Donor substrate, transfer apparatus, and method of making a donor substrate

Abstract

The application discloses a donor substrate, a transfer device and a donor substrate preparation method. The donor substrate is used for transferring a transfer material to a receiving substrate. The donor substrate comprises a base layer, an absorption layer and a transfer layer which are sequentially arranged in a thickness direction. The base layer can be penetrated by laser. The absorption layer can absorb laser to drive the transfer layer to separate. The donor substrate further comprises a protective layer. The protective layer covers a surface of the transfer layer away from the absorption layer. The melting point of the protective layer is higher than that of the transfer layer. The transfer layer can be covered by the protective layer, so that oxidation of the transfer layer in a heating process can be reduced or avoided. The connection strength between the transfer layer and the receiving substrate is ensured, and the welding quality of an LED is ensured.

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 method for preparing the donor substrate. 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 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 a laser irradiates a local area of ​​the absorption layer of the donor substrate, the absorption layer absorbs the laser energy and generates bubbles. At the same time, the solder paste layer is heated and molten. The expansion of the bubbles forces the solder paste in that area to peel off and be pushed towards the receiving substrate. During the heating process of the solder paste, the molten solder paste is easily oxidized. The oxidized solder paste weakens the adhesion between the solder paste layer and the receiving substrate, causing the solder paste layer to separate from the receiving substrate, resulting in poor LED connection or connection failure. 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 reduce or avoid oxidation of the transfer layer during the heating process.

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

[0005] According to the first embodiment of the present invention, the donor substrate is used to transfer transfer material to the receiving substrate, comprising a base layer, an absorption layer and a transfer layer sequentially stacked along the thickness direction. The base layer is capable of allowing laser light to pass through, and the absorption layer is capable of absorbing laser light to drive the transfer layer to separate. The donor substrate further includes a protective layer that covers the surface of the transfer layer opposite to the absorption layer, and the melting point of the protective layer is higher than that of the transfer layer.

[0006] The donor substrate according to embodiments of the present invention has at least the following beneficial effects:

[0007] This invention reduces or avoids oxidation of the transfer layer during the heating process by covering the transfer layer with a protective layer, ensuring the connection strength between the transfer layer and the receiving substrate, and thus ensuring the welding quality of the LED.

[0008] In other embodiments of the present invention, the material of the protective layer is the same as the material of the pads of the receiving substrate.

[0009] In other embodiments of the present invention, the protective layer is made of copper, gold, or silver.

[0010] In other embodiments of the invention, the material of the protective layer is a metal whose metallic reactivity follows that of the material of the transfer layer.

[0011] In other embodiments of the present invention, the transfer layer comprises multiple transfer films, wherein the multiple transfer films are stacked sequentially along the thickness direction.

[0012] In other embodiments of the invention, the transfer layer comprises 2 to 10 layers of the transfer film, each layer of the transfer film having a thickness of 0.2 to 1 micrometer.

[0013] In other embodiments of the present invention, the surface of the transfer layer facing away from the absorption layer is provided with a partition groove to separate multiple transfer portions, and the absorption layer is capable of driving a single transfer portion to separate.

[0014] The transfer device according to the second embodiment of the present invention includes:

[0015] The base is used to place the receiving substrate;

[0016] A laser assembly, connected to the base, is used to generate laser light;

[0017] The donor substrate is connected to the base, the base layer is disposed facing the laser assembly, and the transfer layer is disposed facing the base;

[0018] The laser and the donor substrate can move relative to each other to achieve the transfer of the transfer layer.

[0019] The transfer device according to the third embodiment of the present invention includes:

[0020] The base is used to place the receiving substrate;

[0021] A laser assembly, connected to the base, is used to generate laser light;

[0022] The donor substrate is connected to the base, the base layer is disposed facing the laser assembly, and the transfer layer is disposed facing the base;

[0023] The laser and the donor substrate are capable of relative movement to achieve the transfer of the transfer layer. The laser assembly 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.

[0024] The donor substrate preparation method according to the fourth embodiment of the present invention includes the following steps:

[0025] Prepare the base layer with the absorbent layer attached;

[0026] Multiple transfer films are progressively applied to the surface of the absorption layer away from the substrate, and the multiple transfer films are stacked along the thickness direction to form a transfer layer.

[0027] A protective layer is added to the surface of the transfer layer opposite to the absorption layer.

[0028] 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

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0030] Figure 1 This is a side view of the donor substrate in one embodiment of the present invention;

[0031] Figure 2 for Figure 1 A schematic diagram of the transfer of the donor substrate;

[0032] Figure 3 This is a side view of the donor substrate in another embodiment of the present invention;

[0033] Figure 4 This is a side view of the donor substrate in another embodiment of the present invention;

[0034] Figure 5 This is a side view of the donor substrate in another embodiment of the present invention.

[0035] Figure 6 for Figure 4 Bottom view of the central donor substrate;

[0036] Figure 7 This is a three-dimensional schematic diagram of a transfer device according to an embodiment of the present invention;

[0037] Figure 8 for Figure 7 Side view of the transfer device.

[0038] Figure label:

[0039] 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, transfer film 135, protective layer 140, and protective film 141;

[0040] Base 200;

[0041] Receiving substrate 300;

[0042] Laser component 400;

[0043] Mounting base 500. Detailed Implementation

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Reference Figure 1The 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 addition, this embodiment also provides a protective layer 140, which can reduce or prevent oxidation of the transfer layer 130 during the melting stage and ensure the connection strength between the transfer layer 130 and the receiving substrate 300. The following is a detailed description in conjunction with the accompanying drawings.

[0050] The base layer 110, absorbent layer 120, transfer layer 130, and protective layer 140 are connected sequentially. Specifically, the absorbent layer 120 is connected between the base layer 110 and the transfer layer 130, and the transfer layer 130 is located between the absorbent layer 120 and the protective layer 140. Figure 1 As 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, the transfer layer 130 is attached to the lower surface of the absorption layer 120, and the protective layer 140 is attached to the lower surface of the transfer layer 130.

[0051] 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.

[0052] 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.

[0053] 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 300, allowing the separated transfer material to move towards and adhere to the receiving substrate 300. (Refer to...) Figure 2When 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 bulging reaches a certain extent, the material to be transferred will detach from the main structure of the transfer layer 130. Before the material to be transferred detaches, it will be heated to a molten state. In related technologies, the transfer layer 130 is in direct contact with air, and the heating time is relatively long (about 1 to 2 seconds). In the molten state, it is very easy to react with oxygen in the air to generate oxides. The oxides have poor adhesion properties, making it difficult for the transfer material to adhere firmly to the receiving substrate 300.

[0054] To address the aforementioned issues, the donor substrate 100 in this embodiment further includes a protective layer 140. The protective layer 140 covers the side of the transfer layer 130 facing away from the absorber layer 120, such as the lower side shown in the figure. When the transfer layer 130 is heated to a molten state, the protective layer 140 isolates the transfer layer 130 from air, preventing oxidation of the molten transfer layer 130 upon contact with oxygen. The melting point of the protective layer 140 is higher than that of the transfer layer 130. When the transfer layer 130 is heated and in a molten state, the protective layer 140 can maintain its shape and cover the surface of the transfer layer 130.

[0055] Based on the above, the present invention covers the transfer layer 130 with a protective layer 140, which can reduce or avoid oxidation of the transfer layer 130 during heating, ensure the connection strength between the transfer layer 130 and the receiving substrate 300, and thus ensure the welding quality of the LED.

[0056] In other embodiments, the protective layer 140 is made of the same material as the pads of the receiving substrate 300. This way, when the separated material to be transferred is connected to the receiving substrate 300 via the protective layer 140, the shared material increases the connection strength between the material to be transferred and the receiving substrate 300. Typically, the pads of the receiving substrate 300 are made of copper, so the protective layer 140 can be made of copper. Of course, if the pads of the receiving substrate 300 are made of gold or silver, the protective layer 140 can also be made of gold or silver.

[0057] In other embodiments, the protective layer 140 is a metal whose active metal arrangement is located after the material of the transfer layer 130. Taking the material of the transfer layer 130 as tin as an example, the protective layer 140 can be made of materials such as copper, gold, or silver. The melting point of the above materials is much higher than that of tin, and they are more stable than tin. When the transfer layer 130 is heated to a molten state, the protective layer 140 made of the above materials can maintain its own shape, and will not oxidize at low temperatures (e.g., ≤200°C, at which point the transfer layer 130 can melt), or the degree of oxidation is very low, thereby ensuring the connection strength between the protective layer 140 and the receiving substrate 300.

[0058] In conjunction with the above embodiments, the material of the protective layer 140 can be copper, which has a high melting point and will not be affected by heating. The material of the pads is also usually copper. Therefore, using the same material allows the material to be transferred to be firmly connected to the pads. At the same time, the molten material to be transferred will change from a layered structure to a droplet structure. Copper has good ductility, which allows the protective layer 140 to adapt to the shape change of the material to be transferred, thereby maintaining the encapsulation of the material to be transferred. Finally, copper has good stability and will not oxidize when heated at a low temperature, which can ensure the connection strength between the protective layer and the receiving substrate 300.

[0059] In other embodiments, reference is made to Figure 3 The transfer layer 130 has a multi-layer structure, specifically comprising multiple transfer films 135. These multiple transfer films 135 are stacked sequentially along the thickness direction. Thus, the transfer layer 130 can be formed in a step-by-step process, for example, by forming the transfer films 135 layer by layer through processes such as vapor deposition until the required thickness is achieved. Since the transfer layer 130 is relatively thick, for example, 2 to 10 micrometers, directly forming it using a single-piece process would result in stress concentration. In this embodiment, the transfer layer 130 is formed into a multi-layer structure through a step-by-step film deposition process, which reduces the thickness of each transfer film 135, thereby mitigating the stress concentration problem to some extent and preventing defects such as warping of the transfer layer 130.

[0060] Based on the above embodiments, the transfer layer 130 includes 2 to 10 transfer films 135, each transfer film 135 having a thickness of 0.2 micrometers to 1 micrometer. The small thickness of a single film helps to eliminate internal stress, and the total thickness requirement of the transfer layer 130 can also be met by layering and stacking.

[0061] Because 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 separation 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 is generated during the separation of the material to be transferred. All of these factors will affect the transfer effect.

[0062] Based on the above issues, referring to Figure 4 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 4As 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.

[0063] In another specific embodiment, such as Figure 5 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.

[0064] 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.

[0065] Furthermore, in the above embodiments, the protective layer 140 is also divided into multiple protective films 141 by the partition groove 131, and each transfer portion 132 has a protective film 141 on the surface opposite to the absorption layer 120.

[0066] 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.

[0067] In some embodiments, the separating groove 131 is formed by removing material. Specifically, a transfer layer 130 and a protective layer 140 of uniform thickness can be formed on the absorption layer 120 first by means of methods such as vapor deposition, and then the separating groove 131 can be formed on the transfer layer 130 and the protective layer 140 of uniform thickness by means of methods such as etching, thereby separating the transfer portion 132 and the protective film 141. Since the thickness of the first-formed transfer layer 130 is uniform, the thickness of the subsequently separated transfer portion 132 can also be kept consistent, further achieving uniform transfer. Of course, the transfer portions 132 can also be formed directly on the absorption layer 120.

[0068] As a specific partitioning method for the transfer unit 132, refer to Figure 6 The surface of the transfer layer 130 facing away from the transfer layer 130 is provided with multiple first partition grooves 133 and multiple second partition grooves 134. The first partition grooves 133 and the second partition grooves 134 can both be the partition grooves 131 mentioned above. The first partition grooves 133 and the second partition grooves 134 are both straight grooves with a constant width. The multiple first partition grooves 133 are arranged in parallel and spaced apart, and the multiple second partition grooves 134 are arranged in parallel and spaced apart. The first partition grooves 133 and the second partition grooves 134 are perpendicular to each other. That is, the first partition grooves 133 intersect with each of the second partition grooves 134, and similarly, the second partition grooves 134 intersect with each of the first partition grooves 133, thereby separating rectangular transfer portions 132. The rectangular transfer portions 132 are adapted to the welding position of the receiving substrate, which facilitates welding.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] Reference Figure 7 , Figure 8 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 transfer device may also be equipped with other mounting structures, such as a mounting base 500 for the donor substrate 100.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] This invention also discloses another transfer device, referring to... Figure 7 , Figure 8 It also includes the aforementioned base 200, laser component 400, and donor substrate 100. In this embodiment, 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 portion 132. When the projection of the spot covers the transfer portion 132, the projection is spaced apart from other adjacent transfer portions 132. This ensures that the absorption layer 120 corresponding to a single transfer portion 132 is completely within the irradiation range of the laser, allowing all absorption layers 120 in that area to absorb the laser and expand. The thrust received by the transfer portion 132 is more uniform. At the same time, the laser will not irradiate the absorption layers 120 corresponding to other transfer portions 132, thus preventing the movement of other transfer portions 132.

[0079] 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.

[0080] 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.

[0081] This invention also discloses a method for preparing a donor substrate, comprising the following steps:

[0082] S100 prepares a base layer 110 with an absorbent layer 120 attached thereto, the absorbent layer 120 being attached to one side of the base layer 110;

[0083] In step S200, multiple transfer films 135 are progressively added to the surface of the absorption layer 120 facing away from the substrate. Specifically, this can be done through a vapor deposition process, resulting in a more uniform overall distribution of the film layers. The multiple transfer films 135 are stacked along the thickness direction to form the transfer layer 130. The transfer layer 130 includes 2 to 10 transfer films 135, each with a thickness of 0.2 micrometers to 1 micrometer. The small thickness of a single film helps to eliminate internal stress, and the layered stacking method also meets the total thickness requirement of the transfer layer 130.

[0084] S300 adds a protective layer 140 to the surface of the transfer layer 130 away from the absorption layer 120. Similarly, the protective layer 140 can also be added by vapor deposition.

[0085] In some other embodiments, the method for preparing the donor substrate further includes the following steps:

[0086] In S400, a partition groove 131 is formed on the protective layer 140 and the transfer layer 130, thereby dividing the transfer layer 130 into a plurality of transfer portions 132 and the protective layer 140 into a plurality of protective films 141.

[0087] 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. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

Claims

1. A donor substrate for transferring transfer material to a receiving substrate, characterized in that, The substrate includes a base layer, an absorption layer, and a transfer layer stacked sequentially along its thickness direction. The base layer allows laser light to pass through, and the absorption layer absorbs the laser light to drive the transfer layer to separate. The donor substrate also includes a protective layer that covers the surface of the transfer layer opposite to the absorption layer. The protective layer has a higher melting point than the transfer layer and is made of copper. The protective layer can adapt to changes in the shape of the material to be transferred to maintain the encapsulation of the material.

2. The donor substrate according to claim 1, characterized in that, The protective layer is made of the same material as the pads of the receiving substrate.

3. The donor substrate according to claim 1, characterized in that, The transfer layer comprises multiple transfer films, which are stacked sequentially along the thickness direction.

4. The donor substrate according to claim 3, characterized in that, The transfer layer comprises 2 to 10 layers of the transfer film, each layer having a thickness of 0.2 to 1 micrometer.

5. The donor substrate according to claim 1, characterized in that, The transfer layer has a partition groove on its surface facing away from the absorption layer to separate multiple transfer sections, and the absorption layer can drive a single transfer section to separate.

6. A transfer device, characterized in that, include: The base is used to place the receiving substrate; A laser assembly, connected to the base, is used to generate laser light; The donor substrate according to any one of claims 1 to 4 is connected to the base, the base layer is disposed facing the laser assembly, and the transfer layer is disposed facing the base; The laser and the donor substrate can move relative to each other to achieve the transfer of the transfer layer.

7. A transfer device, characterized in that, include: The base is used to place the receiving substrate; A laser assembly, connected to the base, is used to generate laser light; The donor substrate of claim 5 is connected to the base, the base layer is disposed facing the laser assembly, and the transfer layer is disposed facing the base; The laser and the donor substrate are capable of relative movement to achieve the transfer of the transfer layer. The laser assembly 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.

8. A method for preparing a donor substrate, used to prepare the donor substrate according to any one of claims 1 to 5, characterized in that, Includes the following steps: Prepare the base layer with the absorbent layer attached; Multiple transfer films are progressively applied to the surface of the absorption layer away from the substrate, and the multiple transfer films are stacked along the thickness direction to form a transfer layer. A protective layer is attached to the surface of the transfer layer opposite to the absorption layer. The protective layer is made of copper and can adapt to changes in the shape of the material to be transferred in order to maintain the encapsulation of the material to be transferred.

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