CN-122002993-A - Manufacturing method of driving substrate, driving substrate and manufacturing method of LED chip assembly

Abstract

The application relates to a driving substrate manufacturing method, a driving substrate and an LED chip assembly manufacturing method. The manufacturing method of the driving substrate comprises the steps of providing a driving substrate, evaporating a sacrificial layer on the back surface of the driving substrate, patterning the sacrificial layer to form a plurality of grooves, and evaporating a metal layer in the grooves, wherein the thermal expansion coefficient of the metal layer is larger than that of the sapphire substrate. According to the application, the sacrificial layer is firstly evaporated on the back surface of the driving substrate, then patterning is carried out, and then the metal layer is evaporated in the groove formed by patterning, so that the sapphire substrate is epitaxially bonded on the driving substrate, and a compressive stress can be generated by using the metal layer, so that the tensile stress of the silicon-based CMOS in the bonding process is reduced, the risk of chapping is reduced, and the wafer bonding yield is improved.

Inventors

• ZHOU XIUHENG
• ZHAO YONGZHOU
• XU LIANGYU
• MA FEIFAN
• WANG XIBIN

Assignees

• 重庆康佳光电科技有限公司

Dates

Publication Date

20260508

Application Date

20241101

Claims (9)

1. 1. A method of manufacturing a drive substrate, comprising: providing a driving substrate; evaporating a sacrificial layer on the back surface of the driving substrate; patterning the sacrificial layer to form a plurality of grooves; And evaporating a metal layer in the groove, wherein the thermal expansion coefficient of the metal layer is larger than that of the sapphire substrate.
2. 2. The method of claim 1, wherein the metal layer comprises one or more of Ti, al, cu, cr, ag, zn, au.
3. 3. The method of claim 1, further comprising, after said depositing a metal layer in said recess: And polishing the metal layer.
4. 4. The method of claim 1, further comprising, after said depositing a metal layer in said recess: and evaporating a metal bonding layer on the front surface of the driving substrate.
5. 5. The method of claim 1, wherein the sacrificial layer is made of SiO 2 、SiN X or a glue.
6. 6. The method of manufacturing a drive substrate according to any one of claims 1 to 5, wherein patterning the sacrificial layer to form a plurality of grooves includes: The sacrificial layer is patterned to form a plurality of annular grooves on the sacrificial layer.
7. 7. A method of fabricating an LED chip assembly, the method comprising: providing a driving substrate manufactured by the driving substrate manufacturing method according to any one of claims 1 to 6; Providing an epitaxial wafer, wherein the epitaxial wafer comprises a substrate and an epitaxial layer grown on the substrate; Evaporating a one-bond metal layer on the epitaxial layer; And carrying out gold bonding on the bonding metal layer and the metal bonding layer so as to bond the epitaxial wafer to the driving substrate.
8. 8. The LED chip assembly manufacturing method of claim 7, further comprising: and removing the sacrificial layer.
9. 9. A drive substrate, characterized by comprising: driving the substrate body; The sacrificial layer is arranged on the back surface of the driving substrate body; A plurality of grooves are formed in the sacrificial layer; The grooves are used for filling metal materials, and the thermal expansion coefficient of the metal materials is larger than that of the sapphire substrate.

Description

Manufacturing method of driving substrate, driving substrate and manufacturing method of LED chip assembly Technical Field The invention relates to the technical field of LED chips, in particular to a manufacturing method of a driving substrate, a driving substrate and a manufacturing method of an LED chip assembly. Background In the Micro-LED near-to-eye display field, it is generally required to heterointegrate a sapphire-based GaN epitaxial wafer with a silicon-based CMOS drive back plate, and then manufacture a wafer to obtain a Micro display device. However, in wafer bonding, since the CMOS driving back plate is silicon-based and the sapphire substrate is the main substrate, the sapphire substrate and the silicon substrate have a difference in thermal expansion coefficient during the temperature raising and lowering process of bonding, so that a larger stress is generated during the bonding process, thereby causing the silicon-based CMOS back plate to be pulled apart and reducing the yield of the product. Disclosure of Invention In view of the above-mentioned shortcomings of the prior art, the present application is directed to a method for manufacturing a driving substrate, a driving substrate and a method for manufacturing an LED chip assembly, which are aimed at solving the problem of low product yield caused by cracking of a silicon-based CMOS back plate in wafer bonding. In a first aspect, the present application provides a method for manufacturing a driving substrate, including: providing a driving substrate; evaporating a sacrificial layer on the back surface of the driving substrate; patterning the sacrificial layer to form a plurality of grooves; And evaporating a metal layer in the groove, wherein the thermal expansion coefficient of the metal layer is larger than that of the sapphire substrate. In one possible embodiment, the material of the metal layer includes one or more of Ti, al, cu, cr, ag, zn, au. In a possible embodiment, after said evaporating a metal layer in said recess, said method further comprises: And polishing the metal layer. In a possible embodiment, after said evaporating a metal layer in said recess, said method further comprises: and evaporating a metal bonding layer on the front surface of the driving substrate. In a possible embodiment, the material of the sacrificial layer is SiO 2、SiNX or a glue. In one possible embodiment, the patterning the sacrificial layer to form a plurality of recesses includes: The sacrificial layer is patterned to form a plurality of annular grooves on the sacrificial layer. In a second aspect, the present application further provides a method for manufacturing an LED chip assembly, the method comprising: providing a driving substrate manufactured by the driving substrate manufacturing method according to any one of the first aspect; Providing an epitaxial wafer, wherein the epitaxial wafer comprises a substrate and an epitaxial layer grown on the substrate; Evaporating a one-bond metal layer on the epitaxial layer; And carrying out gold bonding on the bonding metal layer and the metal bonding layer so as to bond the epitaxial wafer to the driving substrate. In a possible embodiment, the method further comprises: and removing the sacrificial layer. In a third aspect, the present application also provides a driving substrate, including: driving the substrate body; The sacrificial layer is arranged on the back surface of the driving substrate body; A plurality of grooves are formed in the sacrificial layer; The grooves are used for filling metal materials, and the thermal expansion coefficient of the metal materials is larger than that of the sapphire substrate. The beneficial effects are that: According to the manufacturing method of the driving substrate, the driving substrate and the manufacturing method of the LED chip assembly, the sacrificial layer is firstly evaporated on the back surface of the driving substrate, then patterning is carried out, and then the metal layer is evaporated in the groove formed by patterning, so that when the sapphire substrate is epitaxially bonded to the driving substrate, a compressive stress can be generated by the metal layer, the tensile stress of the silicon-based CMOS in the bonding process is reduced, the risk of chapping is reduced, and the wafer bonding yield is improved. Drawings FIG. 1 is a schematic diagram showing a conventional wafer bonding process; FIG. 2 is a schematic diagram showing the occurrence of cracks in the CMOS after wafer bonding shown in FIG. 1; FIG. 3 is a schematic flow chart of a method for manufacturing a driving substrate according to an embodiment of the present application; Fig. 4 is a schematic diagram of a process for evaporating a sacrificial layer in a method for manufacturing a driving substrate according to an embodiment of the present application; FIG. 5 is a schematic diagram illustrating a process of forming a recess in a sacrificial layer in a method for fabricati