Wellste: Your Leading Anodized Aluminum Heat Sink Manufacturer

Our anodized aluminum heat sink are designs and manufactured using all the standard methods including machining, extrusion, surface finishes and many more.

From the start, we designed a product which fulfilled your specific applications in fit, form and function.

Our anodized aluminum heat sink can be delivered to 100KG MOQ and can deliver this orders 20 days or less. But we can also accelerate lead time and deliver within 5 days if standard aluminum heat sink is available in stock.

When selecting the anodized aluminum heat sink it is not enough to consider just on the dimensions, it is extremely important to choose anodized heat sink which perform for a longer-term and safe functioning of elements, machine and systems.

At Wellste, our technical staff will help you by giving full advice on your products, sharing engineering knowledge and construct the perfect anodized aluminum heat sink on that meet your demand.

At Wellste, we also offer anodized aluminum heat sink in a wide variety of designs that are available to you such as extruded heatsink, skived fin, die casting, bonded types and much more.

You can choose from square, round, and flat types heatsinks. Thus, there are thousands available mould for your alternative.

Furthermore, we provide one-stop custom aluminium fabrication, such as CNC /Punching/Tapping/Welding/Drilling /Milling that will help you save time and cost.

Moreover, Wellste provide custom anodized aluminum heat sink for customers’ custom mechanics product solutions that will satisfies their particular requirements.

You can customize your own design with our advanced tooling machinery. Whether you need it for your electronic project or product, Wellste surely satisfy your needs.

All of our anodized aluminum heat sink products are RoHS Compliant, which make them safe on the restriction of the use in particular dangerous substances in electronic components.

Wellste, as a professional anodized aluminum heat sink supplier and manufacturer, we always ensure to aim a high level of customers’ satisfaction. As an ISO9001-2001 certificated company.

Wellste can guarantee quality anodized aluminum heat sink products including durability, reliability and performance.

Anodized Aluminum Heat Sink: The Ultimate FAQ Guide

If you have any question about anodized Aluminum heat sink, you will find the answer right here.

Whether you want to learn about features, properties, or any other feature about these heat sink – the information you need is right here.

So keep reading to learn more.

What Is Anodized Aluminum Heat Sink?

Black Anodized Aluminum Heat Sink

This is a heat sink that has undergone an electrochemical process leading to the occurrence of an oxide layer on the metal surface thus preventing it from corroding.

Anodizing aluminum heat sink gives it an exceptional durable finish.

Why Should You Anodize Aluminum Heat Sink?

There are numerous reasons why the aluminum heat sink should be anodized, some of the benefits of anodizing include;

The corrosion resistance is improved, prevents discoloration and fading when the aluminum comes in contact with materials like salts.

The wear resistance is improved

Additionally, electrical isolation is improved depending on the film thickness and the alloy used.

Also, the surface emissivity is increased

There an improvement in décor appearance

Increased durability, the aluminum heat sink will be durable as a result of anodizing thus offering significant advantage.

The significant advantages offered amongst them are economic advantages like maintenance and operational savings.

Maintenance ease, with anodizing, there is no scars and wears from installing, fabrication, handling frequent cleaning and much more.

Ease of maintenance is guaranteed as rinsing or cleaning using water and mild soap will give the surfaces their original look.

Color stability, by anodizing the surfaces of the aluminum heat sink, the coat provides a good stability to ultraviolet rays.

The surface also does not chip or peel.

Aesthetics, through anodizing, there is an assurance of large increasing numbers of color alternatives and gloss thus eliminating color variations.

Therefore, anodizing the aluminum heat sinks allows it to maintain its metallic appearance.

Health and safety, the process of anodizing is a safe process to human health and the environment.

The anodized finish is usually nontoxic, chemically stable, heat resistant and does not decompose.

Cost, the anodizing process is affordable as well as the maintenance process thus giving a long term greater value.

Heat dissipation; through the anodizing process, heat dissipation is improved.

It is because of the oxide layer formed after the anodizing process that has thermal radiative properties that are high.

The high thermal radiative properties make the formed oxide layer to have the potential of effectively releasing heat externally.

Light weight; the aluminum heat sink that has anodized is always light which weighs approximately 60% less than stainless steel and copper.

When the material is light, shipping of the material becomes easier and cost effective as it is not bulky.

Anodizing Aluminum Heat Sink Is Affordable And Improves Aesthetic Appearance

Are There Limitations Of Anodized Aluminium Heat Sink?

There are no limitations of anodized aluminium heat sink as it works to the advantage of the users.

How Can You Anodize Aluminium Heat Sink?

The aluminium heat sink is put into an acid electrolyte bath where there is presence of electric current going the medium.

Then, there is mounting of a cathode on the inside of the anodizing tank.

The aluminium heat sink acts as the anode.

Since the cathode and anode are present, oxygen ions are released from the electrolyte which combines with the aluminium atoms.

The oxygen ions and aluminium atoms combine on the heat sink surface thus making it anodized.

Diagram Showing Anodizing Of Aluminum Process

How Do You Manufacture Anodized Aluminium Heat Sink?

Anodized aluminum heat sink is manufactured via the process below;

Step one

The part made of aluminum is immersed in a hot tank that contains a cleaning agent solution.

This step has various purposes which include, removing surface dirt from the aluminum surface, avoid solution contamination is subsequent tanks.

Also, the aluminum has to be cleaned to avoid the actual tank contamination as a result of foreign material present on the surface.

Step two

Etching is then performed; it involves suspending the parts in a tank that has a solution of sodium hydroxide.

The purpose of etching is to remove the natural shine of aluminum and providing textured appearance that is soft and matte.

Through this process, the contrast on the aluminum surface is enhanced in order to have a clear appearance.

Step three

The aluminum heat sink is immersed into the anodizing tank that contains water mixture and diluted acid that transmits electrical current.

The solution of water and diluted acid should be one that is able to let electric current pass through it.

When there is no conductivity of electric current in the solution, anodization will not take place on the surfaces.

The type of diluted acid used and temperature are critical as they have an impact on the desired finish and colour.

Here, the aluminum heat sink is the anode thus the negative side of the electrical circuit is connected to it.

The positive side of the electrical circuit is connected on the inner parts of the tank which introduces electricity in the tank.

The inner parts of the tank, they normally act as the cathode.

The quantity and place of the cathodes relate to the shape and sizes of the immersed part of the aluminum surfaces.

Immersed parts equal to the surface area of the aluminum heat sink that should be treated.

Surfaces that are close to the cathode usually have an anodic coating that is thicker as compared to the other parts.

For sulphuric anodizing, a direct power current producing up to 24 volts is used, the voltage is held between 18 -24.

Depending on the surface area of the surface to be anodized, the amount of current is controlled where 12-16 amps are required for every square foot.

The electrolyte solution is agitated during the entire process to provide an even solution temperature.

The anodizing process takes less than one hour under normal conditions of choosing a suitable acid and temperature.

Step four

For color addition, the anodized parts are put in a tank that contains a soluble organic dye that is diluted with water.

The soluble dye is any colour according to the preferences of the user as they can be made in many colours.

Colour can be added to the anodized aluminum heat sink in two different ways which are the electrolyte and dip colouring.

Step five

The dyed outer surface of the aluminum heat sink is then sealed to prevent stain and bleach from the sunlight.

For coatings that are not dyed, the anodized aluminum part is put in de-ionized water for about 20 minutes.

By dipping the aluminum parts into de-ionized water, unstructured pores are converted to a more crystalline hydrate form.

At this point, the quality can be checked on factors like conductivity, thickness and physical properties.

What Is The Function Of Anodized Aluminum Heat Sink?

An anodized aluminum heat sink increases the flow away of heat that comes from a heating device.

The heat sink helps in the cooling process of the device thus preventing situations like overheating of the device.

The process is accomplished through increasing the working surface area of the device.

Also, by increasing the surface area of the low temperature fluid moving on the device surface, facilitates the cooling process.

The anodizing effect on the surface of the aluminum heat sink helps it from any type of corrosion that might occur.

Anodized Aluminum Heat Sink helps In Cooling The Device

Do Anodized Aluminum Heat Sinks Come In Different Colors?

Yes, anodized aluminum heat sinks can come in different colours such as blue, red, black, green, silver, bronze and much more.

However, there are two different ways that can be used when adding colour to the anodized aluminum heat sinks.

The ways that can be used on the addition of colour on the aluminum heat sink are electrolyte and dip colouring.

Electrolyte Colouring

During the anodizing process, the aluminum heat sink is immersed into a tank solution together with the metallic salts.

The aluminum heat sink has pores; the pores are then filled with salts that have the ability to make a very strong surface coating.

The surface coating made, it prevents any type of corrosion and it can resist the ultraviolet rays.

Dip Colouring

The aluminum heat sink parts that should be colored are immersed into a tank containing the desired dye colour.

The pores present on the surface of the aluminum heat sink absorb the dye after being immersed in the tank.

Later on, the surface of the heat sink is then boiled in water that is de-ionized to prevent any further reactions.

With this type of method, there are many colour variations compared to the electrolytic method of colouring.

Electrolyte And Dip Coloring Are Methods To Choose From When Choosing Colors For Your Heat Sink

How Do You Test Quality Of Anodized Aluminum Heat Sink?

The quality of anodized aluminum heat sink can be tested in various ways that include the following;

Conductivity

An anodized aluminum heat sink’s quality can be tested by having a look at its conductivity properties.

The conductivity of an aluminum heat sink can reveal whether it is anodized or not anodized.

The conductivity test is done on the surface of the aluminum heat sink with the use of a multimeter.

If the heat sink surface conducts more heat, then the surface has been anodized and it will give a low resistance.

However, if the surface conducts less heat, then it is not anodized thus a it will give resistance that is high.

Mechanical Test

The quality of anodized aluminum heat sink can be tested mechanically by using a penny to scratch on its surface.

For instance, the penny leaves behind streak of copper on the surface, its shows that the surface is harder than copper.

Thus, it will make the surface considered as anodized.

On the other side, if the penny scratches the polish, then the aluminum heat sink will not be anodized.

An anodized aluminum heat sink surface is considered to be so hard and strong that it resists any physical damage.

Physical Properties

Anodized aluminum heat sink has a very high heat resistant with a melting point of about 1221 degrees F.

The physical properties of the anodized aluminum heat sink can be tested by subjecting it melting.

The temperature at which it starts to melt should be observed to ensure if aluminum heat sink is anodized or not.

In case it is anodized, and then it should start melting at the given temperature.

Thickness

Thickness is amongst the key factors while testing the quality of an anodized aluminum heat sink.

To determine the thickness, it is measured by calculating the weight per unit area.

Not only can calculation is used while measuring the thickness of an anodized aluminum heat sink but also the eddy current method.

The eddy current can be done using an eddy current coating thickness gage.

On the two methods, eddy current method is the most preferred advantageous over the calculation method.

The method allows the inspector to verify if the anodizing process has occurred across all the surfaces of the heat sink.

How Does Anodized Aluminum Heat Sink Work?

The anodized aluminum heat sink has fins that resemble the radiator.

The fins increase the surface area of heat absorption from the device that constantly warms due to its functionality.

The fins then relay the heat outside to the surrounding.

For instance, in a CPU, heat from the computer transfers to the fins which is thereafter released by the fun.

A fun is always attached to the fin to ease air circulation.

To facilitate the process, the fun runs in anticlockwise direction to trap hot air that has been absorbed by the fins.

At this point, there is another fan on the motherboard which drives the hot air away from the computer.

When the aluminum heat sink is anodized, it becomes more conductive hence it fastens the heat transfer out of the computer.

Through fastening the process of heat transfer out of the computer, it results to faster cooling of the computer.

How Can You Improve Efficiency Of Anodized Aluminum Heat Sink?

The efficiency of an anodized aluminum heat sink can be improved in ways such as;

The Arrangement, Size, Shape And Location Of Anodized Aluminum Heat Sinks

When the configuration is optimized, fluid flow resistance becomes reduced thus increasing flow of air through the anodized aluminum heat sink.

This is because of the medium of coolant flow is highly impacted by the arrangement of the fins on the heat sink.

Additionally, the performance of the heat is determined by the size, shape and design of the fins.

When the size and shape of the fins are optimized, heat transfer density is maximized hence improving the efficiency.

The performance of different shapes and configuration of the fins are achievable through modelling.

Using A Material Of High Thermal Conductivity

Putting in use a material with high thermal conductivity and at the same time decreasing the aspect ratio, boosts the efficiency.

The materials with higher thermal conductivity transmit heat so fast thus preventing the system from overheating.

When overheating has been prevented, the efficiency of the anodized aluminum heat sink will be improved.

Thermal Interface Materials

The surface gaps, defects and roughness increase the resistance of the thermal contact thus reducing thermal solution effectiveness.

The defects increase the resistance of heat flow by reducing area of thermal contact between heat sink and an electric component.

Through doing that, the efficiency of the anodized aluminum heat sink is improved.

Thermal resistance reduction is achieved by having an increase in the pressure interface and decreasing the roughness of the surface.

Which Are The Available Features Of Anodized Aluminum Heat Sink?

Fins Are Protrusions That Increase Surface Area

The available features on the anodized aluminum heat sinks include;

The fins: -they have the responsibility of increasing the surface area of the absorption of heat.

Aluminum alloys – since they are good in conductivity, they are used for efficient transfer of heat.

Oxide layer – the layer comes in place after the anodizing process of the heat sink thus it prevents the surfaces from corroding.

Is There Recommended Film Thickness Of Anodized Aluminum Heat Sink?

The recommended film thickness of anodized aluminum heat sink is about 8μm.

The thickness of an anodized aluminum heat sink should be thicker to help increase the surface area contact.

Having a larger surface area contact makes the heat to be distributed more evenly on the plate thus better transmission of heat.

How Do You Determine Thermal Conductivity Of Anodized Aluminum Heat Sink?

The thermal conductivity of anodized aluminum heat sink can be determined by the use of Steady-state thermal analysis.

The analysis technique evaluates the thermal equilibrium of a system where the temperature is at constant over a particular period of time.

On the technique, thermal conductivity is determined through; measuring the temperature difference at a separation under a heat flow.

The heat flow should be a steady state through the sample.

What Can Affect Heat Conductivity Of Anodized Aluminum Heat Sink?

Factors that can affect the conductivity of anodized aluminum heat sink are;

Size And Shape

The conductivity of the heat is affected by the size, shape and design of the fins.

When the size and shape of the fins are not optimized, heat transfer density is minimized hence affecting heat conductivity.

Material Used

Putting in use a material with low thermal conductivity affects conductivity of heat as they will lead to low heat transmission.

The materials with higher thermal conductivity transmit heat so fast thus preventing the system from overheating.

Thermal Interface Materials

The surface gaps, defects and roughness increase the resistance of the thermal contact thus reducing thermal solution effectiveness.

The defects increase the resistance of heat flow by reducing area of thermal contact between heat sink and an electric component.

Thermal resistance reduction is achieved by having an increase in the pressure interface and decreasing the roughness of the surface.

When the processes are not adhered to, the anodized aluminum heat sink will not have good heat conductivity.

What Should You Consider When Choosing Anodized Aluminum Heat Sink?

When choosing an anodized aluminum heat sink, the following factors should be considered;

Operating Temperature Of The Machine

The machines operating temperature should be observed so as to fit a heat sink that can absorb and drive away heat.

Having an anodized heat sink that cannot absorb and drive away heat, the machine will not cool down but over heat.

Heat Dissipation Characteristics

Anodized aluminum heat sinks should redirect the flow of heat away from the hot machine for instance a CPU.

The process is attainable as the heat sinks increase the surface area of the device.

They absorb heat thus making them cool the device, and then the absorbed heat is released in the outside surrounding.

Maximum Operation Limits For The Components

The heat sink should be able to cool down the devices or machinery thus preventing them from overheating.

How Much Does Anodized Aluminum Heat Sink Cost?

Depending on the sizes, shapes and designs of the anodized aluminum heat sinks, they cost from $10.

Which Material Grade Are Anodized Aluminum Heat Sink Made Of?

The material grade anodized aluminum heat sinks are from is the aluminum alloys.

Aluminum alloys are much more affordable than other materials like copper that can perform the same purpose.

Aluminum Alloys Are The Material Of Choice

Aluminum alloys have their advantage as they are malleable, strong and they are ideal for the process of extrusion.

Which Are The Available Sizes Of Anodized Aluminum Heat Sink?

The available sizes of the anodized aluminum heat sinks are the standard and customized sizes.

How Can You Increase Surface Area For Heat Dissipation In Anodized Aluminum Heat Sink?

The surface area of for heat dissipation in anodized aluminum heat sinks can be increased by addition of serrated fins.

With more fins, the surface area of heat absorption is increased as well as the surface area at which it is emitted.

Also, the surface area can be increased with the presence of thicker heat sink surfaces which absorb more heat.

Does Anodized Aluminum Affect Heat Transfer In Anodized Aluminum Heat Sink?

Yes, the anodized aluminium affects the heat transfer in anodized aluminium heat sinks.

It is much possible as the anodized coatings have a lower thermal conductivity hence the heat transfer will be low.

Does Anodized Aluminum Heat Sink Wear Off?

No, anodized aluminum heat sink does not wear off by themselves.

The anodizing process is permanent because it actually “grows” out of the material base of aluminum.

On the other hand, an acid wash can remove the coating.

Therefore, the anodized aluminum heat sink does not wear off by itself but can be worn off by an acid wash.

Apart From Anodizing, Is There Other Surface Finish You Can Apply On Aluminum Heat Sink?

Yes, apart from anodizing there are other surface finish that can be applied on the aluminum heat sink such as;

Mechanical finishes

The aluminum heat sink can undergo buffing, grinded and blasted thus improving surface quality for other cosmetic finishes

Pre-treatment

The aluminum heat sink can be cleaned with acidic or alkali materials.

Pre-treatment coating is ten applied to the surfaces to enhance paint adhesion and resistance from corrosion.

Bright dipping

The extrusion is bright dipped which will give a specular finish.

The extrusion is dipped in a solution made of nitric and phosphorus acids which gives a “mirror” finish.

Liquid paint

Liquid paints come in a variety of colours and they give a film thickness that is uniform.

The liquid coatings contain volatile organic compounds.

Powder coatings

The product can be applied on the surface of aluminum heat sink after extrusion.

The solid particles fuse together to form a film of thickness that is uniform.

Figure 8- Powder Coated Aluminum Heat Sink

Additional Resources:

• Principle Of Heat Sink
• Die Casting Heat Sink
• Pin Fin Heat Sink
• Bonded Fin Heat Sink
• Skived Fin Heat Sink

For all your anodized aluminum heat sink needs, contact us now.