QPT, a leading power electronics company, has recently filed a patent for an innovative die-attachment method known as qAttach. This technique aims to enhance heat dissipation and reliability in power electronics packaging, addressing critical challenges in high-power semiconductor applications.

As power transistors handle increasing amounts of energy, effective heat removal becomes paramount to maintain performance and prevent overheating. Traditional attachment methods often employ sinter layers between 30 to 60 microns thick, which can impede thermal transfer from the die to the substrate. QPT's qAttach process significantly reduces the thickness of this attachment layer to potentially less than a micron, thereby facilitating more efficient heat conduction away from the chip.

Rob Gwynne, QPT's Chief Technology Officer, explained, "The problem with the current attachment approach is that the sinter layer, which fixes the die to the substrate, is typically 30 to 60 microns thick and this forms a thermal barrier that impedes the transfer of heat away from the chip. We use reliable, well-established technologies from other fields in a novel way to enable us to create the qAttach attachment layer that is potentially down to a fraction of a micron thick. This major reduction in the thermal barrier thickness means that our solution is up to ten times better at transferring waste heat away from the chip. As we refine the process, we are expecting even better thermal transmission rates through this layer."

The qAttach process is particularly beneficial for Gallium Nitride (GaN) transistors, which are increasingly utilized in high-voltage applications due to their efficiency and high-frequency operation. However, the relatively small die size of high-voltage GaN transistors presents challenges in heat dissipation. By implementing qAttach, more heat can be efficiently removed from the die, enabling GaN transistors to operate at higher power levels without the risk of overheating. This advancement opens up new possibilities for GaN technology in automotive, industrial motor control, and other high-power, high-voltage applications.

QPT's novel packaging structure involves a sandwich configuration comprising a heat sink, substrate, qAttach layer, die, another qAttach layer, substrate, and heat sink, with the printed circuit board (PCB) surrounding the structure at the sides. This design allows for rapid heat transfer through the ultra-thin qAttach layers, enhancing overall thermal management and reliability of the electronic components.

In summary, QPT's development of the qAttach process represents a significant advancement in power electronics packaging. By substantially improving heat removal and reliability, this innovation paves the way for more efficient and robust high-power electronic systems, particularly those employing GaN transistors in demanding applications.