Metal Core PCB

A Metal Core Printed Circuit Board (MCPCB), also known as a thermal PCB or metal backed PCB, is a type of PCB that has a metal material as its base for the heat spreader portion of the board. The thick metal (almost always aluminum or copper) is covering 1side of the PCB.

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, 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.

Based on the different positions of PCB metal core and trace layers,MCPCB can be classified into five basic types： Single layer MCPCB (only one trace layer on one side) COB MCPCB (chip-on-board MCPCB, one trace layer) Double layers MCPCB (two trace layers on the same side)

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.

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 metalcore PCB. The usual dielectric layer's thickness ranges from .075mm to .2mm (.003 inch - .008 inch).
How thick or how thin the layer is will depend on the current and voltage.

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/mK.
Aluminum can disseminate heat pretty quickly.
Copper-Based PCB: Copper has more thermal conductivity than aluminum ranging from 4W/mK to 7W/mK. This base disseminates heat much more efficiently than aluminum-based PCB.

Thermal Conductivity
CEM3 or FR4 is not good at heat conductors. f 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
lt 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
lt provides more dimensional stability than other types of PCBs. The aluminum metal core change its size to 2.5. 3% after the temperature reaches 30° Celcius to 140 - 150°Celcius
Less Distortion
As the metal core PCBs come with good dissipation and thermal conductivity properties, they are 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. TheMCPCBs 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: lf you compare it to a regular board, the component mounting process for metal core PCB is pretty complex

The metal core PCB fabrication process is ①Grinding plate (500# brush)→②Washing→③Passivation→④Washing×3→⑤Blow-drying→⑥Drying. Grinding plate: Grinding the iron surface only, grinding the plate according to FR4 parameters.

Metal core PCBs must follow a particular process due to the presence of the metal layer in the stack. If the board is a single-layer board with no layer transitions back to the metal plate, then the standard FR4 dielectrics can be used, where the dielectric layer is pressed and bonded to the metal plate.

For multilayer dielectric stackups, the metal core must first be drilled to allow for a layer transition without creating a short circuit. First, slightly larger holes are drilled into the metal layer, and the holes are plugged with an insulating gel. This gel is cured and hardened, allowing it to be plated with copper, just like a standard via. The rest of the stackup is pressed and bonded with the metal layer, and through-holes are drilled through the stackup, followed by plating and cleaning.

The first board must check the circuit without scratches, black tin surfaces, other defects, and uniform wear marks.

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. 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, 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.

Price Compare: metal core PCB v’s fr4
Fr4 PCB is a very conventional PCB type of electronic industry.
In the LED industry, Fr4 PCB does not use first widely, its metal core PCB uses more widely.
That is the reason why many people don’t know metal core PCB but call it LED PCB.
Due to thermal management, metal core PCB has to consider more heat than the conventional PCB design process.
Add the metal material also not so cheap.
Resulting in most metal core PCB boards is more expensive than the FR4 PCB board.

Heat Performance compares: metal core PCB v’s fr4
In traditional electronic PCB design theory, the electronic transfer is the first, then the layout.
Metal core PCB design is more than above two points, add consider a PCB heat transfer.
You know in LED lighting applications, heat increase is the biggest problem.
If you choose high-performance metal, this situation may change.
By the way, most metal core PCB heat performance is better than FR4 PCB.

The stack-up of metal core PCB board VS.Fr4
We have compared the price and performance, In this part we will discuss the construct or stack up of metal core PCB.
Metal core PCB has three layer stack up.
And FR4 stacks up depending on each application, it can have 1, 2, 3, or even more later.
In three layer stack up of metal core PCB, the dielectric layer is most different from fr4 PCB.
Metal core PCB has high heat management most reason is it has a dielectric layer.

The application compares: metal core PCB VS FR4
Fr4 PCB application has more widely than metal core PCB.
But in the LED industry, most engineers will choose metal core PCB for new projects.
For example, a single-layer metal core PCB stack up, the base is a metal core, the top is copper, the dielectric layer is in the middle. MCPCB is used instead of traditional FR4 or CEM3 PCB because of the ability to efficiently dissipate heat away from the components. This is achieved by using a Thermally Conductive Dielectric Layer

LED industry uses 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 PCBThey are not vulnerable to heat distortion.

Heat Dissipation
Metal core PCBs are famous for their heat conductivity. lf 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. Magnetic Shielding
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 lf you don't run the proof test, you can end up with aflawed 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.
n 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.

YMSPCB is the leading PCB manufacturer in China. We offer original 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 12 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.