Your Reliable Metal Core PCB Manufacturer in China

If your PCB board temperature starts rising, you will feel more heat than the components of the circuit board. Excessive heat is never good for any circuit board as that can damage the components and, as a result, creates malfunctions in the device.

You can not cool down the excessive heat from an electronic device with the help of regular fans. That’s why metal core PCB becomes handy in heat management.

So, the conductive cooling system of metal board PCBs is a very suitable option.

In the conductive cooling procedure, the metal core transfers heat from the hot part to the cooler part using direct contact.

You must know heat always moves from a hot object to a cool object and the metal core cools down the board using this straightforward process.

There are five types of metal core PCBs where the metal core is used. They are :

Single-layer PCB

A single-layer PCB comes with a metal core. Here manufacturers use aluminum or copper alloy on just a single side of the circuit board. Then they solder mask the nonconducting dielectric layer, IC components, and the copper circuit layer.

Metal Core PCB Single Layer

Here the heat from foil and components transfers smoothly to the base palet because of prepreg dielectric. The metal base plate provides mechanical integrity to the single-sided substrate. Here are some applications of single-layer PCB:

• Audio Equipment
• LED lighting
• Relays (Automotive)
• Packaging equipment
• Sensors

COB Metal Core PCB

You will find a microchip in COB MCPB. The microprocessor or integrated circuit is wired and directly bonded to the board to provide power to the board. It also touches the metal core directly to transfer heat.

COB Metal Core PCB

In typical metal core PCBs, there is a dielectric layer in-between the metal core and copper layer. But in COB, you will find no dielectric layer as the chip touches the metal core directly.

Typically manufacturers use aluminum as the metalcore. As a result, its thermal conductivity is higher than 200W/m.K. Here are some applications of COB metal core PCB:

• High power LED
• Electric lighting
• Automotive
• Power supply
• E-book’s LED front light
• Parking lot and street light
• Horticulture and Agriculture lighting
• Many other products demand thermal solutions.

Double Layer PCB

In a double layer PCB, the bottom part contains the metalcore. You will find a two-conductor layer on top of it. For the metal parts, manufacturers use aluminum, iron alloys, or copper. The dielectric layer is in between the metal core and the copper layer.

Double Layer Metal Core PCB

Two-layer PCBs need an additional step for laminating the metal core and imaged thermal conductive laminate. If you compare it to FR4, this process demands advanced technology and lots of experience.

Here are some applications that use double-layer PCB:

• Inverters, Power rectifier relays, and other power modules.
• Automation equipment for office
• Preamplifiers, Balanced amplifiers, and other audio equipment
• Electronic regulators and power controllers in automobile
• High-frequency amplifiers, transmit circuits, and other electronic equipment are used in communication technology.

Multilayer PCB

This is the most robust type of PCB, which gives designers the highest level of flexibility. In multi-layer PCB, you will find more than two layers of copper such as 4L, 6L, 8L, etc.

These PCBs offer numerous benefits in design and are compact-sized.

Multilayer Metal Core PCB

As for its complexity, the manufacturers need much-advanced technology, high skills, and experience to produce multi-layer metal core PCB.

Here are some applications that use multi-layer PCB:

• Atomic Accelerators
• Equipment for the space program
• Satellite Systems
• File Servers
• Heart Monitors
• Signal Transmission Systems
• Nuclear Detection Systems
• Weather Analysis devices
• Fiber Optic Receptors

Three types of metals are used at the base of metal core PCB or MCPCB. They are Aluminium, Copper, and Iron alloy.

Aluminum is the most prevalent metal for metal core printed circuit boards, especially in the LED light industry, because of its low cost. Copper provides better performance but is expensive. Iron alloy or steel is more rigid than copper and aluminum, but the thermal conductivity is less.

Which base to choose depends on you and the application you are working on.

Aluminum PCB

The formation of Aluminium PCB is

Circuit layer (Copper Layer) + Dielectric Layer or Insulted Layer + Aluminum Layer.

Aluminum core PCB

Cost: The price depends on the PCB thickness and thermal conductivity. If you purchase from a US factory, the price will increase. China factory prices are lower. We provide a very competitive price for aluminum metal core PCB.

Copper Core PCB

The formation of Copper Core PCB is as follow:

Copper Layer + Insulted Layer + Copper Substrate.

Aluminum core PCB

Iron-Based PCB

The formation of Iron-based PCB is:

Copper Layer + Insulted Layer + Steel Substrate.

Manufacturers use two types of steel as the metal base: stainless steel and regular steel.

Thickness Of Metal Core Layer

Typically aluminum is 1.0mm to 3.2mm thick in a metal core PCB. You will find a heat sink with a metal base to dissipate the heat away and save the components.

The thickness depends on the circuit board and the application type for which you will use the metal core PCB.

Thickness Of Thermal Conductivity  Or Dielectric Layer

The usual dielectric layer’s thickness ranges from .075mm to .2mm (.003 inch – .008 inch).

How thick or how thin the layer will depend on the current and voltage.

Thickness Of Metal Core PCB

In a metal core PCB, the dielectric layer is the most important as it has to maintain the electronic insulation even though it is thermal conductive in nature.

This thickness is crucial in an MCPB because it has to be thick enough to prevent the copper circuit from shorting out and, at the same time, thin enough to maintain high thermal performance.

These can work in a high-temperature environment. That’s why metal core PCBs come with high thermal conductivity. The Typical values of metal core PCBs conductivity range from 1W/mK to 7W/mK.

Here are some tips on how you can improve thermal management in a metal core PCB:

• Construction or design: it’s better to separate signal conductors and high power. Enlarge the copper thickness and use additional thermal vias.
• Heavy Copper PCBs: Copper has an excellent thermal conductor. Heavy coppers like 10oz, 20oz, 30oz enhance heat dissipation.
• Aluminum-Based PCB: The thermal conductivity of aluminum base PCB is 1W/m·K to 3 W/m·K. Aluminum can disseminate heat pretty quickly.
• Copper-Based PCB: Copper has more thermal conductivity than aluminum ranges from 4W/m·K to 7W/m·K. This base disseminates heat much more efficiently than aluminum-based PCB.

Thermal Conductivity

CEM3 or FR4 is not good at heat conductor. If the heat conduction of the base materials used in PCB is less, that can damage the components of the PCB board. That’s when metal core PCBs become handy.

MCPCBs have excellent thermal conduction properties, which protect the components from being damaged.

Heat Dissipation

It provides excellent heat dissipation capability. A metal core PCB can remove heat from ICs very efficiently. The thermally conductive layer then transfers the heat to the metal base.

Scale Stability

It provides more dimensional stability than other types of PCBs. The aluminum metal core changes its size to 2.5 ~ 3%  after the temperature reaches from 30° Celcius to 140 – 150°Celcius

Less Distortion

As the metal core PCBs come with good dissipation and thermal conductivity properties, they are less susceptible to distortion that can happen for induced heat. Because of this property metalcore, PCBs are the first choice for power applications that need high switching.

Thermal Expansion

You must know that every object expands and shrinks when it is exposed to heat and cool. The MCPCBs come with excellent thermal expansibility. That means metal core PCBs are well capable of overcoming thermal expansion and contraction problems. This feature makes the equipment more durable and long-lasting.

Every PCB has its own advantages and disadvantages. Like them, metal core PCBs also have some drawbacks. They are :

• Weight: Metalcore PCBs weigh higher than regular FR4 PCBs. Therefore, the applications become slightly heavier.
• Expansive: Compared to typical FR4 PCBs, metal core PCBs are expensive. You can not blame that, as the manufacturing process is far more complex than regular PCBs.
• Component Mounting Process: If you compare it to a regular board, the component mounting process for metal core PCB is pretty complex

Here are the steps of the manufacturing and fabrication process of metal core PCBs:

Step 1: First, you have to design the PCB with appropriate software to provide the blueprint you want to manufacture. After finishing the metal core PCB design, you will send it to your manufacturer.

Step 2: This step is to print the metal core PCB design. Here manufacturers use black ink to detonate copper traces and clear ink to identify non-conductive areas. In the outer layer, they use the reverse process.

Step 3: At this step, the manufacturer pre-bonds copper to a laminate piece, which works as the structure for PCB. For revealing the blueprint, they etch away the copper. You have to strengthen the resistance with ultraviolet light.

Then you have to wash the board with an alkaline solution. This way, you can remove the rest of the photoresist.

Step 4: Now, it’s time to remove all unnecessary copper. You have to use a powerful solution for washing the board. And then do the alignment.

You can use an optical inspection machine to make sure there are no flaws.

Step 5: Now, it’s time to laminate the PCB layer. The external layer is copper foil made. You have to press the PCB layers with metal clamps.

Step 6: Here, you will drill the board. Use an X-ray machine to locate the drill spots. For more precise drilling, use a computer-aided drill.

Step 7: After completing the drilling, it’s time to plant the board. Use a series of chemicals to wash the PCB to cover the PCB with a thick copper layer. This will also cover the holes you drilled in the previous step.

Step 8: Now it’s time to imagine and plant the external layer. You can protect the copper by adding a coat of Tin on the metal core PCB’s outer layer.

Step 9: You will do the final etching to the outer layer. After washing the unwanted copper, your metal core PCB is prepared for solder masking.

Step 10: Now, you can apply a solder mask to the PCB and then use ultraviolet light. You have to remove the solder maks’s marked portion. Then bake the final piece of solder mask in an oven.

Step 11: Use a silkscreen to finish the PCB. Use a surface finish material in this process to protect the components and the copper.

You should perform electrical tests before starting cutting. Use a suitable method to cut the board.

Watch the video on aluminum POB printing

You should only use surface-mounted components instead of plated through design in your design. As you know, the bottom layer of a metal core PCB consists of a thick metal piece, so if you use plated through-hole, that will create a short.

Metal Core PCB surface mounting

You don’t need vias in Metalcore PCBs to disseminate heat from the board. The whole bottom part of the metal core PCB is built with metal with efficient thermal conductivity. So, you don’t need vias to cool down the board.

Because of the metal base, most metal core PCBs need minimal drilling. Sometimes a few large mounting holes are required.

Metal Core PCB Vs FR4 PCB

Here is the difference between metal core PCB and FR4 PCB

LED industry use metal core PCBs for various applications because:

• For their stability, they are best for high-density applications.
• They are more efficient in dissipating thermal heat compared to FR4 PCB.
• They are not vulnerable to heat distortion.

Heat Dissipation

Metal core PCBs are famous for heat conductivity. If the MCPCB is made of a conventional substrate you should realize that they are poor conductors.

High-quality metal core PCBs have higher dissipation capabilities.

Thermal Expansibility

You should consider thermal contraction and expansion seriously. Good metal core PCB always comes with a minimal thermal expansion rate. In the time of increased temperature, it becomes more resilient.

MCPCB heat pad

Magnetic Shielding

If electromagnetic interference happens, metal core PCB can shield the components. they have copper and aluminum cores and therefore provide an excellent magnetic shield.

Yes. Multilayer metal core PCBs come with a heat sink. The heat sinks of multilayer PCBs cool the internal layers. Single-layer metal core PCB does not need a heat sink to disseminate heat.

Yes, it is. You should run a proof test for metal core PCB; otherwise, you can not identify the flaws. Problems arise in the production phase mostly. If you don’t run the proof test, you can end up with a flawed board.

You can use various testing procedures for detecting the problems. For instance, you can identify most flaws with the help of a visual automated inspection machine.

In some cases, manual inspections are also very crucial.

You should perform the tests in every phase of the production. Moreover, you should also test the diodes, capacitors, and resistors.

PCBMay is the leading PCB manufacturer in China. We offer original PCB design, PCB assembly, and PCB fabrication.

Metalcore PCB is not as straightforward as FR4 PCBs and needs lots of experience for high-quality products. With more than 15 years of experience, we provide metal-core PCBs with the highest standard.

We use state-of-the-art technology and highly-skilled engineers and workers to manufacture our PCBs. Because of this quality, our PCBs are used in more than 60 countries worldwide.

We hope after reading this article now you know many things about metal core PCB. Are you planning on a project or want to know more about this topic? We are more than happy to answer any questions. Just send us a message, and we will be in touch immediately.