A method for cutting a silicon-based OLED micro display device

Abstract

The application discloses a kind of silicon-based OLED micro display device cutting methods, first wafer and glass cover plate are aligned and attached in vacuum chamber again UV heat curing;Then paste UV film on the back of wafer;After that, choose grinding wheel cutting, and the glass cover plate bonding area is half-cut;Another UV film is pasted in bonding area, and the UV film on the bonding area is removed, and the glass debris adhered thereon is removed;Finally, the glass cover plate and wafer are fully cut, the application adopts the mode of grinding wheel cutting, and the bonding area glass is removed first, and then the cover plate glass and wafer are fully cut, which can effectively reduce the glass edge collapse caused by extrusion of the bonding area glass during cutting process;During the whole cutting operation process, the glass cover plate and wafer do not need to be cracked, and the risk of pad pressure injury and scratch caused by glass cracking is avoided, the product yield is improved, and the reliability of the product is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro display device processing, and particularly relates to a silicon-based OLED micro display device cutting method. BACKGROUND

[0002] At present, a silicon-based OLED micro display device on the market has a silicon wafer with a thickness of about 725 um as a substrate, and a glass cover plate with a thickness of about 500 um for protecting a display area. A mainstream 12-inch / 8-inch silicon-based OLED micro display production line adopts a large piece bonding mode, that is, a 12-inch / 8-inch silicon wafer and a 12-inch / 8-inch glass cover plate are bonded in a vacuum environment after alignment, and then the bonded wafer and the glass are cut and diced respectively, and finally segmented into small pieces Die. The bonding mode has the advantages of high bonding efficiency and high yield, and meets the requirements of mass production, but the bonding area on the wafer is covered by the glass, and the bonding process such as Wire Bonding or PFC Bonding needs to be removed by cutting.

[0003] In the conventional cutting process, the glass cover plate is cut by a knife wheel, and then the glass is diced, and the glass edge collapse is large, generally greater than or equal to 100 um, and the dust generated in the glass cutting process is not easy to clean, which affects the appearance yield. In addition, in the dicing process, the glass of the bonding area will be extruded to cause pad bruising and scratching risk, which leads to the risk of short circuit or open circuit of the bonding, and affects the reliability of the final product. SUMMARY

[0004] The present application aims to provide a silicon-based OLED micro display device cutting method to solve the problems in the background art.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions.

[0006] A silicon-based OLED micro display device cutting method comprises the following steps:

[0007] Step 1: after the silicon wafer containing OLED and CMOS and the glass cover plate after cleaning and drying are bonded in a vacuum chamber after alignment, UV heat curing is performed;

[0008] Step 2: a UV film is attached to the back of the cured wafer;

[0009] Step 3: a grinding wheel is selected to perform a half-cut on the bonding area of the glass cover plate;

[0010] Step 4: another UV film is attached to the bonding area, so that the glass debris at the half-cut position is attached to the UV film;

[0011] Step five: Uncover the UV film on the bonding area, take off the glass debris adhered thereon, and clean the half-cut position of the bonding area;

[0012] Step six: Perform full cutting operation on the glass cover plate and the wafer to obtain independent chip particles;

[0013] Step seven: Perform UV irradiation on the UV film to reduce the adhesion, then perform film expansion and sorting to obtain the required single chip.

[0014] As a further scheme of the present application, in step three, when the glass in the bonding area is half-cut, first cut the glass cover plate at position one without cutting through, and reserve a height of 5-15 um, and then cut the glass cover plate at position two through the silicon layer by about 5 um.

[0015] As a further scheme of the present application, in step five, when the UV film on the bonding area is uncovered, the included angle between the UV film and the plane of the glass cover plate is less than 45 degrees.

[0016] As a further scheme of the present application, in step six, when the glass cover plate and the wafer are subjected to full cutting operation, first cut the glass cover plate into a grid shape by a cover plate cutting device, and then cut the wafer through the grid slot by a wafer cutting device to obtain independent chip particles.

[0017] As a further scheme of the present application, in the cutting operation of step six, pure water is continuously supplied from an external water supply device to flush the surface of the glass cover plate to remove the cutting debris in real time.

[0018] Compared with the prior art, the present application has the following beneficial effects: the present application provides a silicon-based OLED micro display device cutting method to solve the problems of the prior art, and adopts the sand wheel cutting mode to first cut and remove the bonding area glass, and then perform full cutting on the cover plate glass and the wafer, which can effectively reduce the glass edge collapse caused by the extrusion of the bonding area glass during the cutting process.

[0019] During the whole cutting operation, the glass cover plate and the wafer do not need to be subjected to the splitting operation, which avoids the risk of pad bruising and scratching of the bonding area caused by glass splitting, improves the product yield, and increases the reliability of the product; during the cutting process, the surface of the glass is flushed with pure water, which can effectively remove the glass debris and dust, avoid the interference of the glass debris and dust on the cutting operation, and also avoid the possible scratching of the glass cover plate or the wafer caused by the glass debris and dust. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The method flowchart of the present application is shown in the figure;

[0021] Figure 2 The schematic diagram of the state of the glass cover plate and the wafer after UV curing of the present application;

[0022] Figure 3 The schematic diagram of the state of the bonding area after half cutting of the present application;

[0023] Figure 4 The schematic diagram of the state of the glass cover plate and the wafer during full cutting operation of the present application.

[0024] In the figure: 1, glass cover plate; 2, wafer; 3, half cutting groove; 4, grid groove. Embodiment

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0026] Please refer to Figures 1-4 In the embodiments of the present application, a silicon-based OLED micro display device cutting method is provided. First, a wafer 2 containing OLED and CMOS which is thin film packaged is cleaned and dried, and a glass cover plate 1 is cleaned and dried. After alignment and lamination in a vacuum chamber, UV curing is performed. A UV film is attached to the back of the cured wafer 2.

[0027] A cover plate cutting device using a grinding wheel cutting is selected to perform half cutting on the bonding area of the glass cover plate 1. During half cutting, first, the position 1 of the glass cover plate 1 is cut, but not cut through, leaving a height of 5-15 um. Then, the position 2 of the glass cover plate 1 is cut through, cutting into the silicon layer by about 5 um. The position 1 is close to the AA display area, and the position 2 refers to the area close to the cutting path. By using twice cutting, a half cutting groove 3 is cut out in the bonding area, which facilitates the pre-removal of the glass in the bonding area, preventing the glass in the bonding area from being pressed and broken during the subsequent cutting process.

[0028] Another UV film is attached to the bonding area, so that the glass debris at the half cutting position is adhered to the UV film. The UV film on the bonding area is removed, taking the glass debris adhered thereto, so as to realize the cleaning of the half cutting position of the bonding area. In this embodiment, the UV film is attached to the bonding area for adhering and removing the debris generated during the half cutting operation. In specific implementation, a vacuum suction device connected externally can also be used to remove the debris generated during the half cutting operation by using a vacuum suction nozzle.

[0029] When the UV film on the bonding area is peeled off, the angle between the UV film and the plane of the glass cover plate 1 is less than 45 degrees, so that the film peeling operation is more labor-saving, the deformation of the UV film when the film is peeled off is reduced, the glass debris can be stably adhered to the UV film, and the removal effect is ensured;

[0030] After the film peeling is completed, the pure water is continuously supplied from the external water supply device to flush the surface of the glass cover plate 1, and the full cutting operation is performed on the glass cover plate 1 and the wafer 2. First, the cover plate cutting device cuts the grid groove 4 on the glass cover plate 1 to divide the glass cover plate 1 into a grid shape, and then the wafer 2 cutting device cuts the wafer 2 through the grid groove 4 to cut the wafer 2 into a grid shape to obtain independent chip particles. The above-mentioned cover plate cutting device and wafer 2 cutting device are implemented by the prior art means. Since the materials of the glass cover plate 1 and the wafer 2 are different, different cutting devices need to be used for cutting operation. If the same cutting device can meet the cutting needs of the two materials during specific implementation, two cutting devices are not needed. After the cutting is completed, the UV film is irradiated by UV to reduce its adhesion, and then the film is expanded and sorted to obtain the required single chip.

[0031] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above-mentioned disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any simple modification, equivalent change and modification of the above-mentioned embodiments made according to the technical essence of the present application still belong to the scope of the technical solution of the present application.

Claims

1. A method for cutting a silicon-based OLED microdisplay device, characterized in that, Includes the following steps: Step 1: Align and bond the wafer (2) and the glass cover plate (1) in a vacuum chamber, and then perform UV thermal curing; Step 2: Apply a UV film to the back of the cured wafer (2); Step 3: Use a grinding wheel to cut the bonding area of ​​the glass cover (1) in half. When cutting the bonding area of ​​the glass in half, first cut the first position of the glass cover (1) without cutting through, leaving a height of 5-15um; then cut the second position of the glass cover (1) through, cutting into the silicon layer by 5um. Step 4: Take another UV film and stick it to the bonding area so that the glass shards at the half-cut position adhere to the UV film; Step 5: Peel off the UV film on the bonding area, removing any glass shards adhering to it, thus cleaning the half-cut area of ​​the bonding area; Step 6: Perform a full dicing operation on the glass cover (1) and the wafer (2) to obtain independent chip particles.

2. The method for cutting a silicon-based OLED microdisplay device according to claim 1, characterized in that, In step five, when the UV film on the bonding area is peeled off, the angle between the UV film and the plane of the glass cover plate (1) is less than 45 degrees.

3. The method for cutting a silicon-based OLED microdisplay device according to claim 1, characterized in that, In step six, when performing a full dicing operation on the glass cover plate (1) and the wafer (2), the cover plate dicing equipment first cuts out a grid groove (4) in the glass cover plate (1) to divide the glass cover plate (1) into a grid shape. Then, the wafer (2) dicing equipment passes through the grid groove (4) to cut the wafer (2) into a grid shape, thus obtaining independent chip particles.

4. The method for cutting a silicon-based OLED microdisplay device according to claim 1, characterized in that, In step one, the wafer (2) is a silicon wafer (2) containing OLED and CMOS that has been thin-film packaged, and the glass cover (1) is cleaned and dried before alignment and bonding.

5. The method for cutting a silicon-based OLED microdisplay device according to claim 1, characterized in that, During the cutting operation in step six, the surface of the glass cover plate (1) is rinsed with pure water.

Images