Heat Pipes

COFAN’S HEAT PIPES ARE SUPERCONDUCTORS
WITH EXTRAORDINARY HEAT TRANSFER CAPACITY.

Cofan’s heat pipe is a thermal management device designed
to transfer heat efficiently from one point to another using
the principles of phase transition and thermal conductivity.
It consists of a sealed hollow tube containing a working
fluid and a wick structure that facilitates the movement of
the fluid within the tube.

Cofan’s Heat pipes offer several advantages. They have high thermal conductivity, allowing for the transfer
of heat over long distances with minimal temperature drop, far superior to solid conductors of the same size.
They operate passively, relying on natural physical processes without the need for external power. Additionally,
heat pipes are flexible and can be bent and shaped to fit various applications, making them highly versatile.
They also provide efficient heat distribution along their length, which is beneficial for temperature-sensitive components.

heat pipe feature

Heat Pipe Features

High conductivity (5,000 watts/meter·K to 200,000 watts/meter·K)
Energy-efficient
Lightweight
Low cost
Flexibility of many different size and shape options
100% Inspection of all heat pipes, before and after bending
Passed stringent heat transfer tests to reach a minimum temperature grade within a minimal time period (Delta ΔT; 4 degrees C, time period ~ 7 seconds
Longest heat pipe on the market, all the way up to 4700 mm

heat pipe technology

Heat pipe includes three main components: the container, the working fluid, and the wick structure. The container, usually made of metal such as copper or aluminum, provides the structure and holds the working fluid. Inside the container, the working fluid, which can be water, ammonia, acetone, or various refrigerants, undergoes phase changes to transfer heat. The wick structure, made from materials like sintered metal, screen mesh, or grooved surfaces, lines the inner walls of the container and aids in the capillary action needed to return the condensed fluid back to the evaporator section.

Main Components

Container
High strength, high thermal conductivity
Working fluid
Flexibility of many different size and shape options
High latent heat, high thermal conductivity
Wick/capillary structure
State-of-the-art copper powder sintering for maximum performance
Maintains effective capillary action when bent or used against gravity

Heat is absorbed from the source through vaporization and released at a sink through condensation. The vapor travels from source to sink through the central channel, while the liquid travels from sink to source through the porous wick. The rapid growth of the electronics and personal computer industries has introduced challenging heat dissipation problems. Heat pipes effectively transport heat with minimal drops in temperature.

heat pipe application

Heat pipes are used in a wide range of applications including electronics cooling in laptops, desktops, and servers to cool CPUs, GPUs, and other heat-generating components. In aerospace, they are used for temperature control in satellites and spacecraft. They also play a role in managing the heat generated by high-power LED lights, improving energy efficiency in HVAC systems, and cooling sensitive equipment in medical devices.

GPU/CPU

Laptop

Server

Aerpspace

Led

Medical

cofan's heat pipe products

Product Information

Diameter x Length [mm]	Part No.	Diameter x Length [mm]	Part No.	Diameter x Length [mm]	Part No.	Diameter x Length [mm]	Part No.
4 x 70	91-1028-70	5 x 100	91-1029-100	6 x 125	91-1030-125	8x 125	91-1031-125
4 x 175	91-1028-175	5 x 125	91-1029-125	6 x 150	91-1030-150	8 x 150	91-1031-150
4 x 100	91-1028-100	5 x 150	91-1029-150	6 x 170	91-1030-170	8 x 175	91-1031-175
4 x 125	91-1028-125	5 x 175	91-1029-175	6 x 200	91-1030-200	8 x 200	91-1031-200
4 x 200	91-1028-200	5 x 200	91-1029-200	6 x 225	91-1030-225	8 x 300	91-1031-300
4 x 250	91-1028-250	5 x 225	91-1029-225	6 x 250	91-1030-250
4 x 225	91-1028-225	5 x 225	91-1029-250	6 x 300	91-1030-300
4 x 300	91-1028-300	5 x 300	91-1029-300

heat pipe data sheet

	Wick Structure			Standard Length/mm			Special Length/mm	Performance 100-350 L/mm
	Mesh	Groove	Sintered	60-120	121-200	210-400	601-4700	Power/W	Terminal Resistance ºC/w
⌀2	●			●	●			3-6	0.62-1.66
⌀3	●		●	●	●	●		10-15	0.33-0.5
⌀4	●	●	●	●	●	●		15-28	0.17-0.33
⌀5	●	●	●	●	●	●	● (Groove & Mesh)	30-50	0.1-0.2
⌀6	●	●	●	●	●	●	● (Groove & Mesh)	50-70	0.07-0.15
⌀8	●	●	●	●	●	●	● (Mesh)	60-90	0.05-0.1
⌀10	●	●	●		●	●	● (Mesh)	130-160	0.03
⌀12	●				●	●	● (Mesh)	130-160	0.03
⌀14	●					●	● (Mesh)	180-220	0.08

wick structure comparison

Wick Structure	Screen Mesh	Groove	Sintering Powder
Image
Rate Process	Easy	Easy	Hard
Capillary	Bad	Good	Better
Flat (Min.)	t=2.0	t=1.5	t=2.5
Bend (Min.)	2* Heat Pipe Diameter [D]	2* Heat Pipe Diameter [D]	3* Heat Pipe Diameter [D]
Resistance (t = 3mm)	0.250 ~ 0.350	0.030 ~ 0.040	0.030 ~ 0.045
Heat Flux	35	40	45
Cost	Low	Medium	High

heat pipe working fluid

Main Components

High Surface tension - generate high capillary force and resists the environment
High Vapor pressure – reduces vapor velocity
High latent heat – transfers more heat with less fluid
High thermal conductivity – lower ΔT and reduces nucleate boiling at the wick/wall interface
Low vapor viscosity – increases fluid flow capacity

Working Fluid	Relative Figure of Merit [80ºC]	Useful Range [ºC]	Wick Vessel Material	Life [hrs]
Ammonia	0.45	-60 ~ 100	AL SS304	36000
Ammonia	0.45	-60 ~ 100	AL SS304	36000
Freon 113	-10 ~ 100	86	CU AL SS304	25000
Aceton	300	0 ~ 120	CU AL SS304	50000
Methanol	450	10 ~ 120	CU AL SS304	less than 50000
Ethanol	340	0 ~ 120	CU SS304	24000
Water	40000	30 ~ 250	CU	7500000

copper screen mesh

Assessment Parameter	Diameter (mm)	Diameter (mm)	Diameter (mm)	Diameter (mm)
Thickness	4	5	6	8
t = 2.0mm	.65 ~ .09; 15	.50 ~ .80; 18	.35 ~ .60; 35	.30 ~ .55; 45
t = 2.5mm	.65 ~ .09; 18	.45 ~ .65; 22	.25 ~ .40; 40	.20 ~ .35; 50
t = 3.0 mm	.50 ~ .70; 20	.45 ~ .60; 22	.25 ~ .35; 45	.20 ~ .30; 55
Round	.50 ~ .70; 20	.40 ~ .35; 25	.20 ~ .35; 45	.15 ~ .30; 60
Units; R [ºC/W]; Qmax [Watt]

copper groove

Copper grooves inside heat pipes are intricate patterns that enhance the device’s efficiency by:

Facilitating Capillary Action: (The grooves enable the liquid working fluid to flow through narrow spaces, aiding in its distribution.
Increasing Surface Area: More surface area improves the evaporation and condensation processes, enhancing heat exchange.
Enhancing Wicking: The grooves act as a wick, drawing the condensed liquid back to the evaporator section, ensuring continuous operation.

Assessment Parameter	Diameter (mm)	Diameter (mm)	Diameter (mm)	Diameter (mm)
Thickness	4	5	6	8
t = 2.0mm	⏤	.40 ~ .70; 5	.40 ~ .60; 5	⏤
t = 2.5mm	⏤	.04 ~ 06; 25	.03 ~ .05; 40	⏤
t = 3.0 mm	⏤	.02 ~ .05; 30	.03 ~ .04; 60	⏤
t = 4.5 mm	⏤	⏤	⏤	.003 ~ 0.15; 70
Round	⏤	.03 ~ .05; 35	.20 ~ .03; 65	.002 ~ .007; 80
Units; R [ºC/W]; Qmax [Watt]

copper sintering powder

Advantages of Copper Sintering Powder

High Capillary Performance: Excellent fluid movement
Large Surface Area: Enhanced evaporation and condensation
Uniform Distribution: Even fluid distribution
Improved Heat Transfer: Efficient heat absorption and dissipation
Versatility: Suitable for electronics, aerospace, medical devices, and industrial applications

Assessment Parameter	Diameter (mm)	Diameter (mm)	Diameter (mm)	Diameter (mm)
Thickness	4	5	6	8
t = 2.0mm	⏤	.035 ~ .60; 5	⏤	⏤
t = 2.5mm	⏤	.04 ~ 06; 25	.03 ~ .05; 40	⏤
t = 3.0 mm	⏤	.02 ~ .05; 30	.03 ~ .04; 60	⏤
t = 4.5 mm	⏤	⏤	⏤	.003 ~ 0.15; 70
Round	⏤	.03 ~ .05; 35	.20 ~ .03; 65	.002 ~ .007; 80
Units; R [ºC/W]; Qmax [Watt]

customized bending & flattening

Thickness	3	4	5	6	8	9	9.6	10	12	12.7	16
Minimum Bending Radious [2*D]	6	8	10	12	16	18	19	20	24	25	32
Standard Bending Radious [3*D]	9	12	15	18	24	27	29	30	36	38	48
Recommended Bending Radious [4*D]	12	16	20	24	32	36	38	40	48	51	64
Minimum Bending Angle [⌀]	90º
Recommended Bending Angle [⌀]	120º

copper heat pipe spec.

Diameter	Thickness	Thickness Tolerance	Width	Width Tolerance	Bend Radius	Invalid end Length	Q'max	(Sintered) Length	(Groove) Length	(Mesh) Length
𝜑2	1.50	± 0.05mm	2.40	± 0.15mm	Rc7 ↑	Head end: 5.0 Tail end: 1.0	6W ↑	⏤	⏤	60-200mm
𝜑3	2.50	± 0.05mm	3.42	± 0.15mm	Rc9 ↑	Head end:5.0 Tail end: 1.0	12W ↑	70-200mm	⏤	50-350mm
	2.00		3.67
	1.80		3.82
	1.20		4.09
𝜑4	2.50	± 0.05mm	5.03	± 0.15mm	Rc12 ↑	Head end:7.0 Tail end: 3.0	20W↑	80-1000mm	60-2350mm	60-1000mm
	2.00		5.29
	1.50		5.56
	1.20		5.71
𝜑5	3.00	± 0.05mm	6.30	± 0.15mm	Rc15 ↑	Head end:7.0 Tail end: 5.0	30W ↑	80-1000mm	60-2350mm	60-1500mm
	2.50		6.62
	2.00		6.90
	1.50		7.15
𝜑6	4.00	± 0.05mm	7.32	± 0.15mm	Rc18↑	Head end:9.0 Tail end:6.0	35W ↑	80-1000mm	60-2350mm	60-2350mm
	3.50		7.65
	3.00		7.96
	2.00		8.45
𝜑8	5.00	± 0.05mm	9.98	± 0.15mm	Rc24 ↑	Head end:11.0 Tail end:8.0	50W ↑	90-1000mm	80-2350mm	80-2350mm
	4.00		10.60
	3.00		11.06
	2.00		11.85
𝜑10	9.00	± 0.05mm	10.80	± 0.15mm	Rc30 ↑	Head end:15.0 Tail end:12.0	80W ↑	100-1000mm	90-2350mm	90-4700mm
	7.00		12.08
	5.00		13.20
	3.00		14.20
𝜑12	8.00	± 0.05mm	14.90	± 0.15mm	Rc36 ↑	Head end:15.0 Tail end: 15.0	120W ↑	⏤	⏤	100-2350mm
𝜑12	6.00	± 0.05mm	15.90	± 0.15mm	Rc36 ↑	Head end:15.0 Tail end: 15.0	120W ↑	⏤	⏤	100-2350mm
𝜑14	10.00	± 0.05mm	17.00	± 0.15mm	Rc45 ↑	Head end: 20.0 Tail end: 20.0	160W ↑	⏤	⏤	100-2350mm
𝜑14	8.00	± 0.05mm	18.00	± 0.15mm	Rc45 ↑	Head end: 20.0 Tail end: 20.0	160W ↑	⏤	⏤	100-2350mm

Diameter (mm)	Thickness, t +0.05/-0.10 [mm]	DiamWidth, W ± 0.15 [mm]
3	1.2	3.94
	1.5	4.10
	2.0	3.65
	2.5	3.32
	3.0	N/A
4
	1.5	5.49
	2.0	5.23
	2.5	4.96
	3.0	4.65
	4.0	N/A
5
	1.4	7.14
	1.5	6.77
	2.0	6.60
	2.3	6.50
	2.5	6.26
	3.0	5.95
	4.0	5.63
	5.0	N/A
6	1.5	8.69
	2.0	8.41
	2.3	8.25
	2.4	8.20
	2.5	8.16
	2.7	8.00
	3.0	7.84
	3.5	7.57
	4.0	7.30
	4.8	6.86
	5.0	6.63
	5.3	6.60
	6.0	N/A
8	2.0	Undone
	2.5	11.26
	3.0	10.97
	3.5	10.71
	4.0	10.45
	4.5	10.20
	5.0	9.96
	6.0	9.36
	8.0	N/A