Donor substrate, transfer apparatus and transfer method

Abstract

The application discloses a donor substrate, a transfer device and a transfer method. The donor substrate comprises a base layer, an absorbing layer and a transfer layer connected in sequence. The surface of the transfer layer away from the absorbing layer is provided with a separation groove to separate a plurality of transfer parts. The base layer can be penetrated by laser, and the absorbing layer can absorb laser to drive the transfer parts to separate. Since each transfer part is separated by the separation groove, the adhesion between the transfer part and adjacent other transfer parts during separation can be reduced or eliminated, the material amount of each transfer is ensured to be substantially consistent, the problem of uneven transfer is improved, the generation of debris is reduced, and the problem of debris splashing is improved. In addition, the transfer part is formed on the transfer layer, and the absorbing layer or the base layer does not need to be modified, that is, the base layer or the absorbing layer does not need to be specially designed, and therefore the applicability is higher.

Description

Technical Field

[0001] This invention relates to the field of display device manufacturing technology, and in particular to a donor substrate, a transfer device, and a transfer method. Background Technology

[0002] With the development of technology, Micro LED and Mini LED are increasingly used in display devices. Due to the extremely small particle diameter of solder paste on Micro LED and Mini LED (e.g., less than 15 micrometers), most of them currently use laser-induced forward transfer process to supply solder paste to LEDs. The laser-induced forward transfer process requires a donor substrate, which includes an absorption layer and a solder paste layer attached to the absorption layer. When the absorption layer of the donor substrate is irradiated by a laser, the absorption layer absorbs the laser energy and generates bubbles. The expansion of the bubbles forces the solder paste in a certain area to peel off and be pushed towards the receiving substrate. Since the solder paste to be transferred needs to be separated from the surrounding solder paste, and this separation is uncontrollable, problems such as uneven transfer and splattering will occur, affecting the transfer effect of the solder paste and thus affecting the soldering quality of the LED. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a donor substrate that can improve problems such as uneven transfer and sputtering, thereby enhancing the transfer effect.

[0004] The present invention also proposes a transfer apparatus and a transfer method using the above-mentioned donor substrate.

[0005] The donor substrate according to the first embodiment of the present invention includes:

[0006] It includes a base layer, an absorption layer and a transfer layer connected in sequence. The surface of the transfer layer facing away from the absorption layer is provided with a partition groove to separate multiple transfer sections. The base layer allows laser light to pass through, and the absorption layer absorbs laser light to drive the transfer sections to separate.

[0007] The donor substrate according to embodiments of the present invention has at least the following beneficial effects:

[0008] Because the transfer sections are separated by partition grooves, adhesion between the transfer sections and adjacent transfer sections during separation can be reduced or eliminated, ensuring that the amount of material transferred each time is approximately consistent. This improves the problem of uneven transfer and also reduces the generation of debris, thus reducing debris splashing. Furthermore, since the transfer sections are formed on the transfer layer, no modifications to the absorbent layer or base layer are required; that is, no specially designed base layer or absorbent layer is needed, thus increasing its applicability.

[0009] In other embodiments of the invention, the partition groove extends through the transfer layer.

[0010] In other embodiments of the invention, the partition groove is formed by removing material.

[0011] In other embodiments of the present invention, the surface of the transfer layer facing away from the transfer layer is provided with a plurality of first partition grooves and a plurality of second partition grooves. The plurality of first partition grooves are arranged in parallel and spaced apart, and the plurality of second partition grooves are arranged in parallel and spaced apart. The first partition grooves and the second partition grooves are perpendicular to each other to separate the rectangular transfer portion.

[0012] In other embodiments of the present invention, the width of the first partition groove is 6 micrometers to 12 micrometers, the width of the second partition groove is 6 micrometers to 12 micrometers, and the length of the transfer portion is less than or equal to 10 micrometers.

[0013] The transfer device according to the second embodiment of the present invention includes:

[0014] The base is used to place the receiving substrate;

[0015] Laser components, used to generate laser light;

[0016] The donor substrate is located between the base and the laser assembly, and the transfer layer is disposed facing the base;

[0017] The laser and the donor substrate can move relative to each other to achieve the transfer of the transfer section.

[0018] In other embodiments of the present invention, the laser component is configured such that the projection of the light spot formed by the laser on the donor substrate onto the transfer layer can cover a single transfer portion, and when the projection covers the transfer portion, the projection is spaced apart from other adjacent transfer portions.

[0019] In other embodiments of the present invention, the transfer section is rectangular, the length of the transfer section is less than or equal to 10 micrometers, the light spot is circular, and the diameter of the light spot is less than or equal to 12 micrometers.

[0020] In other embodiments of the present invention, the laser assembly includes a laser source and a laser galvanometer. The laser source is used to generate the laser, and the laser galvanometer is connected to the laser source and can drive the laser to deflect so that the laser moves relative to the donor substrate.

[0021] The transfer method according to the third embodiment of the present invention includes the following steps:

[0022] Prepare a receiving substrate and the donor substrate, place the receiving substrate below the donor substrate, and make the transfer layer face the receiving substrate.

[0023] The absorption layer is irradiated with a laser to transfer a single transfer portion to the receiving substrate;

[0024] The laser is driven to move relative to the receiving substrate in order to transfer another of the transfer units;

[0025] Repeat the above steps until the transfer is complete.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0028] Figure 1 This is a side view of the donor substrate in one embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of donor substrate transfer in related technologies;

[0030] Figure 3 This is a side view of the donor substrate in another embodiment of the present invention;

[0031] Figure 4 This is a bottom view of the donor substrate in one embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of a transfer device according to an embodiment of the present invention.

[0033] Figure label:

[0034] Donor substrate 100, base layer 110, absorber layer 120, transfer layer 130, partition groove 131, transfer part 132, first partition groove 133, second partition groove 134;

[0035] Base 200;

[0036] Receiving substrate 300;

[0037] Laser component 400. Detailed Implementation

[0038] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0040] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0041] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0042] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0043] Reference Figure 1 The accompanying drawing shows a side view of the donor substrate 100 in an embodiment of the present invention. It should be noted that the drawings in this embodiment are only schematic diagrams, and their corresponding shapes and dimensions are not intended to limit the present invention. As shown in the figure, the donor substrate 100 includes a base layer 110, an absorption layer 120, and a transfer layer 130. In this embodiment, by providing a partition groove on the surface of the absorption layer 120, the adhesion between the material to be transferred and the surrounding material is weakened or eliminated, thereby reducing the generation of problems such as uneven transfer and splashing, and ensuring the transfer effect. The following is a detailed description in conjunction with the accompanying drawings.

[0044] The base layer 110, the absorption layer 120, and the transfer layer 130 are connected sequentially; that is, the absorption layer 120 is connected between the base layer 110 and the transfer layer 130. Specifically... Figure 1As shown in the example, the base layer 110, the absorption layer 120 and the transfer layer 130 are arranged in a vertical direction. The absorption layer 120 is attached to the lower surface of the base layer 110 and the transfer layer 130 is attached to the lower surface of the absorption layer 120.

[0045] The base layer 110 serves as the primary load-bearing and mounting structure, capable of cooperating with external structures to secure the donor substrate 100. The material used for the base layer 110 should be transparent to the laser, allowing the laser to pass through. Simultaneously, the base layer 110 needs sufficient strength to maintain the flatness of the absorption layer 120 and transfer layer 130 after they are supported. Typically, the base layer 110 can be made of glass or plastic.

[0046] The absorption layer 120 absorbs the laser light and drives the transfer layer 130 to separate from it. Specifically, after the absorption layer 120 is irradiated by the laser, the irradiated area is ablated, causing a rapid volume expansion. This peels the transfer material connected to that area from the main structure of the transfer layer 130 and ultimately pushes it onto the receiving substrate. The absorption layer 120 can be made of a material with poor wettability to the transfer layer 130, making it easy for the transfer layer 130 to separate from the absorption layer 120. Typically, the transfer layer 130 can be made of materials such as titanium, gold, iron, aluminum, or molybdenum.

[0047] The transfer layer 130 is the object to be transferred, typically tin or a tin alloy. In use, the transfer layer 130 is positioned facing the receiving substrate, allowing the separated transfer material to move towards and adhere to the receiving substrate. In related technologies, the transfer layer 130 is typically a flat, layered structure, see reference [reference needed]. Figure 2 When the absorption layer 120 is ablated by laser irradiation, the resulting vapor bubbles will drive the transfer material (referred to as the material to be transferred for ease of description) in the corresponding area to bulge outward. When the bulge reaches a certain extent, the material to be transferred will detach from the main structure of the transfer layer 130. Since the material to be transferred is connected to the surrounding transfer material and has the same thickness, it is difficult to control the fracture position of the material to be transferred during the detachment process, resulting in a large deviation in the volume of the material to be transferred, thus causing uneven transfer. On the other hand, a lot of debris will also be generated during the separation of the material to be transferred. All of the above factors will affect the transfer effect.

[0048] Based on the above issues, referring to Figure 1 In this embodiment, the donor substrate 100 has a partition groove 131 on the surface (e.g., the lower surface) of the transfer layer 130 facing away from the absorber layer 120. Multiple transfer portions 132 can be formed on the transfer layer 130 through the partition groove 131, and in use, transfer is performed on a unit of individual transfer portions 132. Depending on the depth of the partition groove 131, the present invention provides two specific embodiments, one of which is as follows: Figure 1 As shown, the partition groove 131 completely penetrates the transfer layer 130. At this time, each transfer section 132 is set independently and there is no connection with other transfer sections 132 around it. Therefore, the separation of the transfer section 132 will not be affected by other transfer sections 132, so that the amount of material transferred each time can be roughly consistent, thereby improving the problem of uneven transfer. In addition, since there is no material transferred between the transfer sections 132, no or very little debris will be generated when a single transfer section 132 separates, which can effectively control the problem of debris splashing.

[0049] In another specific embodiment, such as Figure 3 As shown, the partition groove 131 does not completely penetrate the transfer layer 130. Each transfer part 132 is connected to the other by a thin layer of transfer material. In this embodiment, the partition groove 131 can reduce the thickness of the transfer layer 130. That is, the transfer layer 130 at the position corresponding to the partition groove 131 is more likely to break. Therefore, the separation position of the transfer part 132 from the surrounding material can be controlled within the partition groove 131. To a certain extent, the amount of material transferred each time can also be controlled. In addition, since the thickness of the transfer layer 130 at the break point is thinner, the generated debris can also be reduced accordingly.

[0050] It should be noted that this embodiment does not limit the number, length, or cross-sectional shape of the partition grooves 131, as long as the thickness of the material layer between adjacent transfer parts 132 can be reduced.

[0051] In the above embodiments, since each transfer section 132 is separated by the partition groove 131, the amount of material transferred each time can be kept approximately consistent, thereby improving the problem of uneven transfer and reducing the generation of debris, thus improving the problem of debris splashing. Furthermore, in this embodiment, the transfer section 132 is formed on the transfer layer 130, eliminating the need to modify the absorption layer 120 or the base layer 110; that is, no specially designed base layer 110 or absorption layer 120 is required. Therefore, this embodiment has greater applicability.

[0052] In some embodiments, the partition groove 131 is formed by removing material. Specifically, a transfer layer 130 of uniform thickness can be formed on the absorption layer 120 first by means of a method such as vapor deposition, and then the partition groove 131 can be formed on the transfer layer 130 of uniform thickness by means of a method such as etching, thereby separating the transfer portions 132. Since the thickness of the first-formed transfer layer 130 is uniform, the thickness of the subsequently separated transfer portions 132 can also be kept consistent, further achieving uniform transfer. Of course, each transfer portion 132 can also be formed directly on the absorption layer 120.

[0053] As a specific method of separating the transfer section 132, the surface of the transfer layer 130 facing away from the transfer layer 130 is provided with multiple first separating grooves 133 and multiple second separating grooves 134. The first separating grooves 133 and the second separating grooves 134 can both be the aforementioned separating grooves 131. The first separating grooves 133 and the second separating grooves 134 are both straight grooves with a constant width. The multiple first separating grooves 133 are arranged in parallel and spaced apart, and the multiple second separating grooves 134 are arranged in parallel and spaced apart. The first separating grooves 133 and the second separating grooves 134 are perpendicular to each other. That is, the first separating grooves 133 intersect with each of the second separating grooves 134, and similarly, the second separating grooves 134 intersect with each of the first separating grooves 133, thereby separating a rectangular transfer section 132. The rectangular transfer section 132 is adapted to the welding position of the receiving substrate, which facilitates welding.

[0054] In this embodiment, the spacing between adjacent first partition grooves 133 can be equal, the spacing between adjacent second partition grooves 134 can be equal, and the spacing between adjacent first partition grooves 133 and the spacing between adjacent second partition grooves 134 can also be equal. In this way, the shapes of each separated transfer part 132 are the same (all are squares with equal side lengths), so that the amount of material transferred each time remains consistent.

[0055] It should be noted that the transfer part 132 in this embodiment is a uniformly arranged rectangular body, which is convenient for processing and also convenient for controlling the surrounding dimensions.

[0056] Based on the above embodiments, in some specific embodiments, the length of the transfer part 132 is less than or equal to 10 micrometers. This size of the transfer part 132 can adapt to LED soldering in most cases. It should be noted that the length here refers to the length of the longest side of the transfer part 132. For example, when the transfer part 132 is rectangular, the length of the transfer part 132 is less than or equal to 10 micrometers. When the transfer part 132 is square, since all sides are equal in length, any side length is less than or equal to 10 micrometers.

[0057] Based on this, the width of the first partition groove 133 is 6 micrometers to 12 micrometers, and the width of the second partition groove 134 is 6 micrometers to 12 micrometers. In this way, there is a sufficient gap between adjacent transfer sections 132 to prevent the absorption layer 120 corresponding to a certain transfer section 132 from being affected when the laser spot irradiates the absorption layer 120 of the surrounding transfer section 132. At the same time, the gap is not too wide, so as not to affect the effective usable area of ​​the transfer layer 130.

[0058] This invention also discloses a transfer device, which includes a base 200, a laser component 400 and a donor substrate 100 as described in the above embodiments. The transfer device is capable of transferring the transfer portion 132 on the donor substrate 100 to the receiving substrate 300. The following is a detailed description in conjunction with the accompanying drawings.

[0059] Reference Figure 5 The arrows in the diagram indicate the direction of laser irradiation. The base 200, as the main support structure of the transfer device, includes a support member capable of supporting the receiving substrate 300. This support member can be a fixed structure to fix the receiving substrate 300 in its current position, or a driving structure to move the receiving substrate 300. In this embodiment, the support member may be equipped with a vacuum suction cup to adsorb the receiving substrate 300. Furthermore, the base 200 may also be equipped with other mounting structures for mounting the laser assembly 400, the donor substrate 100, etc.

[0060] The laser component 400 is used to generate a laser beam that irradiates the donor substrate 100. In this embodiment, the laser component 400 can generate a flat-top laser with a relatively uniform laser energy distribution, which can achieve uniform expansion of the absorption layer 120.

[0061] The donor substrate 100 is located between the base 200 and the laser assembly 400, specifically above the receiving substrate 300, with a certain gap between them. The base layer 110 of the donor substrate 100 faces the laser assembly 400, i.e., upwards, while the transfer layer 130 faces the receiving substrate 300, i.e., downwards. After the laser passes through the base layer 110 from above, it irradiates the absorption layer 120 and causes expansion, thereby driving the transfer part 132 at the corresponding position to detach and transfer to the corresponding position on the receiving substrate 300.

[0062] The transfer device of this embodiment is suitable for single-point transfer, that is, the transfer of one transfer unit 132 is realized at a time. Based on this, the laser generated by the laser component 400 in this embodiment can move relative to the donor substrate 100 so that the laser can irradiate the absorption layer 120 corresponding to different transfer units 132, thereby realizing the transfer of different transfer units 132. Depending on the difference in the relative movement between the laser and the donor substrate 100, the transfer device can be implemented in different ways. For example, the donor substrate 100 and the receiving substrate 300 can move synchronously, including at least one of horizontal movement and rotation about a vertical axis, while the laser remains stationary in the horizontal direction, so that the laser can irradiate different positions of the donor substrate 100. For another example, the donor substrate 100 and the receiving substrate 300 remain stationary, while the laser can actively move to irradiate different positions of the donor substrate 100. Since only the laser needs to move actively, it helps to ensure accuracy and reduce control difficulty. In order to achieve active movement of the laser, the laser assembly 400 includes a laser source (not shown) and a laser galvanometer. The laser generated by the laser source can be deflected after passing through the laser galvanometer, thereby changing the position of the spot within the scanning range of the laser galvanometer.

[0063] In some embodiments of the transfer device, the laser component 400 is configured such that when the generated laser forms a spot on the donor substrate 100, the projection of the spot onto the transfer layer 130 can cover a single transfer section 132. When the projection of the spot covers the transfer section 132, this projection is spaced apart from other adjacent transfer sections 132. This ensures that the absorption layer 120 corresponding to a single transfer section 132 is completely within the laser's irradiation range, allowing all absorption layers 120 in that area to absorb the laser and expand. This results in a more uniform thrust received by the transfer section 132. Simultaneously, the laser does not irradiate the absorption layers 120 corresponding to other transfer sections 132, preventing the movement of other transfer sections 132.

[0064] For example, the transfer section 132 is rectangular and the light spot is circular. The diameter D of the light spot satisfies: L1 < D < L2 + 2W, where L1 is the length of the diagonal of the transfer section 132, L2 is the length of the long side of the transfer section 132, and W is the width of the partition groove 131. In this way, it can be ensured that the light spot can cover the absorption layer 120 corresponding to a single transfer section 132 without affecting the absorption layer 120 corresponding to adjacent transfer sections 132.

[0065] Specifically, based on the above, the length of the transfer unit 132 is less than or equal to 10 micrometers, and the diameter of the light spot is less than or equal to 12 micrometers, ensuring that the light spot can cover the transfer unit 132, and the diameter of the light spot is controlled within a small range, which can improve the accuracy of the laser.

[0066] The present invention also discloses a transfer method, comprising the following steps:

[0067] S100 prepares the donor substrate 100 and the receiver substrate 300. The donor substrate 100 can be the donor substrate of the above embodiments, for example, including a base layer 110, an absorption layer 120 and a transfer layer 130 connected in sequence. The surface of the transfer layer 130 facing away from the transfer layer 130 is provided with a partition groove 131 to separate multiple transfer parts 132. The base layer 110 can allow the laser to pass through, and the absorption layer 120 can absorb the laser to drive the transfer parts 132 to separate.

[0068] The receiving substrate 300 is disposed below the donor substrate 100, with a certain distance between them, and the transfer layer 130 faces the receiving substrate 300.

[0069] S200 applies a laser from above the donor substrate 100. The laser passes through the base layer 110 and irradiates the absorption layer 120. The absorption layer 120 absorbs the laser and expands to push the individual transfer part 132 to separate and transfer to the corresponding position on the receiving substrate 300.

[0070] S300 drives the laser to move relative to the receiving substrate 300 in order to transfer another transfer unit 132;

[0071] S400 repeats the above steps until the transfer is complete.

[0072] Step 100 also includes a step of positioning the donor substrate 100 and the receiver substrate 300. Specifically, relevant information on the receiver substrate 300 is identified by a machine vision device or the like. The relevant information includes the position, shape and size of the set transfer area. Based on the above information, the donor substrate 100 and the receiver substrate 300 are positioned so that each transfer part 132 on the donor substrate 100 is correspondingly set with the set transfer area on the receiver substrate 300.

[0073] Furthermore, based on the above information, a transfer trajectory can be generated. Taking the active movement of the laser relative to the donor substrate 100 as an example, the laser's movement trajectory can be generated first based on the above information. In step S200, the laser moves according to the above movement trajectory, thereby transferring the transfer units 132 one by one. It should be noted that the laser moves step by step, sequentially transferring each adjacent transfer unit 132 to the receiving substrate 300, which can avoid omissions and achieve high transfer efficiency.

[0074] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A transfer device, characterized in that, include: The base is used to place the receiving substrate; Laser components, used to generate laser light; A donor substrate is located between the base and the laser assembly. The donor substrate includes a base layer, an absorption layer and a transfer layer connected in sequence. The transfer layer has a partition groove on its surface facing away from the absorption layer to separate multiple transfer portions. The base layer allows laser light to pass through, and the absorption layer absorbs laser light to drive the transfer portions to separate. The transfer layer is disposed facing the base. The laser component is configured such that the projection of the light spot formed by the laser on the donor substrate onto the transfer layer can cover a single transfer portion, and when the projection covers the transfer portion, the projection is spaced apart from other adjacent transfer portions. The surface of the transfer layer facing away from the transfer layer is provided with multiple first partition grooves and multiple second partition grooves. The multiple first partition grooves are parallel and spaced apart, and the multiple second partition grooves are parallel and spaced apart. The first partition grooves and the second partition grooves are perpendicular to each other to separate the rectangular transfer portion. The width of the first dividing groove is 6 to 12 micrometers, the width of the second dividing groove is 6 to 12 micrometers, and the length of the transfer portion is less than or equal to 10 micrometers; The dividing groove extends through the transfer layer.

2. The transfer device according to claim 1, characterized in that, The partition groove is formed by removing material.

3. The transfer device according to claim 1, characterized in that, The transfer section is rectangular, and its length is less than or equal to 10 micrometers. The light spot is circular, and its diameter is less than or equal to 12 micrometers.

4. The transfer device according to claim 1, characterized in that, The laser assembly includes a laser source and a laser galvanometer. The laser source is used to generate the laser, and the laser galvanometer is connected to the laser source and can drive the laser to deflect so that the laser moves relative to the donor substrate.

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