High-power operation of assemblies and closely packed components require effective heat transfer to a heat sink in thermal contact with the PCB. Inefficient heat transfer causes assemblies to overheat, which may damage the electrical components or result in failures in operation. The heat dissipated by the components is transferred from the assembly to the heat sink’s cooling surface, which is usually made of metal (aluminium), by so-called thermally conductive adhesives. These materials fill the voids present in the interface between the two objects caused by surface roughness or similar effects.

The process of vacuum bonding.

Pros of the vacuum bonding

• Precludes the need for costly stamping presses
• Reduces the danger of cracking the dies due to unevenly applied pressure
• Less restricted circuit board design
• Eliminates the risk of damaging the circuit board or the mounted electrical components and conductive pathways
• The dispensing technology combined with subsequent vacuum bonding allows cycle times comparable to those achieved with pressure stamping
• Because of the small size of the vacuum box, air is evacuated and reintroduced within the shortest possible time