Method for construction of high power LED multilayer gradient material cooling channel

Abstract

The invention provides a construction method for a high power LED multilayer gradient material heat dispersion channel, which includes steps: 1) GaN-base LED chip preparation: etching a GaN-base LED epitaxial wafer by dry process to form a L shape and expose N-GaN layer surface; vaporizing a indium tin oxide current expansion layer on surface of the P-GaN, vaporizing P, N electrodes and plating pure gold on the P, N electrode; 2) Cu fast heat diffusion board preparation: preparing a L-shaped Cu board, sputtering a layer of Ti or Cr by magnetic control to be used as a adhesive layer; sputtering a layer of AlN on the Ti layer by magnetic control to be used as a insulated layer; vaporizing a layer of thin gold and plating a layer of thick pure gold; 3) pure gold bonding by thermocompression bonding: upside-down mounting the LED chip on the Cu fast heat diffusion board. By employing Au-Au-AlN-Ti multilayer material with high thermal conductance and gradient changed thermal coefficient of expansion to construct the heat dispersion channel between the LED and the Cu fast heat diffusion board, heat diffusion problem of high power LED is resolved, heat diffusion capability and stability of device is increased.

Description

technical field [0001] The invention relates to a manufacturing process of a high-power LED device, in particular to a multi-layer gradient material and a construction method of a high-power LED cooling channel. Background technique [0002] The early gallium nitride-based white LED package was in the form of front mounting, and the heat sink was connected to the sapphire layer through the connection layer. The heat generated in the active area of ​​the LED is conducted to the heat sink via the n-GaN layer, the sapphire substrate and the connection layer. Since the thermal conductivity of sapphire is only 30W / m.k and the thickness is about 100 microns, it forms a large thermal resistance. The heat dissipation form of the LED package in the formal form can only be applied to low-power LEDs. [0003] In order to solve the heat dissipation problem of high-power LEDs, vertical structure LEDs and flip-chip LED structures have emerged. The vertical structure LED uses laser lift...

AI Technical Summary

Problems solved by technology

Since the thermal conductivity of the eutectic alloy of 20% Au-80% Sn is only 53W / m.k, with 1mm 2 The area of ​​the connection layer is calculated, the thermal resistance is as high as 0.5°C / W, and the insulating layer is SiO 2 The thermal conductivity is 1.1W / m.K, the thickness is 0.2 microns, and the thermal resistance is 0.2°C / W. In addition to the thermal resistance of the fast heat conduction plate and the thermal resistance of the interface between layers, the current flip-chip process cannot meet the high-power requirements. Efficient heat dissipation requirements for LEDs

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