Micro device substrate and manufacturing method thereof

Abstract

The invention provides a micro device substrate and a manufacturing method thereof, and relates to the technical field of display, and the micro device substrate comprises a substrate; the bearing glue layer is positioned on one side of the substrate; the plurality of light-emitting chips are positioned on one side, far away from the substrate, of the bearing adhesive layer; the substrate comprises a groove, the groove is located in the side, facing the bearing glue layer, of the substrate, the groove internally comprises a filling part, and the filling part makes contact with the bearing glue layer. According to the micro-device substrate provided by the invention, the groove is formed in the substrate, the filling part in contact with the bearing glue layer is arranged in the groove, and the heating expansion of the bearing glue layer is limited through the groove and the filling part, so that the position offset of the light-emitting chip is reduced, the welding precision is improved, and the welding yield is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a micro-device substrate and a manufacturing method thereof. Background Art

[0002] A micro-LED (micro-LED) display is a display that integrates a high-density, tiny-sized LED array on a substrate to display images. It is regarded as the next generation of display due to its advantages such as high quality, thin body, and low energy consumption, and is gradually becoming the mainstream in display devices. Micro-LEDs are small in size, and their transfer usually uses mass transfer technology, and welding usually uses mass welding technology. During the transfer and welding process of micro-LEDs, a micro-device substrate is required to receive the micro-LEDs, and the micro-LEDs are transferred and welded to the display substrate through the micro-device substrate. However, during the laser welding process, the high temperature causes the glue on the micro-device substrate to expand, and the micro-LEDs cannot match the position of the display substrate pads, resulting in poor welding accuracy and low welding yield.

[0003] Therefore, how to solve the above problems has become one of the technical problems that need to be solved urgently at this stage. Summary of the invention

[0004] In order to solve the above technical problems, the present disclosure provides a micro-device substrate and a manufacturing method thereof, so as to improve welding accuracy and welding yield.

[0005] In a first aspect, the present disclosure provides a micro-device substrate, comprising:

[0006] substrate;

[0007] A receiving adhesive layer, located on one side of the substrate;

[0008] A plurality of light-emitting chips are located on a side of the receiving adhesive layer away from the substrate;

[0009] The substrate comprises a groove, the groove is located at a side of the substrate facing the receiving adhesive layer, the groove comprises a filling portion, and the filling portion is in contact with the receiving adhesive layer.

[0010] In a second aspect, based on the same inventive concept, the present disclosure provides a method for manufacturing a micro-device substrate, comprising:

[0011] providing a substrate;

[0012] Preparing a groove on one side surface of the substrate;

[0013] A filling portion and a receiving adhesive layer are prepared on one side of the substrate including the groove;

[0014] The light emitting chip is received on a side of the receiving adhesive layer away from the substrate.

[0015] The technical solutions provided by the embodiments of the present disclosure have the following advantages compared with the prior art:

[0016] The present disclosure provides a micro-device substrate and a manufacturing method thereof. The micro-device substrate includes: a substrate; a bonding layer located on one side of the substrate; a plurality of light-emitting chips located on the side of the bonding layer away from the substrate. The substrate includes a groove located on the side of the substrate facing the bonding layer, and the groove includes a filling portion in contact with the bonding layer. For the micro-device substrate provided by the present disclosure, by providing a groove in the substrate and a filling portion in contact with the bonding layer in the groove, the thermal expansion of the bonding layer is restricted by the groove and the filling portion, which is beneficial to reducing the position shift of the light-emitting chips, and thus beneficial to improving the soldering accuracy and the soldering yield. Description of the Drawings

[0017] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure.

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 Shown is a top view schematic diagram of a micro-device substrate provided by an embodiment of the present disclosure;

[0020] Figure 2 Shown as Figure 1 a cross-sectional schematic diagram along AA' in

[0021] Figure 3 Shown is a top view schematic diagram of another micro-device substrate provided by an embodiment of the present disclosure;

[0022] Figure 4 Shown is a top view schematic diagram of still another micro-device substrate provided by an embodiment of the present disclosure;

[0023] Figure 5 Shown is a top view schematic diagram of yet another micro-device substrate provided by an embodiment of the present disclosure;

[0024] Figure 6 Shown as Figure 5 a cross-sectional schematic diagram along BB' in

[0025] Figure 7 Shown is a top view schematic diagram of yet another micro-device substrate provided by an embodiment of the present disclosure;

[0026] Figure 8 Another cross-sectional schematic diagram along BB’ in Figure 5 is shown;

[0027] Figure 9 The flow schematic diagram of a manufacturing method of a micro-device substrate provided by an embodiment of the present disclosure is shown;

[0028] Figure 10 The schematic diagram of the micro-device substrate after performing step S11 in Figure 9 is shown;

[0029] Figure 11 The schematic diagram of the micro-device substrate after performing step S12 in Figure 9 is shown;

[0030] Figure 12 The schematic diagram of the micro-device substrate after performing step S13 in Figure 9 is shown;

[0031] Figure 13 The flow schematic diagram of another manufacturing method of a micro-device substrate provided by an embodiment of the present disclosure is shown;

[0032] Figure 14 The schematic diagram of the micro-device substrate after performing step S131 in Figure 13 is shown;

[0033] Figure 15 The schematic diagram of the micro-device substrate when performing step S132 in Figure 13 is shown;

[0034] Figure 16 The schematic diagram of the micro-device substrate after performing step S132 in Figure 13 is shown. Detailed implementation manners

[0035] In order to more clearly understand the above objects, features and advantages of the present disclosure, the solutions of the present disclosure will be further described below. It should be noted that, without conflict, the embodiments of the present disclosure and the features in the embodiments can be combined with each other.

[0036] Many specific details are set forth in the following description in order to fully understand the present disclosure, but the present disclosure may be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only a part of the embodiments of the present disclosure, rather than all of the embodiments.

[0037] In the research, the inventors found that the transfer of micro light-emitting diodes (Micro-LEDs) usually adopts the mass transfer technology, and the welding usually adopts the mass welding technology. During the transfer and welding process of micro light-emitting diodes, a micro-device substrate is required to carry the micro light-emitting diodes and transfer and weld the micro light-emitting diodes to the display substrate through the micro-device substrate. However, during the laser welding process, the high temperature causes the adhesive on the micro-device substrate to expand, and the micro light-emitting diodes cannot be matched with the pad positions on the display substrate, resulting in poor welding accuracy and low welding yield.

[0038] Therefore, how to solve the above problems has become one of the technical problems to be solved urgently at this stage.

[0039] To solve the above technical problems, the present disclosure provides a micro-device substrate and a manufacturing method thereof to improve the welding accuracy and the welding yield.

[0040] Figure 1 The following shows a top view schematic diagram of a micro-device substrate provided by an embodiment of the present disclosure. Figure 2 The following shows Figure 1 a cross-sectional schematic diagram along AA' in Figure 1 and Figure 2 . Referring to

[0041] a substrate 10;

[0042] a receiving adhesive layer 20 located on one side of the substrate 10;

[0043] a plurality of light-emitting chips 30 located on the side of the receiving adhesive layer 20 away from the substrate 10;

[0044] The substrate 10 includes a groove 40 located on the side of the substrate 10 facing the receiving adhesive layer 20. The groove 40 includes a filling portion 50, and the filling portion 50 is in contact with the receiving adhesive layer 20.

[0045] It should be noted that the drawings of the present disclosure are only schematic and do not represent the actual size and actual structure of the micro-device substrate 100. For example, the micro-device substrate 100 in the drawings of the present disclosure is circular only for illustration and can also be in other shapes such as rectangular. For another example, the number of the light-emitting chips 30 in the drawings of the present disclosure is only for illustration and does not represent the actual number of the light-emitting chips 30 in the micro-device substrate 100. For yet another example, in order to clearly show the groove in the drawings of the present disclosure, the receiving adhesive layer is set to be transparent in the top view schematic diagram.

[0046] Specifically, the present disclosure provides a micro-device substrate 100, which includes a substrate 10, an adhesive layer 20, and a light-emitting chip 30 that are stacked. A plurality of light-emitting chips 30 are fixed to the micro-device substrate 100 through the adhesive layer 20. The substrate 10 includes a groove 40 that is recessed along the thickness direction F3 of the substrate 10 and is located on the side in contact with the adhesive layer 20. A filling portion 50 is provided in the groove 40. The filling portion 50 fills the groove 40 and is in contact with the adhesive layer 20.

[0047] It can be understood that the adhesive layer 20 is used to fix the light-emitting chip 30 to the micro-device substrate 100. It has a certain viscosity and elasticity. When the light-emitting chip 30 is transferred and welded to the display substrate through the micro-device substrate 100, during the laser welding process, the high temperature will cause the adhesive layer 20 to expand due to heat, and some of the light-emitting chips 30 cannot match the pad positions of the display substrate, resulting in poor welding accuracy. In the present disclosure, by providing a groove 40 on the substrate 10, at least part of the groove 40 is filled with a filling portion 50 in contact with the adhesive layer 20. The filling portion 50 is in contact with the adhesive layer 20 and has a certain restrictive effect on the adhesive layer 20. The filling portion 50 is also limited by the groove 40, which is beneficial to restricting the thermal expansion of the adhesive layer 20, thereby reducing the position offset of the light-emitting chip 30, and further improving the welding accuracy and the welding yield.

[0048] It should be noted that the filling portion 50 is in contact with the adhesive layer 20 and forms a certain pulling and restricting effect on the adhesive layer 20. The purpose is to reduce the degree of thermal expansion and deformation of the adhesive layer 20. The present disclosure does not specifically limit the material of the filling portion 50, as long as it can improve the thermal expansion and deformation of the adhesive layer 20. An optional implementation provided by the present disclosure is that the filling portion 50 is made of the same material as the adhesive layer 20. Another optional implementation provided by the present disclosure is that the filling portion 50 is made of a material different from that of the adhesive layer 20. The filling portion 50 is in contact with the adhesive layer 20 and forms a certain pulling and restricting effect on the adhesive layer 20, which is beneficial to restricting the thermal expansion and deformation of the adhesive layer 20.

[0049] Please continue to refer to Figure 1 and Figure 2 , in an optional implementation of the present disclosure, at least part of the adhesive layer 20 fills the groove 40 to form the filling portion 50.

[0050] Specifically, in this embodiment, the filling portion 50 is a part of the receiving adhesive layer 20, and the filling portion 50 and the receiving adhesive layer 20 are integrally formed. That is, it is equivalent to clamping a part of the receiving adhesive layer 20 in the groove 40, and the receiving adhesive layer 20 is restricted by the groove 40. In this way, when the receiving adhesive layer 20 is heated, it is beneficial to restrict the expansion of the receiving adhesive layer 20, thereby being beneficial to reducing the position shift of the light-emitting chip 30, and further being beneficial to improving the welding accuracy and increasing the welding yield.

[0051] Please continue to refer to Figure 1 and Figure 2 , in an alternative embodiment of the present disclosure, the orthographic projection of the groove 40 on the plane where the substrate 10 is located does not overlap with the orthographic projection of the light-emitting chip 30 on the plane where the substrate 10 is located.

[0052] Specifically, the present disclosure provides a groove 40 on the substrate 10. Regarding the specific position of the groove 40, in this embodiment, along the direction F3 perpendicular to the plane where the substrate 10 is located, the projection of the groove 40 on the substrate 10 does not overlap with the projection of the light-emitting chip 30 on the substrate 10. In this way, along the direction F3 perpendicular to the plane where the substrate 10 is located, the area of the substrate 10 that supports the light-emitting chip 30 does not include the groove 40, and the support effect of the substrate 10 on the light-emitting chip 30 is better, which is beneficial to the transfer and welding of the light-emitting chip 30, and further beneficial to improving the welding accuracy and increasing the welding yield.

[0053] It should be noted that in the above embodiment, the orthographic projection of the groove 40 on the plane where the substrate 10 is located does not overlap with the orthographic projection of the light-emitting chip 30 on the plane where the substrate 10 is located, but the present disclosure is not limited thereto. Figure 3 The following shows a top view schematic diagram of another micro-device substrate provided by the embodiment of the present disclosure. Please refer to Figure 3 , the orthographic projection of some grooves 40 on the plane where the substrate 10 is located overlaps with the orthographic projection of the light-emitting chip 30 on the plane where the substrate 10 is located, and the orthographic projection of some grooves 40 on the plane where the substrate 10 is located does not overlap with the orthographic projection of the light-emitting chip 30 on the plane where the substrate 10 is located. With such a setting, the area where the grooves 40 can be set is larger, the number of grooves 40 that can be set is more, it is more beneficial to restrict the thermal expansion of the receiving adhesive layer 20, and further beneficial to improving the welding accuracy and increasing the welding yield.

[0054] Figure 4 The following shows a top view schematic diagram of yet another micro-device substrate provided by the embodiment of the present disclosure. Please refer to Figure 4, in an alternative embodiment of the present disclosure, the groove 40 includes a plurality of first sub-grooves 41 extending along the first direction F1 and a plurality of second sub-grooves 42 extending along the second direction F2. The first sub-grooves 41 and the second sub-grooves 42 form a grid structure. The first direction F1 intersects the second direction F2. The first direction F1 is parallel to the plane of the substrate 10, and the second direction F2 is parallel to the plane of the substrate 10; the orthographic projection of the light-emitting chip 30 on the plane of the substrate 10 is located within the grid structure.

[0055] Specifically, in the present disclosure, by providing the groove 40 on the substrate 10 and providing the filling portion 50 in contact with the receiving adhesive layer 20 in the groove 40, the thermal expansion of the receiving adhesive layer 20 is restricted. This embodiment provides a setting manner of the groove 40. The groove 40 includes a plurality of first sub-grooves 41 and a plurality of second sub-grooves 42. The first sub-grooves 41 extend along the first direction F1, and the second sub-grooves 42 extend along the second direction F2. The first sub-grooves 41 and the second sub-grooves 42 intersect to form a grid structure. The groove 40 includes a filling portion 50. The filling portion 50 is in contact with the receiving adhesive layer 20 and has a certain restricting effect on the receiving adhesive layer 20. The filling portion 50 is also restricted by the groove 40, which is beneficial to restricting the thermal expansion of the receiving adhesive layer 20, thereby being beneficial to reducing the position shift of the light-emitting chip 30, and further being beneficial to improving the welding accuracy and the welding yield. The light-emitting chips 30 are arranged in an array on the micro-device substrate 100. The orthographic projection of the light-emitting chip 30 on the plane of the substrate 10 is located within the grid structure formed by the first sub-grooves 41 and the second sub-grooves 42. In this way, the substrate 10 has a good supporting effect on the light-emitting chip 30, which is beneficial to the transfer and welding of the light-emitting chip 30, and further beneficial to improving the welding accuracy and the welding yield.

[0056] Please continue to refer to Figure 4 , optionally, the width of the first sub-groove 41 along the second direction F2 is W1, 5 μm ≤ W1 ≤ 500 μm; and / or, the width of the second sub-groove 42 along the first direction F1 is W2, 5 μm ≤ W2 ≤ 500 μm.

[0057] Specifically, the first sub-groove 41 extends along the first direction F1 and has a width of W1 along the second direction F2. When the width W1 of the first sub-groove 41 along the second direction F2 is less than 5 μm, the width of the first sub-groove 41 is too small. When the filling portion 50 is provided in the first sub-groove 41, the width of the filling portion 50 along the second direction F2 is too small, and the restricting effect of the filling portion 50 on the adhesive layer 20 is limited, which is not conducive to restricting the thermal expansion of the adhesive layer 20. When the width W1 of the first sub-groove 41 along the second direction F2 is greater than 500 μm, the width of the first sub-groove 41 is too large, and the supporting effect of the substrate 10 on the light-emitting chip 30 is poor. Therefore, in the present disclosure, the width W1 of the first sub-groove 41 along the second direction F2 is set to 5 μm ≤ W1 ≤ 500 μm. With such a setting, on the one hand, it is beneficial to increase the restricting effect on the adhesive layer 20, and on the other hand, it is beneficial to improve the supporting effect of the substrate 10 on the light-emitting chip 30. An optional implementation manner provided by the present disclosure is that the width W1 of the first sub-groove 41 along the second direction F2 = 20 μm; another optional implementation manner provided by the present disclosure is that the width W1 of the first sub-groove 41 along the second direction F2 = 50 μm; still another optional implementation manner provided by the present disclosure is that the width W1 of the first sub-groove 41 along the second direction F2 = 300 μm; yet another optional implementation manner provided by the present disclosure is that the width W1 of the first sub-groove 41 along the second direction F2 is set to 10 μm ≤ W1 ≤ 100 μm; yet another optional implementation manner provided by the present disclosure is that the width W1 of the first sub-groove 41 along the second direction F2 is set to 60 μm ≤ W1 ≤ 400 μm.

[0058] Similarly, the second sub-groove 42 extends along the second direction F2 and has a width of W2 along the first direction F1. When the width of the second sub-groove 42 along the first direction F1 is less than 5 μm, the width of the second sub-groove 42 is too small. When the filling portion 50 is disposed in the second sub-groove 42, the width of the filling portion 50 along the first direction F1 is too small, and the restricting effect of the filling portion 50 on the receiving adhesive layer 20 is limited, which is not conducive to restricting the thermal expansion of the receiving adhesive layer 20. When the width W2 of the second sub-groove 42 along the first direction F1 is greater than 500 μm, the width of the second sub-groove 42 is too large, and the supporting effect of the substrate 10 on the light-emitting chip 30 is poor. Therefore, in the present disclosure, the width W2 of the second sub-groove 42 along the first direction F1 is set to 5 μm ≤ W2 ≤ 500 μm. With such a setting, on the one hand, it is beneficial to increase the restricting effect on the receiving adhesive layer 20, and on the other hand, it is beneficial to improve the supporting effect of the substrate 10 on the light-emitting chip 30. An optional implementation manner provided by the present disclosure is that the width W2 of the second sub-groove 42 along the first direction F1 = 15 μm; another optional implementation manner provided by the present disclosure is that the width W2 of the second sub-groove 42 along the first direction F1 = 30 μm; still another optional implementation manner provided by the present disclosure is that the width W2 of the second sub-groove 42 along the first direction F1 = 280 μm; yet another optional implementation manner provided by the present disclosure is that the width W2 of the second sub-groove 42 along the first direction F1 is set to 20 μm ≤ W2 ≤ 200 μm; yet another optional implementation manner provided by the present disclosure is that the width W2 of the second sub-groove 42 along the first direction F1 is set to 80 μm ≤ W2 ≤ 350 μm.

[0059] Figure 5 FIG. shows a top view schematic diagram of another micro-device substrate provided by an embodiment of the present disclosure. Figure 6 As shown along Figure 5 a cross-sectional schematic diagram of BB' in Figure 5 and Figure 6 Please refer to

[0060] In an optional implementation manner of the present disclosure, the micro-device substrate 100 further includes a limiting portion 60. At least a part of the limiting portion 60 fills at least a part of the groove 40, and at least a part of the filling portion 50 is the limiting portion 60. Along the extending direction of the groove 40, the limiting portion 60 is located in at least a part of the region of the groove 40.

[0061] Specifically, the micro-device substrate 100 further includes a limiting portion 60. Along the direction F3 perpendicular to the plane where the substrate 10 is located, at least a part of the limiting portion 60 is located in the groove 40, and at least a part of the limiting portion 60 is located in the receiving adhesive layer 20. At this time, a part of the limiting portion 60 serves as the filling portion 50, further restricting the thermal expansion of the receiving adhesive layer 20, which is more conducive to reducing the position deviation of the light-emitting chip 30, and thus is conducive to improving the welding accuracy and the welding yield. Optionally, along the extending direction of the groove 40, the limiting portion 60 is located in at least a part of the area of the groove 40. In this way, the position of the limiting portion 60 can be set according to actual needs. Exemplarily, the limiting portion 60 can extend along the first direction F1 or the second direction F2. At the same time, the extending length along the first direction F1 or the second direction F2 can be set according to actual needs. An optional implementation provided by the present disclosure is that the limiting portion 60 fills the entire groove 40, and the filling portion 50 is constituted by the limiting portion 60. With such a setting, the orthographic projection of the limiting portion 60 on the plane where the substrate is located forms a grid structure, and the receiving adhesive layer 20 is embedded in the grid structure, which is further conducive to restricting the thermal expansion deformation of the receiving adhesive layer 20, more conducive to reducing the position deviation of the light-emitting chip 30, and thus conducive to improving the welding accuracy and the welding yield.

[0062] Figure 7 The following shows a top view schematic diagram of another micro-device substrate provided by an embodiment of the present disclosure. Please refer to Figure 7 , In an optional implementation of the present disclosure, the limiting portion 60 includes a first sub-limiting portion 61 and a second sub-limiting portion 62. At least a part of the first sub-limiting portion 61 is located in the first sub-groove 41, at least a part of the second sub-limiting portion 62 is located in the second sub-groove 42, and the first sub-limiting portion 61 and the second sub-limiting portion 62 intersect.

[0063] Specifically, this implementation provides a "cross"-shaped limiting portion 60. The limiting portion 60 includes a first sub-limiting portion 61 and a second sub-limiting portion 62. The first sub-limiting portion 61 is located in the first sub-groove 41, the second sub-limiting portion 62 is located in the second sub-groove 42, and is located at the intersection point of the first sub-groove 41 and the second sub-groove 42. The orthographic projection of the above-mentioned limiting portion 60 on the substrate 10 is in the shape of a "cross". At least a part of the limiting portion 60 is located in the groove 40, and at least a part of the receiving adhesive layer 20 is located in the groove 40. In this implementation, by providing the groove 40 and the limiting portion 60, a part of the receiving adhesive layer 20 is stuck in the groove 40, and the offset of the receiving adhesive layer 20 is restricted by the limiting portion 60. When the receiving adhesive layer 20 is heated, the groove 40 and the limiting portion 60 restrict the expansion deformation of the receiving adhesive layer 20, which is more conducive to reducing the position deviation of the light-emitting chip 30, and thus is conducive to improving the welding accuracy and the welding yield.

[0064] Please continue to refer to Figure 7In an optional embodiment of the present disclosure, it is characterized in that the position-limiting portion 60 is multiplexed as a position-aligning mark point 70, and the position-aligning mark point 70 is used to locate the position of the micro-device substrate 100;

[0065] The length of the alignment mark point 70 along the first direction F1 is S1, 30 μm≤S1≤100 μm;

[0066] The length of the alignment mark 70 along the second direction F2 is S2, 30 μm≤S2≤100 μm.

[0067] Specifically, the micro-device substrate 100 is at least used to transfer and weld the light-emitting chip 30. In the process of transferring or welding the light-emitting chip 30 using the micro-device substrate 100, it is necessary to locate the position of the micro-device substrate 100, so as to transfer or weld the light-emitting chip 30 to a specified position. To locate the position of the micro-device substrate 100, it is necessary to set a positioning mark point 70. In this embodiment, the limiter 60 is reused as the positioning mark point 70. In this way, the setting of the limiter 60 can not only limit the thermal expansion of the receiving adhesive layer 20, but also be used to locate the position of the micro-device substrate 100.

[0068] Regarding the size of the alignment mark point 70, the length of the alignment mark point 70 along the first direction F1 is S1, and the length along the second direction F2 is S2. Optionally, the length S1 of the alignment mark point 70 along the first direction F1 is set to 30μm≤S1≤100μm. When the length S1 of the alignment mark point 70 along the first direction F1 is less than 30μm, the size of the alignment mark point 70 is too small, which is not conducive to positioning the alignment mark point 70 during positioning the micro-device substrate 100; when the length S1 of the alignment mark point 70 along the first direction F1 is greater than 100μm, the size of the alignment mark point 70 is too large, which may lead to inaccurate positioning; therefore, the present disclosure sets the length S1 of the alignment mark point 70 along the first direction F1 to 30μm≤S1≤100μm, which is conducive to positioning the alignment mark point 70 and improving the accuracy of positioning. The present disclosure provides an optional implementation manner that the length S1 of the alignment mark point 70 along the first direction F1 is 35 μm; the present disclosure provides another optional implementation manner that the length S1 of the alignment mark point 70 along the first direction F1 is 60 μm; the present disclosure provides still another optional implementation manner that the length S1 of the alignment mark point 70 along the first direction F1 is set to 40 μm≤S1≤80 μm; the present disclosure provides still another optional implementation manner that the length S1 of the alignment mark point 70 along the first direction F1 is set to 50 μm≤S1≤90 μm.

[0069] Similarly, optionally, the length S2 of the alignment mark point 70 along the second direction F2 is set to 30μm≤S2≤100μm. When the length S2 of the alignment mark point 70 along the second direction F2 is less than 30μm, the size of the alignment mark point 70 is too small, which is not conducive to positioning the alignment mark point 70 during positioning the micro-device substrate 100; when the length S2 of the alignment mark point 70 along the second direction F2 is greater than 100μm, the size of the alignment mark point 70 is too large, which may cause inaccurate positioning; therefore, the present disclosure sets the length S2 of the alignment mark point 70 along the second direction F2 to 30μm≤S2≤100μm, which is conducive to positioning the alignment mark point 70 and improving the accuracy of positioning. The present disclosure provides an optional implementation manner that the length S2 of the alignment mark point 70 along the second direction F2 is 40 μm; the present disclosure provides another optional implementation manner that the length S2 of the alignment mark point 70 along the second direction F2 is 55 μm; the present disclosure provides still another optional implementation manner that the length S2 of the alignment mark point 70 along the second direction F2 is set to 35 μm≤S2≤70 μm; the present disclosure provides still another optional implementation manner that the length S2 of the alignment mark point 70 along the second direction F2 is set to 50 μm≤S2≤90 μm.

[0070] It should be noted that the limiting portion 60 reused as the alignment mark point 70 can be shaped by graphically setting the limiting portion 60 . The present disclosure only uses a “cross” shape as an example for explanation and is not limited thereto.

[0071] Please refer to Figure 5 and Figure 6 In an optional embodiment of the present disclosure, it also includes a limiting portion 60, at least a portion of the limiting portion 60 fills the groove 40 to form a filling portion 50, and along a direction perpendicular to the plane where the substrate 10 is located, the limiting portion 60 is at least partially located in the groove 40, and the limiting portion 60 is at least partially located in the receiving adhesive layer 20.

[0072] Specifically, in the present embodiment, the display panel includes a limiting portion 60. Along a direction F3 perpendicular to the plane where the substrate 10 is located, the limiting portion 60 is partially located in the groove 40 and partially located in the receiving adhesive layer 20. The setting of the limiting portion 60 limits the thermal expansion of the receiving adhesive layer 20, which is beneficial to reducing the position deviation of the light-emitting chip 30, and further beneficial to improving the welding accuracy and increasing the welding yield.

[0073] Figure 8 Shown along Figure 5 Another cross-sectional diagram of BB', please refer to Figure 5 , Figure 6 and Figure 8, in an alternative embodiment of the present disclosure, along the direction F3 perpendicular to the plane of the substrate 10, the distance between the surface of the limiting portion 60 away from the substrate 10 and the substrate 10 is L1, and the distance between the surface of the light-emitting chip 30 away from the substrate 10 and the substrate 10 is L2, where L1 ≤ L2.

[0074] Specifically, this embodiment provides an embodiment of the height of the limiting portion 60. As Figure 6 and Figure 8 shown in the perspective view, when the distance L1 between the surface of the limiting portion 60 away from the substrate 10 and the substrate 10 is greater than the distance L2 between the surface of the light-emitting chip 30 away from the substrate 10 and the substrate 10, along the direction F3 perpendicular to the plane of the substrate 10, the surface of the limiting portion 60 away from the substrate 10 is higher than the surface of the light-emitting chip 30 away from the substrate 10. When welding the light-emitting chip 30 to the corresponding display substrate, the limiting portion 60 contacts the display substrate first, which may affect the welding of the light-emitting chip. Therefore, the present disclosure sets L1 ≤ L2, that is, the surface of the limiting portion 60 away from the substrate 10 is lower than the surface of the light-emitting chip 30 away from the substrate 10 (as Figure 6 shown), or the surface of the limiting portion 60 away from the substrate 10 is flush with the surface of the light-emitting chip 30 away from the substrate 10 (as Figure 8 shown). With such a setting, on the one hand, the limiting portion 60 can limit the thermal expansion of the bonding adhesive layer 20, which is beneficial to reducing the position shift of the light-emitting chip 30, and thus beneficial to improving the welding accuracy and the welding yield; on the other hand, when the surface of the limiting portion 60 away from the substrate 10 is flush with the surface of the light-emitting chip 30 away from the substrate 10, during the welding and pressing process, the setting of the limiting portion 60 can play a role in supporting and preventing over-pressing, which is beneficial to protecting the light-emitting chip 30.

[0075] Please refer to Figure 5 and Figure 6 , in an alternative embodiment of the present disclosure, the coefficient of thermal expansion of the limiting portion 60 is less than that of the bonding adhesive layer 20.

[0076] Specifically, in the micro-device substrate 100, the bonding adhesive layer 20 is used to fix the light-emitting chip 30 on the substrate 10, so it has certain viscosity and elasticity. In the prior art, the coefficient of thermal expansion of the bonding adhesive layer 20 is relatively large, and it is prone to thermal expansion and deformation. This embodiment sets that the coefficient of thermal expansion of the limiting portion 60 is less than that of the bonding adhesive layer 20. In this way, when the micro-device substrate 100 is heated, the limiting portion 60 is not easily expanded and deformed relative to the bonding adhesive layer 20, and at the same time, it can play a certain limiting role on the bonding adhesive layer 20, which is beneficial to reducing the position shift of the light-emitting chip 30, and thus beneficial to improving the welding accuracy and the welding yield.

[0077] It should be noted that the coefficient of thermal expansion (CTE) is a physical quantity that characterizes the thermal expansion properties of an object. An object expands and contracts due to temperature changes, and the ratio of its rate of change to the temperature change is called the thermal expansion coefficient. It describes the relative degree of change in the size or volume of an object when the temperature changes. The larger the thermal expansion coefficient, the greater the degree of thermal expansion of the object.

[0078] Please refer to Figure 5 and Figure 8 Optionally, along a direction perpendicular to the plane where the substrate 10 is located, the depth of the groove 40 is H1, 5μm≤H1≤200μm.

[0079] Specifically, the depth of the groove 40 along the direction F3 perpendicular to the plane where the substrate 10 is located is H1. When the depth H1 of the groove 40 is less than 5 μm, the depth of the groove 40 is shallow, the depth of the filling portion 50 is shallow, and the degree of restriction on the receiving adhesive layer 20 is small; when the depth H1 of the groove 40 is greater than 200 μm, the depth of the groove 40 is deep, which may affect the stability of the substrate 10; therefore, the present disclosure sets the depth H1 of the groove 40 along the direction F3 perpendicular to the plane where the substrate 10 is located to 5 μm≤H1≤200 μm. In this way, by setting the groove 40 on the substrate 10, a certain limiting effect is played on the receiving adhesive layer 20 without affecting the stability of the substrate 10, which is beneficial to reducing the position deviation of the light-emitting chip 30, and further beneficial to improving the welding accuracy and improving the welding yield.

[0080] Please continue to refer to Figure 6 and Figure 8 In an optional embodiment of the present disclosure, the light-emitting chip 30 includes a light-emitting substrate 31 and a chip electrode 32 , the light-emitting substrate 31 is in contact with the receiving adhesive layer 20 , and the chip electrode 32 is located on a side of the light-emitting substrate 31 away from the substrate 10 .

[0081] Specifically, the micro-device substrate 100 is used to transfer and weld the light-emitting chip 30. Several light-emitting chips 30 are fixed on the substrate 10 through the receiving adhesive layer 20. The light-emitting chip 30 includes a light-emitting base 31 and a chip electrode 32. The light-emitting base 31 is located between the receiving adhesive layer 20 and the chip electrode 32. After the micro-device substrate 100 is aligned with the display substrate, the chip electrode 32 of the light-emitting chip 30 is aligned with the pad on the display substrate, and the chip electrode 32 is welded to the pad, thereby realizing the welding of the light-emitting chip 30.

[0082] Based on the same inventive concept, the present disclosure provides a method for manufacturing a micro-device substrate. Figure 9 FIG. 1 is a schematic diagram of a process for manufacturing a micro-device substrate provided by an embodiment of the present disclosure. Figure 10 Shown is the execution Figure 9Schematic diagram of the micro-device substrate after step S11 Figure 11 as shown in the execution of Figure 9 Schematic diagram of the micro-device substrate after step S12 in Figure 12 as shown in the execution of Figure 9 Schematic diagram of the micro-device substrate after step S13 in, please refer to Figure 1 , Figure 2 and Figures 9 to 12 , the manufacturing method of the micro-device substrate includes:

[0083] Step S11: Provide a substrate 10;

[0084] Step S12: Prepare a groove 40 on one side surface of the substrate 10;

[0085] Step S13: Prepare a filling part 50 and a bonding layer 20 on the side of the substrate 10 including the groove 40;

[0086] Step S14: Bond a light-emitting chip 30 on the side of the bonding layer 20 away from the substrate 10.

[0087] It should be noted that the manufacturing method of the micro-device substrate in the present disclosure includes, but is not limited to, steps S11 to S14.

[0088] Specifically, the present disclosure provides a manufacturing method of a micro-device substrate. In step S11, a substrate 10 is provided. After executing step S11, the structure of the micro-device substrate 100 is as Figure 10 shown. Optionally, the above-mentioned substrate 10 may be a sapphire substrate, and the sapphire substrate is a sheet-shaped substrate material made of a single-crystal material mainly composed of aluminum oxide (Al 2 O 3 ). The sapphire substrate has extremely strong wear resistance and scratch resistance, can effectively protect the device structure on the surface, and reduce the wear and damage of external factors to it; at the same time, the sapphire substrate can maintain stable physical and chemical properties in a high-temperature environment and is suitable for process processes that need to be carried out under high-temperature conditions; moreover, the sapphire substrate has a low coefficient of thermal expansion, has good dimensional stability when the temperature changes, can have a good match with the epitaxially grown material in terms of thermal expansion, and reduce material defects and performance degradation caused by thermal stress.

[0089] In step S12, a groove 40 is prepared on one side of the substrate 10, and the groove 40 is used for setting the filling part later. After executing step S12, the structure of the micro-device substrate 100 is as Figure 11 shown.

[0090] In step S13, a filling portion 50 and a receiving adhesive layer 20 are prepared. The filling portion 50 is located within the groove 40, and the receiving adhesive layer 20 is located on the side of the substrate 10 including the groove 40. The filling portion 50 is in contact with the receiving adhesive layer 20. After performing step S13, the structure of the micro-device substrate 100 is as shown in Figure 12 shown. An alternative embodiment provided by the present disclosure is that the filling portion 50 and the receiving adhesive layer 20 are made of the same material. Exemplarily, the filling portion 50 is made of a sticky adhesive material that is the same as that of the receiving adhesive layer 20. That is, when preparing the receiving adhesive layer 20, a part of the receiving adhesive layer 20 fills the groove 40 and the receiving adhesive layer 20 is stuck in the groove 40. When the receiving adhesive layer 20 is heated, it plays a certain limiting role on the receiving adhesive layer 20, which is beneficial to reducing the position deviation of the light-emitting chip 30, and thus is beneficial to improving the welding accuracy and the welding yield.

[0091] It should be noted that the receiving adhesive layer 20 is formed by spin coating. Exemplarily, an appropriate amount of the adhesive material of the receiving adhesive layer 20 is dropped at the center of the substrate 10 and rotated at a set speed, and the photoresist is evenly spread on the surface of the substrate 10 by centrifugal force.

[0092] In step S14, a plurality of light-emitting chips 30 are received on the side of the receiving adhesive layer 20 away from the substrate 10, so as to fix the light-emitting chips 30 on the substrate 10, realizing the mass transfer and mass soldering of the light-emitting chips 30. After performing step S14, the structure of the micro-device substrate 100 is as shown in Figure 1 and Figure 2 shown.

[0093] It should be noted that in the manufacturing method of the micro-device substrate provided by the present disclosure, by making the groove 40 on the substrate 10 and arranging the filling portion 50 in the groove 40, the limiting of the receiving adhesive layer 20 is realized. When the receiving adhesive layer 20 is heated, it plays a certain limiting role on the receiving adhesive layer 20, which is beneficial to reducing the position deviation of the light-emitting chip 30, and thus is beneficial to improving the welding accuracy and the welding yield.

[0094] Figure 13 The figure shows a schematic flow chart of another manufacturing method of the micro-device substrate provided by the embodiment of the present disclosure. Figure 14 The figure shows the schematic diagram of the micro-device substrate after performing step S131 in Figure 13 . Figure 15 The figure shows the schematic diagram of the micro-device substrate when performing step S132 in Figure 13 . Figure 16 The figure shows the schematic diagram of the micro-device substrate after performing step S132 in Figure 13 . Please refer to Figure 5 、 Figure 6 、 Figure 9 and Figures 13 to 16, in an alternative embodiment of the present disclosure, a filling portion 50 and a receiving adhesive layer 20 are prepared on the side of the substrate 10 including the groove 40. Specifically:

[0095] Step S131: Prepare the receiving adhesive layer 20 on the side of the substrate 10 including the groove 40, and pattern the receiving adhesive layer 20 to form an adhesive groove communicating with the groove 40;

[0096] Step S132: Prepare a limiting layer on the side of the substrate 10 including the groove 40, and pattern the limiting layer to form at least one filling portion 50 and at least one limiting portion 60.

[0097] Specifically, in the method for manufacturing the micro-device substrate provided in this embodiment, after preparing the filling portion 50 and the receiving adhesive layer 20, steps S131 and S132 are further included. In step S131, the receiving adhesive layer 20 is patterned to form an adhesive groove 21, and the adhesive groove 21 communicates with the groove 40 on the substrate 10. After performing step S131, the structure of the micro-device substrate is as Figure 14 shown. Optionally, the receiving adhesive layer 20 is patterned by a photolithography process. In step S132, a limiting layer 600 is prepared on the side of the substrate 10 including the groove 40, and then the limiting layer 600 is patterned. Optionally, the limiting layer 600 is imaged by a photolithography process. After forming the limiting layer, the structure of the micro-device substrate 100 is as Figure 15 shown. Then, the limiting layer 600 is patterned to form at least one filling portion 50 and at least one limiting portion 60. After performing step S132, the structure of the micro-device substrate 100 is as Figure 6 shown. The limiting portion 60 fills part of the groove 40 and the adhesive groove 21, acts as the filling portion 50, and realizes the limitation of the receiving adhesive layer 20. When the receiving adhesive layer 20 is heated, it plays a certain limiting role on the receiving adhesive layer 20, which is beneficial to reducing the position deviation of the light-emitting chip 30, and thus is beneficial to improving the welding accuracy and the welding yield.

[0098] As can be seen from the above embodiments, the micro-device substrate and its manufacturing method provided by the present disclosure at least achieve the following beneficial effects:

[0099] The present disclosure provides a micro-device substrate and its manufacturing method. The micro-device substrate includes: a substrate; a receiving adhesive layer located on one side of the substrate; a plurality of light-emitting chips located on the side of the receiving adhesive layer away from the substrate; the substrate includes a groove, the groove is located on the side of the substrate facing the receiving adhesive layer, and the groove includes a filling portion, and the filling portion is in contact with the receiving adhesive layer. The micro-device substrate provided by the present disclosure restricts the thermal expansion of the receiving adhesive layer through the groove and the filling portion provided on the substrate, which is beneficial to reducing the position deviation of the light-emitting chip, and thus is beneficial to improving the welding accuracy and the welding yield.

[0100] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising said element.

[0101] The above are only specific embodiments of the present disclosure, enabling those skilled in the art to understand or implement the present disclosure. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments described herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A micro-device substrate, characterized in that: include: substrate; A receiving adhesive layer, located on one side of the substrate; A plurality of light-emitting chips are located on a side of the receiving adhesive layer away from the substrate; The substrate comprises a groove, the groove is located at a side of the substrate facing the receiving adhesive layer, the groove comprises a filling portion, and the filling portion is in contact with the receiving adhesive layer.

2. The micro-device substrate according to claim 1, characterized in that: At least a portion of the receiving adhesive layer fills the groove to form the filling portion.

3. The micro-device substrate according to claim 1, characterized in that: The orthographic projection of the groove on the plane where the substrate is located does not overlap with the orthographic projection of the light-emitting chip on the plane where the substrate is located.

4. The micro-device substrate according to claim 1, characterized in that: The groove includes a plurality of first sub-grooves extending along a first direction and a plurality of second sub-grooves extending along a second direction, the first sub-grooves and the second sub-grooves form a grid structure, the first direction intersects with the second direction, the first direction is parallel to the plane where the substrate is located, and the second direction is parallel to the plane where the substrate is located; The orthographic projection of the light emitting chip on the plane where the substrate is located is located within the grid structure.

5. The micro-device substrate according to claim 4, characterized in that: The width of the first sub-groove along the second direction is W1, 5 μm≤W1≤500 μm; and / or, A width of the second sub-groove along the first direction is W2, 5 μm≤W2≤500 μm.

6. The micro-device substrate according to claim 4, characterized in that: It also includes a limiting portion, at least part of which fills at least part of the groove, at least part of the filling portion is the limiting portion, and along the extension direction of the groove, the limiting portion is located in at least a partial area of ​​the groove.

7. The micro-device substrate according to claim 6, characterized in that: The limiting portion includes a first sub-limiting portion and a second sub-limiting portion, the first sub-limiting portion is at least partially located in the first sub-groove, the second sub-limiting portion is at least partially located in the second sub-groove, and the first sub-limiting portion and the second sub-limiting portion intersect.

8. The micro-device substrate according to claim 7, characterized in that: The position limiting portion is multiplexed as a positioning mark point, and the positioning mark point is used to locate the position of the micro-device substrate; The length of the alignment mark point along the first direction is S1, 30 μm≤S1≤100 μm; The length of the alignment mark point along the second direction is S2, 30 μm≤S2≤100 μm.

9. The micro-device substrate according to claim 1, characterized in that: It also includes a limiting portion, at least part of which fills the groove to form the filling portion, and along a direction perpendicular to the plane where the substrate is located, the limiting portion is at least partially located in the groove, and at least part of which is located in the receiving adhesive layer.

10. The micro-device substrate according to claim 9, characterized in that: Along a direction perpendicular to the plane where the substrate is located, a distance between a side surface of the limiting portion away from the substrate and the substrate is L1, a distance between a side surface of the light emitting chip away from the substrate and the substrate is L2, and L1≤L2.

11. The micro-device substrate according to claim 9, characterized in that: The thermal expansion coefficient of the limiting portion is smaller than the thermal expansion coefficient of the receiving adhesive layer.

12. The micro-device substrate according to claim 1, characterized in that: Along a direction perpendicular to the plane where the substrate is located, the depth of the groove is H1, 5 μm≤H1≤200 μm.

13. The micro-device substrate according to claim 1, characterized in that: The light-emitting chip comprises a light-emitting base and a chip electrode. The light-emitting base is in contact with the receiving adhesive layer. The chip electrode is located on a side of the light-emitting base away from the substrate.

14. A method for manufacturing a micro-device substrate, characterized in that: include: providing a substrate; Preparing a groove on one side surface of the substrate; A filling portion and a receiving adhesive layer are prepared on one side of the substrate including the groove; The light emitting chip is received on a side of the receiving adhesive layer away from the substrate.

15. The method for manufacturing a micro-device substrate according to claim 14, characterized in that: A filling portion and a receiving adhesive layer are prepared on one side of the substrate including the groove, specifically: A receiving adhesive layer is prepared on one side of the substrate including the groove, and the receiving adhesive layer is patterned to form an adhesive groove penetrating the groove; A limiting layer is prepared on a side of the substrate including the groove, and the limiting layer is patterned to form at least one filling portion and at least one limiting portion.

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