Your Professional Aluminum PCB Manufacturer in China

Aluminum boards are also mentioned as CCL. CCL refers to Copper Clad Laminate. Aluminum PCB stackup is the same as traditional PCBs like FR4.

The Construction Of Aluminum PCB

The base material of the aluminum PCB is aluminum. Aside from this, the following are basic construction of the PCB.

• The layer of Copper Foil: The fundamental layer of any PCB is the copper layer, so as an aluminum circuit board. It is basically thicker than traditional PCBs. The is normal 1 oz to 10 oz thick.
• Dielectric Layer: The conductivity of the dielectric layer is one of its distinguishing characteristics. It has a conventional thickness range of 50 µm to 200 µm, and it is made of polyethylene. The heat resistance of the dielectric layer, on the other hand, is lower.
• AluminiumBase: The aluminum substrate serves as the foundation for the aluminum core printed circuit boards. It has a significant heat-reducing effect. As a result, aluminum is used in high-temperature applications because of its heat dissipation properties.
• AluminiumBase Membrane Layer: The membrane layer keeps the surface of the PCB protected. This layer is selective.

The performance of aluminum base PCBs is more advanced than standard FR4 PCBs. Aluminium PCBs perform distinguishable in the following segments.

Aluminum PCBs Have Most Heat Dissipation Ability

Heat Dissipation

The heat dissipation of standard substrates like FR4, or CEM3 is poor. They cannot dissipate more temperature at a time. So, high heat leads to component failure. But, aluminum has a great heat dissipation property.

FR4 has a temperature resistance of 20 to 22 degrees Celsius per watt at 20 to 22 degrees Celsius. The temperature range for aluminum, on the other hand, is 1 to 2 degrees Celsius.

Thermal Expansion

The coefficient of thermal expansion of aluminum is around 22 ppm and the copper is 18 ppm. These two are almost closed. So the balanced coefficient of thermal expansion can withstand copper. This ensures the durability and reliability of the PCBs.

Dimension stability

Aluminum base PCBs have excellent dimensional stability. When aluminum PCBs encounter a temperature from 30 to 150°, the change of aluminum occurs around 2.5 to 3%.

Other Performance

Aluminium PCBs are durable and reliable. They also have electromagnetic shielding and high dielectric strength. Aluminum-clad PCBs have good heat resistance and physical properties that also save costs in production.

Designing and aluminum PCB manufacturing processes are similar to standard PCBs. Every PCB design starts with the schematic drawing. The following are the manufacturing steps of aluminum core PCBs.

Schematic Drawing

The very first process of designing the PCB is schematic drawing. Schematic is the blueprint of PCBs. Schematic ensures every detail of PCBs. The further movement of the PCB manufacturing goes depending on the schematic draw.

atic draw.

An Example Of PCB Schematic

Layout Design

By schematic capturing, you need to design the layout of the PCB. It is the visual design part of the aluminum base PCBs.

Layout Printing

After completely designing the layout, this time you need to print the PCB on the aluminum substrate PCB board. However, the board should be ready before printing with the required number of layers, and proper stackup.

See how aluminum core PCBs are printed.

Etching Traces

After printing the PCB, this time you need to etch the conductive traces. The traces will allow the component to pass the current and signals.

Component Placement

After etching the traces, now place the components in the right places. Component placing is one of the crucial parts of PCB manufacturing. You may use SMT or through-hole PCB assembly technology for component placement.

For the through-hole process, proper soldering is a must.

Routing

Now route the components with each other. After routing the components, the PCBs are ready for application.

PCB Testing

PCB testing is another important fact of PCB manufacturing. Testing is needed to ensure the PCB is manufactured as per the design and performance required.

During the manufacturing of aluminum substrate PCBs, you have to face some challenges to overcome.

Copper Etching

In aluminum substrate PCBs, the copper foil used is comparatively thicker. If it goes over 3 oz, you need width etching. However, the copper etching process must follow the design requirements. If not, you may experience a trace width out of tolerance.

You Will Face Some Challenges In Copper Etching Of Aluminum Base PCB

Solder Mask Printing

As for the use of thicker copper foil, the solder mask printing becomes more complex in aluminum PCBs. That is why you need two times solder mask printing. You also must use premium quality solder mask oil. Sometimes, you may use resin filling for solder masking.

Mechanical Manufacturing

PCB V-scoring, drilling, molding, and other mechanical processes are examples of PCB mechanical processes. Internal vias are essentially where they are left. As a result, the electrical strength of the PCBs may be compromised.

For low-volume production, you may use electrical and professional milling in this scenario. In the end, this will improve mechanical strength.

As aluminum-clad PCBs are extra durable, and highly heat-dissipating, using them in electronics is a bang for the buck. There are many sectors that use aluminum PCB. The following are some of the sectors.

LED Industry

LED lights and circuit boards are the main users of aluminum boards. Aluminum-clad PCBs for LEDs ensure the lowest possible temperature. Along with this, aluminum PCBs also bring the highest brightness and lowest costs.

LED Industry Vastly Uses Aluminum Base PCB

Along with the LED industry, there are a bunch of used aluminum boards in different sectors.

• For long-term reliability and durability, the automotive industry uses aluminum
• Street lights, traffic control systems, interior decoration lights, etc.
• Industrial vehicles like ignition systems, safety controls, etc.
• Microwave, semiconductor, radiator, motor control.
• High-frequency PCBs in communications.
• Audio equipment like amplifiers, power amp, input, and output amplifiers.
• Inverters, solid relays.
• Stabilizer, AC-DC adaptor.
• Computer power supply, floppy disks, and so on.

Aluminium PCBs significantly reduce the amount of heat generated by the PCB’s components. It is the major benefit of aluminum printed circuit boards, as well as the primary rationale for their adoption.

Aluminium Substrate PCBs Are Highly Heat Dissipating

• Aluminum can be refined. They are low-costing as well. So, making aluminum substrate PCBs is more cost-effective than other materials.
• Aluminum is a non-toxic material. You can also recycle them. Ultimately, aluminum PCBs are environmentally friendly.
• High heat or temperature is always vital for electronics. On the other hand, aluminum is a highly heat-dissipating material. Aluminum absorbs heat from all of its constituents and dissipates it into the atmosphere.
• Aluminum is a highly durable and strong material. Along with standard durability, aluminum is also safe from accidental breakage. So, using aluminum PCB will not give you the tension of breaking.
• Aluminum is a lightweight material that has a high degree of toughness in addition to being very lightweight. As a result, aluminum printed circuit boards have exceptional strength while weighing little.

Aluminium PCBs are found in various types in terms of layers, and state. They are as follows.

Single-Sided Aluminium-Clad PCB

• Single-Sided PCBs: Single-sided PCBs have a single conductive copper layer above the material substrate. On the other side, components are placed and soldered on one side.
• Double-Sided PCBs: Double-sided PCBs hold two thin conductive copper layers on both sides of the board. Electrical holes are used to connect sides with each other.
• Rigid PCBs: Rigid PCBs are rigid in the state. As aluminum is a rigid material, so, basically the structure of aluminum base PCBs is rigid in general.
• High-Frequency PCBs: High-frequency PCBs pass high frequency in the applications. These PCBs are used in extensive applications.

Electrical grounding is a secondary channel for electrical current to go through. It enables the current to be returned to the ground in the event of a malfunction in the electrical wiring system.

Grounding is a physical link between electronics and the earth’s magnetic field.

Grounding is one of the most crucial facts of electronics. It is highly essential for the following reasons.

Gives Protection Against Electrical Overload

If there is an electrical overload, the grounding will save your electronics. If there is lightning in the sky, this may dangerously affect your electronics. Grounding will return back the excessive current to the earth.

Grounding Saves Your PCBs From Damages

Voltage Stabilization

Grounding helps to distribute the proper amount of power across the entire electrical system. This ensures the circuit does not face an overload of voltage.

Preventing Injuries, Damage, And Death

Improper grounding brings risk to your electronic system. This could damage your system, and also can injure you. This could also drive you to death. Proper grounding in electronics prevents these events.

If you understand the importance of grounding, now you might want to properly ground your aluminum PCBs during manufacturing. There are some basic rules to follow for proper grinding.

Do Not Leave Anything Unattached

Let’s have a look at them.

• You must attach every electrically conductive part to the ground plane of your PCB. Don’t leave anything unattached.
• You must ensure a dedicated ground layer for the entire PCB. This creates a ground current loop which is good for the PCBs.
• Ensure a single ground point comes together to the ground plane. It is better to use your dedicated ground layer as the common point.
• Make sure you complete your grounding before the routing of the components.
• Minimize the use of vias as high as possible. Instead, send the components to the ground plane directly.

Surface finish is one of the most crucial facts of your PCB manufacturing. The surface finishes protect your PCBs’ conductive copper from oxidation and corrosions.

However, surface finish selection depends on the costs, applications of the PCBs, and many other facts. Your aluminum PCB manufacturer and designer will determine which surface finish is suitable for the particular PCBs.

The following are some most popular surface finishes.

HASL– Hot Air Soldering Leveling

It is the most common type of surface finish. You need to dip the PCB in molten solder to cover the exposed copper with the solder.

ENIG and ENEPIG

Electroless Nickel Immersion Gold is the combination of gold and nickel. The nickel covers the copper, and the gold covers the nickel for protection.

On the other hand, In the ENEPIG, palladium is used with nickel and gold. This is also very efficient and cost-effective.

ImAg – Immersion Silver

Hin silver plating is used on the conductive copper traces and other exposed copper of the PCBs.

OSP Surface Finish

It is an organic and transparent surface finish. OSP is a water-based surface finish that selectively bonds with copper.

OSP Surface Finish In Metal Core PCB

ImSn- Immersion Tin

Like Immersion Silver, Immersion Tin uses thin tin plating on the conductive copper traces and other exposed copper.

There are some precise and effective ways to prevent excessive heat on your aluminum base PCBs. If you properly utilize them, high cannot be generated on your PCBs.

Use High-Grade Materials For Aluminum PCB

• Use a properly sized heatsink based on the size of the PCB and its application. Attach the heatsink in the proper way.
• Consider the high-grade materials including high-grade aluminum and other materials of the PCBs.
• Select the high-grade components as well.
• Keep the analog and digital components away from each other.
• Use a thick plate and board for the PCB. The thick boards can consume more heat than thinner ones.
• Apply proper laminations on the PCB. Proper lamination helps to mitigate high heat.

Aluminium PCBs are the same in structure as standard PCBs. The main difference is the use of aluminum as the base layer of the PCBs.

By the way, aluminum-backed PCBs are extensively used as LED PCBs and power converting electronics.

Aluminum Base PCBs Are Highly Heat Dissipating

Because aluminum is extensively a heat-dissipating material. It can mitigate and dissipate high heat more easily than other materials like FR4.

So, the components of the PCBs easily pass the heat to the aluminum board and the board dissipates the heat to the air.

On the other hand, LEDs create extensive heat which cannot be normally handled by using the normal materials. That is why the LED industry uses aluminium PCBs.

Aluminium PCBs also extend the lifespan of LED devices.

Though aluminum and FR4 are two highly used materials for PCBs, there are many significant differences between them. Let’s check the comparison between aluminum PCB vs FR4.

Performance Comparison

The heat-dissipating power of aluminum is significantly greater than FR4. It is because the thermal conductivity of aluminum is great.

Mechanical Property

Aluminium PCBs are mechanically superior to FR4. This brings more strength and toughness for the aluminum substrate PCBs.

Electromagnetic Shielding

The electromagnetic shielding property is greater in aluminum than in FR4. This prevents the interferences and radiations of the PCBs.

Aluminum Is Superior To FR4 In Performance

Coefficient of Thermal Expansion

The rate of thermal expansion in FR4 is more than in aluminum. The large thermal expansion disrupts the physical structure of the PCBs. So, aluminum is more stable and generates a balanced expansion rate.

Testing is another important fact for PCBs. Because testing helps you to find out the faults of the PCBs. So, if you don’t want faulty PCBs which will drive you to financial loss, you just go through the PCB testing.

There are several testing methods here to use for PCB testing. Following are some popular ones.

In-Circuit Testing (ICT)

ICT is the most common PCB testing method. It is also the most expensive as well. However, ICT testing covers the whole PCB circuits to test. It is designed for 100% coverage.

ICT Is Designed For Covering 100 Percent Circuits

Flying Probe Testing

It is the less expensive version of ICT testing. The flying probe is designed for specific testing. This includes shorts, opens, capacitance, resistance, diode, and inductance of the PCBs.

Automated Optical Inspection (AOI)

In AOI, single 2d or two 3d cameras are used to take photos of the PCBs. After taking the photos, they are compared with the schematic of the PCB to ensure everything is manufactured correctly.

To meet the designed requirements, you must ensure the quality of your aluminum PCBs. Because low quality PCB cannot serve as per your needs.

So, how could you be assured about the quality of your aluminum-backed PCBs?

Check the following facts on your PCBs to be assured about the quality of your PCBs.

• Check if high-grade materials are used.
• Meet the required design factors.
• Meet the requirements of electrical connections.
• The surface finish is appropriately applied.
• Vias, holes, layers, etc., all are placed organized.
• The PCBs are capable of withstanding high temperature, humidity, and resistance.
• Make sure the mechanical properties comply with the installation requirements.

To get the best qualitative PCBs, you must select a highly experienced and skilled aluminum PCB manufacturer.

To find out the best CB manufacturer, you should check for the following facts about the manufacturer.

• Long-time industry experience.
• Highly skilled.
• Advanced manufacturing plant infrastructure.
• Professional staff.
• Extensive tools and machines for producing aluminum base PCBs.
• IPC certification for manufacturing PCBs.

Unlike other materials, the flux that is needed for soldering is specific to aluminum. For aluminum soldering, high in alloy works perfectly forming intermetallics. However, it takes time to form aluminum intermetallic.

You also can use Sodium Persulfate for aluminum PCB soldering.

The intermetallics ensure the stronger solder joint for aluminum. By the way, you need soldering iron, solder flux, soldering paste for soldering the aluminum PCBs.

The following are the steps to solder a PCB.

• Preparing soldering iron.
• Preparing the surface of the PCB.
• Placing the PCB components.
• Generate some heat.
• Solder the joints with the soldering iron. Be careful during the soldering.
• Then finish up the process.

Check on how to solder LEDs in metal-clad PCBs.

Aluminium PCBs are mostly used in the LED industry. However, the uses of aluminum base PCBs are wide.

By the way, manufacturing aluminum-clad PCBs demands great skills and expertise. A highly experienced aluminum PCB manufacturer can produce extensive qualitative PCBs.

So, to get your desired qualitative aluminum base PCBs, you may rely on PCBMay. PCBMay is the one-stop PCB manufacturer that will ensure you the highest PCB quality.

So, get the best PCB quote, you may contact us with your requirements.