CN113555307A

CN113555307A - Method and apparatus for automatically aligning crystal grains and wafer with magnetic material layer

Info

Publication number: CN113555307A
Application number: CN202010334010.4A
Authority: CN
Inventors: 刘台徽; 刘仲熙
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2021-10-26

Abstract

The invention discloses an automatic alignment crystal grain arrangement method and device, which arranges and transfers a plurality of crystal grain arrays by matching crystal grains with magnetic substance layers and utilizing the magnetic action, and then performs alignment. Because the magnetic attraction is strong, the crystal grains are not dropped and arranged irregularly, and the processing speed of the display panel is increased and the excellent rate is increased.

Description

Method and apparatus for automatically aligning crystal grains and wafer with magnetic material layer

Technical Field

The invention relates to a method and a device for automatically aligning crystal grain arrangement and a wafer with a magnetic substance layer, in particular to a method for transferring crystal grains in batches.

Background

Panel technology is the mainstream of modern technology, and how to achieve low power consumption, high light emitting efficiency and low cost is a constant goal of technology development. Compared with the traditional liquid crystal display panel (LCD) and light emitting diode panel (LED), the single crystal grain of the OLED can emit light automatically without a back plate, and the panel has the advantages of high contrast, high saturation, more bright color and low power consumption. In addition, the OLED can be directly matched with the fingerprint identification under the screen, so that the space can be saved, the thickness of the panel can be reduced, and the panel can be bent and folded, and is the mainstream of the current display panel. However, since the lifetime of the material is limited, the OLED has image sticking (i.e. burn-in), color fading and screen flashing after long-term use, so the OLED is only used for mobile phones and tablet computers, i.e. electronic products with fast replacement time, and is less used as a display panel of a television.

In view of the defects of the OLED, milli-and micro-LEDs, which are LEDs, have recently been developed, but finer-grained LEDs are used to reach the size of pixels and the like. Furthermore, the technology of micro light emitting diodes has achieved the same purpose as that of OLEDs, and solves the problem of OLED image branding, and has the advantages of high brightness, high resolution, color saturation, power saving, fast response speed and low power consumption.

However, although micro-LEDs have better performance than LEDs and OLEDs, the grains are fine (on the order of microns and nanometers), and the problems of poor yield, slow process speed, and high manufacturing cost are easily encountered when transferring and arranging arrays in the prior art.

Disclosure of Invention

The present invention provides a method for automatically aligning a die arrangement, which can rapidly arrange a plurality of dies in an array and transfer the dies in batch, thereby improving the yield, speeding up the manufacturing process and reducing the cost.

Accordingly, the present invention provides a method for automatically aligning a die arrangement, comprising the steps of: (a) providing a wafer, and arranging a magnetic substance layer on the wafer; (b) cutting the wafer into a plurality of crystal grains; (c) providing a crystal grain picker, wherein the crystal grain picker picks up the plurality of crystal grains by utilizing the magnetic action and carries out array sequencing; (d) providing an alignment device, wherein the alignment device comprises an alignment platform and a crystal grain moving layer positioned above the alignment platform, and the alignment platform is provided with a plurality of groups of alignment pieces which are ordered; and (e) transferring the plurality of crystal grains subjected to array sorting to the surface of the crystal grain moving layer, enabling each crystal grain to correspond to each alignment piece, and aligning the plurality of crystal grains subjected to array sorting by utilizing the magnetic action.

In the preferred embodiment, each of the plurality of sets of ordered alignment elements is individually displaceable and may or may not be magnetically active.

In a preferred embodiment, the step (e) is further followed by the step (f) of demagnetizing the magnetic material layer of each of the dies.

In a preferred embodiment, the magnetic effect of steps (c) and (e) is generated by applying a current.

In a preferred embodiment, before the plurality of dies in the step (e) are transferred, the plurality of dies are turned over so that the side of the plurality of dies having the magnetic material layer faces the alignment platform; wherein, the step of turning over comprises: (e-1) providing a first adhesive tape, so that the first adhesive tape is attached to the plurality of crystal grains and is far away from the target platform; (e-2) turning over the first adhesive tape, providing a second adhesive tape, and enabling the second adhesive tape to be attached to the side faces, without the first adhesive tape, of the plurality of crystal grains; and (e-3) removing the first adhesive tape, and placing the side surface of the plurality of crystal grains, from which the first adhesive tape is removed, on the surface of the crystal grain moving layer; wherein, the viscosity of the second adhesive tape is greater than that of the first adhesive tape.

In a preferred embodiment, the magnetic material layer is formed in step (a) by (1) printing techniques or (2) photoresist coating and photolithography techniques.

In a preferred embodiment, in the step (a), the magnetic material layer comprises a magnetic material, and the magnetic material is arranged in each of the grains in a straight shape, a cross shape formed by arranging a plurality of dots, or a square shape formed by arranging a plurality of dots.

In a preferred embodiment, the die includes a red die, a green die, or a blue die.

Another object of the present invention is to provide a wafer with a magnetic material layer, wherein the wafer can be cut into a plurality of grains, and the magnetic material is in a shape of a straight line, a cross with a plurality of dots, or a square with a plurality of dots.

Another objective of the present invention is to provide an apparatus for automatically aligning dies using the above method, which includes a die pick-up and an aligning device. Wherein, the crystal grain picker picks up a plurality of crystal grains by utilizing the magnetic action; the alignment equipment comprises a crystal grain moving layer and an alignment platform arranged below the crystal grain moving layer, wherein the alignment platform is provided with a plurality of groups of alignment pieces which are ordered; wherein, in the several arrays of ordered alignment elements, each alignment element can individually move position and individually generate magnetic action or not generate magnetic action.

Compared with the prior art, the invention has the following advantages:

1. the prior art separates the cut crystal grains by using an expansion film, but the problem of nonuniform crystal grain spacing (dense middle and wide outer edge interval) after separation is caused by nonuniform thickness of the expansion film. In comparison, the method and the device for automatically aligning the crystal grain arrangement of the invention separate and arrange the plurality of crystal grains in an array by utilizing the magnetic action between the crystal grain picker and the magnetic substance layers of the crystal grains, so that the problem of inconsistent crystal grain spacing caused by uneven expansion film thickness is solved, and the array arrangement is completed after the crystal grains are separated.

2. In the prior art, a lot of dies are transferred by electrostatic adsorption and pressing (stamp), or a parallel array of dies is transferred by moving an arm once, however, the former has the problem of poor yield due to die falling off, and the latter has the problems of irregular arrangement and slow process speed. In contrast, when the method and apparatus for automatically aligning the die arrangement according to the present invention transfers the die in batch, the die pick-up device can effectively adsorb the die by using the magnetic effect, and when the die is placed on the aligning platform, the die is firmly fixed by the magnetic effect, i.e., the problem of die falling off is improved, and the problem of slow process speed is improved by batch transfer. In addition, when the invention is positioned in the contraposition, the positions of the crystal grains can be displaced and adjusted through the magnetic adsorption force of the contraposition piece of the contraposition platform and the crystal grains with the magnetic substance layer, thereby achieving the purposes of accurate and effective contraposition and orderly ordering of the crystal grains after array ordering.

Drawings

Fig. 1 is a flow chart illustrating a method for automatic die arrangement according to the present invention.

Fig. 2 is an external view of the aligning apparatus of the present invention.

Fig. 3-1 and 3-2 are schematic diagrams illustrating the flip-over and transfer processes of the dies in the step (e) in the method of the present invention.

FIG. 4 is a schematic diagram showing the shape of a magnetic material in a wafer having a magnetic material layer according to the present invention.

Fig. 5 is a schematic diagram of transferring red, green or blue dies to the alignment apparatus in the step (e) of the method of the present invention.

Description of reference numerals:

a support table

Magnetic action of M

1 wafer

2 magnetic substance layer

21 magnetic substance

3 crystal grains

31(B) blue grains

31(G) Green grains

31(R) blue crystal grain

4-die pick-up device

5 linear grain group

7 laser cutting knife

8 alignment equipment

81 alignment platform

811 alignment member

82 grain moving layer

9 first adhesive tape

11 second adhesive tape.

Detailed Description

The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.

Please refer to fig. 1 and 2; as shown in fig. 1, the method for automatically aligning the die arrangement of the present invention comprises the steps of: (a) providing a wafer 1 on a support platform A, and arranging a magnetic substance layer 2 on the wafer 1; (b) cutting the wafer 1 into a plurality of dies 3 by using a laser cutting blade 7; (c) providing a die pick-up device 4, wherein the die pick-up device 4 picks up the plurality of dies 3 by magnetic action and performs array sorting; (d) providing an alignment apparatus 8, as shown in fig. 2, the alignment apparatus 8 includes an alignment stage 81 and a die moving layer 82 disposed above the alignment stage 81, wherein the alignment stage 81 has a plurality of alignment elements 811 arranged in a sequence of a plurality of groups; and (e) transferring the plurality of dies 3 arranged in array to the surface of the die-moving layer 82, so that each die 3 corresponds to each alignment element 811, and aligning the plurality of dies 3 arranged in array by magnetic action. Further, the step (e) is further followed by the step (f) of demagnetizing the magnetic material layer 2 of each of the dies 3; the method of degaussing comprises using a chemical and equipment for a photoresist stripping process to remove the magnetic material 21 of the die 3, so that the magnetic material 21 does not remain on the die 3.

The provision of the magnetic substance layer 2 in the above-mentioned step (a) is accomplished by (1) a printing technique or (2) a resist coating and photo etching technique, and specific examples thereof include: mixing the photoresist and the magnetic substance 21 powder, coating the mixture on the wafer 1, and developing the wafer after developing and exposing the wafer; alternatively, the photoresist is coated on the wafer 1, and then the magnetic material 21 powder is coated, and then developed after development and exposure.

In the step (b), the wafer 1 is cut by a general wafer 1 cutting technique, such as laser cutting knife 7 or diamond knife cutting, and the invention is not limited thereto.

The step (c) can be performed in two ways, the first way comprising: (c-1) the die pick-up device 4 repeatedly picking up a part of the plurality of dies 3 to arrange all of the plurality of dies 3 in the X-direction or the Y-direction into a plurality of linear die groups 5; and (c-2) the die pick-up device 4 repeatedly picks up some of the dies 3 in the linear die groups 5 in a direction perpendicular to the X direction or the Y direction and transfers the dies to the alignment apparatus 8, so as to arrange all of the dies 3 in the array on the support table a. The steps of the second mode include: (c-1) the die pick-up device 4 repeatedly picking up a part of the plurality of dies 5 to arrange all of the plurality of dies in the X-direction or the Y-direction into a plurality of linear die groups 5; and (c-2) the die pick-up device 4 repeatedly picks up the plurality of dies 3 in the plurality of linear die groups 5 in a direction perpendicular to the X direction or the Y direction, and transfers all of the plurality of dies 3 to the alignment apparatus 8 after arranging all of the plurality of dies 3 in an array.

Before the transferring, the plurality of dies 3 in the step (e) are turned over to make the side of the plurality of dies 3 having the magnetic material layer 2 face the alignment platform 81, as shown in fig. 3-1 and 3-2, and the steps include: (e-1) providing a first tape 9, so that the first tape 9 is attached to the side of the plurality of dies 3 having the magnetic material layer 2 and is away from the supporting platform A; (e-2) turning over the first tape 9 to provide a second tape 11, so that the second tape 11 is attached to the opposite sides of the plurality of dies 3 without the first tape 9; and (e-3) removing the first tape 9 and placing the side of the plurality of crystal grains 3 with the magnetic substance layer 2 on the surface of the crystal grain moving layer 82; subsequently, the alignment stage 81 can align the magnetic action M between the alignment member 811 and the magnetic material 2. Wherein, the viscosity of the second adhesive tape 11 is greater than that of the first adhesive tape 9, so that the plurality of dies 3 can be firmly attached to the second adhesive tape 11 without falling off when the first adhesive tape 9 is removed. In addition, the step (e) is a repeatable step, and as shown in fig. 5, when different kinds of dies (red-blue die 33(R), green die 32(G), and blue die 31(B)) are to be flipped and transferred, the step (e) can be repeated.

The magnetic action in the above steps (c) and (e) is generated by energization.

In the present invention, the support platform a is a platform capable of cutting the wafer 1, and a thin film for cutting the wafer 1, such as a blue film or a UV film, may be disposed on the surface of the support platform a.

In the present invention, the first tape 9 and the second tape 11 can be common tapes for adhering the wafer 1 or the die, such as a blue film or a UV film, but the present invention is not limited thereto.

In the present invention, as shown in fig. 2, the alignment apparatus 8 includes an alignment stage 81 and a die-moving layer 82 disposed on the alignment stage 81, and the alignment stage 81 has a plurality of alignment elements 811 arranged in a sequence. Wherein, the crystal grain moving layer 82 can be glass with smooth surface or semi-liquid substance, both of which are preferably transparent, and the plurality of crystal grains 3 can move on the surface of the crystal grain moving layer 82; the semi-liquid material is a material that has fluidity after being heated and melted and solidifies after being cooled, and the surface tension and density of the material can be controlled by adjusting the composition, and materials having a melting point of about 50 to 90 degrees are preferred, such as wax, acrylic resin (i.e., acrylic resin), fatty acid derivatives, and the like. When the position of one or more dies 3 is to be fine-tuned, the alignment element 811 magnetically attracts the die 3 to be fine-tuned and moves to precisely align the die 3. Moreover, each of the alignment members 811 can be individually moved and can individually generate magnetic action or not generate magnetic action, so as to facilitate the individual adjustment of the position-biased dies 3 during alignment, for example, as shown in fig. 5, when transferring the red dies 31(R) arranged in an array onto the surface of the die-moving layer 82, only the alignment member 811 corresponding to the red die 31(R) can generate magnetism, and the other alignment members 811 are non-magnetic, so that the red dies 31(R) can be correctly transferred to the position on the alignment platform 81.

In the present invention, the size of the crystal grain 3 is less than 100 μm, preferably 5-100 μm, more preferably 5-50 μm, and most preferably 5-10 μm, and the present invention is not limited thereto. The crystal grain 3 is commonly used for different types of crystal grains of display equipment; the method comprises the steps of including red grains, green grains or blue grains according to color types; the structure includes flip chip (flip chip), horizontal (horizontal) and Vertical (Vertical), and the like, and the invention is not limited thereto.

In the present invention, the shape of the magnetic material 21 includes a cross shape (as shown in fig. 4(a)), a line shape (as shown in fig. 4(b)), a cross shape formed by arranging a plurality of dots (as shown in fig. 4(c) or (d)), or a square shape formed by arranging a plurality of dots (as shown in fig. 4(e) to (f)); in which a cross shape is preferred, and the present invention is not limited thereto. The material of the magnetic substance 21 is a general substance that can produce a magnetic action, and specifically, it is, for example, neodymium iron boron magnet powder, isotropic magnet, or anisotropic magnet, and the present invention is not limited thereto.

In the present invention, the die pickup 4 has a pickup surface facing the support table a, and the pickup surface is provided with a magnetic substance capable of generating magnetism by energization. When the pick-up surface is magnetic, it can generate magnetic action with the magnetic substance layer 2 of the plurality of crystal grains 3 to pick up the plurality of crystal grains 3, such as: when the plurality of crystal grains 3 are to be picked up (pickup), the magnetic action is opposite attraction; when the plurality of dies 3 are to be placed (place), the magnetic effect may be non-effective (i.e., non-magnetic) or like-pole repulsion. Further, the die pick-up device 4 is connected to a moving apparatus (e.g. a moving arm) capable of actuating the die pick-up device 4 in a manner of vertical movement, horizontal movement, or at a fixed height, the pick-up surface faces the support table a and rotates clockwise or counterclockwise, and the invention is not limited thereto. Because the attractive force of the magnetic action is large, the crystal grain picker 4 is not easy to fall off or skew when transferring and arraying the plurality of crystal grains 3, has alignment performance, and can effectively finish transferring and arraying.

As shown in fig. 5, the method for automatically aligning the crystal grain arrangement and the device for automatically aligning the crystal grain arrangement of the invention can be used for the manufacturing process of the display panel, and sequentially turn and transfer the red crystal grain 31(R), the green crystal grain 31(G) and the blue crystal grain 31(B) after array arrangement to the surface of the crystal grain moving layer 82 of the aligning device 8, and then generate magnetic action with the magnetic substance layer 2 of the red crystal grain 31(R), the green crystal grain 31(G) and the blue crystal grain 31(B) through the aligning piece 811 in the aligning platform 81 to align each crystal grain 3, so that the arrangement alignment of the crystal grain 3 array can be more accurate, and the bit offset can be reduced. After the array sorting and transferring are completed by using the method and the device of the invention, the subsequent manufacturing processes of other display panels can be continued, such as detecting or linking crystal grains with circuit boards and the like. The order in which the red die 31(R), the green die 31(G), and the blue die 31(B) are disposed on the alignment stage 81 can be adjusted as needed, and the invention is not limited thereto.

In summary, the method and apparatus for automatically aligning the arrangement of dies of the present invention utilizes the magnetic effect to sequence and transfer arrays, and because the magnetic effect has strong adsorption force, there is no problem of die falling and deflection, the dies can be effectively transferred and aligned, and the batch transfer can effectively improve the problem of slow process speed. Therefore, the method and the wafer with the magnetic material layer are beneficial to being applied to electronic products, in particular to display panels.

The construction, features and functions of the present invention are described in detail in the embodiments illustrated in the drawings, which are only preferred embodiments of the present invention, but the present invention is not limited by the drawings, and all equivalent embodiments modified or changed according to the idea of the present invention should fall within the protection scope of the present invention without departing from the spirit of the present invention covered by the description and the drawings.

Claims

1. A method for automatically aligning a die arrangement, comprising the steps of:

(a) providing a wafer, and arranging a magnetic substance layer on the wafer;

(b) cutting the wafer into a plurality of crystal grains;

(c) providing a crystal grain picker, wherein the crystal grain picker picks up the plurality of crystal grains by utilizing the magnetic action and carries out array sequencing;

(d) providing an alignment device, wherein the alignment device comprises an alignment platform and a crystal grain moving layer positioned above the alignment platform, and the alignment platform is provided with a plurality of groups of alignment pieces which are ordered; and

(e) transferring the plurality of crystal grains subjected to array sorting to the surface of the crystal grain moving layer, enabling each crystal grain to correspond to each alignment piece, and aligning the plurality of crystal grains subjected to array sorting by utilizing the magnetic action.

2. The method of claim 1, wherein each of said plurality of sets of ordered alignment elements is individually positionally displaceable and individually magnetically active or non-magnetically active.

3. The method of claim 1 or 2, further comprising step (f) degaussing the magnetic material layer of each of the dies after step (e).

4. A method according to claim 1 or 2, wherein the magnetic effect of steps (c) and (e) is generated by energisation.

5. The method of claim 1 or 2, wherein the dies in step (e) are flipped before transferring so that the side of the dies having the magnetic material layer faces the alignment stage; wherein, the step of turning over comprises:

(e-1) providing a first adhesive tape, so that the first adhesive tape is attached to the plurality of crystal grains and is far away from the target platform;

(e-2) turning over the first adhesive tape, providing a second adhesive tape, and enabling the second adhesive tape to be attached to the side faces, without the first adhesive tape, of the plurality of crystal grains; and

(e-3) removing the first tape, and placing the side surface of the plurality of crystal grains, from which the first tape is removed, on the surface of the crystal grain moving layer;

wherein, the viscosity of the second adhesive tape is greater than that of the first adhesive tape.

6. The method of claim 1 or 2, wherein in step (a), the magnetic material layer is formed by printing or photoresist coating and photolithography.

7. The method according to claim 1 or 2, wherein in the step (a), the magnetic material layer comprises a magnetic material, and the magnetic material is in a shape of a straight line, a cross formed by an arrangement of a plurality of dots, or a square formed by an arrangement of a plurality of dots within each of the grains.

8. The method of claim 1 or 2, wherein the die comprises a red die, a green die, or a blue die.

9. A wafer with magnetic substance layer is characterized in that the wafer can be cut into a plurality of crystal grains, and the magnetic substance is in a straight line shape, a cross shape formed by arranging a plurality of dots or a square shape formed by arranging a plurality of dots in each crystal grain.

10. An apparatus for automatically aligning die alignment using the method of any one of claims 1 or 8, comprising:

a die pick-up device for picking up a plurality of dies by magnetic action; and

the alignment equipment comprises a crystal grain moving layer and an alignment platform arranged below the crystal grain moving layer, wherein the alignment platform is provided with a plurality of groups of alignment pieces which are ordered; wherein, in the several arrays of ordered alignment elements, each alignment element can individually move position and individually generate magnetic action or not generate magnetic action.