Display panel and display device

Abstract

The present disclosure relates to a display panel and a display device. The display panel comprises: a driving substrate; a bonding layer is arranged on one side of the driving substrate, and the bonding layer comprises a plurality of bonding structures; a plurality of light emitting chips are arranged on one side of the driving substrate, and the light emitting chips are provided with a plurality of electrodes on the side of the bonding layer of the driving substrate; the electrodes are electrically connected with the bonding structures; and a filling layer is arranged at least in the gap between the light emitting chips and the driving substrate; wherein the filling layer between the light emitting chips and the driving substrate comprises first filling structures and second filling structures arranged at intervals; and the thermal expansion coefficient of the second filling structures is smaller than that of the first filling structures. Through the technical scheme of the present disclosure, the risk of weld drop or fracture of the bonding structure due to mechanical fatigue is reduced, the reliability of the bonding structure is improved, and the reliability of the display panel is also improved.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and more particularly to a display panel and a display device. Background Technology

[0002] With the continuous development of science and technology, various display devices have been widely used in people's daily lives and work, bringing great convenience to people's lives. As the market demand for displays expands and application areas broaden, display products are showing a diversified development trend.

[0003] In related technologies, during thermal cycling tests of display panels, the test temperature ranges from -40°C to 85°C. The difference in thermal expansion coefficients between the filler layer and the bonding structure in the bonding layer of the display panel is significant. During high-temperature testing, the filler layer expands outward, compressing the bonding structure; during low-temperature testing, the filler layer contracts inward, stretching the bonding structure. The bonding structure is subjected to repeated compression and stretching during thermal cycling tests, which can easily lead to relative displacement with the driving substrate, resulting in mechanical fatigue and causing solder joint detachment or breakage, thus affecting the reliability of the display panel. Summary of the Invention

[0004] To address the aforementioned technical problems, this disclosure provides a display panel and a display device that reduces the risk of solder joint detachment or breakage due to mechanical fatigue in the bonding structure, improves the reliability of the bonding structure, and consequently improves the reliability of the display panel.

[0005] In a first aspect, this disclosure provides a display panel, including:

[0006] A driving substrate; a bonding layer is disposed on one side of the driving substrate, the bonding layer comprising multiple bonding structures;

[0007] Multiple light-emitting chips are located on one side of the driving substrate, and multiple electrodes are disposed on the side of the light-emitting chips facing the bonding layer of the driving substrate; the electrodes are electrically connected to the bonding structure.

[0008] A filling layer, wherein the filling layer is at least located in the gap between the light-emitting chip and the driving substrate;

[0009] The filling layer between the light-emitting chip and the driving substrate includes a first filling structure and a second filling structure arranged at intervals; the coefficient of thermal expansion of the second filling structure is less than that of the first filling structure.

[0010] Secondly, this disclosure also provides a display device, including a display panel as provided in the first aspect.

[0011] The technical solution provided in this disclosure has the following advantages compared with the prior art:

[0012] This disclosure provides a display panel and a display device. The display panel includes: a driving substrate; a bonding layer disposed on one side of the driving substrate, the bonding layer including multiple bonding structures; multiple light-emitting chips located on one side of the driving substrate, with multiple electrodes disposed on the side of the light-emitting chips facing the bonding layer of the driving substrate; the electrodes being electrically connected to the bonding structures; and a filling layer located at least in the gap between the light-emitting chips and the driving substrate; wherein the filling layer between the light-emitting chips and the driving substrate includes a first filling structure and a second filling structure arranged at intervals; the coefficient of thermal expansion of the second filling structure is less than that of the first filling structure. Therefore, by providing the first filling structure and the second filling structure arranged at intervals in the filling layer between the light-emitting chips and the driving substrate, and with the second filling structure having a lower coefficient of thermal expansion than the first filling structure, the difference between the coefficient of thermal expansion of the filling layer and the bonding structure is reduced. This reduces the force exerted by the filling layer on the bonding structure, making the stress on the bonding structure more uniform. The bonding structure is less prone to relative displacement with the driving substrate, reducing the risk of solder joint detachment or breakage due to mechanical fatigue, improving the reliability of the bonding structure, and consequently improving the reliability of the display panel and enhancing product reliability. Attached Figure Description

[0013] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0014] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A cross-sectional structural diagram of a display panel provided in an embodiment of this disclosure;

[0016] Figure 2 A cross-sectional structural schematic diagram of another display panel provided in an embodiment of this disclosure;

[0017] Figure 3 This is a top view of a filling layer provided in an embodiment of the present disclosure;

[0018] Figure 4 For along Figure 3 A schematic diagram of the cross-sectional structure of the middle segment AA';

[0019] Figure 5 for Figure 3 A schematic diagram of the cross-sectional structure of segment BB' along the middle line;

[0020] Figure 6 A cross-sectional structural schematic diagram of another display panel provided in an embodiment of this disclosure;

[0021] Figure 7 for Figure 6 The diagram shows a top view of the display panel structure.

[0022] Figure 8 for Figure 6 A magnified view of a portion of region C in the middle;

[0023] Figure 9 for Figure 8 The diagram shows a top view of the filling layer structure.

[0024] Figure 10 This is a top view of another filling layer provided in an embodiment of the present disclosure;

[0025] Figure 11 A cross-sectional structural schematic diagram of another display panel provided in an embodiment of this disclosure;

[0026] Figure 12 This is a partially enlarged cross-sectional view of a display panel provided in an embodiment of the present disclosure;

[0027] Figure 13 A partially enlarged cross-sectional view of another display panel provided in an embodiment of this disclosure;

[0028] Figure 14 A partially enlarged cross-sectional view of another display panel provided in an embodiment of this disclosure;

[0029] Figure 15 A partially enlarged cross-sectional view of another display panel provided in an embodiment of this disclosure;

[0030] Figure 16 This is a top view of a display panel provided in an embodiment of the present disclosure;

[0031] Figure 17 This is a schematic diagram of the structure of a display device provided in an embodiment of the present disclosure.

[0032] The correspondence between the reference numerals and the structural names in the attached drawings is as follows: 1. Driving substrate; 2. Light-emitting chip; 3. Electrode; 4. Bonding layer; 5. Filling layer; 6. Surface modification layer; 7. Protrusion structure; 100. Display panel; 31. First electrode; 32. Second electrode; 41. Bonding structure; 51. First filling structure; 52. Second filling structure; 511. Hole structure. Detailed Implementation

[0033] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0034] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0035] In related technologies, during thermal cycling tests of display panels, the test temperature ranges from -40°C to 85°C. If there is a significant difference in the coefficients of thermal expansion between the filler layer and the bonding structure located between the light-emitting chip and the driving substrate, the filler layer will expand outward during high-temperature testing, compressing the bonding structure. Conversely, during low-temperature testing, the filler layer will contract inward, stretching the bonding structure. Therefore, during thermal cycling tests, the bonding structure is subjected to repeated compression and stretching, which can easily lead to relative displacement, resulting in mechanical fatigue and causing solder joint detachment or breakage, thus affecting the reliability of the device.

[0036] To address the aforementioned problems, this disclosure provides a display panel comprising: a driving substrate; a bonding layer disposed on one side of the driving substrate, the bonding layer including multiple bonding structures; multiple light-emitting chips located on one side of the driving substrate, with multiple electrodes disposed on the side of the light-emitting chips facing the bonding layer of the driving substrate; the electrodes being electrically connected to the bonding structures; and a filling layer located at least in the gap between the light-emitting chips and the driving substrate; wherein the filling layer between the light-emitting chips and the driving substrate includes a first filling structure and a second filling structure arranged at intervals; the coefficient of thermal expansion of the second filling structure is less than that of the first filling structure. Therefore, by setting the coefficient of thermal expansion of the second filling structure to be less than that of the first filling structure, the difference between the coefficients of thermal expansion of the filling layer and the bonding structures is reduced. This reduces the force exerted by the filling layer between the light-emitting chips and the driving substrate on the bonding structures, making the stress on the bonding structures more uniform. The bonding structures are less prone to relative displacement with the driving substrate, reducing the risk of solder joint detachment or breakage due to mechanical fatigue, improving the reliability of the bonding structures, and consequently improving the reliability of the display panel.

[0037] Figure 1 This is a cross-sectional structural diagram of a display panel provided in an embodiment of the present disclosure. Figure 1Three light-emitting chips 2 are illustrated in the example. The light-emitting chips 2 can be LED chips, specifically Micro LED chips, Mini LED chips or other types of LED chips, or other types of light-emitting units. This disclosure does not limit the types of light-emitting units. Figure 1 The three light-emitting chips 2 in the display panel can be, for example, a red light-emitting chip 2, a green light-emitting chip 2, and a blue light-emitting chip 2, to achieve full-color display of the display panel. Figure 1 Different colored light-emitting chips 2 are distinguished by different filling patterns. Subsequent embodiments can be understood by referring to these examples, and will not be described in detail here.

[0038] The driving substrate 1 may have a circuit structure for transmitting electrical signals to the light-emitting chip 2 to drive the light-emitting chip 2 to emit light. The light-emitting chip 2 used in this embodiment may be, for example, a flip-chip light-emitting chip 2. The electrodes 3 of the light-emitting chip 2 are located on the same side of the light-emitting chip 2. The electrodes 3 of the light-emitting chip 2 are electrically connected to the driving substrate 1 through a bonding structure 41 in the bonding layer 4 to form an electrical signal loop between the light-emitting chip 2 and the driving substrate 1, thereby emitting light based on the electrical signals transmitted from the driving substrate 1.

[0039] Since there is a certain gap after the light-emitting chip and the driving substrate are bonded, a filler layer is also provided in the display panel. The filler layer is used to fill the gap between the light-emitting chip and the driving substrate to achieve planarization. The bonding layer is generally made of metal material with a small coefficient of thermal expansion, while the filler layer has a large coefficient of thermal expansion. In the thermal cycling test, the filler layer between the light-emitting chip and the driving substrate undergoes large deformation due to thermal expansion and contraction. The filler layer between the light-emitting chip and the driving substrate exerts a large compressive and tensile force on the bonding structure, and the bonding structure is prone to relative displacement during the thermal cycling test. Therefore, in this embodiment, the filler layer 5 between the light-emitting chip 2 and the driving substrate 1 is provided, including a first filler structure 51 and a second filler structure 52 with different coefficients of thermal expansion. The first filler structure 51 and the second filler structure 52 are arranged alternately to improve the thermal expansion uniformity of the filler layer 5. The thermal expansion coefficient of the second filler structure 52 is... The coefficient of thermal expansion is less than that of the first filling structure 51, thereby reducing the difference between the coefficient of thermal expansion of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 and the coefficient of thermal expansion of the bonding structure 41. The expansion and contraction of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 are reduced during the thermal cycling test. The force exerted by the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 on the bonding structure 41 is reduced, making the force on the bonding structure 41 more consistent. The bonding structure 41 is less likely to undergo relative displacement with the driving substrate 1, reducing the risk of solder joint detachment or breakage caused by mechanical fatigue of the bonding structure 41, improving the reliability of the bonding structure 41, and thus also improving the reliability of the display panel.

[0040] Optionally, such as Figure 1 As shown, the coefficient of thermal expansion of the first filling structure 51 is greater than that of the bonding layer 4.

[0041] Specifically, such as Figure 1 As shown, the coefficient of thermal expansion of the first filling structure 51 is greater than that of the bonding layer 4, resulting in a large difference in the coefficient of thermal expansion between the filling layer 5 and the bonding layer 4. Therefore, in this embodiment, a second filling structure 52 with a smaller coefficient of thermal expansion is arranged alternately with the first filling structure 51. The second filling structure 52 reduces the difference in the coefficient of thermal expansion between the filling layer 5 and the bonding structure 41 between the light-emitting chip 2 and the driving substrate 1. The expansion and contraction of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 are reduced during the thermal cycling test, thereby reducing the force exerted by the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 on the bonding structure 41. This makes the force on the bonding structure 41 more consistent, and the bonding structure 41 is less likely to undergo relative displacement with the driving substrate 1. This reduces the risk of solder joint detachment or breakage due to mechanical fatigue of the bonding structure 41, improves the reliability of the bonding structure 41, and consequently improves the reliability of the display panel.

[0042] Optionally, such as Figure 1 As shown, the coefficient of thermal expansion of the second filling structure 52 is less than that of the bonding layer 4.

[0043] Specifically, such as Figure 1 As shown, the coefficient of thermal expansion of the second filling structure 52 can be set to be less than that of the bonding layer 4. When the coefficient of thermal expansion of the first filling structure 51 is greater than that of the bonding layer 4, the second filling structure 52 can reduce the difference between the coefficient of thermal expansion of the first filling structure 51 and the bonding layer 4, thereby making the coefficient of thermal expansion of the filling layer 5 closer to that of the bonding layer 4. This reduces the degree of expansion and contraction of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 during the thermal cycling test, thereby reducing the force exerted by the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 on the bonding structure 41. This makes the stress on the bonding structure 41 more consistent during the thermal cycling test, reducing the risk of solder joint detachment or breakage caused by mechanical fatigue of the bonding structure 41, improving the reliability of the bonding structure 41, and thus improving the reliability of the display panel.

[0044] Optionally, such as Figure 1 As shown, the filling layer 5 is also filled between adjacent light-emitting chips 2; the filling layer 5 between adjacent light-emitting chips 2 includes a first filling structure 51.

[0045] Specifically, such as Figure 1As shown, a filling layer 5 is also provided between adjacent light-emitting chips 2, and the filling layer between adjacent light-emitting chips 2 includes a first filling structure 51. The filling layer 5 is used to fill the gap between adjacent light-emitting chips 2. Subsequently, when the transparent cover plate is pressed onto the side of the light-emitting chip 2 away from the driving substrate 1, the filling layer 5 can protect the light-emitting chip 2, avoiding damage from compression, and improving the reliability of the display panel. The filling layer 5 between adjacent light-emitting chips 2 also has a planarization effect, which is beneficial to the flatness of the surface of the light-emitting side of the light-emitting chip 2, improving the display effect of the display panel. In addition, the filling layer 5 between adjacent light-emitting chips 2 can also prevent water and oxygen from corroding the light-emitting chip 1.

[0046] In some embodiments, such as Figure 1 As shown, the first filling structure 51 in the filling layer 5 between adjacent light-emitting chips 2 and the first filling structure 51 in the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 can be made of the same material, which can achieve planarization and filling in the same process, simplifying the manufacturing process.

[0047] Figure 2 This is a schematic cross-sectional view of another display panel provided in an embodiment of this disclosure. Optionally, as... Figure 2 As shown, the filling layer 5 is also filled between adjacent light-emitting chips 2; the filling layer 5 between adjacent light-emitting chips 2 includes at least one first filling structure 51 and at least one second filling structure 52 arranged at intervals.

[0048] Specifically, such as Figure 2 As shown, the filling layer 5 disposed between adjacent light-emitting chips 2 further includes at least one first filling structure 51 and at least one second filling structure 52 arranged at intervals. The coefficient of thermal expansion of the first filling structure 51 is, for example, greater than that of the bonding layer 4, and the coefficient of thermal expansion of the second filling structure 52 is, for example, less than that of the bonding layer 4. By setting the first filling structure 51 and the second filling structure 52 with different coefficients of thermal expansion between adjacent light-emitting chips 2, the difference in coefficients of thermal expansion between the first filling structure 51 and the bonding layer 4 is reduced by the second filling structure 52. This makes the coefficient of thermal expansion of the filling layer 5 between adjacent light-emitting chips 2 also close to that of the bonding layer 4, reducing the degree of expansion and contraction of the filling layer 5 between adjacent light-emitting chips 2 during thermal cycling tests. This reduces the force exerted by the filling layer 5 between adjacent light-emitting chips 2 on the bonding structure 41, lowers the risk of solder joint detachment or breakage of the bonding structure 41 due to mechanical fatigue, further makes the stress on the bonding layer 4 more consistent, avoids relative displacement between the bonding structure 41 and the driving substrate 1, and improves the reliability of the bonding structure 41.

[0049] Figure 3This is a top view schematic diagram of a filling layer provided in an embodiment of the present disclosure. Optionally, in conjunction with... Figure 2 and Figure 3 The first filling structure 51 includes multiple hole structures 511; the second filling structure 52 is located inside the hole structures 511.

[0050] Specifically, in combination Figures 2 to 3 Multiple hole structures 511 can be provided in the first filling structure 51. Figure 2 The example shows nine hole structures 511, each of which is filled with a second filling structure 52. The second filling structure 52, which has a smaller coefficient of thermal expansion, reduces the difference in the coefficient of thermal expansion between the filling layer 5 and the bonding layer 4, making the stress on the bonding layer 4 more consistent, avoiding relative displacement of the bonding layer 4, and reducing the risk of solder joint detachment or breakage due to mechanical fatigue of the bonding structure 41.

[0051] In some embodiments, a second filling structure 52 may be formed first, such as a columnar structure. After the bonding layer 4 is bonded to the electrode 3, a first filling structure 51 is filled between the light-emitting chip 2 and the driving substrate 1, thereby forming a first filling structure 51 and a second filling structure 52 arranged at intervals. In other embodiments, the first filling structure 51 may be filled first, and a plurality of hole structures 511 may be formed in the first filling structure 51. Then, the second filling structure 52 may be filled into the plurality of hole structures 511, thereby forming a first filling structure 51 and a second filling structure 52 arranged at intervals.

[0052] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of segment AA' along the middle line. Figure 4 The cross-section along the direction of line segment AA' is shown as an example, and the filling layer 5 includes only the first filling structure 51. Figure 5 for Figure 3 A schematic diagram of the cross-sectional structure of segment BB' along the middle line. Figure 5 The cross-section along the direction of line segment BB' is shown as an example. The filling layer 5 includes a first filling structure 51 and a second filling structure 52 arranged at intervals.

[0053] It should be noted that the number of holes 511 in the first filling structure 51 can be set according to the actual usage requirements and manufacturing process of the display panel, and this embodiment does not limit this. The specific filling method of the first filling structure 51 and the second filling structure 52 can also be selected according to the actual manufacturing process of the display panel, and this embodiment does not limit this.

[0054] Figure 6 This is a cross-sectional structural diagram of another display panel provided in an embodiment of this disclosure. Figure 7 for Figure 6 The diagram shows a top view of the display panel. Optionally, in conjunction with... Figure 1 , Figure 2 , Figure 6 and Figure 7 Electrode 3 includes a first electrode 31 and a second electrode 32. Along the direction from the first electrode 31 to the second electrode 32, the first filling structure 51 and the second filling structure 52 are stacked.

[0055] For example, combined Figure 1 , Figure 2 and Figure 6 The first electrode 31 and the second electrode 32 can be, for example, an anode and a cathode, respectively. The anode and cathode of the light-emitting chip 2 are electrically connected to the driving substrate 1 through a bonding structure 41. Figure 1 and Figure 6 Taking the display panel shown as an example, an arrayed second filling structure 52 can be formed between two bonding structures 41 bonded to the same light-emitting chip 2. The first filling structure 51 fills the space between the light-emitting chip 2 and the bonding structure 41, as well as between adjacent light-emitting chips 2, so that the first filling structure 51 and the second filling structure 52 between the light-emitting chip 2 and the driving substrate 1 are stacked. Figure 2 Taking the display panel shown as an example, an array of second filling structures 52 can be formed between adjacent bonding structures 41. The first filling structure 51 is filled between the light-emitting chip 2 and the bonding structure 41, as well as between adjacent light-emitting chips 2, so that the first filling structure 51 and the second filling structure 52 between the light-emitting chip 2 and the driving substrate 1, as well as the first filling structure 51 and the second filling structure 52 between adjacent light-emitting chips 2, are stacked and arranged.

[0056] Because the materials constituting the first filling structure 51 and the second filling structure 52 are different, their coefficients of thermal expansion are also different. If, along the direction from the first electrode 31 to the second electrode 32, the first filling structure 51 is filled on the side closer to the first electrode 31, and the second filling structure 52 is filled on the side closer to the second electrode 32, there will be a significant interface effect between the first filling structure 51 and the second filling structure 52. That is, the coefficient of thermal expansion on one side of the filling layer 5 is smaller, while the coefficient of thermal expansion on the other side is larger. The filling layer 5 cannot be considered as a whole, resulting in poor mechanical properties. Therefore... Figure 1 , Figure 2 and Figure 6 The example shows that, along the direction from the first electrode 31 to the second electrode 32, the first filling structure 51 and the second filling structure 52 are stacked and alternately arranged, which improves the uniformity of the filling layer 5, improves the mechanical properties of the filling layer 5, and improves the interface effect between the first filling structure 51 and the second filling structure 52.

[0057] Optionally, such as Figure 6 As shown, the first filling structure 51 is also located between the second filling structure 52 and the light-emitting chip 2.

[0058] For example, such as Figure 6 As shown, the second filling structure 52 is typically made of a rigid material. During the process of bonding the light-emitting chip 2 to the bonding layer 4 to electrically connect the light-emitting chip 2 and the driving substrate 1, the second filling structure 52 can easily scratch the light-emitting chip 2 when it comes into contact with it. To avoid damaging the light-emitting chip 2, this embodiment of the present disclosure provides a first filling structure 51 between the second filling structure 52 and the light-emitting chip 2. The first filling structure 51 can space the second filling structure 52 and the light-emitting chip 2, so that the second filling structure 52 does not directly contact the light-emitting chip 2, protecting the light-emitting chip 2 from scratches by the second filling structure 52, reducing the risk of damage to the light-emitting chip 2, and improving the reliability of the display panel.

[0059] Optionally, such as Figure 6 As shown, a first filling structure 51 is disposed between the electrode 3 and the second filling structure 52 along a direction parallel to the driving substrate 1.

[0060] Specifically, such as Figure 6 As shown, since the second filling structure 52 is generally made of rigid material and the electrode 3 and bonding structure 41 are both made of metal material when manufacturing the display panel, the electrode 3 and bonding structure 41 cannot be completely in contact with the second filling structure 52. That is, there is a gap between the electrode 3 and bonding structure 41 and the second filling structure 52. Therefore, by placing the first filling structure 51 in the gap between the second filling structure 52 and the electrode 3, and in the gap between the second filling structure 52 and the bonding structure 41, the flatness of the display panel is improved.

[0061] Figure 8 for Figure 6 A magnified view of a portion of region C in the middle. Figure 9 for Figure 8 The diagram shows a top view of the filling layer. Optionally, combined with... Figure 8 and Figure 9 The projected area of ​​the second filling structure 52 closer to the bonding structure 41 on the driving substrate 1 is greater than the projected area of ​​the second filling structure 52 farther from the bonding structure 41 on the driving substrate 1.

[0062] Specifically, in combination Figure 8 and Figure 9During thermal cycling tests, the force exerted by the filler layer 5 on the bonded structure 41 is smaller when it is closer to the center position DD' of the two adjacent bonded structures 41, and the force exerted by the filler layer 5 on the bonded structure 41 is larger when it is closer to the bonded structure 41. Therefore, the difference between the thermal expansion coefficient of the filler layer 5 at the center position DD' of the two adjacent bonded structures 41 and the thermal expansion coefficient of the bonded structure 41 can be greater than the difference between the thermal expansion coefficient of the filler layer 5 at the position closer to the bonded structure 41 and the thermal expansion coefficient of the bonded structure 41.

[0063] Since the coefficient of thermal expansion of the second filling structure 52 is less than that of the first filling structure 51, the difference in the coefficient of thermal expansion between the filling layer 5 and the bonding layer 4 can be reduced by using the second filling structure 52. Therefore, in this embodiment, the projected area of ​​the second filling structure 52 near the bonding structure 41 on the driving substrate 1 is larger than that of the second filling structure 52 far from the bonding structure 41 on the driving substrate 1. This makes the difference between the coefficient of thermal expansion of the filling layer 5 near the bonding structure 41 and the coefficient of thermal expansion of the bonding layer 4 smaller than the difference between the coefficient of thermal expansion of the second filling structure 52 far from the electrode 3 and the coefficient of thermal expansion of the bonding layer 4. That is, the coefficient of thermal expansion of the filling layer 5 near the bonding structure 41 is closer to that of the bonding layer 4, thereby reducing the force exerted by the filling layer 5 near the bonding structure 41 on the bonding layer 4 and improving the reliability of the bonding structure 41.

[0064] Figure 10 This is a top view of another filling layer structure provided in an embodiment of the present disclosure. In some embodiments, a symmetrical light-emitting chip 2 is taken as an example. Figure 10 The example illustrates that, along the longitudinal central axis EE' away from the light-emitting chip 2, the projected area of ​​the second filling structure 52 gradually increases and the projected area of ​​the first filling structure 51 gradually decreases, or along the transverse central axis FF' away from the light-emitting chip 2, the projected area of ​​the second filling structure 52 gradually increases and the projected area of ​​the first filling structure 51 gradually decreases, in order to reduce the difference in the coefficient of thermal expansion between the filling layer 5 and the bonding structure 41, thereby reducing the force exerted by the filling layer 5 on the bonding layer 4 near the bonding structure 41 and improving the reliability of the bonding structure 41.

[0065] Figure 11 This is a schematic cross-sectional view of another display panel provided in an embodiment of this disclosure. Optionally, as... Figure 11 As shown, the first filling structure 51 and the second filling structure 52 are stacked in a direction perpendicular to the driving substrate 1.

[0066] For example, such as Figure 11As shown, a first filling structure 51 can be formed on the side of the light-emitting chip 2, and a second filling structure 52 can be formed on the side of the bonding layer 4. After the light-emitting chip 2 and the bonding layer 4 are bonded, the filling structure and the second filling structure 52 can be stacked in a direction perpendicular to the driving substrate 1. In some embodiments, the height of the second filling structure 52 can be set to be less than or equal to the height of the bonding structure 41 in a direction perpendicular to the driving substrate 1, so as to avoid the protrusion of the second filling structure 52 affecting the electrical connection between the electrode 31 and the bonding structure 41.

[0067] Therefore, by stacking the first filling structure 51 and the second filling structure 52 along a direction perpendicular to the driving substrate 1, the thermal expansion uniformity of the filling layer 5 is improved. The second filling structure 52 reduces the difference between the thermal expansion coefficient of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 and the thermal expansion coefficient of the bonding structure 41. The expansion and contraction of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 are reduced during the thermal cycling test. The force exerted by the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 on the bonding structure 41 is reduced, making the force on the bonding structure 41 more uniform. The bonding structure 41 is less likely to undergo relative displacement with the driving substrate 1, reducing the risk of solder joint detachment or breakage due to mechanical fatigue of the bonding structure 41 and improving the reliability of the bonding structure 41.

[0068] Optionally, the first filling structure 51 includes an organic material, and the second filling structure 52 includes a metallic material.

[0069] For example, the first filling structure 51 can be an organic material, such as an acrylic, epoxy, or siloxane resin, used for planarization between the light-emitting chip 2 and the driving substrate 1, as well as between adjacent light-emitting chips 2. The second filling structure 52 can be made of the same metal material as the bonding structure 41, such as copper. The coefficient of thermal expansion of the metal material is lower than that of the organic material; therefore, using the metal material as the second filling structure 52 can reduce the difference in the coefficient of thermal expansion between the filling layer 5 and the bonding structure 41. Alternatively, the second filling structure 52 can be made of a metal material with a coefficient of thermal expansion lower than that of the bonding structure 41 to further reduce the difference in the coefficient of thermal expansion between the filling layer 5 and the bonding structure 41.

[0070] In some embodiments, in the field of transparent display panel applications, the first filling structure 51 between adjacent light-emitting chips 2 and the first filling structure 51 between light-emitting chip 2 and driving substrate 1 can both be made of transparent organic materials to meet the requirements of transparent display.

[0071] In some embodiments, combined with Figure 1 and Figure 3When the second filling structure 52 fills the cavity structure 511, the second filling structure 52 and the bonding structure 41 formed by chemical plating can be formed simultaneously, achieving a simplified process. In the chemical plating process, the metal ion concentration is adjusted to make the columnar second filling structure 52 and the bonding structure 41 have different heights. Along the direction perpendicular to the driving substrate 1, the height of the second filling structure 52 is greater than the height of the bonding structure 41. If both the bonding structure 41 and the second filling structure 52 are formed by chemical plating, since the bonding structure 41 requires nickel metal bonding and gold can be used to prevent the oxidation of the copper-nickel metal layer, nickel and gold will also be plated on the second filling structure 52. In addition, the organic material in the first filling structure 51 is a polyimide-based resin material suitable for chemical plating. The specific process flow of the chemical plating process and the specific film structure of the bonding structure 41 are well known to those skilled in the art and will not be described in detail here.

[0072] It should be noted that other processes can also be used to fill the organic material with the metal material. The corresponding organic material and metal material can be selected according to the corresponding process and the usage requirements of the display panel. This disclosure does not limit this.

[0073] Optionally, the first filling structure 51 also includes a metal oxide cleaner.

[0074] Specifically, the first filling structure 51 not only contains organic materials but may also include a metal oxide cleaner. For example, the first filling structure 51 can be an epoxy-based organic material containing a metal oxide cleaner. The metal oxide cleaner can clean the oxides formed on the surface of the bonding structure 41, improving the electrical properties of the bonding structure 41 and increasing the bonding strength between the bonding structure 41 and the electrode 3. This avoids the problem of decreased bonding strength caused by corrosion and oxidation of the metal in the bonding structure 41. Furthermore, the first filling structure 51 containing the metal oxide cleaner has fluidity before the light-emitting chip 2 is bonded to the bonding layer 4, preventing protrusions in the first filling structure 51 from affecting the electrical connection between the electrode 31 and the bonding structure 41.

[0075] Optionally, the first filling structure 51 includes organic materials, and the second filling structure 52 includes inorganic materials.

[0076] Specifically, the first filling structure 51 may include organic materials such as resins, serving a planarization function. The second filling structure 52 may be an inorganic material such as SiNx, SiOx, or SiNO, whose coefficient of thermal expansion is lower than that of the bonding structure 41. The bonding structure 41 is made of metallic materials, while the coefficient of thermal expansion of organic materials is much greater than that of the bonding structure 41. Therefore, by including an inorganic material with a coefficient of thermal expansion lower than that of the bonding structure 41 in the second filling structure 52, the difference in coefficients of thermal expansion between the filling layer 5 and the bonding structure 41 can be reduced, making the stress on the bonding structure 41 more uniform and improving the reliability of the bonding structure 41.

[0077] In some embodiments, in the field of transparent display panel applications, the first filling structure 51 between adjacent light-emitting chips 2 and the first filling structure 51 between light-emitting chip 2 and driving substrate 1 may include, for example, transparent organic materials to meet the requirements of transparent display.

[0078] Figure 12 This is a partially enlarged cross-sectional schematic diagram of a display panel provided in an embodiment of this disclosure. Optionally, as... Figure 12 As shown, a surface modification layer 6 is provided between adjacent first filling structure 51 and second filling structure 52; the surface modification is used to hydrophilically modify the surface of the second filling structure 52 adjacent to the first filling structure 51.

[0079] Specifically, such as Figure 12 As shown, the first filling structure 51 and the second filling structure 52 contain materials with different properties. Therefore, the interfacial bonding force between the first filling structure 51 and the second filling structure 52 is low. In order to improve the interfacial bonding force between the first filling structure 51 and the second filling structure 52, a surface modification layer 6 can be provided between adjacent first filling structures 51 and second filling structures 52 to perform hydrophilic modification on the surface of the second filling structure 52 near the first filling structure 51. The surface of the second filling structure 52, for example, an inorganic material, is changed from hydrophobic to hydrophilic, thereby enhancing the adhesion between the second filling structure 52 and the first filling structure 51 and improving the bonding effect between the second filling structure 52 and the first filling structure 51.

[0080] For example, hexamethyldisilazane (HMDS) can be coated on the surface of the second filling structure 52 adjacent to the first filling structure 51 as a surface modification layer 6. Hexamethyldisilazane can act as an adhesive aid, changing the hydrophobicity of the surface of the second filling structure 52 near the first filling structure 51 to hydrophilicity, thereby enhancing the adhesion between the second filling structure 52 and the first filling structure 51.

[0081] It should be noted that the specific materials used in the surface modification layer can be set according to the actual manufacturing requirements of the display panel, and this disclosure does not limit this.

[0082] Figure 13 This is a partially enlarged cross-sectional view of another display panel provided as an embodiment of this disclosure. Optionally, as... Figure 13 As shown, the surface of the second filling structure 52 adjacent to the first filling structure 51 includes a plurality of protrusion structures 7.

[0083] For example, such as Figure 13 As shown, multiple protrusions 7 can be provided on the surface of the second filling structure 52 near the first filling structure 51. The first filling structure 51 is, for example, an organic material. The organic material has a certain fluidity and deformation ability during the pressing process with the second filling structure 52. The organic material can be filled into the protrusions 7. The protrusions 7 increase the surface area of ​​the second filling structure 52, thereby increasing the contact area between the second filling structure 52 and the first filling structure 51. This can enhance the adhesion between the first filling structure 51 and the second filling structure 52 and improve the bonding effect between the second filling structure 52 and the first filling structure 51.

[0084] Figure 14 This is a partially enlarged cross-sectional view of another display panel provided in an embodiment of this disclosure. Figure 14 The diagram illustrates a schematic of the light-emitting chip 2 before bonding with the bonding structure 41. Multiple protrusions 7 are provided on the surface of the first filling structure 51 adjacent to the second filling structure 52. The recessed positions of the first filling structure 51 correspond to the protruding positions of the second filling structure 52, and the protruding positions of the first filling structure 51 correspond to the recessed positions of the second filling structure 52. This increases the contact area between the first filling structure 51 and the second filling structure 52, and enhances the adhesion between the first filling structure 51 and the second filling structure 52.

[0085] Optionally, the total volume of the first filling structure 51 filling the space between the light-emitting chip 2 and the driving substrate 1 and the total volume of the second filling structure 52 filling the space between the light-emitting chip 2 and the driving substrate 1 satisfy the following:

[0086] (CTE1*X1+CTE2*X2) / 2=CTE3;

[0087] X1=V1 / (V1+V2); X2=V2 / (V1+V2);

[0088] Wherein, CTE1 is the coefficient of thermal expansion of the first filling structure 51, CTE2 is the coefficient of thermal expansion of the second filling structure 52, and CTE3 is the coefficient of thermal expansion of the bonding layer 4; V1 is the total volume of the first filling structure 51 between the light-emitting chip 2 and the driving substrate 1; and V2 is the total volume of the second filling structure 52 between the light-emitting chip 2 and the driving substrate 1.

[0089] Specifically, in this embodiment of the present disclosure, the coefficient of thermal expansion of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 is equal to the coefficient of thermal expansion of the bonding structure 41, so that the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 and the bonding structure 41 are regarded as a whole. Figure 15 A partially enlarged cross-sectional schematic diagram of another display panel provided in an embodiment of this disclosure, referring to... Figure 15 When the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 and the bonding structure 41 are regarded as a whole, the force F1 from the left side of the whole structure and the force F2 from the right side of the whole structure can cancel each other out, making the force on the bonding structure 41 more consistent, improving the reliability of the bonding structure 41, reducing the risk of solder joint detachment or breakage due to mechanical fatigue, and improving the reliability of the bonding structure 41.

[0090] Figure 16 This is a top view structural diagram of a display panel provided in an embodiment of this disclosure. Optionally, as... Figure 16 As shown, the difference between the coefficient of thermal expansion of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 near the edge of the display panel and the coefficient of thermal expansion of the bonding structure 41 is smaller than the difference between the coefficient of thermal expansion of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 near the center of the display panel and the coefficient of thermal expansion of the bonding structure 41.

[0091] Specifically, such as Figure 16 As shown, the difference between the coefficient of thermal expansion of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 at position M near the edge of the display panel and the coefficient of thermal expansion of the bonding structure 41 is CTE. a The difference between the coefficient of thermal expansion of the filling layer 5 between the light-emitting chip 2 near the center N of the display panel and the coefficient of thermal expansion of the bonding structure 41 is CTE. b From a macroscopic perspective of the display panel, the filling layer 5 near the edge M of the display panel deforms more, exerting a greater force on the bonding structure 41. This makes the bonding structure 41 more prone to solder joint detachment or breakage. Conversely, the filling layer 5 near the center N of the display panel deforms less, exerting a smaller force on the bonding structure 41. This reduces the risk of solder joint detachment or breakage in the bonding structure 41. This embodiment of the present disclosure sets a CTE. a Less than CTE b The coefficient of thermal expansion of the filling layer 5 between the light-emitting chip 2 and the driving substrate 1 near the edge of the display panel is closer to that of the bonding structure 41, thereby reducing the force of the filling layer 5 near the edge M of the display panel on the bonding structure 41, reducing the risk of solder joint detachment or breakage of the bonding structure 41, and improving the reliability of the display panel.

[0092] The display panel provided in this embodiment includes a driving substrate, multiple light-emitting chips, and a filling layer. By providing a first filling structure and a second filling structure arranged at intervals in the filling layer between the light-emitting chips and the driving substrate, and the thermal expansion coefficient of the second filling structure is smaller than that of the first filling structure, the difference between the thermal expansion coefficient of the filling layer and the thermal expansion coefficient of the bonding structure is reduced. The force exerted by the filling layer between the light-emitting chips and the driving substrate on the bonding structure is reduced, making the stress on the bonding structure more consistent. The bonding structure is less likely to undergo relative displacement with the driving substrate, reducing the risk of solder joint detachment or breakage due to mechanical fatigue, improving the reliability of the bonding structure, and thus improving the reliability of the display panel and the product's trustworthiness.

[0093] Based on the same inventive concept, this disclosure also provides a display device, including a display panel as described in any of the above-described display panel embodiments. Therefore, this display device possesses the technical features of the display panel provided in this disclosure and can achieve the beneficial effects of the display panel provided in this disclosure. Similarities can be found in the above description of the display panel provided in this disclosure, and will not be repeated here.

[0094] For example, Figure 17 This is a schematic diagram of the structure of a display device provided in an embodiment of this disclosure. Figure 17 As shown, the display device provided in this embodiment includes the display panel 100 provided in any of the above embodiments of this disclosure. Figure 17 The embodiments use mobile phones as an example to illustrate the display device. It is understood that the display device provided in the embodiments of this application can be any electronic product with display function, including but not limited to the following categories: mobile phones, televisions, laptops, desktop monitors, tablets, digital cameras, smart bracelets, smart glasses, in-vehicle displays, medical devices, industrial control equipment, touch interactive terminals, etc. The embodiments of this invention do not make any special limitations in this regard.

[0095] The display device provided in this disclosure includes the above-described display panel, and therefore can solve the same technical problems as the above-described display panel embodiments and achieve the same technical effects, which will not be repeated here.

[0096] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0097] The above are merely specific embodiments of this disclosure, enabling those skilled in the art to understand or implement this disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to these embodiments, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A display panel, characterized in that, include: Drive substrate; A bonding layer is provided on one side of the driving substrate, and the bonding layer includes multiple bonding structures; Multiple light-emitting chips are located on one side of the driving substrate, and multiple electrodes are disposed on the side of the light-emitting chips facing the bonding layer of the driving substrate; the electrodes are electrically connected to the bonding structure. A filling layer, wherein the filling layer is at least located in the gap between the light-emitting chip and the driving substrate; The filling layer between the light-emitting chip and the driving substrate includes a first filling structure and a second filling structure arranged at intervals; the coefficient of thermal expansion of the second filling structure is less than that of the first filling structure; the difference between the coefficient of thermal expansion of the filling layer between the light-emitting chip and the driving substrate near the edge of the display panel and the coefficient of thermal expansion of the bonding structure is less than the difference between the coefficient of thermal expansion of the filling layer between the light-emitting chip and the driving substrate near the center of the display panel and the coefficient of thermal expansion of the bonding structure.

2. The display panel of claim 1, wherein, The coefficient of thermal expansion of the first filling structure is greater than that of the bonding layer.

3. The display panel of claim 1, wherein, The coefficient of thermal expansion of the second filling structure is less than that of the bonding layer.

4. The display panel of claim 1, wherein, The filling layer is also disposed between adjacent light-emitting chips; the filling layer between adjacent light-emitting chips includes the first filling structure.

5. The display panel of claim 1, wherein, The filling layer is also disposed between adjacent light-emitting chips; the filling layer between adjacent light-emitting chips includes at least one first filling structure and at least one second filling structure arranged at intervals.

6. The display panel of claim 1, wherein, The first filling structure includes multiple pore structures; the second filling structure is located within the pore structures.

7. The display panel of claim 1, wherein, The electrode includes a first electrode and a second electrode, and the first filling structure and the second filling structure are stacked in a direction from the first electrode to the second electrode.

8. The display panel of claim 7, wherein, The first filling structure is also located between the second filling structure and the light-emitting chip.

9. The display panel of claim 7, wherein, Along a direction parallel to the driving substrate, the first filling structure is disposed between the electrode and the second filling structure.

10. The display panel according to any one of claims 6-9, characterized in that, The projected area of ​​the second filling structure closer to the bonding structure on the driving substrate is greater than the projected area of ​​the second filling structure farther away from the bonding structure on the driving substrate.

11. The display panel of claim 1, wherein, The first filling structure and the second filling structure are stacked in a direction perpendicular to the driving substrate.

12. The display panel of any one of claims 1-9, wherein, The first filling structure comprises an organic material, and the second filling structure comprises a metallic material.

13. The display panel of claim 12, wherein, The first filling structure also includes a metal oxide cleaner.

14. The display panel of any one of claims 1-9, wherein, The first filling structure comprises an organic material, and the second filling structure comprises an inorganic material.

15. The display panel of claim 14, wherein, A surface modification layer is provided between adjacent first filling structure and second filling structure; the surface modification is used to hydrophilically modify the surface of the second filling structure adjacent to the first filling structure.

16. The display panel of claim 14, wherein, The surface of the second filling structure adjacent to the first filling structure includes multiple protrusions.

17. The display panel of claim 1, wherein, The total volume of the first filling structure filling the space between the light-emitting chip and the driving substrate and the total volume of the second filling structure filling the space between the light-emitting chip and the driving substrate satisfy the following: (CTE1*X1+CTE2*X2) / 2=CTE3; X1=V1 / (V1+V2); X2=V2 / (V1+V2); Wherein, CTE1 is the coefficient of thermal expansion of the first filling structure, CTE2 is the coefficient of thermal expansion of the second filling structure, and CTE3 is the coefficient of thermal expansion of the bonding layer; V1 is the total volume of the first filling structure between the light-emitting chip and the driving substrate; and V2 is the total volume of the second filling structure between the light-emitting chip and the driving substrate.

18. A display device comprising: Includes the display panel as described in any one of claims 1-17.

Images