Chip mass transfer method, chip substrate and positioning plate

Abstract

This invention provides a method for mass transfer of chips, comprising the following steps: placing a chip in a liquid, solidifying the liquid encapsulating the chip to form spheres, with each sphere encapsulating one chip to be transferred; placing the spheres on a target substrate, such that each hole on the target substrate receives a sphere containing the chip; removing the solid material from the spheres, allowing the chip to fall into a hole on the target substrate, thus enveloping the chip in the holes of the target substrate. This invention, by solidifying the liquid encapsulating the chip to form spheres and placing them on a target substrate, ensuring that each hole on the target substrate receives a sphere containing the chip; and by removing the solid material from the spheres and allowing the chip to fall into a hole on the target substrate, enables rapid detection of whether the transfer is complete through the monitoring of the solidified or gelled liquid, and allows for timely targeted repair of any untransferred areas, thereby improving the transfer speed and yield of mass transfer technology.

Description

Technical Field

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

[0002] Micro-LED (micro-light-emitting diode) display technology holds immense promise, but the current obstacle to its industrialization lies in the mass transfer of semiconductor chips. Traditional mass transfer technologies are generally constrained by chip production, requiring continuous production and transfer processes, resulting in low transfer efficiency. While fluid assembly can separate production and transfer steps at extremely high speeds, the irregular shape of semiconductors and the uncontrollable nature of the fluid make it difficult to detect complete transfer, compromising chip transfer accuracy and leading to low yields.

[0003] It should be noted that the information disclosed in the background section above is only for understanding the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of improving yield while ensuring the speed of mass transfer technology, and to provide a mass transfer method, chip substrate and positioning plate.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a method for mass transfer of chips, comprising the following steps:

[0007] S1: Place the chip to be transferred in a specific liquid, and solidify or gel the liquid encapsulating the chip to form spheres, with each sphere encapsulating one chip to be transferred;

[0008] S2: Place the sphere on the target substrate so that the sphere containing the chip falls into each open hole on the target substrate;

[0009] S3: Remove all solid materials from the sphere except for the chip, and the chip falls into the hole in the target substrate, so that the chip is completely enveloped by the hole in the target substrate.

[0010] In some embodiments, the step between step S1 and step S2 further includes the following step: setting a positioning plate on a target substrate, the positioning plate having an array of positioning holes, the positioning holes being aligned with corresponding holes on the target substrate, wherein the inscribed circle diameter of the positioning hole is set to be smaller than the diameter of the sphere, and the positioning hole allows the chip to pass through.

[0011] In some embodiments, if it is necessary to transfer different types of chips to the same substrate, before step S1, the method includes: setting the different types of chips and the holes to which they are to fall into the target substrate to different sizes according to different types; step S2 includes: placing the sphere corresponding to the largest chip among the chips to be transferred on the target substrate; after step S3, the method includes: removing chips that have not completely fallen into the holes and then proceeding to step S2, continuing to transfer the largest chip among the chips to be transferred until all chips have been transferred.

[0012] In some embodiments, if it is necessary to transfer different types of chips to the same substrate, before step S1, the following steps are included: setting the diameter of the spheres wrapping different types of chips to different sizes, and setting the diameter of the corresponding positioning holes to different sizes, so that the spheres can just fall on the target positioning holes and pass through the larger non-corresponding positioning holes; step S2 includes: placing the smaller diameter spheres on the positioning plate so that each positioning hole of the positioning plate has a chip-wrapping sphere. After the spheres of this type are placed, continue to place spheres with a larger diameter until all positioning holes have spheres. After aligning the positioning holes with the corresponding holes on the substrate, step S3 is executed.

[0013] In some embodiments, if it is necessary to transfer different types of chips to the same substrate, the steps before step S2 include: obtaining multiple positioning plates, the positioning hole array of each positioning plate being the same as the expected transfer position of the target type of chip on the target substrate; the steps after step S3 include: replacing the positioning plates and proceeding to step S2 to continue transferring the chips to be transferred until all chips are transferred.

[0014] In some embodiments, if the chip to be transferred is distinguished by its front and back sides, step S2 includes: if it is necessary to adjust the orientation, adjusting the orientation of the chip already placed on the hole to be consistent.

[0015] In some embodiments, magnetic, electrostatic, or gravitational methods are used to align the orientation of the chips, which employ a center-of-gravity offset geometry design, or to impart magnetism or electrostatics to the same surface.

[0016] In some embodiments, step S1 includes: using microfluidics to solidify or gel the liquid encapsulating the chip to form a sphere.

[0017] The present invention also provides a chip substrate manufactured using the method described above.

[0018] In some embodiments, a positioning plate has an array of positioning holes aligned with corresponding holes on a target substrate, wherein the diameter of the inscribed circle of the positioning hole is set to be smaller than the diameter of a sphere, and the positioning holes allow a chip to pass through, enabling the above-described method to be implemented.

[0019] The present invention has the following beneficial effects:

[0020] This invention solidifies or gels the liquid encapsulating the chip to form spheres, and places these spheres on a target substrate, ensuring that each open hole on the substrate is filled with a chip-encapsulated sphere. After removing all solid matter except the chip from the spheres, the chip falls into the holes of the target substrate. This design completely separates chip production from chip transfer, enabling large-scale parallel assembly. Furthermore, solidifying or gelling the liquid encapsulating the chip to form spheres prevents chip damage and defects caused by collisions, reducing the probability of needing repair. Using solidified or gelled liquid to encapsulate the chip allows for rapid detection of complete transfer, enabling timely targeted repair of any untransferred areas, thereby improving the transfer speed and yield of mass transfer technology. Attached Figure Description

[0021] Figure 1 This is a flowchart of a chip mass transfer method according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of three types of chips to be transferred in Embodiment 2 of the present invention;

[0023] Figure 3 This is a schematic diagram of the target substrate in Embodiment 2 of the present invention;

[0024] Figure 4 This is a schematic diagram of the chip mass transfer method in Embodiment 2 of the present invention;

[0025] Figure 5 This is a top view of the positioning plate in Embodiment 3 of the present invention;

[0026] Figure 6 This is a front view of the target substrate in Embodiment 3 of the present invention;

[0027] Figure 7 These are schematic diagrams of the three types of chips to be transferred in Embodiment 3 of the present invention;

[0028] Figure 8 This is a schematic diagram of the chip mass transfer method in Embodiment 3 of the present invention;

[0029] Figure 9a This is a top view of the positioning plate 1 in Embodiment 4 of the present invention;

[0030] Figure 9b This is a front view of the positioning plate 1 in Embodiment 4 of the present invention;

[0031] Figure 10a This is a top view of the positioning plate 2 in Embodiment 4 of the present invention;

[0032] Figure 10b This is a front view of the positioning plate 2 in Embodiment 4 of the present invention;

[0033] Figure 11a This is a top view of the positioning plate 3 in Embodiment 4 of the present invention;

[0034] Figure 11b This is a front view of the positioning plate 3 in Embodiment 4 of the present invention;

[0035] Figure 12 This is a front view of the target substrate in Embodiment 4 of the present invention;

[0036] Figure 13 These are schematic diagrams of the three types of chips to be transferred in Embodiment 4 of the present invention;

[0037] Figure 14 This is a schematic diagram of the chip mass transfer method in Embodiment 4 of the present invention;

[0038] The attached figures are labeled as follows:

[0039] 1-Chip 1, 2-Chip 2, 3-Chip 3, 4-Chip 4, 5-Chip 5, 6-Chip 6, 7-Positioning plate 1, 8-Positioning plate 2, 9-Positioning plate 3. Detailed Implementation

[0040] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0041] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be used for fixing, coupling, or communication.

[0042] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present 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 limitations on the present invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0044] like Figure 1 As shown, this embodiment of the invention provides a chip mass transfer method, including the following steps:

[0045] S1: Place the chip to be transferred in a specific liquid, and solidify or gel the liquid encapsulating the chip to form spheres, with each sphere encapsulating one chip to be transferred;

[0046] S2: Place the sphere on the target substrate so that the sphere containing the chip falls into each open hole on the target substrate;

[0047] S3: Remove all solid materials from the sphere except for the chip, and the chip falls into the hole in the target substrate, so that the chip is completely enveloped by the hole in the target substrate.

[0048] The steps between step S1 and step S2 also include the following:

[0049] A1: Place the sphere on a screening plate with a hole diameter larger than the preset maximum sphere size, vibrate it fully to screen, and retain the sphere that passes through the holes of the screening plate;

[0050] A2: Place the sphere on a screening plate with holes smaller than the preset minimum sphere size, vibrate it fully to screen, and retain the spheres that do not pass through the holes of the screening plate for the next step.

[0051] A complete envelope ensures that, at the very least, the holes on the target substrate can completely cover the chip in the orthographic projection of both. However, to reduce the probability of the chip getting stuck, it is recommended that the inscribed circle of the holes on the target substrate be larger than the circumscribed circle of the chip.

[0052] Chip substrate refers to the substrate containing the transferred chip after the chip transfer.

[0053] Example 1

[0054] The produced chips have the same size and diameter or circumscribed circle diameter. Depending on whether the chip has a front and a back, they are divided into those with front and back and those without. If the chip to be transferred has a front and a back, then magnetism or electrostatic discharge is applied to the same side.

[0055] The chip to be transferred is placed in a specific liquid and mixed to form a suspension. Microfluidic technology is used to solidify or gel the liquid containing the chip to form spheres of uniform diameter, with each sphere containing one chip to be transferred.

[0056] The specific liquid can be an EUV-curing liquid or a microfluidic liquid. Common examples include sodium alginate gelled with calcium ions or a+b to achieve curing. As long as the liquid does not corrode the chip and cause it to fail, it is acceptable. Physical methods can be used to lower the liquid to below its solidification temperature, which will not damage the chip.

[0057] You can also add a step by using multiple screening plates to screen spheres with the correct diameter. For example, if you need 49-50 micrometer pores, set a 50-micrometer sieve plate, vibrate it fully, and spheres larger than 50 micrometers will not pass through. Then, remove the spheres that remain on the plate to remove the liquid and recycle them. Then, use a 49-micrometer sieve plate, and spheres of 49-50 micrometers will not pass through. This way, you can keep the 49-50 micrometer spheres that remain on the plate.

[0058] The advantage of this step is enhanced consistency, for example, it can reduce transfer failures that may occur after removing the encapsulating material due to the sphere being too large or too small.

[0059] Furthermore, the target substrate does not necessarily mean that the chip will ultimately be on this substrate; it may be transferred a second time. However, the goal of achieving a regular arrangement has been achieved.

[0060] In some embodiments, a positioning plate may be used, which may be disposed on a target substrate. The positioning plate has an array of positioning holes that are aligned with corresponding holes on the target substrate. The diameter of the inscribed circle of the positioning hole is set to be smaller than the diameter of a sphere, and the positioning hole allows the chip to pass through.

[0061] A sufficient number of spheres are placed on the positioning plate or target substrate. Gravity, liquid / gas actuation, or other methods are used to ensure that each hole on the positioning plate or target substrate is filled with a sphere encasing the chip. If the chip to be transferred needs to have its front and back sides distinguished, i.e., the orientation needs to be adjusted, methods such as magnetic fields or electrostatic fields can be used to make the semiconductor chips face the same.

[0062] For example, if one side is connected to electrodes, then all electrode surfaces should face that direction. The orientation is adjusted using the principle that torque is non-zero; the force of the field will cause the chip to point in the direction where torque is zero. Theoretically, by changing the electrostatic or magnetic field by at least two 90° angles, the orientation can be made consistent, and both sides should be aligned.

[0063] Because the particles fall randomly into the sphere, and after the encapsulating material is removed, some may need to have their electrodes facing upwards while others face downwards, which does not meet the requirements.

[0064] It is also possible to adjust the orientation by setting the chip to a specific chip shape, causing its center of gravity to be significantly offset from the geometric center, thereby utilizing vibration and gravity.

[0065] The solid material encasing the semiconductor chip is removed using physical or chemical methods. If a positioning plate is present, the semiconductor chip falls onto the target substrate through holes in the positioning plate. If no positioning plate is present, the semiconductor chip falls directly onto the target substrate.

[0066] If it is necessary to transfer different types of chips to the same substrate, the following methods can be used to supplement Embodiment 1 of the present invention: three cases are divided into not using a positioning plate, using a single positioning plate, and using multiple positioning plates.

[0067] Example 2

[0068] Example 2 illustrates a method without using a positioning plate. Different types of chips and their corresponding holes in the target substrate are set to different sizes according to their type. The chips are then transferred sequentially from largest to smallest. After transferring the larger chips, those that cannot fit into the smaller holes are removed, and the transfer continues with the largest chip. This process is repeated multiple times to complete the transfer of all chips. All solid matter except the chips is removed from the sphere, allowing the chips to fall into the holes in the target substrate, ensuring the chips are completely enveloped by the holes.

[0069] Example 2 is an example without using a positioning plate. The chips to be transferred are of three types: chip 1, chip 2, and chip 3. This example illustrates a chip transfer process that distinguishes between the front and back sides. The three types of chips to be transferred in Example 2 are as follows: Figure 2 As shown, the target substrate used in Example 2 is as follows: Figure 3 As shown, the hole sizes on the target substrates differ.

[0070] like Figure 4 As shown, place the target substrate with different hole sizes; place the largest sphere that wraps the chip 3; adjust the orientation (to prevent it from falling into the target substrate in the opposite direction); remove the external wrapping material; remove the chips that have not fallen into the target substrate; repeat the above steps to transfer other spheres from large to small to obtain the target substrate after transfer.

[0071] Example 3

[0072] Example 3 uses a single positioning plate. The diameters of the spheres encasing different types of chips are set to different sizes, and the corresponding positioning hole diameters are also set to different sizes. This ensures the spheres fall precisely into the target positioning hole and pass through larger, non-corresponding positioning holes. First, smaller diameter spheres are placed on the positioning plate, ensuring each positioning hole has a chip-encasing sphere. Once the placement of that type of sphere is complete, larger diameter spheres are placed, repeating this process until all positioning holes have spheres. After aligning the positioning holes with the corresponding holes on the substrate, all solid material except the chip is removed from the spheres. The chip then falls into the hole on the target substrate, completely enveloping the chip in the hole.

[0073] Example 3 illustrates the use of a single positioning plate. The chips to be transferred are of three types: chip 4, chip 5, and chip 6. This example demonstrates a chip transfer process that distinguishes between the front and back sides. In Example 3, the positioning plate is as follows: Figure 5 As shown, the target substrate used in Example 3 is as follows: Figure 6 As shown, in Example 3, the three types of chips to be transferred are as follows: Figure 7 As shown.

[0074] like Figure 8 As shown, a sphere encasing chip 4 is placed in a smaller hole on the positioning plate, and the sphere will pass through a larger hole; a sphere encasing chip 5 is placed in a larger hole, and similarly, the sphere will pass through a larger hole; a sphere encasing chip 6 is placed in an even larger hole; the orientation is adjusted (to prevent it from falling into the target substrate in the opposite direction); the target substrate is aligned; the external encasing material is removed, and the target substrate after transfer is obtained.

[0075] The diagram is for illustrative purposes only and does not imply that the hole positions and other dimensions are necessarily the same; it is only for ease of understanding.

[0076] Example 4

[0077] Example 4 illustrates the use of multiple positioning plates. The positioning hole array on each positioning plate corresponds to the expected transfer position of the target type of chip on the target substrate. The hole arrays of the positioning plates are arranged in the same order according to the expected transfer positions of the same type of chip on the target substrate. After step S3, the process includes: replacing the positioning plate and proceeding to step S2 to continue transferring the chips to be transferred until all chips have been transferred.

[0078] The number of positioning plates is determined; for example, if RGB three-color full color is used, three types are used; if RGBW is used, four types are used. It is recommended to match the type of transfer chip.

[0079] Example 4 illustrates the use of three positioning plates. The chips to be transferred are of three types: chip 4, chip 5, and chip 6. This example demonstrates a chip transfer process that distinguishes between the front and back sides. In Example 4, positioning plate 1 is as follows... Figure 9a and Figure 9b As shown, in embodiment 4, the positioning plate 2 is as follows: Figure 10a and Figure 10b As shown, in embodiment 4, the positioning plate 3 is as follows: Figure 11a and Figure 11b As shown, the target substrate used in Example 4 is as follows: Figure 12 As shown, in Example 4, the three types of chips to be transferred are as follows: Figure 13 As shown.

[0080] like Figure 14 As shown, place the spheres that wrap the chip 4 in all the holes of the positioning plate 1; align the positioning plate with the target substrate, or the order can be reversed with the previous step; adjust the orientation (to prevent it from falling into the target substrate in the opposite direction); remove the external wrapping material; repeat the above steps to transfer other types of chips to obtain the target substrate after transfer.

[0081] The diagram is for illustrative purposes only and does not represent a necessary technical requirement. Figure 1 The parameters such as type, shape, size, orientation, height, position, and arrangement of the chip can be modified, and the order can also be changed. The numbers have no special meaning.

[0082] It should be noted that the chip, positioning plate, and target substrate can have different diameters or shapes. Only the basic relationships need to be met: if the sphere a enclosing the chip needs to pass through the hole in positioning plate 1 and fall into target substrate x, the diameter of a should be larger than the inscribed circle diameter of the hole in positioning plate 1, and the shape of the chip within sphere a should be completely enclosed by the hole in the target substrate. If there is no positioning plate, the shape of the chip within sphere a should be completely enclosed by the hole in the target substrate.

[0083] Traditional mass transfer methods require continuous chip manufacturing and transfer processes. However, this invention completely separates chip manufacturing and transfer, and its simple principle enables large-scale parallel assembly. Liquid encapsulation prevents chip collisions during self-assembly, reducing the likelihood of chip damage and defects, and decreasing the probability of needing repair. Compared to other fluid self-assembly technologies, the liquid composition can be flexibly changed, and transfer completion can be quickly determined using methods such as fluorescence detection. If a positioning plate is used, light transmission can be used to determine whether there are spheres encapsulating the chip in the holes, and then spheres can be placed where they did not fall in, allowing for faster identification. Targeted repair of untransferred areas is also possible, reducing costs and improving yield while minimizing transfer steps and significantly increasing transfer efficiency. This invention improves the transfer speed and yield of mass transfer technology with a simple and easy-to-implement principle.

[0084] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A method for mass transfer of chips, characterized in that, Includes the following steps: S1: Place the chip to be transferred in a specific liquid, and solidify or gel the liquid encapsulating the chip to form spheres, with each sphere encapsulating one chip to be transferred; S2: Place the sphere on the target substrate so that each open hole on the target substrate is covered by the sphere containing the chip. The presence of the chip-encased sphere on the hole can be determined by fluorescence detection or illumination. S3: Remove all solid materials from the sphere except for the chip, and the chip falls into the hole in the target substrate, so that the chip is completely enveloped by the hole in the target substrate.

2. The method as described in claim 1, characterized in that, Between steps S1 and S2, the following steps are also included: setting a positioning plate on the target substrate, the positioning plate having an array of positioning holes, the positioning holes being aligned with corresponding holes on the target substrate, wherein the inscribed circle diameter of the positioning hole is set to be smaller than the diameter of the sphere, and the positioning hole allows the chip to pass through.

3. The method as described in claim 1, characterized in that, If it is necessary to transfer different types of chips to the same substrate, before step S1, the following steps are included: setting the different types of chips and the holes to be placed into the target substrate according to different types and sizes. Step S2 includes: placing the sphere corresponding to the largest chip among the chips to be transferred onto the target substrate. After step S3, the following steps are included: removing chips that have not completely fallen into the holes and then proceeding to step S2, continuing to transfer the largest chip among the chips to be transferred until all chips have been transferred.

4. The method as described in claim 2, characterized in that, If it is necessary to transfer different types of chips to the same substrate, before step S1, the process includes: setting the diameter of the spheres wrapping different types of chips to different sizes, and setting the diameter of the corresponding positioning holes to different sizes, so that the spheres can just fall on the target positioning holes and pass through the larger non-corresponding positioning holes; step S2 includes: placing the smaller diameter spheres on the positioning plate so that each positioning hole on the positioning plate has a chip-wrapping sphere. After placing the spheres of this type, continue to place spheres with a larger diameter until there are spheres in all positioning holes. After aligning the positioning holes with the corresponding holes on the substrate, step S3 is executed.

5. The method as described in claim 2, characterized in that, If it is necessary to transfer different types of chips to the same substrate, the steps before step S2 include: obtaining multiple positioning plates, the positioning hole array of each positioning plate being the same as the expected transfer position of the target type of chip on the target substrate; the steps after step S3 include: replacing the positioning plates and proceeding to step S2 to continue transferring the chips to be transferred until all chips are transferred.

6. The method according to any one of claims 1-5, characterized in that, If the chip to be transferred is distinguished by its front and back sides, step S2 includes: if it is necessary to adjust the orientation, adjust the orientation of the chips that have been placed on the holes to be consistent.

7. The method as described in claim 6, characterized in that, The orientation of the chips is aligned using magnetic, electrostatic, or gravitational methods, and the chips employ a center-of-gravity offset geometric design, or are given magnetism or electrostatic properties on the same surface.

8. The method as described in claim 1, characterized in that, Step S1 includes: using microfluidic technology to solidify or gel the liquid encapsulating the chip to form a sphere.

Images