Thermal Clad & Metal Backed Printed Circuit Boards

Epec offers thermal clad and metal printed circuit boards with a full selection of high performance or low cost materials from leading suppliers around the world. Thermal clad PCB's are a dielectric metal base with a bonded copper circuit layer. This creates superior heat transfer to help cool components while eliminating problems associated with managing fragile ceramics.

With a wide range of electrical and thermally conductive interface pads, thermally conductive gap fillers, thermal phase change materials and thermally conductive electrically insulating materials, we can manufacture thermal clad & metal backed printed circuit boards that exceed all of our customers' expectations.

Thermal Clad Layers

Thermal clad is a unique layered system comprised of the follow layers.

Circuit Layer:

Printed circuit foil with thickness of 1oz to 5 oz.

Dielectric Layer:

Many different options which offer electrical isolation with minimum thermal resistance. Also used to bond the circuit layer and base material together. Each specific dielectric has its own UL recognition.

Base Layer:

Most often Aluminum, but can also be copper. The most commonly used thickness is 0.040" (1.0mm) although many thicknesses are available.

Thermal Clad and Metal Backed Printed Circuit Boards

Specification of Aluminum Based Copper-clad Laminate

Item Unit Specification Test Condition
Insulation Thickness µm Max
Solder Resistance (288°C) Sec. Min 600 IPC-TM-650
Thermal Shock 288°C * 10"/cycle Min 6 Times IPC-TM-650
Peel Strength (Normal status) lb/in Min 9 IPC-TM-650 2.4.8
Breakdown Voltage V/mil   750 IPC-TM-650 2.5.6
Volume Resistivity (Normal status >E+14) Ω * cm   1.8x1015 IPC-TM-650
Surface Resistivity (Normal status >E+12) Ω   3.5x1014 IPC-TM-650
Dielectric Constant
1 MHz Normal Status
1 GHz Normal Status
Dissipation Factor
1 MHz Normal Status
1 GHz Normal Status
Water Absorption %   0.2 IPC-TM-650
Thermal Conductivity
(measured on insulation layer only)
W/m°C   1.0 ASTM-E1461
Flammability 94V-0   Pass IPC-TM-650 2.3.9
Tg °C   100 IPC-TM-650 2.2.24
Td °C   410 TBD (5wt% loss)
MOT (RTI) °C   130 UL 746B
CTI (Comparative Tracking index) V   600 (PLC=0) UL 746E DSR

Thickness & Dimension of Aluminum Based Copper-clad Laminate

Product Category CS-AL-88/89 L1 (The thickness of resin is 2-8mil)
Dimension m/m 300-340 x 500-520
405/400 x 500-520
600-620 x 500-520
1200-1240 x 500-520
1200-1240 x 1020-1060
Thickness of Single Sided PCB
with Aluminum Substrate
2.0 1/0 1.5 1/0 1.5 2/0 1.0 1/0 0.8 1/0
Thickness of Double Sided
PCB with Aluminum Substrate
2.0 1/1 1.5 H/H 1.5 1/1 1.0 1/1 0.8 1/1

* The above thickness excludes the thickness of resin and the thickness of copper and Aluminum can be combined arbitrarily.
* The thickness of copper foil: H oz. - 5.0 oz. The thickness of aluminum plate: 0.2 - 5.0mm.
* Halogen free material.
* Compliance with RoHS and REACH.

Formable Thermal Printed Circuit Board Solutions

A unique proposition is Formable Thermal LED PCB Solutions. Unlike brittle ceramic or epoxy systems, the dielectric is formulated using a flexible thermally loaded material.

This allows component placement using standard paste and reflow techniques, the board is formed to shape after assembly giving a one piece system removing the need for interconnecting wires.

Thermal Clad PCB Material

  • Bergquist
  • Thermagon
  • Arlon
  • Denka

Thermal Clad PCB Specifications

  • 1 & 2 Layer Dielectrics
  • Up to 5 oz finished Cu
  • Al and CU base material up to .250" thick
  • HASL, ENIG and Pb Free HASL finish available

Thermal Clad PCB Benefits

  • Lower Operating Temperatures
  • Improved Product Durability
  • Increased Power Density
  • Increased Thermal Efficiency
  • Reduced Number of Interconnects
  • Lower Junction Temperatures
  • Reduced PCB Size
  • Eliminates Older Hardware
  • Minimizes Labor Required for Assembly
  • Wide Variety of Form Factors
  • Minimize Thermal Impedance

Thermal Clad Printed Circuit Board Applications

You can improve the durability and performance of your product by using Thermal Clad circuit boards. Simple designs and low thermal impedance of the dielectric out performs all other printed circuit board insulators for power and high-operating temperature components. Below are some example of applications using thermal clad and aluminum backed PCB's.

Power Conversion:

Thermal clad offers a variety of thermal performances is compatible with mechanical fasteners and is highly reliable.


Using Thermal Clad PCB's assures the lowest possible operating temperatures and maximum brightness, color and life.

Motor Drives:

Thermal Clad dielectric choices provide the electrical isolation needed to meet operating parameters and safety agency test requirements.

Solid State Relays:

Thermal clad offers a very thermally efficient and mechanically robust substrate.


The automotive industry uses Thermal clad boards as they need long term reliability under high operating temperatures coupled with their requirement of effective space utilization.

America's Oldest, A History of Innovation.  Learn More →
Our History

As the oldest production Printed Circuit Board Company in North America, perhaps in the world, the 60-year plus story of Epec is connected to the development of the PCB and the electronics industry.

See our history timeline →

  • Epec Founded in 1952
  • IPC Founded in 1957
  • Epec Builds PCB for Apollo 11