

At the time of joining, metal scrap is discharged around the joint by pressing force (1.2t) from the top of the tool and the force moving sideways. As shown in the image below, the joint marks by the tool remain (slightly discoloration due to frictional heat)

FSW processing

Process❸ After Finishing

1mm cutting from joined end face
The boundary of the joint cannot be determined as shown in the image below, and it can be understood that the main plate and the lid are integrated.

After Finishing

Example 2: Aluminum Cold Plate

Product Customized Liquid Cold plate
Material Aluminum (A6061)
Processing method Friction stir welding (FSW), Machining center

Process❶ Water cooling groove machining and Fitting step processing on the lid

Using a machining center, water cooling groove processing (groove through which cooling water flows) is performed on the main body plate.

After that, fitting step processing on the lid is carried out (step-machining to fit in the lid).


Process❷ Knock the lid

Knock the lid into the processed fitting step.


Process❸ FSW bonding

FSW junctions between the outer periphery of the lid and the water-cooled groove.
FSW bonding improves adhesion between the lid and the stepped surface.


Process❹ Finish cutting

Cut the outer periphery and FSW joint surface at the machining center.
This ensures the plane accuracy of the joint face.


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