CN114927458A

CN114927458A - Chip transfer method, Micro-LED display device and manufacturing method

Info

Publication number: CN114927458A
Application number: CN202210588481.7A
Authority: CN
Inventors: 郭婵; 龚政; 潘章旭; 李育智; 邹胜晗; 王建太; 陈志涛
Original assignee: Institute of Semiconductors of Guangdong Academy of Sciences
Current assignee: Institute of Semiconductors of Guangdong Academy of Sciences
Priority date: 2022-05-26
Filing date: 2022-05-26
Publication date: 2022-08-19

Abstract

The application provides a chip transfer method, a Micro-LED display device and a manufacturing method, wherein an adhesive tape is attached to an original substrate with a chip under the action of pressure, the adhesive tape and the chip are peeled off from the original substrate together, the adhesive tape with the chip is attached to a provided glass substrate under the action of pressure to remove air, the viscosity of the adhesive tape is weakened by adopting ultraviolet light irradiation, and finally the adhesive tape with the weakened viscosity of the chip is attached to a target substrate to transfer the chip to the target substrate. According to the scheme, the viscosity of the adhesive tape is weakened based on an ultraviolet irradiation mode, and temporary glass substrates are introduced during viscosity reduction, so that the adhesive tape is quickly subjected to viscosity reduction in an oxygen-discharging environment, the process time is shortened, the process cost is reduced, and the transfer yield and the transfer accuracy are improved.

Description

Chip transfer method, Micro-LED display device and manufacturing method

Technical Field

The invention relates to the technical field of semiconductor manufacturing, in particular to a chip transfer method, a Micro-LED display device and a manufacturing method.

Background

In the Micro-LED display field, a large number of Micro LED chips manufactured on a wafer need to be transferred to a circuit substrate by using a transfer technology, and are further packaged together with other chips. The transfer of the yield, precision, speed and programmable micro LED chips is the core of reducing the production cost.

In the prior art, the technology mainly comprises a PDMS stamp, fluid self-assembly, electrostatic force assembly, magnetic adsorption, roller transfer printing and the like. The existing process for weakening the viscosity of the transfer adhesive tape mainly adopts the treatment of heating, cooling and the like on the hot adhesive tape, and the process needs long time, thus leading to the increase of the cost. And the thermal adhesive tape is subjected to viscosity reduction based on a thermal foaming principle, the volume expansion of foaming adhesive in the viscosity reduction process easily causes chip displacement, and the temperature also easily causes thermal deformation of the substrate, so that the problems of transfer precision are solved.

In addition, there is also the light through predetermineeing the wavelength to shine to the transfer base plate for the viscidity of transfer base plate changes, realizes picking up and placing the chip, like the UV tape. Commercial UV tapes have been widely used in the semiconductor field for wafer trimming, but efficient bulk and programmable transfer of micro semiconductor devices on the scale of a few microns (3 μm-100 μm) has been rarely reported. Particularly, the problems of chip displacement, low yield, difficulty in selective transfer, low selective precision and the like of a device with the scale of several micrometers are solved.

Disclosure of Invention

Objects of the present invention include, for example, providing a chip transfer method, a Micro-LED display device and a method of manufacturing the same, which enable fast, high-precision and high-yield transfer of chips.

Embodiments of the invention may be implemented as follows:

in a first aspect, the present invention provides a chip transfer method, comprising:

providing an original substrate, wherein the original substrate is provided with a plurality of chips to be transferred in array arrangement;

attaching an adhesive tape to the original substrate and the chip under the action of pressure;

peeling the tape and the chip from the original substrate;

attaching the adhesive tape with the chips to a provided glass substrate under the action of pressure so as to remove air, weakening the viscosity of the adhesive tape by adopting ultraviolet light irradiation, and attaching the adhesive tape with the chips with weaker viscosity to a target substrate so as to transfer the chips to the target substrate.

In an alternative embodiment, the step of attaching the adhesive tape with the chip to a glass substrate provided to remove air, weakening the adhesiveness of the adhesive tape by ultraviolet light irradiation, and attaching the adhesive tape with the chip weakened in adhesiveness to a target substrate to transfer the chip to the target substrate includes:

attaching the adhesive tape with the chips to a provided glass substrate to remove air, and irradiating the chips by using an optical photomask and ultraviolet light to obtain the chips of an exposure area and the chips of a non-exposure area, wherein the height of the chips of the exposure area is lower than that of the chips of the non-exposure area;

and sequentially transferring the chips of the non-exposure area to a first target substrate and transferring the chips of the exposure area to a second target substrate by using an adhesive tape.

In an alternative embodiment, the step of transferring the chips in the non-exposure region onto the first target substrate and the chips in the exposure region onto the second target substrate in sequence by using the adhesive tape includes:

attaching the adhesive tape with all the chips to a first target substrate under the action of pressure so as to transfer the chips in a non-exposure area to the first target substrate;

peeling the adhesive tape with the chip in the exposure area from the first target substrate, attaching the adhesive tape to a glass substrate, and irradiating by adopting ultraviolet light until the adhesive tape is completely de-adhered;

and attaching the adhesive tape of the chip with the exposure area after complete viscosity reduction to a second target substrate so as to transfer the chip with the exposure area to the second target substrate.

In an alternative embodiment, the target substrate has an adhesion layer on the side to which the chip is attached.

In an alternative embodiment, the step of attaching the tape to the original substrate and the chip under pressure comprises:

applying pressure to the tape and the original substrate in a vertical direction;

and utilizing a vacuumizing device to suck air between the adhesive tape and the original substrate so as to attach the adhesive tape to the original substrate.

and (4) sequentially and uniformly pressing the adhesive tape by using roller equipment so as to ensure that the adhesive tape and the original substrate are attached in a bubble-free state.

In an alternative embodiment, before the step of attaching the tape to the original substrate and the chip under pressure, the method further comprises:

and soaking the original substrate with the chip into an etching solution to form a weak bonding force between the chip and the original substrate.

In an alternative embodiment, the irradiation wavelength of the ultraviolet light is 320nm to 400 nm.

In a second aspect, the invention provides a method for manufacturing a Micro-LED display device, which includes chip transfer and chip array manufacturing, wherein the chip transfer method described in any of the foregoing embodiments is adopted for chip transfer.

In a third aspect, the invention provides a Micro-LED display device, which is manufactured and formed by the method for manufacturing a Micro-LED display device according to the foregoing embodiment.

The beneficial effects of the embodiment of the invention include, for example:

the application provides a chip transfer method, a Micro-LED display device and a manufacturing method, in the chip transfer method, an adhesive tape is attached to an original substrate with a chip under the action of pressure, the adhesive tape and the chip are peeled off from the original substrate together, the adhesive tape with the chip is attached to a provided glass substrate under the action of pressure so as to remove air, the viscosity of the adhesive tape is weakened by adopting ultraviolet light irradiation, and finally the adhesive tape with the chip with the weakened viscosity is attached to a target substrate so as to transfer the chip to the target substrate. According to the scheme, the viscosity of the adhesive tape is weakened based on an ultraviolet irradiation mode, and temporary glass substrates are introduced during viscosity reduction, so that the adhesive tape is quickly subjected to viscosity reduction in an oxygen-discharging environment, the process time is shortened, the process cost is reduced, and the transfer yield and the transfer accuracy are improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a flowchart of a chip transfer method provided in an embodiment of the present application;

fig. 2(a) to fig. 2(h) are schematic diagrams of various steps in a full-area transferring method provided in an embodiment of the present application;

fig. 3(a) to 3(f) are schematic diagrams illustrating steps of forming a weak bonding force between the Au thin film chip and the original substrate in the embodiment of the present application;

FIGS. 4(a) to 4(g) are schematic diagrams illustrating steps of forming a weak bonding force between a processed chip and an original substrate according to an embodiment of the present application;

fig. 5(a) to fig. 5(j) are schematic diagrams illustrating steps of a selective transfer method according to an embodiment of the present application;

FIG. 6 is a schematic diagram of an optical mask and a chip array after transfer according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of a height curve of a chip in an exposed region and an unexposed region according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of an optical mask used in an embodiment of the present application;

FIG. 9 is a schematic view of another optical mask according to an embodiment of the present disclosure.

Icon: 10-original substrate; 20-chip; 30-adhesive tape; 40-a glass substrate; 50-a target substrate; 51-a first target substrate; 52-second target substrate.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that, if the terms "upper", "lower", "inner", "outer", etc. are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship which the product of the present invention is used to usually place, it is only for convenience of description and simplification of the description, but it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

Furthermore, the appearances of the terms "first," "second," and the like, if any, are only used to distinguish one description from another and are not to be construed as indicating or implying relative importance.

It should be noted that the features of the embodiments of the present invention may be combined with each other without conflict.

The embodiment of the application provides a microchip transfer method which can be used for solving the problems that the existing transfer method is long in process time, difficult to give consideration to cost and yield, high in selective transfer difficulty, low in selective transfer precision and the like. Referring to fig. 1 in conjunction with fig. 2(a) to fig. 2(h), the specific steps of the chip transfer method provided in the embodiment of the present application are described in detail below.

S101, please refer to fig. 2(a), an original substrate 10 is provided, wherein the original substrate 10 has a plurality of chips 20 to be transferred arranged in an array.

In this embodiment, the chip 20 to be transferred may be an interconnection electrode made of an Au thin film, or other functional elements based on the material system. That is, the transfer method provided by the embodiment may be used to transfer the interconnection line. When the chips 20 on the original substrate 10 are an array of Au thin films, the Au thin films may have different shapes, different sizes, and different distances from each other.

Further, the chip 20 to be transferred may also be a chip 20 such as a LED, or the like formed based on a material system such as GaN, GaAs, or the like. That is, the transfer method provided by this embodiment can transfer the uLED array manufactured through the semiconductor process.

In this embodiment, the original substrate 10 can be, for example, Si, SiO ₂ Etc. of the substrate.

In order to facilitate the subsequent transfer of the chip 20 on the original substrate 10, in this embodiment, before the chip 20 is peeled off from the original substrate 10, the transfer method provided by this embodiment further includes the following steps:

the original substrate 10 with the chip 20 is soaked in an etching solution to form a weak bonding force between the chip 20 and the original substrate 10.

In this embodiment, the adopted etching solution and the process method are different for different application scenarios.

For example, when the weakening structure is formed on the Au thin film, in this embodiment, the etching solution used may be the buffered oxide etching solution BOE, or may be diluted. After etching the original substrate 10 and the chip 20 by using the diluted BOE, a weak bonding force may be formed between the chip 20 and the original substrate 10, so that the chip 20 may be subsequently and smoothly peeled off from the original substrate 10.

In this embodiment, the chip 20, such as an Au thin film array, may be fabricated on the original substrate 10 by a photolithography process, and after the fabrication, the original substrate 10 and the chip 20 are put into a diluted BOE solution together. Referring to fig. 3(a) to 3(f), first, referring to fig. 3(a), in the present embodiment, the original substrate 10 is Si + SiO ₂ For example, first, SiO may be deposited on a Si substrate ₂ 。

Referring to FIG. 3(b), it can be found in SiO ₂ A photoresist is coated, for example, AZ2035 may be coated. Further, as shown in FIG. 3(c), the photoresist is partially exposed and developed to expose a portion of SiO ₂ . As shown in FIG. 3(d), on the exposed SiO ₂ And depositing an Au thin film on the photoresist, for example, the thickness of the Au thin film may be 40nm to 250 nm. Referring to fig. 3(e), the photoresist layer may be removed by a developing solution, and the Au thin film on the photoresist layer is also removed. Finally, as shown in fig. 3(f), the original substrate 10 and the remaining Au thin film are soaked with a diluted BOE solution, which is applied to SiO below the Au thin film ₂ Partial etching is performed so that a weak bonding force is formed between the Au thin film and the Si substrate, so that the Au thin film can be subsequently smoothly peeled off from the substrate.

In addition, when aiming at the iled array of the Si-based GaN material system, the etching solution utilized can be TMAH or KOH.

Referring to fig. 4(a) to 4(g), for a iled array of Si-based GaN material system, first, as shown in fig. 4(a), an epitaxial layer may be formed on a Si substrate, wherein the epitaxial layer includes a buffer layer, an N-GaN layer, a multi-quantum well layer and a P-GaN layer. Wherein, the thickness of the Si substrate can be 800um, the thickness of the buffer layer can be 1.5um, the thickness of the N-GaN layer can be 1.6um, and the thickness of the P-GaN layer can be 150 nm. It is to be understood that the thickness of each layer is merely illustrated here, and is not limited thereto. On this basis, as shown in fig. 4(b) and 4(c), the epitaxial layers may be etched respectively to obtain a first groove and a second groove. Wherein the first groove extends to the N-GaN layer, and the second groove extends to the Si substrate (500nm-1 um).

As shown in fig. 4(d), a SiO2 passivation layer is deposited on the surface of the P-GaN layer and in the first groove. Then to SiO ₂ The passivation layer is partially etched to form a metal electrode contact hole, as shown in fig. 4 (e). As shown in fig. 4(f), metal is deposited within the contact hole. Finally, as shown in fig. 4(g), Si is anisotropically etched using an etching solution such as TMAH or KOH, thereby forming a weak bonding force.

S102, referring to fig. 2(b), the tape 30 is attached to the original substrate 10 and the chip 20 under pressure.

In this embodiment, the adhesive tape 30 may be a uv adhesive tape 30, and the adhesive tape 30 is attached to the original substrate 10 and the chip 20, so that the adhesive tape 30 can adhere to the chip 20 to be transferred.

In order to make the adhesive tape 30 perfectly fit to the chip 20 to be transferred, in one possible implementation, the following may be implemented:

the tape 30 and the original substrate 10 are pressed in a vertical direction, and air between the tape 30 and the original substrate 10 is evacuated by a vacuum evacuation device to attach the tape 30 to the original substrate 10.

In this embodiment, the tape 30 can be perfectly attached to the original substrate 10 by combining the vertical pressure application and the vacuum pumping.

In addition, in another possible embodiment, the attachment of the tape 30 to the original substrate 10 may also be achieved by:

the tape 30 is sequentially and uniformly pressed by a roller device so that the tape 30 and the original substrate 10 are attached in a bubble-free state.

S103, referring to fig. 2(c), the tape 30 and the chip 20 are peeled off from the original substrate 10.

The tape 30 adheres well to the chip 20 with the tape 30 adhering well to the original substrate 10. At this time, the tape 30 on the original substrate 10 is peeled off, and the chips 20 attached to the tape 30 are peeled off from the original substrate 10.

S104, referring to fig. 2(d) to 2(h), the adhesive tape 30 with the chip 20 is attached to the provided glass substrate 40 under pressure to remove air, the adhesive tape 30 is weakened by ultraviolet light irradiation, the adhesive tape 30 with the chip 20 weakened in adhesiveness is attached to the target substrate 50, and the chip 20 is transferred to the target substrate 50.

In the present embodiment, a glass substrate 40 is provided as a temporary substrate, and after the chip 20 is peeled off from the original substrate 10 by the tape 30, the tape 30 with the chip 20 is attached to the glass substrate 40, as shown in fig. 2 (d). A force may be applied to the tape 30 on the glass substrate 40 to make the tape 30 adhere well to the glass substrate 40. On the basis, the adhesive tape 30 can be irradiated by ultraviolet light, the wavelength of the ultraviolet light can be 320nm to 400nm, and the output power can be 20mw/cm ² . Under the irradiation of ultraviolet light, the adhesive tape 30 can be made to be detackified.

The glass substrate 40 as a temporary substrate can eliminate the oxygen environment, so that the adhesive tape 30 can be quickly de-adhered in the oxygen environment, the process time is shortened, and the process cost is reduced.

Referring to fig. 2(e), the adhesive tape 30 after the de-bonding is peeled off from the glass substrate 40, and the chip 20 is peeled off from the glass substrate 40. As shown in fig. 2(f), the removed tape 30 is attached to a target substrate 50, wherein the target substrate 50 may be a hard, transparent or flexible substrate such as glass, Si, mica, PET, PO, etc.

The target substrate 50 has an adhesive layer on its side attached to the chip 20, such as an adhesive layer on a UV PET tape, Su 82002/2005, PDMS, TPU, etc. Under the action of the adhesion layer, when the tape 30 is peeled off from the target substrate 50, the chip 20 will be attached to the target substrate 50, as shown in fig. 2 (g). Thus, the chip 20 is finally transferred onto the target substrate 50, as shown in fig. 2 (h).

In this embodiment, the entire array of chips 20 can be transferred in the above manner, and all chips 20 on the original substrate 10 can be transferred to the target substrate 50 at once. Wherein, by providing a glass substrate 40 as a temporary substrate, an oxygen-excluding environment can be provided, and in combination with irradiation of ultraviolet light, the adhesive tape 30 can be quickly detackified, thereby shortening the time required for transfer, reducing the cost, and also improving the transfer yield and accuracy.

In this embodiment, the above-mentioned whole area transfer method will be further described below by referring to two specific embodiments.

The first embodiment is as follows: and 4inch wafer level transfer is realized.

Firstly, the photoetching process is combined to the Si + SiO of 4inch ₂ An Au thin film array was fabricated on the substrate and etched in dilute BOE solution to form a weak binding force. The thickness, length and width of the Au thin film are 250nm 110um 120um respectively, and the dot spacing between the two Au chip centers can be 110 um.

The uv tape 30 is uniformly pressed to adhere the chip and the substrate to be transferred, and a roller tool, for example, in combination with a vacuum device, can be used to apply force and draw air, so as to generate air bubbles between the tape 30 and the substrate.

The adhesive tape 30 is peeled off, and the Au thin film chip is peeled off from the substrate. Then uniformly applying pressure to attach the adhesive tape 30 with the Au thin film chip to the clean glass substrate 40 at 365nm and 20mw/cm ² Is exposed to ultraviolet light for a time period of 3 seconds or more, thereby detackifying the tape 30.

Separating the adhesive tape 30 after the viscosity reduction from the glass substrate 40, uniformly applying pressure to perfectly attach the adhesive tape 30 to the final substrate, and using a roller device in combination with a vacuum-pumping device to make no bubble exist between the adhesive tape 30 and the final substrate. The final substrate may be a rigid, transparent or flexible substrate with an adhesion layer such as glass, Si, mica, PET, PO, etc. And the adhesion layer can be an adhesion layer on the UV PET adhesive tape.

The de-adhered tape 30 is finally peeled off and the Au thin film chip array is transferred to the final substrate in its entirety.

The second embodiment: a blue light array of iled.

Firstly, an uled blue light array with weak bonding force to be transferred is manufactured, wherein, a Si <111> -GaN substrate is adopted, the size of a single uled is 50um by 80um, the dot spacing of the center of the uled is 150um, and the number of the uled in the array can be 50 by 50.

The uv tape 30 is completely attached to the Si substrate, and a roller device may be used in combination with a vacuum apparatus, so that no bubbles are attached between the tape 30 and the substrate.

The tape 30 is removed and the uled array is peeled off from the original substrate.

The tape 30 with the uled array was attached to a clean glass substrate 40 at 365nm, 20mw/cm ² Is exposed for 3 seconds or more to rapidly detackify the tape 30.

The adhesive tape 30 after the viscosity reduction is attached to the final substrate, and a roller device and a vacuum-pumping device can be adopted, so that no bubble is attached between the adhesive tape 30 and the final substrate. The final substrate may be clear glass with an adhesion layer, which may be su8-2002, and may be 2um thick.

The tape 30 is peeled off the final substrate and the uled array will be transferred to the final substrate. In this embodiment, the electrical properties of the uled array before and after transfer do not decay, and the surface of the uled array is clean and free of impurities.

While the entire transfer of the chip 20 is described above, in the present embodiment, selective transfer of the chip 20 can be realized. The method of selective transfer will be described in detail below.

In the prior art, if high-precision selective chip transfer is to be realized, laser selective irradiation is usually adopted in combination with a laser stripping device, and the method greatly increases the process cost.

In this embodiment, when the chip 20 is selectively transferable, the following operations are performed, please refer to fig. 5(a) to 5 (j):

first, similarly, as shown in fig. 5(a) to 5(c), an original substrate 10 is raised, and the original substrate 10 has a plurality of chips 20 thereon, which may be Au thin film arrays, or chips 20 such as uled and LED formed based on GaN, GaAs, or other material systems. Then, the tape 30 is attached to the original substrate 10 and the chip 20 under pressure, and the tape 30 and the chip 20 are peeled off from the original substrate 10. The three steps are the same as the corresponding steps in the whole surface transfer, and the details of this embodiment are not described herein.

Unlike the whole surface transfer, in the alternative transfer, the step S104 is implemented as follows:

referring to fig. 5(d), the tape 30 with the chips 20 is attached to the provided glass substrate 40, and the chips 20 are irradiated by ultraviolet light through an optical mask, so as to obtain the chips 20 in the exposed region and the chips 20 in the non-exposed region, wherein the height of the chips 20 in the exposed region is lower than that of the chips 20 in the non-exposed region.

Then, the tape 30 is used to transfer the non-exposed chips 20 to the first target substrate 51 and the exposed chips 20 to the second target substrate 52 in sequence.

In this embodiment, the chip 20 on the original substrate 10 is partially exposed and partially unexposed under the action of the optical mask. The wavelength of the adopted ultraviolet light can be 365nm, and the output power can be 20mw/cm ² The exposure time may be 0.6s to 1.5 s. The chips 20 in the exposed region and the chips 20 in the non-exposed region form a height difference in the chips 20 due to a mechanism of photo-responsive polymer growth.

In this embodiment, the height difference is formed in the array of the chips 20 to be selectively transferred based on the ultraviolet light-induced polymerization growth, so that the chips 20 with different heights can be selectively transferred in batches.

In batch transfer of the non-exposure area chips 20 and the exposure area chips 20, first, referring to fig. 5(e), the partially exposed adhesive tape 30 is peeled off from the original substrate 10, and the chips 20 are peeled off from the original substrate 10, and then the transfer is performed by:

referring to fig. 5(f), the tape 30 with all the chips 20 is attached to the first target substrate 51 under pressure, so that the chips 20 in the non-exposed area are transferred to the first target substrate 51.

In this embodiment, the first target substrate 51 may be a hard, transparent or flexible substrate such as glass, Si, mica, PET, PO, etc. having an adhesion layer. Whereas the chip 20 in the non-exposed area is more easily contacted to the first target substrate 51 due to its higher height.

Referring to fig. 5(g) and 5(h), the tape 30 with the chips 20 in the exposed areas is peeled off from the first target substrate 51, and is attached to the glass substrate 40, and is irradiated with ultraviolet light until the tape 30 is completely debonded.

In this embodiment, since the chip 20 in the non-exposure area is higher in height and easier to attach to the first target substrate 51, after the tape 30 is peeled off, the chip 20 in the exposure area will be peeled off from the first target substrate 51 together with the tape 30, and the chip 20 in the non-exposure area will be transferred to the first target substrate 51.

Further, the tape 30 of the chip 20 with the exposure region was bonded to a clean glass substrate 40 at 365nm and 20mw/cm ² Is irradiated for a time period of 3 seconds or more, thereby completely detackifying the tape 30.

Referring to fig. 5(i) and 5(j), the tape 30 with the exposed chips 20 after complete de-bonding is attached to a second target substrate 52 to transfer the exposed chips 20 to the second target substrate 52.

In this embodiment, the second target substrate 52 may have an adhesion layer, and the second target substrate 52 may be a hard, transparent or flexible substrate such as glass, Si, mica, PET, PO, etc. The tape 30 is completely de-adhesive due to the adhesion layer, and thus when the tape 30 is peeled off the second target substrate 52, the chips 20 in the exposed area will be transferred onto the second target substrate 52.

In this embodiment, an optical mask is introduced to selectively irradiate the chip 20 to be transferred, and the glass substrate 40 is used as a temporary substrate, so that the ultraviolet light can be accurately projected on the area to be exposed. Thus, the height difference of the microchip 20 due to the polymer growth can be utilized to selectively transfer the microchip 20 with high precision.

Furthermore, the glass can spatially limit the limit of the volume expansion of the polymer, so that the chip is better embedded in the polymer and is not removed during the selective transfer process.

The selective transfer scheme provided in this example, in which the chips in the exposed areas are not removed because they are embedded in the polymer, and the chips in the unexposed areas are removed because they are not embedded in the polymer.

In this embodiment, two specific embodiments are listed below to further describe the above-mentioned selective transferring method.

The third embodiment is as follows:

and (4) combining photoetching and dry-wet etching processes to manufacture the GaN chip array to be transferred with weak bonding force. The Si <111> -GaN substrate is adopted, the size of the GaN chip is 50um 80um, the number of the GaN chips is 50 x 50, and the dot spacing of the center of the GaN chip is 150 um.

The uv tape 30 is perfectly attached to the GaN chip to be transferred on the Si substrate, and a roller device and a vacuum-pumping device can be used, so that no air bubbles exist between the tape 30 and the Si substrate.

The adhesive tape 30 on the Si substrate is peeled off, and the GaN chip is peeled off from the Si substrate together.

The tape 30 with GaN chips was attached to a clean glass substrate 40 with uniform pressure, and the GaN chip array was selectively exposed to ultraviolet light using an optical mask (e.g., a heart shape on the upper left side in fig. 6). The wavelength of the ultraviolet light can be 365nm, and the output power can be 20mw/cm ² Time of exposureCan be in the range of 0.6s to 1.5 s. At this time, as shown in fig. 7, the GaN chips of the exposed area and the non-exposed area have a height difference of about 1.6um due to a mechanism of the growth of the photo-responsive polymer. The GaN chip in the exposed area is lower, and the GaN chip in the unexposed area is higher.

The exposed tape 30 is applied with uniform pressure to a first target substrate 51, which may have an adhesive layer, such as an adhesive layer on uv PET commercial tape, 51.

After the tape 30 is removed, the GaN chips in the non-exposure region are transferred to the first target substrate 51 because they are higher and more easily contact the first target substrate 51, while the GaN chips in the exposure region remain on the tape 30, as shown in fig. 6, which is a schematic view of the tape 30 covered with a heart-shaped optical mask and a schematic view of the GaN chips transferred to the first target substrate 51.

As shown in the lower right of FIG. 6, which is a schematic view of the GaN chip left on the tape 30, the tape 30 with the GaN chip in the exposed area is further bonded to a clean glass substrate 40 at 365nm and 20mw/cm ² Is exposed for 3 seconds and more until the tape 30 is completely detackified.

Finally, the fully de-bonded tape 30 is attached to the second target substrate 52 with the adhesion layer, and the remaining GaN chips can be transferred to the second target substrate 52. The second target substrate 52 is a final substrate, which may be a transparent glass plate with an adhesion layer, which may be su8-2002, and may have a thickness of 2 um.

The fourth embodiment is as follows:

and (3) manufacturing the uled blue light array to be transferred with weak binding force by combining photoetching and dry wet etching processes: si <111> substrate, uled size is 50um 80um, spacing between uled center points is 150um, teter structure.

The uv tape 30 is perfectly attached to the uled on the Si substrate, and a roller device and a vacuum-pumping device can be adopted, so that the uv tape 30 is attached to the Si substrate without bubbles.

The uv tape 30 was peeled off and the uled chip was peeled off from the Si substrate together.

UniformityPressure is applied to attach the tape 30 with the singulated chips to a clean glass substrate 40, an optical mask (arrow shaped as shown in fig. 8, or LED letter shaped as shown in fig. 9) is introduced, and the array of singulated chips is selectively exposed to ultraviolet light. The wavelength of the ultraviolet light can be 365nm, and the output power can be 20mw/cm ² The exposure time may be 0.6s to 1.5 s. In addition, the uled of the exposed area and the uled of the non-exposed area form a height difference.

The exposed tape 30 is applied with uniform pressure to the first target substrate 51, which has an adhesion layer on the first target substrate 51, which may be an adhesion layer on a uv PET commercial tape.

Upon peeling off tape 30, the uled of the non-exposed area is more easily contacted to first target substrate 51 due to the higher, and thus, the uled of the non-exposed area is transferred to first target substrate 51, while the uled of the exposed area is left on tape 30.

The chip transfer method provided by the embodiment can achieve an oxygen-discharging environment by using the glass substrate 40 as a temporary substrate, and the adhesive tape 30 is an anaerobic viscosity-reducing polymer, and can reduce viscosity rapidly by combining with the irradiation of ultraviolet light, thereby greatly shortening the transfer process time and improving the transfer yield. When the transfer of the 4inch wafer level is realized, the yield can reach 99.9 percent.

In addition, in this embodiment, the height difference of the microchip 20 due to the photo-induced polymer growth is further utilized, so that the selective transfer of the microchip 20 with high precision can be realized.

Another embodiment of the present application further provides a method for manufacturing a Micro-LED display device, including chip transfer and chip manufacturing, wherein the chip transfer process can be implemented by using the chip transfer method shown in the above embodiment, so as to obtain a chip 20 with a higher yield and improve the display effect of the Micro-LED display device.

Another embodiment of the present application further provides a Micro-LED display device, where the Micro-LED display device includes a display panel, and the display panel may be manufactured according to the method for manufacturing the Micro-LED display device in the above embodiment.

The Micro-LED display device provided by the embodiment is manufactured by the manufacturing method, so that the Micro-LED display device has the advantages of high yield, good display effect and the like.

In summary, the embodiment of the present application provides a chip transfer method, a Micro-LED display device and a method of manufacturing the same, in which an adhesive tape 30 is attached to an original substrate 10 having a chip 20 under pressure, the adhesive tape 30 and the chip 20 are peeled off together from the original substrate 10, the adhesive tape 30 having the chip 20 is attached to a glass substrate 40 provided under pressure to remove air, the adhesive tape 30 is weakened in adhesiveness by ultraviolet light irradiation, and finally the adhesive tape 30 having the weakened in adhesiveness of the chip 20 is attached to a target substrate 50 to transfer the chip 20 to the target substrate 50. This scheme adopts and weakens the viscidity of sticky tape 30 based on the ultraviolet irradiation mode to the viscidity is reduced and is introduced interim glass substrates 40 simultaneously, makes sticky tape 30 reduce the viscidity fast under the oxygen environment of row, has shortened process time, reduces technology cost, and has improved transfer yields and accuracy.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method of chip transfer, the method comprising:

providing an original substrate, wherein the original substrate is provided with a plurality of chips to be transferred which are arranged in an array;

peeling the tape and the chip from the original substrate;

attaching the adhesive tape with the chip to a provided glass substrate under pressure to remove air, weakening the adhesiveness of the adhesive tape by ultraviolet light irradiation, and attaching the adhesive tape with the chip with the weakened adhesiveness to a target substrate to transfer the chip to the target substrate.

2. The chip transfer method according to claim 1, wherein the step of attaching the tape with the chips to a glass substrate provided to remove air, weakening the adhesive property of the tape with ultraviolet light irradiation, and attaching the tape with the weakened adhesive property of the chips to a target substrate to transfer the chips onto the target substrate comprises:

3. The chip transfer method according to claim 2, wherein the step of transferring the chips in the non-exposure region onto the first target substrate and the chips in the exposure region onto the second target substrate in sequence by using the adhesive tape comprises:

peeling the adhesive tape of the chip with the exposure area from the first target substrate, attaching the adhesive tape to a glass substrate, and irradiating the adhesive tape by adopting ultraviolet light until the adhesive tape is completely de-adhered;

4. The chip transfer method according to claim 1, wherein the target substrate has an adhesion layer on the side to which the chip is attached.

5. The chip transfer method of claim 1, wherein said step of applying tape under pressure to said original substrate and chip comprises:

6. The chip transfer method of claim 1, wherein said step of applying tape under pressure to said original substrate and chip comprises:

7. The method of claim 1, wherein prior to the step of applying tape under pressure to the original substrate and chip, the method further comprises:

and soaking the original substrate with the chip into an etching solution to form weak bonding force between the chip and the original substrate.

8. The chip transfer method according to claim 2, wherein the irradiation wavelength of the ultraviolet light is 320nm to 400 nm.

9. A method of fabricating a Micro-LED display device, comprising chip transfer and chip array fabrication, wherein the chip transfer is performed by the chip transfer method of any one of claims 1 to 8.

10. A Micro-LED display device, characterized in that it is manufactured by the method for manufacturing a Micro-LED display device according to claim 9.