Manufacturing method of micro display device

Abstract

According to the manufacturing method of the micro-display device provided by the invention, the positive or negative three-dimensional structures are prepared on a pair of wafers to be bonded respectively, the two wafers are pre-bonded under the action of alignment and pressure, and the pre-bonding process is carried out at normal temperature, so that the temperature influence is avoided, and even if a pair of heterogeneous wafers is bonded, the yield of the wafers is greatly improved. The metal plug and the metal pad are bonded by using a heating furnace after pre-bonding, and displacement caused by different thermal expansion coefficients is avoided, the sapphire substrate of the LED is peeled off by using laser after pre-bonding, and finally, the metal plug and the metal pad are bonded by using the heating furnace for heating and bonding.

Description

technical field [0001] The invention belongs to the technical field of semiconductor microdisplays, in particular to a method for manufacturing a microdisplay device. Background technique [0002] Micro-Led is the latest generation of display technology. On the road of industrialization and commercialization of Micro-Led, there are still many technical problems that need in-depth research. Among them, the difficulty in the process of combining the Micro-Led light-emitting chip and the driver chip is the main problem hindering its commercialization. Existing technical solutions include Stamp mass transfer, laser transfer, electrostatic transfer, electromagnetic transfer, fluid self-assembly, etc. However, the above-mentioned technical solutions all have the problems of low single-step yield and long time. Small-sized head-mounted AR / VR requires a small display (about ≤0.5 inches), so the wafer-to-wafer solution has the advantages of high yield and short time. However, the ...

AI Technical Summary

Problems solved by technology

However, the traditional wafer-to-wafer planar bonding process has the problem of high requirements on the bonding interface, and the following conditions must be met at the same time: homogeneous bonding (heterogeneous bonding is more likely to cause bonding dislocation or bonding cracks due to different thermal expansion coefficients) defects), the size of the two bonded wafers is the same, CMP Disting≤150 (Dish depth) or ≤50 , and roughness Rq≤0.5nm, etc.

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