Light emitting diode packaging structure

Abstract

A light-emitting diode packaging structure comprises a substrate, a light-emitting element and a packaging layer, the light-emitting element is located on the substrate, the packaging layer is located on the substrate and covers the light-emitting element, the packaging layer is provided with a top face, and the projection of the top face on the substrate is of an asymmetric structure in the upper view direction.

Description

Technical Field

[0001] The invention relates to a light emitting diode packaging structure. Background Art

[0002] When the light-emitting element in the LED package structure emits light, the light leaves the light-emitting element at different angles, so the light uniformity of the LED package structure is often affected by the light emission angle of the light-emitting element. Therefore, improving the light uniformity of the LED package structure to achieve a good display effect has become a very important part of the LED package structure design. Summary of the invention

[0003] The present disclosure provides a light emitting diode packaging structure with good display effect.

[0004] According to one embodiment of the present disclosure, a light-emitting diode packaging structure includes a substrate, a light-emitting element and a packaging layer, wherein the light-emitting element is located on the substrate, and the packaging layer is located on the substrate to cover the light-emitting element, wherein the packaging layer has a top surface, and in the upward viewing direction, the projection of the top surface on the substrate is an asymmetric structure.

[0005] Based on the above, in the light-emitting diode packaging structure of the embodiment of the present invention, the light-emitting element is located on the substrate, the packaging layer covers the light-emitting element, and in the upward viewing direction, the projection of the top surface of the packaging layer on the substrate is an asymmetric structure. Therefore, when the light-emitting element emits light at different angles, since the packaging layer is an asymmetric structure, light at different angles can be uniformly emitted from the light-emitting diode packaging structure, thereby improving the light uniformity of the light-emitting diode packaging structure, and improving the problem of insufficient utilization of large-angle light, thereby improving the display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 A three-dimensional schematic diagram of a light emitting diode packaging structure according to an embodiment of the present disclosure.

[0007] Figure 2 for Figure 1 A side view schematic diagram of a light emitting diode packaging structure.

[0008] Figure 3 for Figure 1 A top view of a light emitting diode packaging structure.

[0009] FIG. 4A to FIG. 4E for Figure 3 Schematic diagram of the cross section along I-I'.

[0010] Description of reference numerals:

[0011] 100A, 100B, 100C, 100D, 100E: LED packaging structure

[0012] 110: Substrate

[0013] 110S1, 110S2: Side wall

[0014] 120: Encapsulation layer

[0015] 120-1: Part One

[0016] 120-2: Part 2

[0017] 120-1b: Bottom

[0018] 130a, 130b, 130c, 130d, 130e: light emitting elements

[0019] 131, 132: Conductive pad

[0020] C: Groove

[0021] C1, C2, C3, C4, C5, C6: round

[0022] D1: First direction

[0023] D2: Second direction

[0024] D3: Third direction

[0025] H1, H2, H3a, H3b, H3c, H3d, H3e, t1, t2, t3: Height

[0026] M: Colloidal layer

[0027] R1, R2, R3, R4, R5, R6: diameter

[0028] TS: Top surface

[0029] t4: Depth

[0030] WA1, WA2, W1, W2, W3, W4: Length

[0031] WL: Wire DETAILED DESCRIPTION

[0032] Figure 1 A three-dimensional schematic diagram of a light emitting diode packaging structure according to an embodiment of the present disclosure.

[0033] Figure 2 for Figure 1 The light emitting diode package structure 100A includes a substrate 110 and a package layer 120. The package layer 120 includes a first portion 120-1 and a second portion 120-2.

[0034] The ratio of the height H1 of the LED package structure 100A along the third direction D3 to the height H2 of the package layer 120 along the third direction D3 is, for example, 1:5 to 1:20. For example, the height H1 of the LED package structure 100A along the third direction D3 is, for example, 500 to 2000 microns and H2 is, for example, 100 to 600 microns. Preferably, H1 may be, for example, 0.9 mm. The length W1 of the substrate 110 along the first direction D1 in the LED package structure 100A is, for example, 800 to 3500 microns. Preferably, W1 may be, for example, 2.6 mm.

[0035] Figure 3 for Figure 1 The top view of the LED package structure. The package layer 120 of the LED package structure 100A has a top surface TS. In the top view direction, a square area with a length WA1 of 1.5 mm along the first direction D1 and a length WA2 of 1.5 mm along the second direction D2 is used as an example for explanation. The projection of the top surface TS on the substrate 110 may be an asymmetric structure. The asymmetric structure may include a plurality of circles, and the plurality of circles may have different diameters. For example, the asymmetric structure may include six circles of different diameters that overlap alternately. The first circle C1 may have a diameter R1 of, for example, 0.66 mm, the second circle C2 may have a diameter R2 of, for example, 0.63 mm, the third circle C3 may have a diameter R3 of, for example, 0.65 mm, the fourth circle C4 may have a diameter R4 of, for example, 0.64 mm, the fifth circle C5 may have a diameter R5 of, for example, 0.67 mm, and the sixth circle C6 may have a diameter R6 of, for example, 0.8 mm, that is, the diameter ratio of the first circle C1, the second circle C2, the third circle C3, the fourth circle C4, the fifth circle C5, and the sixth circle C6 may be, for example, 0.66:0.63:0.65:0.64:0.67:0.8, but the present invention is not limited thereto. Therefore, since the top surface of the packaging layer is an asymmetric structure in the upward viewing direction, the asymmetric structure includes a plurality of circles, each of which has a different diameter. When the light emitting element emits light at different angles, the light at different angles can be uniformly emitted from the light emitting diode packaging structure, thereby improving the light uniformity of the light emitting diode packaging structure and improving the problem of insufficient utilization of large-angle light.

[0036] It is explained here that the diameter measurement in this embodiment is a line segment passing through the center of each circle and having both endpoints on the circumference, or the longest chord on the circle, which can be, for example, a line segment passing through the center of the circle along the first direction D1 and having both endpoints on the circumference, or a line segment passing through the center of the circle along the second direction D2 and having both endpoints on the circumference, or a line segment passing through the center of the circle along any direction and having an angle with the first direction D1 or the second direction D2 on a horizontal plane and having both endpoints on the circumference.

[0037] Figure 4A for Figure 3 Schematic cross-sectional view along I-I'. The light-emitting diode package structure 100A includes a substrate 110, an encapsulation layer 120, a colloid layer M and a light-emitting element 130a. The light-emitting element 130a is located on the substrate 110. The encapsulation layer 120 is located on the substrate 110. The first portion 120-1 of the encapsulation layer 120 covers the light-emitting element 130a and the second portion 120-2 surrounds the light-emitting element 130a. The light-emitting element 130a is a horizontal chip. The light-emitting element 130a can be coupled to the substrate 110 through the conductive pad 131 and the conductive pad 132. In detail, the light-emitting element 130a can be connected and coupled to the substrate 110 through the conductive wire WL and the conductive pad 131 and the conductive pad 132. The substrate 110 includes, for example, a polymer film, a porous film, a glass substrate, a glass fiber substrate, a ceramic, or other suitable materials or a combination of the above materials, but is not limited thereto.

[0038] The height t1 of the substrate 110 along the third direction D3 is, for example, 75 micrometers (μm) to 250 micrometers. The preferred t1 may be, for example, 0.1 millimeters. The substrate 110 has two opposite side walls, including a side wall 110S1 and a side wall 110S2, wherein the height t2 of the side wall 110S1 or the side wall 110S2 is, for example, 75 micrometers (μm) to 150 micrometers. The preferred t2 may be, for example, 0.1 millimeters. The height t2 of the side wall 110S1 or the side wall 110S2 in the third direction D3 is greater than or equal to the height t3 of the light-emitting element 130a in the third direction D3. Through the above design, when the light-emitting element emits light at different angles, the light at different angles can be uniformly emitted from the light-emitting diode package structure, thereby improving the light uniformity of the light-emitting diode package structure, and improving the problem of insufficient utilization of large-angle light, thereby improving the display effect.

[0039] The encapsulation layer 120 has a groove C. The material in the groove C includes, for example, a combination of silicone and titanium dioxide (TiO2). The optical reflectivity of the above combination of materials in the groove C at a wavelength of 480 nanometers (nm) may be, for example, 70% to 90%. Alternatively, the material in the groove C includes, for example, white ink, whose optical reflectivity at a wavelength of 480 nanometers (nm) may be, for example, 85% to 99%, and the wavelength of light passing therethrough may be, for example, 480 nanometers (nm). The projection of the groove C on the substrate 110 overlaps with the projection of the light-emitting element 130a on the substrate 110, and the projection area of ​​the groove C on the substrate 110 is larger than the projection area of ​​the light-emitting element 130a on the substrate 110. The groove C has a depth t4 along the third direction D3, and the depth t4 is, for example, 100 micrometers to 500 micrometers. The preferred t4 may be, for example, 0.45 mm. The groove C has a length W4 along the first direction D1, and the length W4 may be, for example, 200 microns to 700 microns. The preferred W4 may be, for example, 1.6 millimeters. The length W4 is less than the length W1 of the substrate 110 along the first direction D1, and the length W4 is greater than the height H1 of the light-emitting diode package structure 100A along the third direction D3. The ratio of the length W4 of the groove C along the first direction D1 to the length W1 of the substrate 110 along the first direction D1 is, for example, 0.26:1 to 0.92:1, and the preferred ratio is 0.61:1. Through the above design, when the light-emitting element emits light at different angles, the light at different angles can be uniformly emitted from the light-emitting diode package structure, thereby improving the light uniformity of the light-emitting diode package structure, and improving the problem of insufficient utilization of large-angle light, thereby improving the display effect.

[0040] The height t3 of the light emitting element 130a along the third direction D3 may be, for example, 300 micrometers to 250 micrometers, and the length W3 of the light emitting element 130a along the first direction D1 may be, for example, 30 micrometers to 3000 micrometers. Preferably, W3 may be, for example, 0.5 millimeters.

[0041] The white light conversion colloid layer M covers the light emitting element 130a and the conductive pads 131 and 132 at the same time, thereby protecting the light emitting element 130a, the conductive pads 131 and 132 from coupling with the substrate 110. The second portion 120-2 of the encapsulation layer 120 surrounds the colloid layer M. The height H3a of the colloid layer M along the third direction is greater than the height t3 of the light emitting element 130a along the third direction D3, and the height H3a of the colloid layer M along the third direction is less than the difference between the height H1 of the light emitting diode encapsulation structure 100a along the third direction D3 and the height t1 of the substrate 110. The bottom surface 120-1b of the first portion 120-1 of the encapsulation layer 120 contacts the sidewall 110S1 or the sidewall 110S2 of the substrate 110. Therefore, since the height H3a of the colloid layer M along the third direction is greater than the height t3 of the light emitting element 130a along the third direction D3 and the height H3a of the colloid layer M along the third direction is less than the difference between the height H1 of the light emitting diode package structure 100a along the third direction D3 and the height t1 of the substrate 110, through the above design, when the light emitting element emits light at different angles, the light at different angles can be uniformly emitted from the light emitting diode package structure, thereby improving the uniformity of the light emission of the light emitting diode package structure and improving the problem of insufficient utilization of large-angle light. In some embodiments, the bottom surface 120b of the encapsulation layer 120 may contact the colloid layer M or not contact the colloid layer M.

[0042] The substrate 110 may have a circuit (not shown), a light-emitting element 130a, such as a light-emitting diode. The light-emitting diode may include, for example, an organic light-emitting diode (OLED), a sub-millimeter light-emitting diode (mini LED), a micro LED or a quantum dot light-emitting diode (QD, such as QLED, QDLED), fluorescence, phosphor or other suitable materials, and the materials may be arranged and combined in any way, but are not limited thereto. In some embodiments, the light-emitting element 130a may be a light-emitting chip, and may be coupled to the substrate 110 in the form of a chip on board (COB), that is, as a light-emitting chip, the circuit on the substrate 110 may be electrically connected. In some embodiments, the light-emitting element 130a may include a light-emitting chip and a colloidal layer M encapsulating the light-emitting chip, and may be coupled to the substrate 110 in the form of a package on board (POB).

[0043] The light emitting element 130a is disposed on the substrate 110, rather than being formed on the substrate 110 by a semiconductor process. The substrate 110 is provided with a conducting pad 131 and a conducting pad 132. The conducting pad 131 and the conducting pad 132 are, for example, electroless nickel immersion gold (ENIG), electroless nickel electroless palladium immersion gold (ENEPIG) or other suitable materials or a combination of the foregoing materials, but not limited thereto. In addition, the substrate 110 may include, for example, a polymer film, glass, silicon, gallium arsenide, gallium nitride, silicon carbide or sapphire, but not limited thereto.

[0044] It should be noted that the following embodiments use the component numbers and some contents of the previous embodiments, wherein similar numbers are used to represent the same or similar components, and the description of the same technical contents is omitted. The description of the omitted parts can refer to the previous embodiments, and the following embodiments will not be repeated.

[0045] Figure 4B This is a partial cross-sectional schematic diagram of the main area of ​​a light emitting diode packaging structure in another embodiment of the present disclosure. Figure 4A and Figure 4B The light emitting diode package structure 100B of this embodiment is Figure 4A Similar to the light-emitting diode package structure 100A, in the present embodiment, the light-emitting element 130b is assembled on the substrate 110 by flip-chip bonding. Specifically, the light-emitting element 130a and the conductive pads 131 and 132 are coupled to the substrate 110 by flip-chip bonding. Therefore, compared to directly manufacturing the light-emitting element on the substrate by semiconductor process, the present embodiment can reduce the warping phenomenon of the substrate 110 caused by the high-temperature process when manufacturing the light-emitting element, so that the light-emitting diode package structure 100B of the present embodiment can have better structural reliability.

[0046] The height H3b of the colloid layer M along the third direction is greater than the height t3 of the light emitting element 130b along the third direction D3, and the height H3b of the colloid layer M along the third direction is less than the difference between the height H1 of the light emitting diode package structure 100b along the third direction D3 and the height t1 of the substrate 110. Thus, through the above design, when the light emitting element emits light at different angles, the light at different angles can be uniformly emitted from the light emitting diode package structure, thereby improving the uniformity of light emission of the light emitting diode package structure, and improving the problem of insufficient utilization of large-angle light, thereby improving the display effect.

[0047] Figure 4C This is a partial cross-sectional schematic diagram of the main area of ​​a light emitting diode packaging structure in another embodiment of the present disclosure. Figure 4B and Figure 4C The light emitting diode package structure 100C of this embodiment is Figure 4B Similar to the light emitting diode package structure 100B, in the present embodiment, the light emitting element 130c is assembled on the substrate 110 in a vertical chip manner. Specifically, the light emitting element 130c is coupled to the substrate 110 via the conductive wire WL and the conductive pad 131 and is coupled to the substrate 110 via the conductive pad 132 in a flip chip bonding manner.

[0048] The height H3c of the colloid layer M along the third direction is greater than the height t3 of the light emitting element 130c along the third direction D3, and the height H3c of the colloid layer M along the third direction is less than the difference between the height H1 of the light emitting diode package structure 100c along the third direction D3 and the height t1 of the substrate 110. Thus, through the above design, when the light emitting element emits light at different angles, the light at different angles can be uniformly emitted from the light emitting diode package structure, thereby improving the uniformity of light emission of the light emitting diode package structure, and improving the problem of insufficient utilization of large-angle light, thereby improving the display effect.

[0049] Figure 4D This is a partial cross-sectional schematic diagram of the main area of ​​a light emitting diode packaging structure in another embodiment of the present disclosure. Figure 4D and Figure 4B The light emitting diode package structure 100D of this embodiment is Figure 4B Similar to the light emitting diode package structure 100B, in this embodiment, the colloid layer M is made by pressing fluorescent glue technology.

[0050] The height H3d of the colloid layer M along the third direction is greater than the height t3 of the light emitting element 130d along the third direction D3, and the height H3c of the colloid layer M along the third direction is less than the difference between the height H1 of the light emitting diode package structure 100d along the third direction D3 and the height t1 of the substrate 110. Thus, through the above design, when the light emitting element emits light at different angles, the light at different angles can be uniformly emitted from the light emitting diode package structure, thereby improving the uniformity of light emission of the light emitting diode package structure, and improving the problem of insufficient utilization of large-angle light, thereby improving the display effect.

[0051] Figure 4E This is a partial cross-sectional schematic diagram of the main area of ​​a light emitting diode packaging structure in another embodiment of the present disclosure. Figure 4E and Figure 4A The light emitting diode package structure 100E of this embodiment is Figure 4A Similar to the light emitting diode package structure 100A, in this embodiment, the colloid layer M is manufactured by using the fluorescent glue dispensing technology.

[0052] Compared to Figure 4A, the colloid layer M shows an elliptical structure, the height H3e of the colloid layer M along the third direction is greater than the height t3 of the light emitting element 130E along the third direction D3, and the height H3e of the colloid layer M along the third direction is less than the difference between the height H1 of the light emitting diode package structure 100E along the third direction D3 and the height t1 of the substrate 110. Thus, through the above design, when the light emitting element emits light at different angles, the light at different angles can be uniformly emitted from the light emitting diode package structure, thereby improving the uniformity of the light emission of the light emitting diode package structure, and improving the problem of insufficient utilization of large-angle light, thereby improving the display effect. In addition, in the present embodiment, the preferred height H3e of the colloid layer M can be, for example, 0.2 mm.

[0053] To summarize, in the light-emitting diode packaging structure of the embodiment of the present invention, the light-emitting element is located on the substrate, and in the upward viewing direction, the projection of the top surface of the packaging layer on the substrate is an asymmetric structure. Therefore, when the light-emitting element emits light at different angles, since the packaging layer is an asymmetric structure, light at different angles can be uniformly emitted from the light-emitting diode packaging structure, thereby improving the light uniformity of the light-emitting diode packaging structure, and improving the problem of insufficient utilization of large-angle light, thereby improving the display effect.

Claims

1. A light emitting diode packaging structure, comprising: substrate; A light emitting element is located on the substrate; as well as A packaging layer, located on the substrate, covering the light emitting element, The packaging layer has a top surface, and in the upward viewing direction, the projection of the top surface on the substrate is an asymmetric structure. 2 . The light emitting diode package structure according to claim 1 , wherein the asymmetric structure comprises a plurality of circles, and the plurality of circles have different diameters. 3 . The light emitting diode package structure according to claim 2 , wherein the asymmetric structure comprises a first circle, a second circle, a third circle, a fourth circle, a fifth circle and a sixth circle which are alternately overlapped. 4 . The light emitting diode package structure according to claim 3 , wherein a diameter ratio of the first circle, the second circle, the third circle, the fourth circle, the fifth circle and the sixth circle is 0.66:0.63:0.65:0.64:0.67:0.

8. 5 . The light emitting diode package structure according to claim 1 , further comprising a colloid layer, wherein the colloid layer covers the light emitting element.

6. The light-emitting diode packaging structure as described in claim 1, wherein the packaging layer has a groove, the projection of the groove on the substrate overlaps with the projection of the light-emitting element on the substrate, and the projection area of ​​the groove on the substrate is larger than the projection area of ​​the light-emitting element on the substrate. 7 . The light emitting diode package structure according to claim 6 , wherein the groove has a depth along the third direction, and the depth is 100 μm to 500 μm. 8 . The light emitting diode package structure as claimed in claim 7 , wherein the groove has a length along the first direction, the length is smaller than the length of the substrate along the first direction and the length of the groove is greater than the height of the light emitting diode package structure along the third direction. 9 . The light emitting diode package structure as claimed in claim 1 , wherein a length of the substrate along the first direction is 800 to 3500 μm. 10 . The light emitting diode package structure according to claim 1 , wherein a height of the light emitting diode package structure along the third direction is 500 to 2000 μm. 11 . The light emitting diode package structure according to claim 1 , wherein the substrate further comprises a side wall, and a height of the side wall along the third direction is 75 μm to 150 μm.

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