OSCILLATING HEAT PIPE

Heat Frames

Heat frames are structural and thermal management components used to conduct heat away from circuit cards, processors, RF devices, power electronics, and other heat-generating elements.

ThermAvant Technologies’ OHP-embedded heat frames are especially valuable when compact packaging and reliability are essential—relying on the ultra-high thermal conductivity of OHPs to achieve this.

ThermAvant Technologies develops and delivers OHP-embedded heat frames in a variety of form factors compatible with VPX, VITA, and next-generation embedded platforms.

Aerospace • Defense • Industrial Systems • Transportation

Oscillating heat pipe heat frame with mounted PCB showing thermal path to chassis for efficient electronic cooling.

OHP Heat Frame Product Gallery

The products below show customized solutions with proprietary details removed.

3U oscillating heat pipe heat frame, chem‑film finish, aluminum construction. 
3U OHP Heat Frame

  • Chem film finish

  • Aluminum

3U oscillating heat pipe heat frame with integrated through-features, press-fit pins, and helicoils. 
3U OHP Heat Frame

  • Integrated through-features

  • Press-fit pins and helicoils

6U oscillating heat pipe heat frame with lightweight aluminum body and complex internal channel routing. 
3U OHP Heat Frames Installed in an OHP-Embedded Chassis
3U oscillating heat pipe heat frames installed in aluminum chassis with multi-OHP thermal sub-system. 
6U OHP Heat Frame

  • Ultra-lightweight

  • Complex internal channel routing

  • Multiple OHP circuits in monolithic part

Simple OHP Heat Frame Example

3U Form Factor

Customized avionics 3U OHP heat frame equipped with COTS wedgelocks designed to receive heat from two circuit cards. Approximately 10 total heat sources, with two accounting for the majority of the 130 W of total thermal dissipation. The customer requires a 30-year service life across multiple gravitational environments. The OHP must enhance conduction to the cold rails, maintaining less than a 10 °C temperature rise across the OHP surfaces.

3U oscillating heat pipe heat frame with COTS wedgelock design and dimensions labeled for aerospace thermal management

3U OHP Heat Frame vs. Alternatives

Thermal performance comparison of aluminum oscillating heat pipe, solid aluminum, and solid copper heat frames under 80 W and 50 W loads.
Aluminum OHP Solid Al Solid Cu
Thermal performance 10 °C per 130 W 30 °C per 130 W
3x worse than OHP 		14 °C per 130 W
1.4x worse than OHP
Mass 135 g
Al 6061 T4 w. ChemFilm 		150 g
1.1x worse than OHP 		500 g
3.6x worse than OHP
Shape & structure • Standard VITA 3U (~3.9" x 5.9") with a minimum thickness of 0.06", equipped with COTS wedgelocks.
• An Aluminum OHP typically has 5% less stiffness and 5% higher modal frequencies than solid aluminum.
Temperature range -55 °C up to 95 °C
Heritage or maturity-level • Over 100 fielded OHP units for airborne application.
• Qualified thru MIL-STD thermal cycling, vibration, shock and pressure cycling.
6U oscillating heat pipe heat frame for high-power mobile applications with labeled dimensions and precision-machined aluminum design.

Complex OHP Heat Frame Example

6U Form Factor

Customized, high-performance 6U OHP heat frame designed for a terrestrial, mobile application. The customer’s previous generation of solid aluminum heat frames could not meet the high thermal conductivity requirements needed to handle the high power density of the primary heat source while maintaining a temperature rise of less than 6 °C between the microchip interface and the cold rails.

6U OHP Heat Frame vs. Alternative

Thermal map comparison of 6U oscillating heat pipe heat frame and solid aluminum alternative under 35 W and 75 W power loads
Aluminum OHP Solid Al
Thermal performance 5 °C per 110 W 25 °C per 110 W
5x worse than OHP
Mass 600 g 650 g
1.1x worse than OHP
Shape & structure • Standard VITA 48.2 6U VPX (~9"x6") with a mimimum thickness of 0.13", equipped with COTS wedgelocks.
• An Aluminum OHP typically has 5% less stiffness and 5% higher modal frequencies than solid aluminum.
Temperature range -55 °C up to 85 °C
Experience/maturity level • Over 1,000 fielded OHP units for ground application.
• Qualified thru MIL-STD thermal cycling, vibration, shock, pressure cycling, etc.

OHP Heat Frame Tech Specs

Maximum design freedom with uncompromising SWaP-C performance.

    • Al and Al composites (from 0 to T6 temper) (most common for heat frames)

    • Cu and Cu composites, including Copper-Molybdenum

    • Ni alloys, including Invar and Kovar

    • Ceramics (device-level spreader applications)

    • Water

    • Ketones

    • Alkanes

    • Alcohols

    • Hydrochlorofluorocarbons

    • Perfluorocarbons

    • Hydrofluorocarbons

    • More from cryogenics (below 100 K) to liquid metals (above 1,000 °C)

    • Heat fluxes range from less than 1 W/cm2 to greater than 300 W/cm2

    • Heat loads per OHP from 1 watt to greater than 10,000 watts

    • Long-distance OHPs operable at 2 cm length to 2 m length

    • Gravity independent (e.g., 0.3 m OHPs successfully tested at 9g of adverse gravity and 1.2m OHP successfully tested at 1g adverse gravity)

    • From less than 1 mm in thickness to up to 2 m in length

    • Customizable widths from less than 2 cm to greater than 1 m

    • Flat or 3D plate with bosses, through or blind holes, etc.

    • Platings and dielectric coatings

    • Chemical conversion coating and anodization

    • Other features (e.g., integral fin structures, fans, thermoelectrics, etc.)

Engineer handling cryogenic fluid transfer in thermal R&D lab with vapor cloud under fluid processing sign.

OHP Heat Frame FAQs

  • Our OHP heat frames combine rugged mechanical support with advanced thermal management by integrating Oscillating Heat Pipes (OHPs) directly into the frame structure. These capillary-driven, passive cooling loops rapidly move heat away from high-flux components—no pumps, fans, or external hardware required. Each frame is engineered to serve as both the mounting surface and the primary thermal pathway, reducing thermal resistance and eliminating the need for bulky cold plates or complex cooling assemblies. Custom-built for VPX, VITA, and other high-power embedded computing formats, our frames are deployed in mission-critical environments including aircraft, UAVs, spacecraft, military ground systems, autonomous vehicles, and industrial platforms.

  • Lead times can be as short as 4 weeks for recurring hardware. Custom designs and new builds typically range from 4 to 6 months for first unit delivery, depending on complexity.

  • Yes. OHPs can: 1) incorporate monolithic or brazed fin structures for convective cooling; 2) integrate pumped fluid loop heat exchangers; and 3) transport and spread heat across surfaces for direct rejection (e.g., radiation to space or convection to an airstream).

  • We offer baseline templates for common VPX and VITA module sizes (3U, 6U), but all frames are customized to meet customer specific power and layout requirements.

  • OHP heat frames serve as both structural and thermal components in embedded systems and often feature integrated two-phase cooling. Heat spreaders are typically passive, less efficient, and may not be load-bearing. ThermAvant’s embedded heat frames use Oscillating Heat Pipe (OHP) technology sealed within the frame to transfer heat quickly and evenly—without fans, pumps, or added weight—making them ideal for size-, weight-, and power-constrained platforms.

  • Yes. The OHP is embedded directly into the frame, with no separate components to fail or add bulk. It appears and functions as a solid structural piece but passively moves heat with zero moving parts. Just specify the form factor—ThermAvant builds to match it as a drop in replacement. 

  • Pulsating Heat Pipes (PHPs) and Oscillating Heat Pipes (OHPs) refer to the same technology. The terms are used interchangeably in the industry. Regardless of terminology, the focus should be on the efficient heat transfer capabilities and applications of the technology.

  • Yes. OHPs can be manufactured with through-holes and threaded or tapped features, allowing for structural mounting to higher-level assemblies and seamless attachment to critical components.

  • Yes. OHPs can be designed and fabricated with complex external geometries and intricate internal channel routing—without compromising the structural integrity of the component.

  • OHP microchannels form structural "I-beam" features within the part’s cross-section. This allows an OHP to retain most of the strength and stiffness of the base material. ThermAvant can provide effective structural properties to support efficient modeling during preliminary design stages at the system level.

  • OHPs offer superior thermal performance due to their structural microchannels and complex routing capabilities. They can reduce part thickness, absorb heat closer to critical components, and more effectively isothermalize rejection surfaces. In contrast, VCs often require greater thickness to maintain rigidity and survive harsh environments. The internal wick structures of both VCs and CCHPs limit their performance and design flexibility for complex 3D geometries.

  • No. OHP drop-in replacements typically reduce mass compared to solid material equivalents. Microchannels are machined into the raw material, and the voids are partially filled with a low-density working fluid.

  • Cold-start behavior is well-characterized through ThermAvant's proprietary limit models and empirical data. When power is applied, OHPs transition smoothly from low-conductance conditions into high-performance nucleate boiling regimes as temperatures rise.

  • Full-fidelity modeling of OHPs is complex. ThermAvant can support your design by providing either 1) effective thermal conductivity values or 2) vapor-node model inputs to accelerate system-level thermal simulations.

  • ThermAvant has manufactured OHPs ranging from meter-scale dimensions to as small as centimeter-scale. Multi-layer OHPs for structural components can be fabricated, and thicknesses have been demonstrated down to the millimeter scale, depending on material constraints.

  • OHPs have been tested in adverse gravitational orientations without major effects on thermal performance compared to traditional wick based heat pipe/vapor chamber solutions. OHPs operate through nucleate boiling and local, high pressure deltas that have sufficient capability to overcome external body forces. 

  • OHPs are manufactured in 4 major steps: 1) initial machining, 2) bonding 3)  final machining 4) fluid charging/sealing. Taking aluminum parts as a reference: OHPs will be roughly 3-5x the price of a solid aluminum, precision machined equivalent due to the added manufacturing steps. Items that will drive unit cost are heat map complexity, final part GD&T, part size, material, etc. OHPs provide system level benefits to mass, space claim, thermal performance, and price (reduction in system level complexity) that offset the recurring hardware price. Please engage the ThermAvant business development team for more information.

Three-part image showing the full lifecycle of oscillating heat pipe development: thermal design modeling on whiteboard, precision lab testing with instrumentation, and vacuum chamber used for high-fidelity thermal validation.

You Bring the Mission.
We Bring the Solution.

Product Development. Manufacturing. Testing.

From concept to final delivery, ThermAvant partners with your team to design and manufacture OHP-embedded solutions that meet the exact needs of your system.

We support every step:

  • Collaborative design and modeling based on your layout and power profile

  • In-house prototyping (in-house brazing and CNC machining capabilities)

  • On-site lab facilities with high fidelity thermal verification testing

  • Precision manufacturing for high-volume delivery with robust demand schedules