Custom Heat Pipes
Heat pipes are initially manufactured in round shapes, but can be customized through a series of bending and flattening processes to form 2D or 3D shapes. Customized heat pipes can transfer heat from the source to almost anywhere that the design requires. Examples of thermal solutions using custom heat pipes can be found on this page.
What We Can Manufacture
For custom copper heat pipes, we can produce different diameters and lengths. Most common diameters are 4mm, 5mm, 6mm, 8mm, and 10mm. Lengths can also range from 80mm to 600mm. Working fluids can either by H20 distilled water or CH3OH methanol. For surface finishes, we offer anti-oxidation and nickel plating. Nickel plated finishes are great for soldering heat pipes to aluminum parts.
Rapid Prototyping of Custom Heat Pipes
We offer rapid prototyping services for custom heat pipes. If tooling is not required, the prototypes can be made within 2 business days. For parts that require special tooling, the turnaround time is 5 business days. Please contact us for more information.
Super Thin Heat Pipes for Smart Phones and Mobile Devices
We make heat pipes that are as thin as 1.0 mm (0.040″), which can be used on smart phones, laptop computers, tablets and other miniature electronic devices. The heat pipes are 100% individually tested to ensure heat transfer efficiency. Other thicknesses including 1.2 mm, 1.5 mm, 1.6 mm and 1.8 mm are also available.
For custom heat pipe designs, we offer two types of working fluids: H20 Distilled Water and CH3OH Methanol. H20 Distilled Water is best for above-room temperature (20°C) applications with operating temperatures of 1°C to 325°C. CH3OH Methanol is best for low-temperature applications with operating temperatures of -75°C to 120°C. Methanol is best for low-temperature application since it does not freeze as easily as water.
Bending of Heat Pipes
To minimize the impact on thermal performance, we recommend the following bending radii and angles as the design guidelines.
|Diameter||Minimum R||Suggested R||Minimum|
|4 mm||9 mm||12 mm||90 °||120 °|
|5 mm||12 mm||15 mm||90 °||120 °|
|6 mm||14 mm||18 mm||90 °||120 °|
|8 mm||20 mm||24 mm||90 °||120 °|
To make sure custom bent heat pipes are manufacturable, the minimum inner radius needs to be at least 2x the diameter of the heat pipe. The Qmax will reduce by about 2.5% for every 45-degree bend. The performance of the heat pipe will decrease by about 20% after the first bend, and then down by 10% for each additional bend.
Flattening of Heat Pipes
The following table provides a guideline for the flattening of heat pipes. For diameters and thicknesses not listed in this table, please contact us.
|Diameter (D)||Thickness (T)||(T) Tolerance||Width (W)||(W) Tolerance|
To Calculate Width
W = Width of Heat Pipe
D = Diameter of Heat Pipe
T = Thickness of Heat Pipe (when flattened)
After flattening, heat pipes cannot by bent out-of-plane (no exceptions). Heat pipes can only be bent out-of-plane when the heat pipe is round.
Heat Transfer Capability
|Heat Pipe Shape||Cross-sectional|
|Heat Transfer Rate
|Flattened Pipe||Ø4 X 2.0T||60-600||10||25|
|Flattened Pipe||Ø5 X 2.0T||60-600||10||31|
|Flattened Pipe||Ø6 X 2.0T||60-600||12||42|
|Flattened Pipe||Ø8 X 2.0T||60-600||25||55|
|No.||Test Item||Test Conditions||Sampling Ratio||Purpose|
|1||High Temp. Aging Test||Ambient Temp. 210 C for 12 hr||100%||Leakage check & aging|
|2||Thermal Response Test||Insert 1/3 – ½ length of pipe into 50°C water. The temp of other end shall rise to standard value in 25 seconds.||100%||Vacuum & leakage check|
|3||Qmax Test||Heating Length = 25-35mm, Test temp = 60°C||100%||To measure the max. heat transfer rate|
|4||Rth Thermal Resistance Test||Fix heat transfer rate and measure temp. difference of heat pipes||>1pcs/2hr||To ensure thermal resistance of each pipe be lower than spec|
|5||Accelerated Life Test||140 C for 1000hr. Performance decrease by less than 7%||By case||To predict life of heat pipe at certain operating temp.|
|6||Continuous Life Test||Continuous testing at normal operating conditions||By case||To measure actual life of heat pipe until failure occurs|
|7||Thermal Cycling Test||Temp. varies from -30 C to 120 C in 10hr, 600 cycles||By case||To measure performance variation after thermal cycling|
Heat Pipe Assembly
With custom heat pipes, we also offer heat pipe assemblies. Please visit our Heat Pipe Assembly Design page for more info.