Friction stir welding for heat sinks with high-density connections
Cooling manufacturing process for dimensionally stable heat sinks with high cooling capacity
Friction stir welding (FSW) is an innovative joining process that is particularly suitable for welding aluminium and magnesium alloys with a low melting temperature. One of the outstanding features of friction welding is that it does not require high-temperature melting of the material, as is otherwise known from laser or inert gas welding.
Instead, the metal is made malleable by frictional heat and stirred and compacted by a rotating tool. This results in a consistent, media- and pressure-tight weld seam of high, reproducible quality. Another advantage of friction stir welding is the robustness of the process against material defects such as pores or hot cracks. This makes it particularly attractive for the production of aluminium heat sinks as liquid heat sinks, as their joints require high thermal conductivity, tightness and reliability.
Instead, the metal is made malleable by frictional heat and stirred and compacted by a rotating tool. This results in a consistent, media- and pressure-tight weld seam of high, reproducible quality. Another advantage of friction stir welding is the robustness of the process against material defects such as pores or hot cracks. This makes it particularly attractive for the production of aluminium heat sinks as liquid heat sinks, as their joints require high thermal conductivity, tightness and reliability.
Advantages of the friction welding manufacturing process
- Uniform joint structure with excellent mechanical and heat transfer properties
- Homogeneous, hard-wearing welded joints that are completely tight and non-porous
- Mixed material ensures excellent and uniform thermal conductivity
- Friction stir welding makes it possible to produce aluminium heat sinks with high fins and therefore very large designs
- Low temperatures during the process prevent structural changes
- No additives or shielding gases required during production
- Various surface finishes possible
(anodising, chromating, painting, powder coating, etc.)
Due to the relatively low processing temperature of FSW, the joints are low-distortion, which is an advantage when manufacturing precise components. The friction stir welding process is emission-free and requires no additives or auxiliary materials such as shielding gas, making it an environmentally friendly alternative.
Friction welding in combination with various techniques
Due to their homogeneous material structure and the resulting excellent mechanical and thermal properties, heat sinks produced using friction stir welding provide an ideal basis for efficient cooling. In combination with other cooling technologies, the cooling performance can be further increased by distributing and dissipating the heat more effectively.
Friction Stir Welding FSW+ scalable width
The Friction Stir Welding process enables almost unlimited enlargement of heat sinks beyond the standard extrusion sizes, allowing flexible customisation to specific requirements. The technology allows closer fin spacing and greater fin heights, which favours improved heat dissipation. The FSW process can also be used for skived fin heat sinks, which expands the application possibilities of this advanced welding technology.
Friction Stir Welding FSW+ heat pipes
Faster heat spreading through heat pipes efficiently distributes heat across the friction welded heatsink, allowing for even heat distribution. This helps to avoid hotspots and transport the heat to more distant locations.
Friction Stir Welding FSW+ fluid channels
FSW can be used to create narrower channels that allow for more efficient cooling compared to traditional coldplates with tubes. In addition, channels created by friction welding offer high pressure stability and mechanical resilience. The direct fluid flow under the heat input surfaces ensures rapid heat dissipation. The technology also allows a high degree of flexibility in the design of the channel geometry and layout, which enables customised adaptation to specific requirements.
Let's talk about your cooling task!
Thomas Würzer
Sales Department
+49 (0)7561 9837-44
t.wuerzer@ekl-ag.de
Make an appointment Enquiries by e-mail
Thomas Würzer
Sales Department
+49 (0)7561 9837-44
t.wuerzer@ekl-ag.de
Make an appointment Enquiries by e-mail
Special areas of application for friction welding
- Aluminium heat sinks with large widths and tall fin heights
- Liquid heat sinks in which the top and bottom plates are connected by friction stir welding
- Power converter coolers for the railway industry, in particular IGBT coolers for electric locomotives and railcars
- Thin sheet coolers for cooling batteries and battery cooling plates for electric lorries
- Water-cooled die-cast aluminium parts
- Aluminium/copper, aluminium/brass and copper/brass mixed connections
Added value and extras
Our full service goes beyond the mere development, series production and logistics of your heat sinks. Do you need special bores or milling on your heat sinks? Do you want your heat sink to not only dissipate a lot of heat, but also look stylish? Would you like a product ready-to-plug-in with all accessories?
Welcome to EKL!
Welcome to EKL!
CNC machining
For prototypes, small series and customised reworking of heat sinks, we have modern 3- and 5-axis CNC milling machinesat our company headquarters. Complex machined and high-precision radiators are our speciality. Working areas of the machines:
Hermle C 400 (5-axis) 850 x 700 x 500 mm | Mikron VCE1000pro (3-axis) 1000 x 560 x 600 mm | Kondia B1050 (3-axis): 1000 x 500 x 600 mm
Hermle C 400 (5-axis) 850 x 700 x 500 mm | Mikron VCE1000pro (3-axis) 1000 x 560 x 600 mm | Kondia B1050 (3-axis): 1000 x 500 x 600 mm
Surface finishing
Our range includes various surface finishes to create a durable, corrosion-resistant surface. Nickel plating increases wear resistance and lustre. Chromating and passivation, especially with Surtec 650, provide additional protection against corrosion. Powder coating is another option for a robust and durable coloured surface. Painting and cathodic dip coating round off our wide range of surface colours and textures.
Attachments & accessories
Depending on the application, screws, springs or push pins ensure the secure and stable attachment of the heat sinks. Backplates provide additional stability and improved heat dissipation. Heat-conducting pastes and pads are naturally part of our range to enable optimum heat transfer between the heat sink and the heat source.
Secure packaging for transport
With a focus on perfect protection during transport, we develop packaging that not only fits perfectly but is also robust. Another important aspect of the range is the use of recyclable materials that contribute to sustainability and environmental friendliness.
FSW heat sinks in typical areas of application
Heat sinks made from aluminium and magnesium alloys by friction stir welding are popular in many areas of application due to their excellent mechanical and thermal properties. This process produces a homogeneous structure that ensures optimised thermal conductivity. The resulting weld seams are uniform and high-strength, resulting in absolutely tight joints without welding pores. Friction stir welding also enables the production of XL heat sinks with large widths by joining several cooling profiles, which is ideal for large-area heat dissipation tasks.
- 30 years of experience
- Engineering in Germany
- Full Service Heat Sink
- Cost-efficient development
- Fast market launch
- Maximum quality
The EKL project stages for your cooling solutionChoose your point of entry!
Our offer is as flexible as your needs. Are you still early in the development phase and want an idea generator for the best cooling solution? Do you have a ready-made device that gets too hot? Or are you simply looking for an alternative or additional supplier for a heat sink already used in series production? In EKL you will always find a flexible, agile and responsible partner for the cooling of your electronic components and complete systems, whatever the project phase. We look forward to your enquiry!
Counselling
Concept
Concept
In personal contact and open dialogue with you, our engineers create the creative space and framework to design the best cooling solution for your requirements from the wealth of options available.
Development
Feasibility / simulation
Feasibility / simulation
We test the idea for your heat sink virtually in the thermal simulation. Realistic computer simulations allow variations in manufacturing processes, system structures and other parameters.
Performance optimisation
Even a well-functioning heat sink can still be optimised. We determine the "how" and "how much" by simulating different materials or cooling technologies, for example, as well as simulating various environmental parameters.
Cost optimisation
An expensive heat sink can often be made significantly cheaper by using an alternative manufacturing process. Whether with the same or application-specific performance: we support your product development in reducing costs.
Production drawing
Prototype construction
Prototype construction
Prototypes from our design department enable early testing and targeted solutions to problems in your device. We create your functional and design prototypes with our in-house CNC production.
Series production
small to large
small to large
By manufacturing in-house and in Asia, we can offer all types of heat sinks from small to large series at competitive unit prices. We impress our long-standing customers with our consistently high quality.
Sampling
Incoming goods inspection
Incoming goods inspection
We make no compromises when it comes to quality: Development takes place in Germany and all series products are analysed by our German test laboratory according to test plans using state-of-the-art methods.
Surface finishing
Anodising, powder coating, painting etc. protect your heat sinks from corrosion and environmental influences. But colour is not just chic, because dark-coloured heat sinks also emit more radiant heat.
Assemblies
Pre-assembly
Pre-assembly
We actively relieve your production with pre-assembled assemblies. This reduces your workload per device and guarantees the highest quality, because as cooling professionals we ensure that the heat sink is optimally attached.
Quality assurance
Test plans
Test plans
We test according to our own and customer-specific test plans using the latest rapid thermal measuring equipment, 3D measuring machines, assembly tests and testing of various application scenarios.
Packaging design
Packaging production
Packaging production
EKL develops and produces customised packaging to optimally protect your sensitive heat sinks or assemblies in the sometimes harsh transport and storage environments.
Warehouse
& Logistics
& Logistics
With large storage capacities, we offer production-related stocking and consignment warehouses, just-in-time deliveries, customised delivery schedules and flexible shipping options for your individual requirements.
Direct comparison of friction stir welding manufacturing processes
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| Extruded heat sinks | Cold forged heat sinks | Soldered heat sinks | Bonded cooling fins | Pressed cooling fins | Friction stir welding | Heatpipes | Vapour Chamber | Crimped heat sinks | Skived Fins | Die casting | Laserwelding | Vacuum brazing | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thermal conductivity | |||||||||||||
| Heat dissipation over long distances | |||||||||||||
| Design freedom and flexibility in shape and size | |||||||||||||
| Low tool costs / initial investment | |||||||||||||
| Favourable unit prices | |||||||||||||
| Low set-up costs | |||||||||||||
| Economic efficiency for small series | |||||||||||||
| Economic efficiency for large series | |||||||||||||
| Can be combined with other technologies | |||||||||||||
| Surface finishing / resistance | |||||||||||||
| Heat transfer | |||||||||||||
| Standard products | |||||||||||||
| Material density | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | |||||||
| Space-saving, large surface area in a small space | |||||||||||||
| Weight-saving | |||||||||||||
| Position dependence / gravity dependence | |||||||||||||
| Machinability | |||||||||||||
| Mechanical stability | |||||||||||||
| Low wear and tear | |||||||||||||
| Homogeneity (material, no additional materials) | |||||||||||||
| Suitability for large coolers | |||||||||||||
| Suitability for small coolers |
• less suitable | ••••• excellently suited | n.a.: not applicable
Let's talk about your cooling task!
Frank Sichler
Sales Manager
+49 (0)7561 9837-47
f.sichler@ekl-ag.de
Make an appointment Enquiries by e-mail
Frank Sichler
Sales Manager
+49 (0)7561 9837-47
f.sichler@ekl-ag.de
Make an appointment Enquiries by e-mail