Cooling designs

Choose the cooling boundary.
Shape the product around it.

Direct liquid, sealed vapor chambers, or a combination: ColdBoard can be explored with different cooling arrangements on each board face. The concepts below show how the same circuit-bearing architecture could support a range of products.

ONE ARCHITECTURE / MULTIPLE CONFIGURATIONS

Choose what surrounds the electronics.

The PCB can carry circuitry and thermal paths while also forming a chamber wall. Select the arrangement for each face, then define how heat leaves the complete product.

01 / DIRECT LIQUID

Liquid on one or both faces

Choose a lower flow region beneath exposed electronics, or flow around both populated faces.

Pumped flow through the moduleExplore direct contact → 02 / VAPOR ONLY

Vapor on one or both faces

Use a chamber below an exposed-top board, or a separate chamber on each populated face.

Heat exits through the housingExplore vapor chambers → 03 / HYBRID

Vapor above, liquid below

A sealed upper vapor region combines with direct liquid cooling underneath.

Different boundaries on each faceExplore the hybrid →

Proposed design families for evaluation and licensing. Chamber geometry, materials and operating limits are application-specific.

01 / DIRECT DIELECTRIC CONTACT

Choose the face that meets the liquid.

Cool the underside while the top stays exposed, or surround both populated faces with dielectric liquid.

The board spans the module and seals against its surrounding frame. In the single-sided arrangement it forms the roof of the lower liquid region, with heat routed from exposed top-side electronics through selected board paths. In the double-sided arrangement, dielectric fluid contacts the upper and lower components and wetted board surfaces directly.

Switches every 3 seconds · Select a tab to hold a view.

Bottom-only liquid cooling with exposed top-side PCB components and representative antenna footprints. The board forms the roof of the lower coolant chamber; thermal paths deliver heat to its wetted underside. — SINGLE-SIDED / COOLING BELOW · The upper components and representative antenna areas are exposed to the environment. Selected board paths transfer heat to the wetted underside, above one lower liquid chamber. Wide openings on opposing short ends serve that chamber. Amber arrows show heat entering the liquid; blue arrows show pumped flow. Download image.

Section showing exposed upper electronics and antenna area, through-board thermal paths and a lower liquid cooling chamber with no upper cover. — The PCB is the liquid chamber’s roof. Cooling stays below the board while the top-side electronics remain dry and exposed. Thermal and antenna geometry is illustrative. View full-size section.

Electrical

Qualify the dielectric fluid and every wetted component, joint, coating and insulation system.

Hydraulic

Distribute flow across the active area and manage pressure loss, bypass and local stagnation.

Mechanical

Design the board, frame, seals and fluid connections for the pressure and service requirements.

02 / VAPOR-ONLY OPTIONS

A sealed vapor chamber
on either—or both—faces.

Use one sealed chamber below an exposed-top board, or place a chamber on each populated face.

The single-sided concept places the vapor chamber below the PCB. Top-side components and antenna areas remain exposed to the environment; selected thermal paths carry heat to the underside evaporator interface. The double-sided concept encloses components on both faces in separately sealed chambers. Each chamber has its own working-fluid charge, vapor space, condenser surface and wick return path.

Heat passes through the condenser housing to the product’s heat-rejection system. Both versions have no pumped liquid passage through the module. “Vapor only” still includes a sealed liquid working fluid that evaporates and condenses.

Switches every 3 seconds · Select a tab to hold a view.

Single sealed vapor chamber beneath a PCB with exposed upper components and representative antenna footprints. Wick lines the lower chamber, and heat moves from the underside evaporator to the base condenser. — SINGLE-SIDED / COOLING BELOW · The upper components and representative antenna areas remain exposed. Heat travels through selected PCB paths to an underside evaporator interface inside the sealed lower chamber. Wick supports condensate return along the inner surfaces; heat leaves through the base condenser toward an external sink. Amber arrows indicate heat transport; blue arrows indicate condensate return. Download image.

Section of a lower vapor chamber beneath exposed upper PCB electronics, with an underside evaporator wick, lower condenser, internal return paths and an external heat sink interface. — The PCB is the vapor chamber’s upper wall; its top-side components are outside the chamber. Working-fluid containment, wick supply, thermal interfaces and antenna clearances need application-specific design. View full-size section.

One active face

Place the cooling chamber below the PCB and leave the upper electronics, antenna area and interfaces exposed. Design thermal transfer through the board together with RF clearances and environmental requirements.

Two active faces

Place a sealed chamber on each populated face. Define the fluid inventory, vapor clearance and return path for each chamber independently.

Choose the external sink

Couple condenser walls to a chassis, air-cooled fins or an external liquid cold plate. A vapor chamber transports and spreads heat; the complete product still needs a path to reject it.

What needs to be resolved for a vapor-only product?

Fluid and electrical compatibility, a continuous liquid supply to heated surfaces, wick performance in the intended orientation, pressure containment, hermetic feedthroughs, board deflection, thermal cycling and external heat rejection must be designed together. The illustrations show possible configurations, not validated products or rated performance.

General two-phase background: evaporation, condensation and wick return. The board-integrated arrangements shown here are proposed ColdBoard concepts.

03 / LIQUID-COOLED VAPOR CHAMBER

The components sit inside
the vapor chamber.

The board itself forms the sealed lower wall of the vapor chamber.

The upper electronics share a sealed working-fluid region. Heat from wetted component surfaces travels through evaporation and condensation to the chamber’s roof. A thin liquid chamber above that solid roof carries the heat away; condensate returns to the heated region. The lower populated face has its own pumped dielectric cooling. Both liquid chambers connect through wide rectangular openings at their opposing short ends.

Front-side hybrid cutaway with the PCB captured between case shoulders, an open upper-left liquid port and continuous upper-case condenser boundary, a sealed vapor chamber with a fine wick lining on its inner ceiling and side walls around the upper components, and lower dielectric cooling; end ports retain their rear walls and arrows show qualitative heat and flow paths — Proposed hybrid arrangement. A fine textured wick lines the vapor chamber’s inner ceiling and side walls. The top liquid chamber cools the condenser wall integrated into the upper case; the lower liquid chamber wets the underside electronics. The case halves capture the PCB perimeter, with lower components mounted to its underside and clear of the chamber floor. Wide end openings illustrate manifold connections; only the front side is cut away. Amber arrows show heat transfer and blue arrows show liquid flow; these are qualitative paths, not simulation results. Download image.

Labeled hybrid section showing the thin top liquid chamber, solid condenser wall and wick, sealed vapor space, heat and condensate paths, board partition, lower dielectric liquid and four end connections — Functional section: top liquid flow, a solid condenser wall, sealed vapor space, condensate return, the circuit-bearing partition and lower liquid flow. The upper components remain inside the vapor chamber. Copper interconnects cross the board stack to serve both populated faces. View full-size section.

Working fluid

Select compatible electrical and phase-change properties for the intended temperature range.

Return and orientation

Define how condensed fluid reaches heated surfaces under the intended operating orientation.

Heat rejection

The top liquid flow removes heat at the condenser wall and carries it to an external heat-rejection loop. Flow distribution, temperatures and condensate return require analysis and testing.

PRODUCT DIRECTIONS FOR LICENSEES

A technology platform.
Many product directions.

Start with the product envelope, device layout and available heat sink. These are illustrative directions a licensee could evaluate.

A / COMPACT MODULE

Air-cooled compute or communications

A one- or two-sided vapor arrangement could spread heat to external fins, with natural or forced airflow selected for the actual load and environment.

B / CHASSIS-COUPLED ASSEMBLY

Power conversion or instrumentation

Use sealed chambers and board-integrated thermal paths to transfer heat toward enclosure interfaces while preserving the required electrical isolation.

C / LIQUID-COOLED PLATFORM

Dense compute or power modules

Pair vapor chambers with external cold plates, or evaluate direct liquid and hybrid boundaries where a cooling loop is already part of the platform.

D / SERVICEABLE BLADE

Modular ASIC systems

The separate blade concept explores a replaceable enclosure with distributed dielectric flow. Other chamber choices would require a new module and interface design.

View the blade concept

EVALUATION & LICENSING

Which boundary fits your product?

Compare the chamber arrangement, external heat sink and product envelope in a focused licensing evaluation.

Discuss your application

Choose the cooling boundary.Shape the product around it.