SERVER POWER SUPPLY · ENGINEERING CASE

Copper Skived Fin Heat Sink for Server Power Supplies

How a German server PSU OEM reduced a 250 W hotspot from 82.5°C to 70°C within a 100 × 100 × 35 mm envelope.

250 W

Thermal load

12.5 K

Lower base hotspot

1,200

Units in first delivery

Bring a proven thermal approach to your next PSU design.

Discuss My PSU Cooling

A Compact PSU. A Clearly Defined Thermal Target

A German server power supply OEM needed more thermal headroom without increasing its cooling envelope.

The project focused on a concentrated 30 × 30 mm heat source inside a forced-air server PSU. The cooling component had to fit the existing mechanical space and work with the installed airflow.

100 × 100 × 35 mm

Heat sink envelope

250 W

Effective heat load

25°C

Inlet air temperature

60 m³/h

Measured airflow through the fins

Acceptance target: base hotspot below 75°C.

Compact forced-air server power supply internal layout in engineering laboratory

Application: a compact, forced-air server power supply.

Start with the same boundary conditions your system will see.

Share My Project Conditions

Why the Original Thermal Design Missed the Limit

The original structure reached about 82.5°C at the base hotspot, exceeding the project limit by 7.5 K.

82.5°C

Original base hotspot

<75°C

Required base hotspot

7.5 K

Above the acceptance limit

Localized heat spreading

A small heat source concentrated 250 W into the base, making the heat path into the fin area critical.

Restricted airflow

Increasing fin density alone could raise flow resistance and move the fan away from the required operating point.

Contact consistency

The interface layer and mounting load needed control so the thermal result could be repeated across assemblies.

Solve the heat path, airflow and interface as one system.

Review My Thermal Bottleneck

Photograph-style isolated C1100 copper skived-fin heat sink on clean pure white studio background with 100mm square footprint and 35mm height

Continuous copper fins and base; precision-machined mounting interface.

One Copper Body. A Shorter Path from Hotspot to Air

A C1100 copper skived-fin heat sink combined a continuous fin-to-base structure with controlled mounting contact.

C1100 copper:Spreads heat from the concentrated source into the available fin area.

0.5 mm fins / 1.2 mm clear spacing:Balances heat transfer area with the available fan pressure.

0.2 mm controlled interface:Keeps the thermal contact layer consistent at the approved assembly condition.

Spring-loaded mounting:Maintains the validated contact load while protecting the assembly.

Match the copper geometry and interface to your actual heat source.

Request a Skived-Fin Design Review

The Fin Stack Was Matched to the Installed Airflow

The design used measured flow through the heat sink, together with the fan pressure–flow curve, to confirm the operating point.

Guide air into the channels

The inlet guide reduces bypass and directs air through the active fin passages.

Check the installed operating point

The fan curve is assessed against the assembled flow resistance, rather than its free-air rating.

Record flow and pressure drop

The report captures measured airflow through the fins and the air-side pressure drop.

Closed transparent acrylic wind duct test bench with copper skived-fin heat sink on base heater

60 m³/h

Measured through the fin stack under the ducted test condition.

Use the fan operating point your installed system can deliver.

Check My Airflow Requirements

Lower Hotspot Temperature. More Thermal Headroom

Under the same installation and measurement conditions, the revised heat sink brought the base hotspot below the 75°C limit.

12.5 K

Reduction in base hotspot

21.7%

Lower hotspot-to-inlet thermal resistance

5 K

Margin below the 75°C limit

Base Hotspot Temperature Target: <75.0°C

Original structure 82.5°C

Copper skived-fin design 70.0°C

0°C 25°C (Inlet) 50°C 75°C (Limit) 100°C

Hotspot-to-Inlet Thermal Resistance Unit: K/W

Original structure 0.23 K/W

Copper skived-fin design 0.18 K/W

0.00 0.08 0.15 0.23 0.30 K/W

Configuration	Base Hotspot	Thermal Resistance (Rθ)	Compliance Status
Original structure	82.5°C	0.23 K/W	Exceeded by 7.5 K
Copper skived-fin design	70°C	0.18 K/W	Passed with 5.0 K Margin

formula: Rθ = (base hotspot − inlet air) / effective heat load

Comparison conditions: 250 W; 30 × 30 mm heat source; 25°C inlet air; 60 m³/h measured through the fins; same installation and measurement method.

Judge thermal improvement against a repeatable set of conditions.

Discuss My Thermal Target

Macro close-up of thermocouple secured in copper heat-sink base for temperature measurement

Base-temperature measurement at the defined hotspot location.

A Result Your Engineering Team Can Reproduce

The validation record ties the thermal result to defined sensor locations, airflow, interface and steady-state criteria.

Effective thermal load 250 W

Heat source area 30 × 30 mm

Inlet air temperature 25°C

Flow through the fins 60 m³/h, measured in the duct

Thermal interface 0.2 mm, approved assembly condition

Reference temperature Base hotspot; inlet-air reference

Sensor map

Locations linked to the test setup.

Flow and pressure record

Installed airflow and air-side pressure drop.

Steady-state record

Stable readings and the applied acceptance criterion.

Align your test method before comparing supplier performance.

Review My Validation Plan

From an Approved Sample to a Repeatable Build

Material, fin geometry, contact surfaces and assembly conditions are carried into a controlled production specification.

Verify the copper lot

C1100 material specification and batch identity follow the manufacturing record.

Control the skived geometry

Fin thickness, clear spacing and fin condition are checked against the approved drawing.

Inspect the mounting interface

Contact surface, hole positions and mounting features are verified in first-article inspection.

Release against the approved build

Thermal sampling, identification and protective packaging follow the control plan.

Dimensional inspection of the copper base and mounting features.

Keep the approved thermal design consistent from batch to batch.

Discuss My Production Requirements

Qualified for Supply. Ready for Repeat Orders

The validated design progressed into a 1,200-unit first delivery, followed by rolling monthly replenishment.

1,200

Units in the first delivery

500–1,000

Units per month in rolling replenishment

For engineering

A defined thermal acceptance condition
An approved drawing and assembly specification
A repeatable reference for incoming checks

For procurement

Batch-linked material and inspection records
Protective packaging for thin copper fins
A rolling release plan for recurring demand

Turn a validated cooling component into a dependable supply item.

Plan My Sample-to-Production Path

Bring Your Server PSU Thermal Challenge to Morton

Share your heat load, space envelope and airflow. Our engineers will help define the next practical step.

Application-focused engineering

Heat source, airflow and mounting reviewed together.

Prototype support

Development samples for fit and thermal validation.

Condition-defined thermal data

Results tied to the approved test conditions.

First-article documentation

Dimensions and critical features linked to the drawing.

Controlled production transfer

Material, process and inspection requirements carried forward.