Category Archives: Cold Plates

Cooling Hot Electronics with Cold Plates

Posted on May 14, 2025 by | Leave a comment

Cold plates have been used for thermal management since the Apollo moon missions in the 1960s. Today, they serve a critical role in cooling high-performance electronics across many industries.

Power electronic devices generate significant heat, and if their chips exceed safe temperature limits, system reliability and longevity are compromised. Effective thermal management is essential, as lowering a chip’s junction temperature by just 10°C can double its operational life.

Cold plates offer highly efficient, localized cooling by transferring heat from hot components—such as power semiconductors—into a liquid coolant flowing through the plate. The heated liquid then moves to a remote heat exchanger, where it cools before recirculating back to the cold plate.

Compared to forced-air cooling, cold plates deliver superior thermal performance. They are typically smaller, quieter, and lighter than fan-based systems, making them an attractive solution in compact or noise-sensitive environments.

Most cold plates consist of thin-walled aluminum or copper blocks with internal channels or tubing for coolant flow. As liquid moves through the plate, it absorbs heat from the attached components and carries it away for external dissipation. Modern designs often use mini-channels instead of traditional tubing. These intricate internal pathways maximize surface contact with the coolant, improving heat transfer and cooling efficiency.

Figure 1 – Cold Plates are Part of a Liquid Cooling Loop that Includes a Pump for Fluid Circulation and a Heat Exchanger to Remove Heat from the Flowing Coolant. [ATS]

More advanced cold plates feature mini-channels in place of tubing. These designs can better match applications and more efficiently transfer heat into the coolant.

Figure 2 – A Cold Plate with Internal Mini-Channels Provides a High Rate of Thermal Transfer to Remove More Component Heat. [ATS]

Tubed Cold Plates Cool Hot Electronics

Embedded tube designs are the simplest cold plates. They feature a stainless steel or copper tube coiled and set into grooves inside a metal base plate. The tubes can be routed in different pathways to optimize thermal transfer performance. The flowing coolant moves heat from the component, away from the cold plate and over to a heat exchanger where it is cooled before being pumped back to the plate.

Figure 3 – A Tubed Cold Plate Can Consist of Copper or Stainless-Steel Tubing Pressed or Embedded in a Metal Plate. [ATS]

These tubed cold plates are cost-effective solutions for low- to moderate-power applications and are ideal for use in automotive, instrumentation, and UPS systems. ATS offers models ranging from 57–914 mm in length and 57–198 mm in width, with push-to-connect fittings for easy installation.

A variation of this design features thermally conductive epoxy completely covering the tubing and flush with the plate’s surface. This not only improves thermal contact but also provides environmental protection by sealing the tube within the plate.

Figure 4 – A Cold Plate’s Tubing Can be Buried and Covered with a Thermally Conductive Epoxy Layer. [1]

Custom Cold Plates Provide Best Cooling Solutions

For more demanding applications—such as cooling BGAs, LEDs, or high-power modules—custom cold plates offer the best performance. These can include embedded tubing or submerged internal fins, which increase surface area and create turbulence to enhance heat transfer.

Figure 5. Custom Liquid Cold Plate with Inlaid Copper Tubing Provides Heat Transfer Away from Hot Electronics [2]

One example uses tightly spaced aluminum pin fins to generate turbulence with minimal pressure drop, achieving high thermal performance while keeping the plate compact. Another design incorporates internal turbulators tailored for IGBT modules, further improving coolant flow and heat dissipation.

ATS designs and manufactures custom cold plates in collaboration with customers or based on in-house thermal analysis. These designs can include complex internal geometries such as microchannels or gyroid lattices, like the 3D-printed cold plate created for race car IGBT cooling—an approach that improves flow guidance while reducing weight.

Figure 6. Close-spaced Pin Fins with Complex Geometry Create Turbulence with Low Flow Rate Values Inside Submerged Fin Cold Plates. [3]
Figure 7. A Custom IGBT-Cooling Cold Plate Features Internal Turbulators to Optimize Coolant Turbulence and Heat Transfer. [4]

ATS constructs cold plates to customer designs and those developed in partnership with our own thermal engineers. ATS coolant-based cold plates can include internal tubing and microchannels in closed loop systems.

Figure 8. Dual-Sided Cold Plates Cool Components on Both of Their Mounting Sides. [ATS]

Dual-sided high-flow cold plates provide equal cooling performance for components mounted on both sides of the plate, increasing efficiency, space savings and economy. The cold plates can be used with coolant flow rates up to 4 gal/min, and provide thermal resistance as low as 0.0021°C/W. [5]

Figure 9 – This 3D-Printed Metal Cold Plate Cools IGBTs on a Race Car. It Features a Gyroid Lattice That Guides Internal Coolant Flow While Reducing the Overall Weight [6]

DIY Cold Plates Optimize Component Cooling

ATS also offers DIY (do it yourself) cold plates with modular dimensions and pre-defined drill zones. Engineers can customize mounting locations to match specific components. Once the ideal configuration is determined, ATS can mass-produce the cold plate to match exact specifications.

Figure 10 – Do It Yourself Cold Plates from ATS Feature Drill Zones for Precision Matching to Heat Sources, and No Drill Zones to Protect Internal Coolant Flow Channels. [ATS]

The Complete Liquid Cooling Loop

Cold plates are just one part of a complete liquid cooling system. As electronics demand more efficient cooling, liquid-based systems are increasingly replacing air-based solutions. A functional loop includes a pump, reservoir, and heat exchanger to remove heat from the circulating fluid.

Figure 11 – A Liquid Cooling Loop Featuring Cold Plates. This is Implemented in Avionics on F-16 Fighting Falcon Jets. [7]

These systems are becoming more cost-effective and safer, making liquid cooling viable for a broader range of applications. Cold plates serve as a critical stage in these loops, offering simplicity, versatility, and high thermal performance.

Plug and Play Liquid Loops

For streamlined implementation, ATS offers the Industrial Cooling Distribution Module™ (iCDM™)—a fully integrated liquid cooling loop in one compact, portable unit. It includes the pump, heat exchanger, reservoir, precision controls, and monitoring displays, eliminating the need to purchase and configure components separately.

Figure 12 – The New Industrial Cooling Distribution Module Contains the Pump, Heat Exchanger, Reservoir and Controls for Managing Coolants in Liquid Cooling Loops. [ATS]

The iCDM connects directly to cold plates or chassis-based cooling systems. It supports models with cooling capacities of 10 kW and 20 kW, each holding up to 2 liters of coolant. The system is compatible with a wide range of wetted materials, allowing flexible deployment across industries. A next-generation iCDM, available soon, is fully automated, with significantly increased cooling capacities up to 1.4MW.

Conclusion

Cold plates can provide essential electronics cooling because of their design versatility and the power of liquid cooling. AI chip cooling cold plates will soon be available for this growing and demanding arena.

ATS engineers are experts in matching thermal solutions to system needs, offering a wide portfolio that includes cold plates, vapor chambers, coolant chillers, and complete liquid loop systems. Whether liquid cooling is the best solution depends on the specific application, and ATS provides detailed analysis to help customers make informed decisions.

References

  1. Wakefield Thermal, http://www.wakefield-vette.com/products/liquid-cooling/liquid-cold-plates/standard-liquid-cold-plates.aspx
  2. Baknor, https://www.baknorthermal.com/liquid-cold-plates-various-channel-options/
  3. COOLTECH, http://www.cooltech.it/products/liquid-cold-plates/
  4. Boyd Corp., https://www.boydcorp.com/thermal/liquid-cooling-systems/liquid-cold-plates.html
  5. ATS, https://www.qats.com/Products/Liquid-Cooling/Dual-Sided-Cold-Plates
  6. nTop, https://www.ntop.com/resources/case-studies/cold-plate-automotive-power-electronics/
  7. ThermOmegaTech, https://www.tot-ad.com/avionics-cooling/

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Manufacturing services for cold plates for electronics cooling

Posted on September 20, 2022 by | 1 comment

Many companies we work with prefer to design their own cold plates and have another company do the DFMA review and the manufacturing. ATS’ extensive capability for manufacturing cold plates is demonstrated in the wide variety of tubed cold plates it produces to meet each customer’s specific requirements. Copper, stainless steel, aluminum, 4 or 48 passes, ATS has the manufacturing capability to make nearly any tubed cold plate. Different examples of these custom cold plates, made in the USA, are described on the ATS website at the link: https://www.qats.com/Products/Liquid-Cooling/Custom-Cold-Plates

cold plate manufacturing for OEM and ODM applications. Both tubed and finned cold plates in copper, stainless steel and other materials

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Posted in Cold Plates, Liquid Cooling, Manufacturing

Engineering How-To: Choosing the Right Fluid to Use with Cold Plates

Posted on February 18, 2020 by | 3 comments

By Norman Quesnel, Senior Member of Marketing Staff
Advanced Thermal Solutions, Inc. (ATS)

Liquid cooling systems transfer heat up to four times better than an equal mass of air. This allows higher performance cooling to be provided with a smaller system. A liquid cooled cold plate can replace spaceconsuming heat sinks and fans and, while a liquid cold plate requires a pump, heat exchanger, tubing and plates, there are more placement choices for cold plates because they can be outside the airflow. [1]

One-time concerns over costs and leaking cold plates have greatly subsided with improved manufacturing capabilities. Today’s question isn’t “Should we use liquid cooling?” The question is “What kind of liquid should we use to help optimize performance?”

Figure 1. A Liquid Cooling System for a Desktop PC with Two Cold Plates. [2]

For liquid cold plates, the choice of working fluid is as important as choosing the hardware pieces. The wrong liquid can lead to poor heat transfer, clogging, and even system failure. A proper heat transfer fluid should provide compatibility with system’s metals, high thermal conductivity and specific heat, low viscosity, low freezing point, high flash point, low corrosivity, low toxicity, and thermal stability. [3]


Today, despite many refinements in liquid cold plate designs, coolant options have stayed relatively limited. In many cases, regular water will do, but water-with-additives and other types of fluids are available and more appropriate for certain applications. Here is a look at these coolant choices and where they are best suited.

Basic Cooling Choices

While water provides superior cooling performance in a cold plate, it is not always practical to use because of its low freezing temperature. Additives such as glycol are often needed to change a coolant’s characteristics to better suit a cold plate’s operating environment.

In fact, temperature range requirements are the main consideration for a cold plate fluid. Some fluids freeze at lower temperatures than water, but have lower heat transfer capability. The selected fluid also must be compatible with the cold plate’s internal metals to limit any potential for corrosion.

Table 1 below shows how the most common cold plate fluids match up to the metals in different cold plate designs.

Table 1: Compatibility Match-ups of Common Cold Plate Metals and Cooling Fluids [1]

The choices of cold plate coolants will obviously have varied properties. Some of the differences between fluids are less relevant to optimizing cold plate performance, but many properties should be compared. Tables 2 and 3 show the properties of some common coolants.

Tables 2 and 3. Comparisons of Properties of Typical Electronic Coolants. [4]

An excellent review of common cold plate fluids is provided by Lytron, an OEM of cold plates and other cooling devices. The following condenses fluid descriptions taken from Lytron’s literature. [5]

The most commonly used coolants for liquid cooling applications today are:

  • Water
  • Deionized Water
  • Inhibited Glycol and Water Solutions
  • Dielectric Fluids

Water – Water has high heat capacity and thermal conductivity. It is compatible with copper, which is one of the best heat transfer materials to use for your fluid path. Facility water or tap water is likely to contain impurities that can cause corrosion in the liquid cooling loop and/or clog fluid channels. Therefore, using good quality water is recommended in order to minimize corrosion and optimize thermal performance. If you determine that your facility water or tap water contains a larger percentage of minerals, salts, or other impurities, you can either filter the water or you can opt to purchase filtered or deionized water. [5,6]

Deionized Water – The deionization process removes harmful minerals, salts, and other impurities that can cause corrosion or scale formation. Compared to tap water and most fluids, deionized water has a high resistivity. Deionized water is an excellent insulator, and is used in the manufacturing of electrical components where parts must be electrically isolated. However, as water’s resistivity increases, its corrosivity increases as well. When using deionized water in cold plates or heat exchangers, stainless steel tubing is recommended. [5, 7]

Inhibited Glycol and Water Solutions – The two types of glycol most commonly used for liquid cooling applications are ethylene glycol and water (EGW) and propylene glycol and water (PGW) solutions. Ethylene glycol has desirable thermal properties, including a high boiling point, low freezing point, stability over a wide range of temperatures, and high specific heat and thermal conductivity. It also has a low viscosity and, therefore, reduced pumping requirements. Although EGW has more desirable physical properties than PGW, PGW is used in applications where toxicity might be a concern. PGW is generally recognized as safe for use in food or food processing applications, and can also be used in enclosed spaces. [5, 8]

Dielectric Fluid – A dielectric fluid is non-conductive and therefore preferred over water when working with sensitive electronics. Perfluorinated carbons, such as 3M’s dielectric fluid Fluorinert™, are non-flammable, non-explosive, and thermally stable over a wide range of operating temperatures. Although deionized water is also non-conductive, Fluorinert™ is less corrosive than deionized water. However, it has a much lower thermal conductivity and much higher price. PAO is a synthetic hydrocarbon used for its dielectric properties and wide range of operating temperatures. For example, the fire control radars on today’s jet fighters are liquid-cooled using PAO. For testing cold plates and heat exchangers that will use PAO as the heat transfer fluid, PAO-compatible recirculating chillers are available. Like perfluorinated carbons, PAO has much lower thermal conductivity than water. [5, 9]

Conclusion

Water, deionized water, glycol/water solutions, and dielectric fluids such as fluorocarbons and PAO are the heat transfer fluids most commonly used in high performance liquid cooling applications.

It is important to select a heat transfer fluid that is compatible with your fluid path, offers corrosion protection or minimal risk of corrosion, and meets your application’s specific requirements. With the right chemistry, your heat transfer fluid can provide very effective cooling for your liquid cooling loop.

References

[1] https://www.aavid.com/product-group/liquidcoldplates/fluid

[2] http://semi-therm.org/wp-content/uploads/2017/04/How-to-design-liquid-cooled-system.pdf

[3] Mohapatra, Satish C., “An Overview of Liquid Coolants for Electronics Cooling,” ElectronicsCooling, May 2006.

[4] http://www.calce.umd.edu/whats_new/2012/Presentations/David %20Saums%20PPt.pdf

[5] http://www.lytron.com/Tools-and-Technical-Reference/Application-Notes/The-Best-Heat-TransferFluids-for-Liquid-Cooling

[6] https://www.thereadystore.com/5-gallon-collapsible-water-container

[7] https://www.amazon.co.uk/IONISED-WATER-Mineralised-DeionisedDistilled/dp/B00X30JKGY/ref=pd_lpo_vtph_263_tr_t_2?_encoding=UTF8&psc=1&refRID=QNAM8H7J8R 1AEDP8W5FF

[8] http://www.rhomarwater.com/products/catalog/envirogard-heat-transfer-fluid-antifreeze

[9] http://www.skygeek.com/anderol-royco-602-cooling-fluid.html

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Posted in Cold Plates, Liquid Cooling, Qpedia Thermal eMagazine

Tubed and Submerged-Fin Cold Plates in Electronics Thermal Management

Posted on February 26, 2019 by | 4 comments

By Norman Quesnel
Senior Member of Marketing Staff
Advanced Thermal Solutions, Inc. (ATS)

Many of today’s electronic devices need the performance of liquid cooling to meet the thermal demands of certain hot components. Liquid cold plates are common cooling systems in high power lasers, fuel cells, battery coolers, motor drives, medical equipment, avionics and other high-power, high-heat flux applications.

Cold Plates
Figure 1. A Custom liquid cold plate design by D6 Industries. [1]

Cold plates provide localized cooling by transferring heat from a device to a liquid that flows to a remote heat exchanger and dissipates into either the ambient or to another liquid in a secondary cooling system. Component heat flows by conduction through a thermal interface material and the metal plate to the metal tubing. Then it flows by convection from the internal surface of the fluid path material into the flowing coolant.

A cold plate in electronics cooling is often an aluminum block with an embedded, coolant-filled metal tube. Another common cold plate type is made with metal shells that are brazed or friction-welded together and filled with a liquid coolant.  On the inside, the metal shells have integral cooling fins that are submerged in the coolant.

Tubed Cold Plates

Embedded tube designs are the simplest version of cold plate cooling devices. They feature a continuous tube set into grooves in a metal plate, and are often bonded in place with thermal epoxy. The flowing coolant moves heat from the component away from the cold plate to a heat exchanger, where it is cooled before being pumped back into the plate. 

A common example of a tubed cold plate features an aluminum plate with an exposed copper tube. The tubes can be routed in different pathways to optimize the thermal performance.

The tubing can be continuous or constructed from straight tubes connected by soldered joints, though joints may increase the potential for leakage.

Figure 2. A Tubed cold plate consists of copper or stainless-steel tubing pressed into a metal plate. [2]

This design can provide a cost-effective thermal solution for component cooling where the heat load is low-to-moderate. Tubed cold plates ensure minimum thermal resistance between the power device and the cold plate by placing the coolant tube in direct contact with the power device’s base. Direct contact reduces the number of thermal interfaces between device and fluid, thus increasing performance for the application.

A variant of this design features a thermal epoxy completely applied over the pressed in tubing and flush with the metal plate surface. These are sometimes called buried tube liquid cold plates. This provides a gap-free thermal interface between the tube and the plate. The epoxy layer protects from any leakage from the metal tube. Another key feature is that that fully buried tube is not exposed to the outside environment.

Figure 3. A buried tube cold plate’s metal tube is covered with a conductive epoxy layer. [3]

The choice of liquid coolant affects thermal performance as well. Choosing the right coolant depends to a great extent on the tube material. Copper tubes are compatible with water and most other common coolants, while stainless steel tubes can be used with deionized water or corrosive fluids.

One cold plate OEM offers a proprietary technology with a tube locking system and pressing techniques that ensure the tube is flush with the plate surface, providing good thermal contact with the component being cooled. This manufacturing method eliminates the need for thermal epoxy between the tube and plate which improves thermal performance. [4]

Submerged Fin Cold Plates

Another type of cold plate is an all-metal construction with brazed or friction welded internal fin field.

Figure 4. Standard, liquid coolant-containing metal cold plate [5]

The integral, internal fins increase the surface area that contacts the fluid and enhances heat transfer. Fin shape and fin density affect the performance of heat exchangers and cold plates. By their geometry, the fins also create turbulence, which minimizes the fluid boundary layer and further reduces thermal resistance.

One high-performance version features tightly packed aluminum pin fins that create turbulence with low flow rate values, resulting in high thermal performance with low pressure drop. In this design, the high density of the internal fins increases the heat transfer area without adding bulk to the cold plate assembly. [6]

Figure 5. Close-spaced pin fins with complex geometry create turbulence with low flow rate values inside submerged fin cold plates. [6]

In most high-performance applications, fins are made of copper or aluminum. Aluminum fins are preferred in aircraft electronic liquid cooling applications due to their lighter weight. Copper fins are mostly used in applications where weight is not an important factor, but compatibility with other cooling loop materials is.

For submerged-fin cold plates, many different fin geometries can be tested to find the best improvement in performance. Some of the most commonly used are louvered, lanced offset, straight, and wavy fins.

Figure 6. Fin designs for submerged-fin cold plates. Clockwise from top: louvered, lanced offset, wavy, and straight fins. [7]

With cooling requirements increasing in many areas of electronics, engineers are turning to liquid cooling to replace air cooling. Lower cost, safer liquid cooling systems have also spurred the trend to liquid cooling.

The prime example is the cold plate – relatively simple in design, affordable, available in alternative versions, and extremely customizable. Cold plates should be considered wherever thermal performance above air cooling is needed.

References:

  1. https://d6industries.com/portfolio/custom-designs-liquid-cold-plate-hydroblock/
  2. https://www.lytron.com/Cold-Plates
  3. http://www.wakefield-vette.com/products/liquid-cooling/liquid-cold-plates/standard-liquid-cold-plates.aspx
  4. https://www.lytron.com/Tools-and-Technical-Reference/Application-Notes/Assessing-the-Quality-of-a-Tubed-Cold-Plate
  5. https://www.qats.com/Products/Liquid-Cooling/Cold-Plates
  6. http://www.cooltech.it/products/liquid-cold-plates/
  7. https://www.lytron.com/Tools-and-Technical-Reference/Application-Notes/Fins-for-Cooling-Success

For more information about Advanced Thermal Solutions, Inc. (ATS) thermal management consulting and design services, visit https://www.qats.com/consulting or contact ATS at 781.769.2800 or ats-hq@qats.com. To register for Qpedia and to get access to its archives, visit https://www.qats.com/Qpedia-Thermal-eMagazine.


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Join ATS for Live Liquid Cooling Webinar

Posted on September 11, 2018 by | Leave a comment

Advanced Thermal Solutions, Inc. (ATS) is hosting a series of monthly, online webinars covering different aspects of the thermal management of electronics. This month’s webinar will be held on Thursday, Sept. 27 from 2-3 p.m. ET and will cover the design and deployment of liquid cold plates in electronics systems. Learn more and register at https://qats.com/Training/Webinars.

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