Metal Core PCB (MCPCB) | IMS PCB | Thermal PCB

Metal core PCB, or IMS PCB, or Thermal PCB is a technology developed to overcome the thermal limitations of the FR4 material. Metal core is a better choice than FR4 if your PCB boards need to work in high temperature environment. Insulated Metal Substrate (IMS) provides electrical isolation between the copper and the metal core by using a special dielectric with the peculiarity of having high thermal conductivity.

What is a Metal Core PCB (MCPCB)?

A Metal Core Printed Circuit Board (MCPCB), or a thermal PCB, is a type of PCB that has a metal material as its base for the heat spreader portion of the board. MCPCB consists of thermal insulating layer (also called IMS PCB), metal plate and copper foil, which has special magnetic conductivity, excellent heat dissipation, high mechanic strength and good processing properties. The purpose of the core of an MCPCB is to redirect heat away from critical PCB components and to less crucial areas such as the metal heatsink backing or metallic core. Common base materials of metal core PCBs are Aluminum, Copper or a mixture of special metal alloys. The chart below lists two common metal core material, MCPCB types, metal core thickness and copper thickness.

Metal Core Material

MCPCB Type

Metal Core Thickness

Copper Thickness

Aluminum

Aluminum Core PCB

0.75mm (30mil)-3.2mm(125mil)
thicker or thinner are possible

1-2oz
thicker is possible

Copper

Copper Core PCB
(or Heavy Copper PCB)

0.75mm (30mil)-3.2mm(125mil)
thicker or thinner are possible

1-10oz
thicker is possible

Copper core PCB has better performance than Aluminum PCB, but its price is relatively more expensive than aluminum core PCB. Customers order Aluminum PCBs more often, because the price of aluminum PCB is much cheaper.


Advantages of Metal Core PCB

Insulated Metal Substrate Technology offers a great list of advantages when an application requires great heat dissipation. Most engineers and designers rely on Metal Core PCB to take its advantages compared to FR4 PCBs:

  • Able to integrate a dielectric polymer layer with a high thermal conductivity for a lower thermal resistance.

  • Able to transfer heat 8 to 9 times faster than FR4 PCBs.

  • Able to dissipate heat, keeping heat generating components cooler which results in increased performance and life.

 

Metal Core PCB Applications

PCBs that require a lot of power usually generate a lot of heat at the same time. If your PCBs need fast cooling it is better to use Metal Core PCB than FR4 PCB. The following list includes some of the most popular applications that work great with this metal core technology.

  • LED Lighting

  • Power Conversion Systems

  • Power Supplies

  • Photovoltaics

  • Telecom & Industrial

  • Automobile Electronics

 

Metal Core PCB Stack-Ups

 

Single-Sided Metal Core PCB (MCPCB)

Double-sided Metal Core PCB (MCPCB)

Multialyer Metal Core PCB (MCPCB)


Metal Core PCB Copper Clad Laminates

Vendor

Part Number

Type

Thermal Conductivity
(W/m·K)

Tg(oC)

Td(oC)

Dk @1MHz

Df @1MHz

Ventec

VT-4B1

Aluminum Base (1100, 5052)

1.0

100

380

4.8

0.016

VT-4B3

Aluminum Base (1100, 5052)

3.0

130

380

4.8

0.016

VT-4B5

Aluminum Base (1100, 5052)

4.2

120

380

4.8

0.016

VT-4B5 SP

Aluminum Base (1100, 5052)

5

120

380

4.8

0.016

VT-4B7 SP

Aluminum Base (1100, 5052)

7

100

380

4.8

0.016

GDM

GL12

Aluminum Base

1.0, 1.5, 2.0

--

--

--

--

BOYU

AL-01-B

Aluminum Base

1.0, 1.5, 2.0

120

--

4.9

0.02

 

Typical Thermal Conductivity of Metal Core

Material

Thermal Conductivity

Copper

380 W/m·K

Aluminum

140 – 220 W/m·K

Prepreg

1 – 8 W/m·K

 

Metal Core PCB Design Guidelines

Here are some MCPCB design guidelines for reference, including NPTH Drills, 1 Layer Metal Core and 2 Layers Metal Core PCBs.

  • NPTH Drills

MCPCB Thickness

Min. Drill Diameter

0.5mm Metal core

0.7mm (or 0.5mm)

0.8mm Metal core

0.7mm

1.0mm Metal core

0.8mm

1.5mm Metal core

0.9mm

2.0mm Metal core

1.0mm

 

  • 1 Layer Metal Core

Capacity

35µm Cu

70µm Cu

Min. conductor width

150µm

200µm

Min conductor spacing

150µm

200µm

Min. annular ring

125µm

200µm

Min. drill (NPTH)

0.7mm

0.7mm

Min. drill spacing

250µm

250µm

 

  • 2 Layer Metal Core with PTHs

Capacity

35µm Cu

70µm Cu

Min. conductor width

150µm

200µm

Min conductor spacing

150µm

200µm

Min. annular ring

125µm

200µm

Min. drill (NPTH)

0.7mm

0.7mm

Min. via (PTH)

0.3mm

0.3mm

Min. drill spacing

250µm

250µm

Min. via spacing

300µm

300µm

Aspect ratio

10:01

10:01