Copper-core heat-sink PCB

Copper-core heat-sink PCB

Copper-Core Heat-Sink PCB

Into a 4,2mm thick stack-up we have implemented two 1,8mm solid-copper-cores with additional heat-sink-blind-vias. In between, complex signal layers are running just like on a standard 4-layer multilayer PCB. This is a combination of a complex multilayer layout and high-performance heat-management. Times are over when heat-management was only possible on simple single-sided or double-sided aluminium-IMS PCBs. Circuit-complexity and extreme heat-management can now be integrated into one heat-sink-PCB.

LED- and high-performance electronics put common printed circuits to a test. Heat management becomes an ever larger topic when designing and installing PCBs. While aluminium IMS-PCBs are widely available standard this copper-core heat-sink multilayer was designed and manufactured for extreme capabilities in terms of complexity of its signals and heat management at the same time.  Two massive solid copper- cores are connected by heat-sink blind vias to the outer layers to increase heat conduction. 

Copper-Core Heat-Sink PCB Cross Section

Almost unchallenged by that, a standard 4-layer multilayer stack-up is implemented around the copper cores. The vias connecting the outer layers have been cleared and isolated prior to lamination and plating. Thanks to our modern z-axis contact-depth drilling capabilities for blind vias we can place the heat-sink blind vias accurately and in a high density so that the multilayer is almost unaffected by this additional heat-management capability.

Inner layers have been manufactured with standard 18µm copper, while outer layers had a finished copper thickness of 50µm to accommodate the higher currents. Copper walls reached the 20µm wall thickness despite an astonishing PCB thickness of 4,2mm. For lamination we used a special heat-conductive prepreg to enhance conductivity. While standard FR4 only has a heat conductance of 0,3...0,4 W/mK this special prepreg ranges at 1,3 W/mK. 

Higher layer multilayers with similar stack-ups are possible at any time. In such cases it may be required to work with one solid copper core only to limit the total thickness. If you require special heat management on your PCB, please send your layout to us. We are happy to suggest the best possible options. 

CharacteristicValue, description
material type FR4, Tg 150°C plus copper
maximum thickness up to 4,8mm
possible copper core thicknesses 1,0mm / 1,5mm / 1,8mm / 2,0mm
copper thickness (signals) 35µm, 55µm, 70µm, 105µm, inner layers 18µm too
maximum layer count depends on copper cores, up to 8 layers
heat conductive prepreg 1,3 W/mk
heat conductive copper around 380W/mK
layer stack-up up to three copper cores, asymmetric stacks possible
aspekt-ratio thermal-blind vias 1:1
Note: Due to non-disclosure agreements we are not allowed to show any more pictures of the PCB, layout or stack-up. We take our customer's desire for secrecy serious.