Folded Fin Heat Sinks for Compact Airflow Paths

Thin aluminum or copper strip, precisely folded and joined to a custom base. Morton helps you balance cooling area, pressure drop, weight, and assembly fit.

Thin-strip fin construction

Aluminum or copper

Custom base integration

Build a lighter cooling assembly around your real operating conditions. Discuss Your Folded Fin Design

Continuous corrugated folded fin core joined to machined thermal base

What Is a Folded Fin Heat Sink?

A continuous metal strip forms a repeating corrugated fin core. Joining the core to a heat-spreading base creates a compact path from the heat source to the moving air.

Continuous folded strip

Connected crests and valleys keep the fin geometry consistent across the core.

A controlled base connection

Brazing, soldering, or thermal adhesive transfers heat into the folded fins.

A defined airflow path

Open passages guide air through the active surface instead of around the assembly.

Start with your heat source, available envelope, and installed airflow. Review My Cooling Envelope

More Cooling Surface. Less Structural Weight

Thin, closely controlled fins put material where it contributes to heat exchange, helping compact equipment use its available airflow more effectively.

High surface density

Thin strip creates substantial exposed area inside a compact fin volume.

Lower fin mass

Use lightweight foil construction where system weight and handling matter.

Flexible fin geometry

Tune pitch, height, and core length around the enclosure and fan.

Base material choices

Match spreading performance, mass, and joining requirements.

Assembly-ready interfaces

Coordinate mounting holes, keep-out zones, and thermal contact surfaces.

Scalable repeatability

Freeze the forming and joining process before repeat production.

Turn your space and weight constraints into a practical fin specification.

Explore a Custom Fin Core

Fin Geometry That Fits Your Air Path

Choose foil thickness, pitch, and fin height together. Each dimension affects forming stability, pressure drop, fin efficiency, and handling strength.

Continuous Folded Fin Detail Folded Core Detail

0.1–0.4 mm

Typical strip thickness

1.5–5 mm

Typical fin pitch

10–100 mm

Typical assembly height

40–300 × 40–400 mm

Typical plan dimensions

Geometry is developed as a complete assembly: strip thickness, bend radius, joining area, and passage size are reviewed together.

Share your space limits and let us evaluate a manufacturable geometry.

Check Fin Geometry

Aluminum or Copper, Selected for the Assembly

Material selection starts with heat spreading, mass, joining compatibility, and the environment in which your equipment operates.

Aluminum folded fins

A low-mass choice for ducted cooling and weight-sensitive equipment. Coordinate the strip alloy, temper, and base with the selected brazing or bonding process.

Low assembly mass
Formability matched to the fold
Surface finish and masking defined

Copper folded fins

High conductivity supports compact heat paths and demanding local heat spreading. Evaluate the added mass, soldering process, and compatibility with the base.

High material conductivity
Solderable material combinations
Corrosion and coating reviewed

Compare material combinations against your thermal and mechanical priorities.

Discuss Material Selection

The Fin-to-Base Joint Is Part of the Thermal Design

A repeatable connection transfers heat into the folded core and holds the geometry through assembly and service.

Brazed assembly

A compatible filler and thermal cycle create a metallurgical connection. Define joint clearance, fixture support, and post-process distortion checks.

Soldered assembly

Suitable material and surface preparation support controlled wetting. Review solder coverage, voiding, and service temperature.

Thermal adhesive assembly

A controlled bondline offers joining flexibility. Verify cure, bond thickness, adhesion, and temperature cycling.

Choose the joining route around your material pair and operating temperature.

Review My Joining Requirements

Match the Fin Core to the Installed Airflow

Fin density only helps when air can pass through it. We consider your fan operating point, duct geometry, and bypass paths together.

Use the system operating point

Provide the fan pressure-flow curve and enclosure resistance. Free-air fan flow does not represent the installed flow.

Control bypass and recirculation

Align the fin passages with the duct, seal bypass gaps, and separate inlet air from heated exhaust.

Balance pitch and serviceability

Allow for dust, filters, acoustic limits, and access for cleaning.

Inputs for an airflow review

Fan curve and speed
Duct cross-section and direction
Inlet air temperature
Filter and grille losses
Noise and dust requirements

Send your fan curve and duct sketch for a focused airflow discussion.

Review My Airflow Path

Folded Fins in Real Equipment Envelopes

Compact fin cores support equipment where controlled airflow, limited space, and repeatable assembly shape the cooling solution.

Enclosed industrial power supply in an electronics laboratory

Industrial power supplies

Fit a lightweight fin core into the forced-air path while maintaining electrical clearances and service access.

Closed rack-mount telecom network appliance

Telecom and networking

Coordinate compact cooling with board layout, ducting, and continuous equipment operation.

Compact industrial edge computer with protected ventilation

Industrial and edge computing

Work around connectors and component keep-outs while managing the actual enclosure airflow.

Enclosed air-side heat exchange duct with guarded axial fan

Air-cooled heat exchange assemblies

Integrate a folded core into an engineered air-side assembly with defined joining and mounting interfaces.

Let us review the airflow and packaging constraints of your application.

Discuss My Application

Custom Interfaces That Simplify Final Assembly

The fin core, base, mounting features, and thermal interface are designed as one assembly so your production team can install it consistently.

Assembly Coordination

Approved drawing revision
Defined contact surface
Accessible fixing points

Mounting pattern

Define hole positions, thread engagement, tooling access, and the assembly datum.

Thermal contact face

Specify local flatness, surface finish, contact area, and the selected TIM.

Keep-out zones

Preserve clearance around fasteners, connectors, insulation, and adjacent components.

Controlled clamping

Coordinate torque, load spread, and hardware to protect the device and the fin core.

Bring your mounting drawing and TIM specification into the design review.

Check Assembly Interfaces

A Controlled Route from Strip to Finished Assembly

Forming, joining, machining, and inspection follow the same drawing and process revision from first article to repeat orders.

STEP 01

Material confirmation

Verify strip and base materials, temper, thickness, and lot identification.

STEP 02

Fin forming

Control pitch, height, bend consistency, and passage alignment.

STEP 03

Core joining

Fixture the core and apply the approved brazing, soldering, or adhesive process.

STEP 04

Interface finishing

Machine specified faces and mounting features; protect the thin fins during handling.

STEP 05

Assembly verification

Inspect critical dimensions, joint condition, cleanliness, and agreed performance.

STEP 06

Protected delivery

Use core supports, part separation, revision labels, and batch-linked packing records.

Align the manufacturing route before you approve tooling and first articles.

Review the Production Route

Thermal Evidence You Can Use in Your System Review

A useful result includes the heat source, inlet temperature, installed airflow, and measurement locations—not only a wattage claim.

Thermal Resistance Definition

Rθ = (Tbase,hotspot − Tair,inlet) / Qeffective

Thermal resistance is reported in K/W. Device junction temperature also includes the device internal and thermal interface temperature rises.

Defined heat input

Record effective heat load, heat-source size and location, interface material, and mounting load.

Measured air conditions

Measure flow through the ducted fin section and record inlet air temperature and air pressure drop.

Repeatable temperature readings

Identify the base hotspot and sensor positions after the assembly reaches steady state.

Comparable reporting

Keep orientation, fan setting, duct arrangement, and acceptance limits consistent between tests.

Define the test conditions and acceptance criteria before the sample build.

Plan a Thermal Validation

Quality Controls for Thin Fins and Reliable Joints

Control the characteristics that affect fit, heat transfer, and repeat supply, with inspection records linked to the approved drawing.

Fin geometry and condition

Check pitch, height, straightness, crushed passages, and handling damage.

Joint quality

Inspect coverage and alignment; verify joint integrity with the agreed sampling and validation plan.

Base and mounting accuracy

Inspect contact faces, holes, threads, datums, and customer-defined critical features.

Batch identity and protection

Link material, process, inspection, and packaging records to the supplied batch.

Documentation for your approval

Material lot records Traceable
First article inspection report FAIR
Critical dimension results CMM
Agreed joint and thermal checks Test Plan
Certificate of conformity CoC
Revision and change records ECO

Tell us which features and documents your quality team needs to release the part.

Build My Quality Checklist

Folded Fin Design Questions, Answered

Resolve the practical trade-offs before locking the fin geometry, material pair, and production route.

How are folded fins different from zipper fins?

Folded fins use a continuous corrugated strip. Zipper fins use individual stamped fins that interlock. Their forming method and joint control are different.

Does a tighter fin pitch always improve cooling?

No. Smaller passages increase flow resistance. The best pitch depends on the fan operating point, duct losses, dust, and the available fin area.

Can the folded core be joined to a custom base?

Yes. We review the material pair, thermal spreading, joining process, mounting features, and distortion limits as one assembly.

Can folded fins be used for natural convection?

The geometry must be evaluated for the available buoyancy flow and orientation. Dense cores are generally developed around controlled forced airflow.

Can heat pipes or a vapor chamber be integrated?

Integration can be reviewed when local spreading limits the design. The attachment, keep-outs, orientation, and complete assembly performance need validation.

What do you need to begin a feasibility review?

Send a drawing or envelope sketch, heat-source details, ambient and airflow conditions, mounting requirements, and expected quantities.

Have a project-specific question about the fin core or assembly?

Ask Our Engineering Team

Send the Inputs That Make an RFQ Useful

A clear technical package lets engineering, quality, and procurement work from the same requirements.

Thermal and mechanical inputs

2D drawing and STEP model, or an envelope sketch
Heat load, source footprint, and target temperature
Inlet air conditions, fan curve, and duct layout
Base material, mounting pattern, TIM, and surface requirements

Supply and approval inputs

Prototype, pilot, and annual quantity estimates
Target sample date and production schedule
Critical dimensions, inspection, and document requirements
Packaging, labels, destination, and revision control

Share the information you have to start a practical design and quotation review.

Start My Folded Fin RFQ

Let’s Build Your Folded Fin Cooling Solution

Share your thermal requirements and assembly constraints. Morton will help you define a practical fin core, joining route, and manufacturing plan.

Application-led engineering

Fin geometry developed around the source, duct, and enclosure.

Material and joint coordination

Aluminum or copper paired with an appropriate joining route.

Drawing-controlled production

The same approved revision guides sample and repeat builds.

Inspection and traceability

Critical features and batch records support your approval process.

Prototype-to-production support

Coordinate first articles, pilot quantities, and repeat supply.

Request a Folded Fin Review

Tell us what you are cooling and the space you have available.