TWI848682B - Display element and display device - Google Patents

Abstract

A display element includes a receiving plate, a first circuit layer, a second circuit layer, a plurality of light emitting elements and an encapsulant layer. The receiving plate includes an insulating layer and a plurality of through vias through the upper and lower surfaces of the receiving plate. The insulating layer has a first coefficient of thermal expansion (CTE). The first circuit layer is disposed on the lower surface of the receiving board and has a plurality of first electrodes. The second circuit lay is disposed on the upper surface of the receive board and has a plurality of second electrodes, and each of the second electrodes is connected with the corresponding first electrode through the corresponding through hole. A plurality of light emitting elements are disposed over the receiving board and the second circuit layer and are electrically connected to the corresponding second electrodes respectively. The encapsulant layer covers the receiving board, the second circuit layer and the light-emitting elements, the encapsulant layer has a second CTE, and the second CTE of the encapsulant layer is smaller than the first CTE of the insulating layer of the receiving board.

Description

Display element and display device

The present disclosure relates to a display element having a packaging structure and a display device including the display element.

The LED display panel includes a driving circuit board and a plurality of LED components on the driving circuit board. Inheriting the characteristics of LEDs, the LED display panel has the advantages of power saving, high efficiency, high brightness and fast response time.

In the manufacturing process of LED display panels, multiple LED components need to be placed on a driving circuit board and packaged. However, the yield of the manufacturing process of LED display panels still needs to be improved.

Some embodiments of the present disclosure provide a display element, comprising: a receiving board, a first circuit layer, a second circuit layer, a plurality of light-emitting elements, and a packaging adhesive layer. The receiving board comprises an insulating layer and a plurality of through holes. The through holes penetrate the upper and lower surfaces opposite to each other of the receiving board. The insulating layer of the receiving board has a first thermal expansion coefficient. The first circuit layer is disposed on the lower surface of the receiving board, and the first circuit layer has a plurality of separated first electrodes. The second circuit layer is disposed on the upper surface of the receiving board, and the second circuit layer has a plurality of separated second electrodes, and each of the second electrodes is connected to each of the first electrodes through each of the corresponding through holes. A plurality of light-emitting elements are arranged on the receiving board and the second circuit layer, and two parts of each light-emitting element are electrically connected to two corresponding adjacent second electrodes. A packaging glue layer covers the receiving board, the second circuit layer and the light-emitting elements, and the packaging glue layer has a second thermal expansion coefficient, which is smaller than the first thermal expansion coefficient of the insulating layer of the receiving board.

In some embodiments, in the display element, a ratio of the second thermal expansion coefficient to the first thermal expansion coefficient is less than or equal to approximately 0.8 and greater than 0.

In some embodiments, in a display device, the Young's modulus of the encapsulation adhesive layer is in a range of about 0.1 MPa to about 10 GPa.

In some embodiments, in the display device, the first thermal expansion coefficient of the insulating layer of the receiving plate ranges from about 30 ppm/°C to about 70 ppm/°C.

In some embodiments, in the display device, the insulating layer of the receiving plate includes at least one of polyimide (PI), benzocyclobutene (BCB), polybenzoxazole (PBO), Su-8 negative photoresist, or WPR photoresist.

In some embodiments, in the display device, the second thermal expansion coefficient of the encapsulation glue layer ranges from about 1 ppm/°C to about 65 ppm/°C.

In some embodiments, in the display device, the second thermal expansion coefficient of the encapsulation glue layer ranges from about 10 ppm/°C to about 40 ppm/°C.

In some implementations, in the display device, the encapsulation adhesive layer includes silicone or epoxy.

In some embodiments, in the display device, the encapsulation glue layer contains an inorganic filling material.

Some embodiments of the present disclosure provide a display device, comprising: a support plate and a display element. The support plate comprises a plurality of pads and a plurality of circuits corresponding to and electrically connected to the pads. The display element is the display element described in the above and below embodiments, wherein the first electrodes of each display element are electrically connected to the corresponding pads of the support plate.

In some implementations, in the display device, there is a gap between the display elements, and the gap is filled with a filling material.

In some implementations, in the display device, the material of the filling material is the same as or different from the material of the encapsulation glue layer.

In some implementations, in the display device, each of the circuits includes at least one of a driving element, a switching element, a line, a diode, a resistor, or a capacitor.

Some embodiments of the present disclosure provide a display device, comprising: a support plate, a plurality of display elements, and a packaging adhesive layer. The support plate comprises a plurality of pads and a plurality of circuits corresponding to and electrically connected to the pads. A plurality of display elements are disposed on the support plate, and there is a gap between two adjacent display elements, and each of the display elements comprises: a receiving plate, a first circuit layer, a second circuit layer, and a plurality of light-emitting elements. The receiving plate comprises an insulating layer and a plurality of through holes. The through holes penetrate the opposite upper and lower surfaces of the receiving plate. The insulating layer of the receiving plate has a first thermal expansion coefficient. The first circuit layer is disposed on the lower surface of the receiving plate, and the first circuit layer has a plurality of separated first electrodes. The second circuit layer is arranged on the upper surface of the receiving board, and the second circuit layer has a plurality of separated second electrodes. Each of the second electrodes is connected to each of the first electrodes through the corresponding through holes. A plurality of light-emitting elements are arranged on the receiving board and the second circuit layer. Two parts of each of the light-emitting elements are electrically connected to the corresponding two adjacent second electrodes. The packaging rubber layer covers the receiving board, the supporting board, the second circuit layer and the light-emitting elements and fills the spaces, and the packaging rubber layer has a second thermal expansion coefficient, and the second thermal expansion coefficient of the packaging rubber layer is less than the first thermal expansion coefficient of the insulating layer of the receiving board. The first electrodes of each display element are electrically connected to the corresponding pads of the supporting plate.

In some embodiments, in the display device, a ratio of the second thermal expansion coefficient to the first thermal expansion coefficient is less than or equal to approximately 0.8 and greater than 0.

In some embodiments, in a display device, the insulating layer of the receiving plate includes at least one of polyimide (PI), benzocyclobutene (BCB), polybenzoxazole (PBO), Su-8 negative photoresist, or WPR photoresist.

In some implementations, in the display device, the encapsulation adhesive layer includes silicone or epoxy.

In some implementations, in a display device, the encapsulation layer includes an inorganic filling material.

In some implementations, in the display device, each of the circuits includes at least one of a driving element, a switching element, a line, a diode, a resistor, or a capacitor.

The following diagrams and detailed descriptions are used to clearly illustrate the spirit of the present disclosure. After understanding the best implementation methods and embodiments of the present disclosure, any person with ordinary knowledge in the relevant technical field can make changes and modifications based on the techniques taught by the present disclosure without departing from the spirit and scope of the present disclosure.

Throughout the specification, the same reference numerals represent the same elements. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to another element, or intermediate elements may also exist. As used herein, "connected" can refer to physical and/or electrical connections. Furthermore, "electrically connected" or "coupled" can mean the presence of other elements between two elements.

It should be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, or layers, these elements, components, regions, or layers should not be limited by these terms. These terms are only used to distinguish one element, component, region, or layer from another element, component, region, or layer. Therefore, the "first" element, component, region, or layer discussed below can be referred to as the "second" element, component, region, or layer without departing from the teachings of this article.

Additionally, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe one element's relationship to another element, as shown in the figures. It should be understood that the relative terms are intended to encompass different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of other elements would then be oriented on the "upper" side of the other elements.

Exemplary embodiments are described herein with reference to schematic top views that are idealized embodiments. Therefore, variations in the shapes of the illustrations as a result of, for example, manufacturing techniques and/or tolerances are to be expected. Therefore, the embodiments described herein should not be construed as limited to the specific shapes of the regions as shown herein, but rather include shape deviations that result, for example, from manufacturing. For example, a region shown or described as flat may typically have rough and/or nonlinear features. In addition, sharp corners that are shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the exact shape of the regions and are not intended to limit the scope of the claims.

In some embodiments of the present disclosure, a display element including a plurality of light-emitting element dies is formed, wherein the display element has a receiving board, a circuit layer, and a packaging glue layer, wherein the receiving board does not include active elements such as driving elements. In this article, the display element may also be referred to as a display assembly.

In some embodiments of the present disclosure, a display device is formed, which includes a support plate and multiple display elements. The support plate has pads and active elements such as driving elements. The multiple display elements are respectively connected to corresponding pads, and the corresponding light-emitting elements in the display elements are controlled by the driving elements.

In some embodiments of the present disclosure, a plurality of light-emitting device dies are transferred to a receiving board and packaged to form a package structure including a plurality of light-emitting device dies, and a plurality of such package structures are placed on a support board including pads, driving circuits and other lines. In other embodiments, a plurality of light-emitting device dies are transferred to a receiving board, and then a plurality of receiving boards are placed on a support board including pads, driving circuits and other lines, and then a packaging glue layer is placed to form a package.

1A and 1B , which respectively illustrate top views of a display element and a display device according to some embodiments. The display element 100 includes a plurality of pixel units 110 arranged in an array and disposed in a receiving plate 130 , wherein each pixel unit 110 may include one or more sub-pixels (not shown).

As shown in FIG. 1B , the display device 200 includes a plurality of display elements 100 arranged in a matrix and disposed in a support plate 210 . Adjacent display elements 100 are separated by a spacer 120 .

FIG2A shows a cross-sectional view of the display device 100. The display device 100 includes a receiving board 130, a first circuit layer 140, a second circuit layer 150, a light emitting device 160, and a packaging glue layer 170.

The receiving plate 130 includes an insulating layer 132 and a plurality of through holes 134 , and the through holes 134 penetrate through the opposite lower surface 136 and upper surface 138 of the receiving plate 130 .

In some embodiments, the material of the receiving plate 130 may include at least one of polyimide (PI), benzocyclobutene (BCB), polybenzoxazole (PBO), Su-8 negative photoresist, or WPR photoresist (WPR series of JSR Corporation).

The first circuit layer 140 is disposed on the lower surface 136 of the receiving plate 130, and the first circuit layer 140 has a plurality of separated first electrodes 142. FIG. 2B is a top view of the first circuit layer 140, showing the arrangement of the plurality of first electrodes 142 in the first circuit layer 140 in a pixel unit 110 according to some embodiments.

The second circuit layer 150 is disposed on the upper surface 138 of the receiving plate 130, and the second circuit layer 150 has a plurality of separated second electrodes 152. Each second electrode 152 is connected to the corresponding first electrode 142 via the corresponding through hole 134. FIG. 2C is a top view of the second circuit layer 150, showing the arrangement of the plurality of second electrodes 152 in the second circuit layer 150 in a pixel unit 110 according to some embodiments.

The materials of the via 134, the first wiring layer 140, and the second wiring layer 150 include metals with good electrical conductivity, such as copper, silver, gold, platinum, chromium, titanium, aluminum, nickel, the like, or a combination thereof.

As shown in FIG. 2A , the light emitting element 160 is disposed above the receiving plate 130 and the second circuit layer 150. The first portion 162A and the second portion 162B of the light emitting element 160 are electrically connected to two corresponding adjacent second electrodes 152. One of the first portion 162A and the second portion 162B is the anode of the light emitting element 160, and the other is the cathode of the light emitting element 160.

In some embodiments, the light emitting elements 160 in a pixel unit 110 may be multi-colored or of the same color. In some embodiments, the light emitting elements 160 in a pixel unit 110 are multi-colored, such as a red light emitting element, a green light emitting element, and a blue light emitting element.

In some embodiments, the plurality of light-emitting elements 160 in a pixel unit 110 are of the same color, and at least one of a color filter material or a quantum dot material is disposed above the display element 100 in the display device 200 to convert the same color light into multi-color light. For example, the light-emitting element 160 emits blue light, which is converted into red light or green light through the color filter material or the quantum dot material.

In some implementations, the light emitting element 160 may be an inorganic light emitting element, an organic light emitting element, or an element made of other suitable materials, or a combination of the aforementioned materials.

In some implementations, the light emitting element 160 may be a micro-LED, a sub-millimeter light emitting diode (Mini-LED), or a light emitting diode having a size larger than a sub-millimeter light emitting diode.

In some embodiments, in the light-emitting element 160, the first portion 162A and the second portion 162B (ie, the cathode and the anode) of the two second electrodes 152 contacting the second circuit layer 150 may be located on the same side of the light-emitting element 160 or on the upper and lower sides of the light-emitting element 160, respectively, or in other suitable directions.

The encapsulation glue layer 170 covers and is above the receiving board 130, the second circuit layer 150 and the light emitting element 160. The encapsulation glue layer 170 can seal the light emitting element 160 to prevent moisture from entering, so as to maintain the performance and service life of the light emitting element 160.

In some implementations, the material of the encapsulation adhesive layer may include silicone or epoxy.

In the manufacturing process of packaging the light-emitting element, a packaging glue layer needs to be set on a plurality of light-emitting element dies. In the process of setting the packaging glue layer, the packaging glue layer needs to be at a relatively high temperature (e.g., about 130° C. to about 170° C.) to bond with the insulating layer of the receiving board below and the metal layer of the circuit layer. However, in some tests, it was found that when a material with a large thermal expansion coefficient is selected as the material of the packaging adhesive layer, the packaging adhesive layer will shrink during the subsequent cooling process, which will increase the interface stress between the insulating layer of the receiving board and the metal layer (such as the through hole, the first circuit layer, or the second circuit layer), causing the metal layer to peel off the insulating layer of the receiving board, especially between the insulating layer of the receiving board and the periphery of the through hole, or between the insulating layer, the through hole and the first circuit layer (or the second circuit layer). As a result, the yield of the display element and the display device formed is reduced.

Since the metal layer peels off the insulating layer of the receiving board, it may be caused by the tensile stress and shear stress between the metal layer and the insulating layer of the receiving board. The generation of this tensile stress and this shear stress mainly comes from the shrinkage effect of the upper packaging glue layer when the temperature drops, which affects the insulating layer of the receiving board, and the shrinkage degree of the packaging glue layer is related to the thermal expansion coefficient of the packaging glue layer. Therefore, in the present disclosure, a stress simulation test is performed to find out the appropriate thermal expansion coefficient of the packaging glue layer and the insulating layer of the receiving board to reduce the tensile stress and shear stress between the metal layer and the insulating layer of the receiving board.

Figures 3A and 3B are stress simulation test diagrams, showing the relationship between the interface stress between the insulating layer and the metal layer of the through hole in the receiving board and the thermal expansion coefficient of the packaging glue layer above. The stress simulated in Figure 3A is shear stress, and the vertical axis is the standardized shear stress; the stress simulated in Figure 3B is tensile stress, and the vertical axis is the standardized tensile stress. The horizontal axis in Figures 3A and 3B is the standardized thermal expansion coefficient. This parameter is the "thermal expansion coefficient of the encapsulating adhesive layer" divided by the "thermal expansion coefficient of the insulating layer of the receiving board", that is, the "ratio of the thermal expansion coefficient of the encapsulating adhesive layer to the thermal expansion coefficient of the insulating layer of the receiving board", which is also referred to as the "ratio of thermal expansion coefficients" in this article. As mentioned above, the vertical axis in Figure 3A is the standardized shear stress. This parameter is the "interface shear stress at different thermal expansion coefficient ratios" divided by the "shear stress when the thermal expansion coefficient ratio is 1", which is also referred to as the "ratio of shear stress" in this article. As mentioned above, the vertical axis in FIG. 3B is the normalized tensile stress. This parameter is the "interface tensile stress at different ratios of thermal expansion coefficients" divided by the "tensile stress when the ratio of thermal expansion coefficients is 1", which may also be referred to as the "tensile stress ratio" in this article.

As shown in FIG. 3A, it can be seen that when the normalized thermal expansion coefficient is greater than 1, the normalized shear stress is greater than 1. That is, compared to the case where the thermal expansion coefficient of the encapsulating adhesive layer is equal to the thermal expansion coefficient of the insulating layer of the receiving board, when the thermal expansion coefficient of the encapsulating adhesive layer is greater than the thermal expansion coefficient of the insulating layer of the receiving board, the interface shear stress between the insulating layer and the metal layer of the through hole in the receiving board is greater. When the normalized thermal expansion coefficient is less than 1, the normalized shear stress is less than 1. That is, compared to the case where the thermal expansion coefficient of the encapsulating adhesive layer is equal to the thermal expansion coefficient of the insulating layer of the receiving board, when the thermal expansion coefficient of the encapsulating adhesive layer is smaller than the thermal expansion coefficient of the insulating layer of the receiving board, the interface shear stress between the insulating layer and the metal layer of the through hole in the receiving board is smaller.

Referring to the curve shown in FIG. 3A , it can be seen that when the value of the normalized thermal expansion coefficient on the horizontal axis decreases from 1.6 to 1, that is, the thermal expansion coefficient of the packaging adhesive layer decreases from 1.6 times the thermal expansion coefficient of the insulation layer of the packaging board to being equal to the thermal expansion coefficient of the insulation layer of the packaging board, the normalized shear stress value decreases from about 1.2 to 1. When the value of the normalized thermal expansion coefficient on the horizontal axis decreases from 1 to nearly 0, that is, the thermal expansion coefficient of the packaging adhesive layer decreases from being equal to the thermal expansion coefficient of the insulation layer of the packaging board to a situation where the thermal expansion coefficient is extremely small, the normalized shear stress decreases from about 1 to about 0.96.

As shown in Figure 3A, when the normalized thermal expansion coefficient decreases from 1.6 to 1, the slope of the curve is larger, that is, the normalized shear stress decreases more. When the normalized thermal expansion coefficient decreases from 1 to about 0, the slope of the curve is smaller, that is, the normalized shear stress decreases less. In other words, when the thermal expansion coefficient of the packaging adhesive layer is reduced to approximately equal to the thermal expansion coefficient of the insulation layer of the packaging board, the interface shear stress can be significantly reduced. When the ratio of the thermal expansion coefficient of the packaging adhesive layer to the thermal expansion coefficient of the packaging adhesive layer is further reduced to 0.8, the interface shear stress can be slightly reduced. When the ratio of the thermal expansion coefficient of the packaging adhesive layer to the thermal expansion coefficient of the packaging adhesive layer is further reduced to less than 0.8, the interface shear stress can be slightly reduced.

As shown in FIG. 3B, it can be seen that when the normalized thermal expansion coefficient is greater than 1, the normalized tensile stress is greater than 1. That is, compared to the case where the thermal expansion coefficient of the encapsulating adhesive layer is equal to the thermal expansion coefficient of the insulating layer of the receiving board, when the thermal expansion coefficient of the encapsulating adhesive layer is greater than the thermal expansion coefficient of the insulating layer of the receiving board, the interface tensile stress between the insulating layer and the metal layer of the through hole in the receiving board is greater. When the normalized thermal expansion coefficient is less than 1, the normalized tensile stress is less than 1. That is, compared to the case where the thermal expansion coefficient of the packaging adhesive layer is equal to the thermal expansion coefficient of the insulating layer of the receiving board, when the thermal expansion coefficient of the packaging adhesive layer is smaller than the thermal expansion coefficient of the insulating layer of the receiving board, the interface tensile stress between the insulating layer and the metal layer of the through hole in the receiving board is smaller.

Referring to the curve shown in FIG. 3B , it can be seen that when the value of the standardized thermal expansion coefficient on the horizontal axis decreases from 1.6 to 1, that is, the thermal expansion coefficient of the packaging adhesive layer decreases from 1.6 times the thermal expansion coefficient of the insulation layer of the packaging board to being equal to the thermal expansion coefficient of the insulation layer of the packaging board, the standardized tensile stress value decreases from about 1.68 to 1. When the value of the normalized thermal expansion coefficient on the horizontal axis decreases from 1 to about 0.8, that is, the thermal expansion coefficient of the packaging adhesive layer decreases from being equal to the thermal expansion coefficient of the insulation layer of the packaging board to 0.8 times the thermal expansion coefficient of the insulation layer of the packaging board, the normalized tensile stress decreases from about 1 to about 0.8. When the value of the normalized thermal expansion coefficient on the horizontal axis decreases from 0.8 to nearly 0, that is, the thermal expansion coefficient of the packaging adhesive layer decreases from being equal to the thermal expansion coefficient of the insulation layer of the packaging board to being extremely small, the normalized tensile stress decreases from about 0.8 to about 0.76.

As shown in Figure 3B, when the standardized thermal expansion coefficient decreases from 1.6 to 0.8, the slope of the curve is larger, that is, the normalized tensile stress decreases by a larger margin. When the standardized thermal expansion coefficient decreases from 0.8 to approximately 0, the slope of the curve is smaller, that is, the normalized tensile stress decreases by a smaller margin. In other words, when the thermal expansion coefficient of the packaging adhesive layer is reduced to approximately equal to the thermal expansion coefficient of the insulation layer of the packaging board, the interface tensile stress can be significantly reduced. When the ratio of the thermal expansion coefficient of the packaging adhesive layer to the thermal expansion coefficient of the packaging adhesive layer is further reduced to 0.8, the interface tensile stress can be further reduced. When the ratio of the thermal expansion coefficient of the packaging adhesive layer to the thermal expansion coefficient of the packaging adhesive layer is further reduced to less than 0.8, the interface tensile stress can be slightly reduced.

Therefore, it can be seen that by adjusting the thermal expansion coefficient of the packaging glue layer, or adjusting the ratio of the thermal expansion coefficient of the packaging glue layer to the thermal expansion coefficient of the insulation layer of the packaging board, the shear stress and tensile stress between the insulation layer and the metal layer of the packaging board can be reduced.

In order to improve the above-mentioned peeling phenomenon between the insulating layer and the metal layer, in some embodiments of the present disclosure, the insulating layer 132 of the receiving board 130 has a first thermal expansion coefficient, and the packaging adhesive layer 170 has a second thermal expansion coefficient, and the second thermal expansion coefficient of the packaging adhesive layer 170 is less than the first thermal expansion coefficient of the insulating layer 132 of the receiving board 130, so that the packaging adhesive layer 170 will not shrink too much during the cooling process, causing excessive stress between the insulating layer 132 and the metal layer in the receiving board 130.

The following provides a comparative example and a test of an embodiment to verify that adjusting the ratio of the thermal expansion coefficient of the packaging glue layer to the thermal expansion coefficient of the insulation layer of the packaging board can reduce the shear stress and tensile stress between the insulation layer and the metal layer of the through hole in the packaging board.

Comparison Example 1:

The material used for the insulation layer of the package board is polyimide (PI), and the thermal expansion coefficient is 50ppm/℃. The material used for the packaging adhesive layer is epoxy resin, and the thermal expansion coefficient is 70ppm/℃. That is to say, in Comparative Example 1, the ratio of the thermal expansion coefficient of the packaging adhesive layer to the thermal expansion coefficient of the insulation layer is 1.4. Then, the stress distribution around the insulation layer and the through hole of the package board is detected.

See the shear stress distribution diagrams of FIG. 4A and FIG. 4B. On the left side of FIG. 4A is the shear stress classification, with different gray levels used to represent the magnitude of the shear stress, where white is the lowest level of shear stress in the detection range, and black is the highest level of shear stress in the detection range. FIG. 4A shows the insulating layer 332 of the receiving plate, and the four white circles are the four through holes 334A, 334B, 334C and 334D in a pixel unit 110 (see FIG. 1A). The four rectangular areas are the outlines of the interfaces between the four second electrodes 342A, 342B, 342C, and 342D of the second circuit layer and the insulating layer. FIG. 4B is an enlarged view showing the through hole 334D at the lower right of FIG. 4A.

In FIG. 4A and FIG. 4B , the dark gray outlines of the four second electrodes 342A, 342B, 342C, and 342D represent that the edges of these electrodes have shear stresses different from the insulating layer 332. That is, compared with the insulating layer 332, the interfaces between the second electrodes 342A, 342B, 342C, and 342D of the second circuit layer and the insulating layer 332 have greater shear stresses. Further referring to the enlarged view of FIG. 4B , the interfaces 300A and 300B between the second electrode 342D, the insulating layer 332, and the through hole 334D are nearly black, indicating that the maximum shear stress is present there.

In addition, the test results show that the maximum shear stress between the insulating layer 332 and the metal layer of the through holes 334A, 334B, 334C and 334D in the receiving plate is 63 MPa.

See Figures 5A and 5B for the tensile stress distribution diagram. On the left side of Figure 5A is the tensile stress classification, with different gray levels representing the magnitude of the tensile stress, where black represents the highest level of tensile stress and white represents the lowest level of tensile stress.

As shown in FIGS. 5A and 5B , the light gray outlines of the four second electrodes 342A, 342B, 342C, and 342D of the second wiring layer represent that there is a tensile stress different from that of the insulating layer 332 at the edges of these electrodes. That is, there is a smaller tensile stress between the second electrodes 342A, 342B, 342C, and 342D of the second wiring layer and the insulating layer 332 than between the second electrodes 342A, 342B, 342C, and 342D of the second wiring layer and the insulating layer 332. Referring further to the enlarged view of FIG. 5B , it is shown that the interfaces 302A and 302B between the second electrode 342D, the insulating layer 332, and the through hole 334D are nearly black, indicating that the maximum tensile stress is present there.

In addition, the test results show that the maximum tensile stress between the insulating layer 332 and the metal layer of the through holes 334A, 334B, 334C and 334D in the receiving plate is 96 MPa.

Embodiment 1:

The material used for the insulation layer of the package board is polyimide, and the thermal expansion coefficient is 50 ppm/°C. The material used for the packaging adhesive layer is epoxy resin, and the thermal expansion coefficient is 30 ppm/°C. That is, in Example 1, the ratio of the thermal expansion coefficient of the packaging adhesive layer to the thermal expansion coefficient of the insulation layer is 0.6. Then, the stress distribution around the insulation layer and the through hole of the package board is detected.

See the shear stress distribution diagrams of FIG. 6A and FIG. 6B. On the left side of FIG. 4A is the shear stress classification, with different gray levels used to represent the magnitude of the shear stress, where white is the lowest level of shear stress in the detection range, and black is the highest level of shear stress in the detection range. FIG. 6A shows the insulating layer 432 of the receiving plate, and the four white circles are four through holes 434A, 434B, 434C, and 434D in a pixel unit 110 (see FIG. 1A). The four rectangular areas represent the boundaries of the four second electrodes 442A, 442B, 442C, and 442D of the second circuit layer, respectively. FIG. 6B is an enlarged view showing the through hole 434D at the lower right of FIG. 6A.

In FIG. 6A and FIG. 6B , the gray outlines of the four second electrodes 442A, 442B, 442C, and 442D represent that the edges of these electrodes have shear stresses different from those of the insulating layer 432. That is, compared to the insulating layer 432, the interfaces between the second electrodes 442A, 442B, 442C, and 442D of the second circuit layer and the insulating layer 432 have greater shear stresses. Further referring to the enlarged view of FIG. 6B , the interfaces 400A and 400B between the second electrode 442D, the insulating layer 432, and the through hole 434D are shown to be close to dark gray, indicating that the maximum shear stress is present there.

In addition, the test results show that the maximum shear stress between the insulating layer 432 and the metal layer of the through holes 434A, 434B, 434C and 434D in the receiving plate is 55.6 MPa.

By comparing Figures 4A to 4B of Comparative Example 1 and Figures 6A to 6B of Embodiment 1, it can be seen that the maximum shear stress of Comparative Example 1 (for example, at interfaces 300A and 300B in Figure 4B) is greater than the maximum shear stress of Embodiment 1 (for example, at interfaces 400A and 400B in Figure 6B).

See Figures 7A and 7B for the tensile stress distribution diagram. On the left side of Figure 7A is the tensile stress classification, with different gray levels representing the magnitude of the tensile stress, where black represents the highest level of tensile stress and white represents the lowest level of tensile stress.

As shown in FIG. 7A and FIG. 7B , the light gray outlines of the four second electrodes 442A, 442B, 442C, and 442D of the second wiring layer represent that there is a tensile stress different from the insulating layer 432 at the edges of these electrodes. That is, there is a smaller tensile stress between the second electrodes 442A, 442B, 442C, and 442D of the second wiring layer and the insulating layer 432 than between the second electrodes 442A, 442B, 442C, and 442D of the second wiring layer. Referring further to the enlarged view of FIG. 7B , it is shown that the interfaces 402A and 402B between the second electrode 442D, the insulating layer 432, and the through hole 434D are nearly dark gray, indicating that the maximum tensile stress is present there.

In addition, the test results show that the maximum tensile stress between the insulating layer 432 and the metal layer of the through holes 434A, 434B, 434C and 434D in the receiving plate is 77.1 MPa.

By comparing Figures 5A to 5B of Comparative Example 1 and Figures 7A to 7B of Embodiment 1, it can be seen that the maximum tensile stress of Comparative Example 1 (for example, at interfaces 302A and 302B in Figure 5B) is greater than the maximum tensile stress of Embodiment 1 (for example, at interfaces 402A and 402B in Figure 7B).

The test results of the above-mentioned Comparative Example 1 and Implementation Example 1 show that when the thermal expansion coefficient of the packaging adhesive layer is reduced from 70 ppm/°C to 30 ppm/°C (that is, the ratio of the thermal expansion coefficient of the packaging adhesive layer to the thermal expansion coefficient of the insulation layer is reduced from 1.4 to 0.6), the maximum interface shear stress can be reduced by approximately 11.7%, and the maximum interface tensile stress can be reduced by approximately 19.7%.

According to some embodiments of the present disclosure, the second thermal expansion coefficient of the packaging adhesive layer 170 is smaller than the first thermal expansion coefficient of the insulating layer 132 of the receiving plate 130, so that the shear stress and tensile stress at the interface between the insulating layer 132 and the through hole 134 in the receiving plate 130 can be reduced, thereby reducing the occurrence of peeling. In some embodiments, the ratio of the thermal expansion coefficient of the packaging glue layer 170 to the thermal expansion coefficient of the insulating layer 132 is less than or equal to about 0.8 and greater than 0, which can further reduce the shear stress and tensile stress at the interface between the insulating layer 132 and the through hole 134 in the receiving plate 130 to further reduce the occurrence of peeling.

Please return to FIG. 2 to continue to refer to the display device 100. In some embodiments, the insulating layer of the receiving plate 130 may include polyimide (PI), benzocyclobutene (BCB), polybenzoxazole (PBO), Su-8 negative photoresist, WPR photoresist, or the like. In some embodiments, the thermal expansion coefficient of the receiving plate 130 ranges from about 30 to about 70 ppm/°C.

In some embodiments, the receiving plate 130 does not include active components such as drive components.

In some embodiments, the encapsulation adhesive layer 170 may include silicone or epoxy. In some embodiments, the thermal expansion coefficient of the encapsulation adhesive layer 170 ranges from about 1 ppm/°C to about 65 ppm/°C. In some embodiments, the thermal expansion coefficient of the encapsulation adhesive layer 170 ranges from about 10 ppm/°C to about 40 ppm/°C.

In some embodiments, the encapsulation adhesive layer 170 may further include an inorganic filler material having a smaller thermal expansion coefficient so that the thermal expansion coefficient of the encapsulation adhesive layer 170 is smaller than the thermal expansion coefficient of the insulating layer 132 of the receiving plate 130. The inorganic filler material may be, for example, silicon dioxide, titanium dioxide, aluminum oxide, yttrium oxide, carbon black, sintered diamond powder, glass, or a combination thereof.

In some embodiments, the packaging glue layer 170 can be disposed on the receiving plate 130 by, for example, glue injection or molding.

Referring to FIG. 8 , a partial cross-sectional view of a display device according to some embodiments is shown. The display device 200 includes a display element 100 and a support plate 210. The support plate 210 includes a base layer 220 and a driving circuit layer 230. The driving circuit layer 230 includes a plurality of pads 240 and circuit elements 250 and 260 corresponding to and electrically connected to the pads 240. In FIG. 8 , the circuit element 260 is schematically shown, and the circuit element 260 may be, for example, at least one of a driving element, a switching element, a line, a diode, a resistor, or a capacitor. In some implementations, the driving circuit layer 230 may include active components, passive components, or circuits required by the display device 200, such as driving components, switching components, storage capacitors, power lines, driving signal lines, timing signal lines, current compensation lines, detection signal lines, etc.

The first electrodes 142 of the first circuit layer 140 of the display element 100 are electrically connected to the corresponding pads 240 of the driving circuit layer 230 of the support plate 210 and the circuit elements 250 and 260.

As shown in FIG. 8 , the light-emitting element 160 is electrically connected to the circuit element 260 in the driving circuit layer 230 of the support plate 210 via the first electrode 142 and the pad 240 , so that the driving element and other circuit elements in the circuit element 260 in the driving circuit layer 230 of the support plate 210 can control these light-emitting elements 160 to emit light.

In some embodiments, the base layer 220 of the support plate 210 is a rigid substrate or a flexible substrate, such as a glass plate, a ceramic plate or a polymer substrate, wherein the material of the polymer substrate is, for example, polyimide (PI), polyethylene terephthalate (PET), liquid crystal polymer, or a combination thereof. The substrate of the support plate can be a single-layer or multi-layer structure.

In some embodiments, the support board 210 may be a printed circuit board, a flexible circuit board, a flexible printed circuit (FPC), a chip on film (COF), or other suitable circuit boards.

In some embodiments, the display element 100 is disposed on the completed support plate 210, so the display element 100 and the support plate are two independent elements. Therefore, the display element 100 and the support plate 210 can be manufactured in two different manufacturing sites.

In some embodiments, after the plurality of light-emitting elements 160 are electrically connected to the second electrode 152 of the receiving board 130, a packaging glue layer 170 is provided to form a packaging structure, and then the plurality of packaging structures are provided on a support board 210 including a driving circuit layer 230 to form a display device 200. In other words, the completed display element 100 (with the packaging glue layer) is provided on the support board 210.

In other embodiments, after the light-emitting element 160 is electrically connected to the second electrode 152 of the receiving board 130, the receiving board 130 including the plurality of light-emitting elements 160 is disposed on the supporting board 210 including the driving circuit layer 230 to form an intermediate structure; and then the packaging layer 170 is disposed to cover the intermediate structure. In other words, the plurality of unfinished display elements 100 (without the packaging layer) are disposed on the supporting board 210, and then the packaging layer 170 is applied, so that the plurality of display elements 100 located on the supporting board 210 have a common packaging layer 170.

9A to 9D, which illustrate several intermediate steps of a method for forming a display device according to some implementations.

As shown in FIG. 9A , a plurality of light emitting elements are disposed on a receiving board. The receiving board 130 includes an insulating layer 132 and a through hole 134. A first circuit layer 140 is disposed on a lower surface 136 of the receiving board 130, and a second circuit layer 150 is disposed on an upper surface 138 of the receiving board 130. In some embodiments, a plurality of light emitting elements 160 may be disposed on the receiving board 130 and bonded to a plurality of corresponding second electrodes 152 by mass transfer technology. Therefore, a first portion 162A (e.g., an anode) and a second portion 162B (e.g., a cathode) of each light emitting element 160 are electrically connected to the corresponding second electrode 152, the through hole 134, and the first electrode 142.

As shown in FIG. 9B , a packaging layer is disposed above the light emitting element, the receiving board, and the second circuit layer to form a packaging structure, i.e., a display element. In the display element 100 , the packaging layer 170 is disposed above the light emitting element 160 , the receiving board 130 , and the second circuit layer 150 .

In some embodiments, since the display element 100 with the encapsulation adhesive layer 170 needs to be placed on the support plate 210, the material of the encapsulation adhesive layer 170 is preferably a material with a higher hardness, such as a Young's modulus greater than 0.1 MPa, which is beneficial to the subsequent transposition process and less likely to deform. In such an embodiment, if the Young's modulus of the encapsulation adhesive layer 170 is less than 0.1 MPa, the hardness of the encapsulation adhesive layer 170 will be too soft and will not be conducive to the subsequent transposition process, for example, it will cause damage to the circuit and reduce the yield. In some embodiments, the Young's modulus of the encapsulation adhesive layer 170 ranges from about 0.1 MPa to about 10 GPa. For example, the material of the encapsulation adhesive layer 170 includes epoxy resin.

As shown in FIG. 9C , a display element and a supporting board to be connected are provided. A plurality of display elements 100 are aligned with a supporting board 210 to be connected. The supporting board 210 includes a base layer 220 and a driving circuit layer 230. A plurality of first electrodes 142 of the first circuit layer 140 of the display element 100 are aligned with corresponding pads 240 of the driving circuit layer 230 of the supporting board 210.

As shown in FIG. 9D , the display element is assembled with the support plate to form a display device. A plurality of display elements 100 may be disposed above the support plate 210 , and a plurality of first electrodes 142 of the display element 100 correspond to the pads 240 of the driving circuit layer 230 and are electrically connected to the circuit element 260 in the driving circuit layer 230 , for example, a transistor 262 is shown in FIG. 9D .

10A to 10B illustrate a plurality of intermediate steps of a method for forming a display device according to some embodiments. When a plurality of display elements 100 are disposed on a support plate 210 , two adjacent display elements 100 are separated by a spacer 120 .

In some embodiments, after the display devices are connected to the support board, another encapsulation layer 180 may be added in the space 120. FIG. 10B shows the space 120 between two adjacent display devices 100 being filled with the encapsulation layer 180.

In some alternative embodiments, as shown in FIG. 10C , the encapsulation layer 182 may also cover a plurality of display elements 100. That is, two layers of encapsulation layers 170 and 182 are disposed above the light-emitting element 160 in the display device 200, the first layer of encapsulation layer is the encapsulation layer 170 of the individual display element 100, and the encapsulation layers 170 of the various display elements 100 are separated. The second layer of encapsulation layer is the encapsulation layer 182 above each display element 100 and in the spacer 120 between the plurality of display elements 100.

In some embodiments, the material of the encapsulation adhesive layers 180 and 182 may be the same as the material of the encapsulation adhesive layer 170. In other embodiments, the material of the encapsulation adhesive layers 180 and 182 may be different from the material of the encapsulation adhesive layer 170.

11A to 11D, which illustrate several intermediate steps of a method for forming a display device according to some implementations.

As shown in FIG. 11A , a plurality of light emitting elements are disposed on a receiving board. The receiving board 130 includes an insulating layer 132 and a through hole 134. A first circuit layer 140 is disposed on a lower surface 136 of the receiving board 130, and a second circuit layer 150 is disposed on an upper surface 138 of the receiving board 130. In some embodiments, a plurality of light emitting elements 160 may be disposed on the receiving board 130 and bonded to a plurality of corresponding second electrodes 152 by mass transfer technology. Therefore, a first portion 162A (e.g., an anode) and a second portion 162B (e.g., a cathode) of each light emitting element 160 are electrically connected to the corresponding second electrode 152, the through hole 134, and the first electrode 142.

As shown in FIG. 11B , a receiving board including a plurality of light-emitting elements and a supporting board to be connected are provided. A plurality of receiving boards 130 including a plurality of light-emitting elements 160 are aligned with a supporting board 210 to be connected. The supporting board 210 includes a base layer 220 and a driving circuit layer 230. The driving circuit layer 230 includes a pad 240 and circuit elements 250 and 260. The plurality of first electrodes 142 of the first circuit layer 140 are respectively aligned with the corresponding pads 240 of the driving circuit layer 230 of the supporting board 210.

FIG. 11C shows that the receiving plate including a plurality of light emitting elements is assembled with the supporting plate to form the intermediate structure 270. The receiving plates of the plurality of light emitting elements 160 are connected to the supporting plate 210 to form the intermediate structure 270. The plurality of first electrodes 142 of the first circuit layer 140 are respectively connected to the corresponding pads 240 of the supporting plate 210.

FIG. 11D shows that a packaging layer is disposed on the intermediate structure, that is, on the light-emitting element, the receiving board, and the second circuit layer. The packaging layer 170 is disposed on the intermediate structure 270, that is, on the light-emitting element 160, the receiving board 130, and the second circuit layer 150. By disposing the packaging layer 170, the display element 100 having the packaging layer 170 is formed on the supporting board 210.

12A and 12B illustrate a plurality of intermediate steps of a method for forming a display device according to some embodiments: A plurality of receiving plates 130 including light emitting elements 160 are disposed on a supporting plate 210 , and two adjacent receiving plates 130 are separated by a spacer 120 .

FIG. 12B shows that a packaging layer is disposed above the light-emitting element, the receiving board, and the second circuit layer and filled in the space. The packaging layer 170 covers the intermediate structure 270, that is, covers the light-emitting element 160, the receiving board 130, and the second circuit layer 150 and fills in the space 120. Therefore, a plurality of display elements 100 are formed on the support board 210, separated by the space 120, and the space 120 is filled with the packaging layer 170. That is, the plurality of display elements 100 and the space 120 between the display elements 100 have a common packaging layer 170.

In multiple implementations provided in the present disclosure, multiple light-emitting device dies are transferred to a receiving plate, and multiple smaller receiving plates and supporting plates containing the light-emitting device dies are assembled into a larger display panel, which can reduce the transfer time of multiple light-emitting device dies.

In addition, by adjusting the ratio of the thermal expansion coefficient of the packaging glue layer covering the display element and the thermal expansion coefficient of the insulating layer of the receiving board, the peeling phenomenon between the insulating layer and the metal layer of the through hole in the receiving board can be reduced, thereby improving the yield of the formed display element and display device.

Although the present disclosure has been disclosed in a plurality of embodiments and examples as above, they are not intended to limit the present disclosure. Anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the scope defined in the attached patent application.

100: Display component

110: Pixel unit

120: Interval

130: receiving board

132: Insulation layer

134: Perforation

136: Lower surface

138: Upper surface

140: First circuit layer

142: First electrode

150: Second circuit layer

152: Second electrode

160: Light-emitting element

162A: Part 1

162B: Part 2

170: Encapsulation glue layer

180: Encapsulation glue layer

182: Encapsulation glue layer

200: Display device

210:Support plate

220: Base layer

230: Drive circuit layer

240:Pad

250: Circuit components

260: Circuit components

262: Transistor

270:Intermediate structure

300A, 300B: Interface

302A, 302B: Interface

332: Insulation layer

334A, 334B, 334C, 334D: Through hole

342A, 342B, 342C, 342D: second electrode

400A, 400B: Interface

402A, 402B: Interface

432: Insulation layer

434A, 434B, 434C, 434D: Through hole

442A, 442B, 442C, 442D: second electrode

To make the above and other purposes, features, advantages and embodiments of the present disclosure more clearly understandable, the attached drawings are described as follows. FIG. 1A is a top view of a display element according to some embodiments. FIG. 1B is a top view of a display device including a plurality of display elements according to some embodiments. FIG. 2A is a cross-sectional view of a display element according to some embodiments. FIG. 2B is a top view of a first circuit layer in FIG. 2A according to some embodiments. FIG. 2C is a top view of a second circuit layer in FIG. 2A according to some embodiments. FIG. 3A is a diagram based on a stress simulation test, showing the relationship between the interface shear stress between the metal layer of the insulating layer and the through hole in the receiving board and the thermal expansion coefficient of the packaging glue layer above. FIG. 3B is a diagram based on a stress simulation test, showing the relationship between the interface tensile stress between the insulating layer and the metal layer of the through hole in the receiving plate and the thermal expansion coefficient of the packaging glue layer above. FIG. 4A is a shear stress distribution diagram based on a comparative example, showing the shear stress distribution between the insulating layer and the four through holes in the receiving plate. FIG. 4B is an enlarged view of the through hole near the lower right of FIG. 4A. FIG. 5A is a tensile stress distribution diagram based on a comparative example, showing the tensile stress distribution between the insulating layer and the four through holes in the receiving plate. FIG. 5B is an enlarged view of the through hole near the lower right in FIG. 5A. FIG. 6A is a shear stress distribution diagram according to an embodiment, showing the shear stress distribution between the insulating layer and the four through holes in the receiving plate. FIG. 6B is an enlarged view of the through hole near the lower right in FIG. 6A. FIG. 7A is a tensile stress distribution diagram according to an embodiment, showing the tensile stress distribution between the insulating layer and the four through holes in the receiving plate. FIG. 7B is an enlarged view of the through hole near the lower right in FIG. 7A. FIG. 8 is a partial cross-sectional view of a display device according to some embodiments. Figures 9A to 9D are cross-sectional views of multiple intermediate structures in multiple intermediate steps of a method for manufacturing a display device according to some embodiments. Figures 10A to 10B are cross-sectional views of multiple intermediate structures in multiple intermediate steps of a method for manufacturing a display device according to some embodiments. Figure 10C is a cross-sectional view of an intermediate structure according to an alternative embodiment. Figures 11A to 11D are cross-sectional views of multiple intermediate structures in multiple intermediate steps of a method for manufacturing a display device according to some embodiments. Figures 12A to 12B are cross-sectional views of multiple intermediate structures in multiple intermediate steps of a method for manufacturing a display device according to some embodiments.

Domestic storage information (please note in the order of storage institution, date, and number) None Foreign storage information (please note in the order of storage country, institution, date, and number) None

100: Display component

130: Receiver board

132: Insulation layer

134: Through hole

136: Lower surface

138: Upper surface

140: First circuit layer

142: First electrode

150: Second circuit layer

152: Second electrode

160: Light-emitting element

162A: Part 1

162B: Part 2

170: Encapsulation glue layer

Claims (19)

A display element comprises: a receiving board, comprising an insulating layer and a plurality of through holes penetrating a lower surface and an upper surface opposite to each other of the receiving board, wherein the insulating layer of the receiving board has a first thermal expansion coefficient; a first circuit layer, arranged on the lower surface of the receiving board, and the first circuit layer has a plurality of phase-separated first electrodes; a second circuit layer, arranged on the upper surface of the receiving board, and the second circuit layer has a plurality of phase-separated second electrodes, wherein each of the second electrodes is connected to each of the first electrodes through each of the corresponding through holes; and a plurality of light-emitting elements, arranged on the receiving board and the second circuit layer. The invention relates to a method for manufacturing a light-emitting device, wherein the two parts of each light-emitting element are electrically connected to the two adjacent second electrodes respectively; and a packaging adhesive layer covers the receiving board, the second circuit layer and the light-emitting elements, a top surface of the packaging adhesive layer is higher than a top surface of the second circuit layer and a top surface of each of the light-emitting elements, the packaging adhesive layer directly contacts the insulating layer and the second circuit layer of the receiving board and seals the light-emitting elements, and the packaging adhesive layer has a second thermal expansion coefficient, and the second thermal expansion coefficient of the packaging adhesive layer is less than the first thermal expansion coefficient of the insulating layer of the receiving board. A display element as described in claim 1, wherein the ratio of the second thermal expansion coefficient to the first thermal expansion coefficient is less than or equal to about 0.8 and greater than 0. A display device as described in claim 1, wherein the Young's modulus of the encapsulation adhesive layer is in the range of about 0.1 MPa to about 10 GPa. The display element as described in claim 1, wherein the first thermal expansion coefficient of the insulating layer of the receiving plate ranges from about 30 ppm/°C to about 70 ppm/°C. The display element as described in claim 1, wherein the insulating layer of the receiving plate comprises polyimide (PI), benzocyclobutene (BCB), or polybenzoxazole (PBO). The display device as described in claim 1, wherein the second thermal expansion coefficient of the packaging glue layer ranges from about 1ppm/℃ to about 65ppm/℃. The display device as described in claim 1, wherein the second thermal expansion coefficient of the packaging glue layer ranges from about 10ppm/℃ to about 40ppm/℃. The display device as described in claim 1, wherein the packaging adhesive layer comprises silicone or epoxy. A display element as described in claim 1, wherein the encapsulation glue layer contains an inorganic filler material. A display device comprises: a support plate, comprising a plurality of pads and a plurality of circuits corresponding to and electrically connected to the pads; and a plurality of display elements as described in any one of claims 1 to 9, wherein the first electrodes of each display element are electrically connected to the corresponding pads of the support plate. A display device as described in claim 10, wherein there is a gap between the display elements, and each of the gaps is filled with a filling material. A display device as described in claim 11, wherein the material of the filling material is the same as or different from the material of the packaging glue layer. A display device as described in claim 10, wherein each circuit includes at least one of a driving element, a switching element, a line, a diode, a resistor or a capacitor. A display device comprises: a support plate, comprising a plurality of pads and a plurality of circuits corresponding to and electrically connected to the pads; a plurality of display elements, arranged on the support plate, with a spacing between two adjacent display elements, each of the display elements comprising: a receiving plate, comprising an insulating layer and a plurality of through holes penetrating an upper surface and a lower surface of the receiving plate, and the insulating layer of the receiving plate The edge layer has a first thermal expansion coefficient; a first circuit layer, disposed on the lower surface of the receiving plate, and the first circuit layer has a plurality of separated first electrodes; a second circuit layer, disposed on the upper surface of the receiving plate, and the second circuit layer has a plurality of separated second electrodes, wherein each of the second electrodes is connected to each of the first electrodes through each of the corresponding through holes; and a plurality of light-emitting elements, The light-emitting components are placed on the receiving board and the second circuit layer, wherein the two parts of each light-emitting component are electrically connected to the two adjacent second electrodes respectively; and an encapsulation layer covers the receiving board, the support board, the second circuit layer and the light-emitting components and fills the spaces, and a top surface of the encapsulation layer is higher than a top surface of the second circuit layer and a top surface of each of the light-emitting components. The top surface, the packaging adhesive layer directly contacts the insulating layer and the second circuit layer of the receiving board and seals the light-emitting elements, and the packaging adhesive layer has a second thermal expansion coefficient, which is less than the first thermal expansion coefficient of the insulating layer of the receiving board; wherein the first electrodes of each display element are electrically connected to the corresponding pads of the supporting board. A display device as described in claim 14, wherein the ratio of the second thermal expansion coefficient to the first thermal expansion coefficient is less than or equal to approximately 0.8 and greater than 0. A display device as described in claim 14, wherein the insulating layer of the receiving plate comprises polyimide (PI), benzocyclobutene (BCB), or polybenzoxazole (PBO). A display device as described in claim 14, wherein the packaging adhesive layer comprises silicone or epoxy. A display device as described in claim 14, wherein the encapsulation glue layer contains an inorganic filler material. A display device as described in claim 14, wherein each circuit includes at least one of a driving element, a switching element, a line, a diode, a resistor, or a capacitor.