Packaging structure, backlight module and display device

Abstract

The utility model provides a packaging structure, a backlight module and a display device, and relates to the technical field of LED display. The packaging structure comprises a packaging adhesive layer, an LED chip, a base material, a first solder resist ink layer and a second solder resist ink layer. The LED chip is embedded in the packaging adhesive layer and is exposed on the surface of the packaging adhesive layer; the first solder resist ink layer is arranged on the base material, the first solder resist ink layer is provided with a first window, and the first window is matched with the LED chip; the second solder resist ink layer is arranged on the first solder resist ink layer, the second solder resist ink layer is provided with a second window, and the second window is matched with the packaging adhesive layer; the substrate is provided with a bonding pad, and the bonding pad is exposed out of the first window and is connected with the LED chip. According to the backlight module, the solder resist ink is reserved between the packaging glue layer and the base material, the brightness loss of the backlight module can be reduced, meanwhile, the packaging glue layer is prevented from being overlapped on the second solder resist ink layer, and therefore electrode pseudo soldering caused by the fact that the LED chip is raised by the solder resist ink after the thickness is increased is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of LED display, in particular to a packaging structure, a backlight module and a display device. Background Art

[0002] At present, when the backlight module uses CSP (Chip Scale Package) to encapsulate the lamp bead chips, if the thickness of the printed white oil is increased to improve the reflectivity of the PCB (Printed Circuit Board), there will be defects such as large loss of brightness of the backlight module or cold soldering of the chip electrodes. Utility Model Content

[0003] In order to solve the problems existing in the prior art, one of the purposes of the utility model is to provide a packaging structure.

[0004] The utility model provides the following technical solutions:

[0005] A packaging structure, comprising:

[0006] Encapsulation glue layer;

[0007] The LED chip is embedded in the packaging glue layer and exposed on the surface of the packaging glue layer;

[0008] Base material;

[0009] A first solder resist ink layer is disposed on the substrate, wherein the first solder resist ink layer is provided with a first window, and the first window is adapted to the LED chip; and

[0010] A second solder resist ink layer, disposed on the first solder resist ink layer, the second solder resist ink layer being provided with a second window, the second window being adapted to the packaging adhesive layer;

[0011] Wherein, a solder pad is arranged on the substrate, the solder pad is exposed in the first window, and is connected to the LED chip.

[0012] As a further optional solution for the packaging structure, the packaging glue layer has a packaging surface facing the substrate, the LED chip has a welding surface facing the substrate, the welding surface is exposed on the packaging surface, and the welding surface is flush with the packaging surface.

[0013] As a further optional solution to the packaging structure, an electrode is provided on the welding surface, and the electrode is connected to the welding pad.

[0014] As a further optional solution to the packaging structure, the packaging surface is bonded to the first solder resist ink layer.

[0015] As a further optional solution for the packaging structure, the sum of the thicknesses of the first solder resist ink layer and the second solder resist ink layer is H, and 40 μm≤H≤50 μm.

[0016] As a further optional solution for the packaging structure, the thickness of the first solder resist ink layer is h1, h1≤30 μm;

[0017] The thickness of the second solder resist ink layer is h2, where h2≤30 μm.

[0018] As a further optional solution for the packaging structure, the thickness of the first solder resist ink layer is 20 μm.

[0019] As a further optional solution to the packaging structure, 25 μm≤h2≤30 μm.

[0020] Another object of the utility model is to provide a backlight module.

[0021] The utility model provides the following technical solutions:

[0022] A backlight module comprises the above packaging structure.

[0023] Another object of the present invention is to provide a display device.

[0024] The utility model provides the following technical solutions:

[0025] A display device comprises the above packaging structure or the above backlight module.

[0026] The embodiments of the present invention have the following beneficial effects:

[0027] In the above-mentioned packaging structure, a first solder resist ink layer and a second solder resist ink layer are sequentially arranged on the substrate, which increases the thickness of the solder resist ink, is conducive to improving the reflectivity of the PCB, and thus improving the brightness of the backlight module. Among them, the first solder resist ink layer is provided with a first window adapted to the LED chip, so that the LED chip is connected to the pad exposed in the first window, and the solder resist ink is retained between the packaging glue layer and the substrate, which can reduce the brightness loss of the backlight module. In addition, the second solder resist ink layer is provided with a second window adapted to the packaging glue layer, so as to avoid the packaging glue layer being placed on the second solder resist ink layer, thereby avoiding the electrode cold soldering caused by the LED chip being lifted by the solder resist ink with increased thickness, and ensuring a stable connection between the LED chip and the pad.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A partial structural schematic diagram of a backlight module in the related art is shown;

[0031] Figure 2 A schematic diagram showing a window opening according to the package size after thickening the solder mask ink layer;

[0032] Figure 3 A schematic diagram showing a thickened solder resist ink layer and a window opening according to the size of the LED chip is shown;

[0033] Figure 4 A schematic diagram of the structure of a packaging structure before packaging is shown in an embodiment of the utility model;

[0034] Figure 5 A schematic diagram of a packaging structure after packaging is shown in an embodiment of the utility model;

[0035] Figure 6 Shows Figure 5 Enlarged schematic diagram at point A in the middle.

[0036] Description of main component symbols:

[0037] 100-packaging glue layer; 110-packaging surface; 200-LED chip; 210-welding surface; 220-electrode; 300-substrate; 310-soldering pad; 400-first solder resist ink layer; 410-first window; 500-second solder resist ink layer; 510-second window; 600-solder resist ink layer; 610-window. DETAILED DESCRIPTION

[0038] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0040] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of the template herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0043] See also Figure 1 In the related art, the backlight module includes a PCB and a plurality of lamp beads. The PCB includes a substrate 300 and a solder resist ink layer 600 (such as white oil) printed on the substrate 300, and the lamp beads are composed of an LED (light-emitting diode) chip 200 and a packaging glue layer 100 half-wrapped outside the LED chip 200.

[0044] The solder resist ink layer 600 is formed with a window 610 to expose the pad 310 disposed on the substrate 300 , and the size of the window 610 is adapted to the LED chip 200 .

[0045] During packaging, the LED chip 200 is aligned with the window 610 and is connected to the pad 310 by soldering with solder paste, and the packaging glue layer 100 is placed on the solder resist ink layer 600 around the window 610 .

[0046] Typically, the thickness of the solder resist ink layer 600 is about 20 μm, the reflectivity of the PCB is low, and the brightness of the backlight module is low.

[0047] In order to increase the brightness of the backlight module, the reflectivity of the PCB needs to be increased, and the thickness of the solder resist ink layer 600 printed on the substrate 300 should also be increased accordingly.

[0048] Please combine Figure 2 After the solder resist ink layer 600 is thickened, if a window is opened at the lamp bead patch position according to the package size so that the size of the window 610 is adapted to the packaging glue layer 100, there is no solder resist ink layer 600 on the substrate 300 at the bottom of the packaging glue layer 100, so that the area of ​​the substrate 300 exposed at the bottom of the lamp bead is too large, the reflectivity of the PCB is low, and the brightness loss of the backlight module is serious.

[0049] Please combine Figure 3 After the solder resist ink layer 600 is thickened, if a window is opened at the lamp bead patch position according to the size of the LED chip 200 so that the size of the window 610 is adapted to the LED chip 200, the packaging glue layer 100 will be placed on the thicker solder resist ink layer 600 around the window 610, thereby raising the electrode 220 of the LED chip 200 and causing cold soldering, thereby causing poor connection between the lamp bead and the PCB.

[0050] Example

[0051] Please also read Figure 4 and Figure 5 This embodiment provides a packaging structure, including a packaging glue layer 100, an LED chip 200, a substrate 300, a first solder resist ink layer 400 and a second solder resist ink layer 500.

[0052] The LED chip 200 is embedded in the packaging layer 100 and exposed on the surface of the packaging layer 100 .

[0053] The first solder resist ink layer 400 is disposed on the substrate 300 . The first solder resist ink layer 400 is provided with a first window 410 , and the first window 410 is adapted to the LED chip 200 .

[0054] The second solder resist ink layer 500 is disposed on the first solder resist ink layer 400 . The second solder resist ink layer 500 is provided with a second window 510 , and the second window 510 is matched with the packaging glue layer 100 .

[0055] It can be understood that the LED chip 200 is embedded in the encapsulation layer 100, and the size of the LED chip 200 is smaller than the size of the encapsulation layer 100. Accordingly, the size of the second window 510 adapted to the encapsulation layer 100 is larger than the size of the first window 410 adapted to the LED chip 200, and the first window 410 is completely exposed in the second window 510.

[0056] In addition, a solder pad 310 is disposed on the substrate 300 . The solder pad 310 is exposed from the first window 410 and is connected to the LED chip 200 .

[0057] In the above-mentioned packaging structure, the first solder resist ink layer 400 and the second solder resist ink layer 500 are sequentially arranged on the substrate 300, which increases the thickness of the solder resist ink, is conducive to improving the reflectivity of the PCB, and thus improving the brightness of the backlight module. Among them, the first solder resist ink layer 400 is provided with a first window 410 adapted to the LED chip 200, so that the LED chip 200 is connected to the pad 310 exposed in the first window 410, and the solder resist ink is retained between the encapsulation glue layer 100 and the substrate 300, which can reduce the brightness loss of the backlight module. In addition, the second solder resist ink layer 500 is provided with a second window 510 adapted to the encapsulation glue layer 100, so as to avoid the encapsulation glue layer 100 being placed on the second solder resist ink layer 500, thereby avoiding the LED chip 200 being lifted by the solder resist ink after the thickness is increased, resulting in the electrode 220 being cold-welded, and ensuring the stable connection between the LED chip 200 and the pad 310.

[0058] In some embodiments, solder resist ink is first printed on the surface of the substrate 300 to form a first solder resist ink layer 400, and a first window 410 is formed by developing. Then, solder resist ink is printed on the surface of the first solder resist ink layer 400 facing away from the substrate 300 to form a second solder resist ink layer 500, and a second window 510 is formed by developing.

[0059] Specifically, the encapsulation layer 100 has an encapsulation surface 110 facing the substrate 300, and the LED chip 200 has a welding surface 210 facing the substrate 300. The surface of the LED chip 200 exposed from the encapsulation layer 100 specifically refers to the welding surface 210 exposed from the encapsulation surface 110, and the welding surface 210 is flush with the encapsulation surface 110, and the other surfaces of the LED chip 200 except the welding surface 210 are wrapped by the encapsulation layer 100.

[0060] Please combine Figure 6 Furthermore, an electrode 220 is disposed on the welding surface 210 , and the electrode 220 is connected to the welding pad 310 .

[0061] During packaging, solder paste is first printed or coated on the solder pad 310, and then the LED chip 200 is placed on the solder pad 310 when the LED chip 200 is aligned with the first window 410. The solder paste is then heated and melted, and after the solder paste cools and solidifies, a solder joint is formed between the electrode 220 and the solder pad 310, thereby achieving a connection between the electrode 220 and the solder pad 310.

[0062] Furthermore, when the LED chip 200 is attached to the pad 310, the encapsulation adhesive layer 100 is placed on the first solder resist ink layer 400. After the encapsulation is completed, the encapsulation surface 110 is attached to the first solder resist ink layer 400.

[0063] In some embodiments, the sum of the thicknesses of the first solder resist ink layer 400 and the second solder resist ink layer 500 is H, which satisfies 40 μm≤H≤50 μm.

[0064] Compared with the conventional 20 μm thick solder resist ink layer, the solder resist ink in the above packaging structure is thicker and the reflectivity of the PCB is higher, thereby being able to improve the brightness of the backlight module.

[0065] Optionally, the sum of the thicknesses of the first solder resist ink layer 400 and the second solder resist ink layer 500 may be 40 μm, 41 μm, 42 μm, 43 μm, 44 μm, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm, 50 μm, or any value between 40 μm and 50 μm.

[0066] In some embodiments, the thickness of the first solder resist ink layer 400 is h1, satisfying h1≤30 μm. Meanwhile, the thickness of the second solder resist ink layer 500 is h2, satisfying h2≤30 μm.

[0067] The thickness of the first solder resist ink layer 400 is controlled to be no greater than 30 μm. Even if the encapsulation glue layer 100 is placed on the first solder resist ink layer 400, the electrode 220 of the LED chip 200 will not be lifted to cause cold soldering, thereby ensuring a stable connection between the LED chip 200 and the pad 310.

[0068] Optionally, the thickness of the first solder resist ink layer 400 may be 10 μm, 15 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, or any value not greater than 30 μm.

[0069] Furthermore, in this embodiment, the thickness of the first solder resist ink layer 400 is 20 μm, which is consistent with or similar to the thickness of a conventional solder resist ink layer.

[0070] Optionally, the thickness of the second solder resist ink layer 500 may be 10 μm, 15 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, or any value not greater than 30 μm.

[0071] Further, in this embodiment, the thickness of the second solder resist ink layer 500 is not less than 25 μm and not more than 30 μm.

[0072] Exemplarily, the thickness of the second solder resist ink layer 500 may be 25 μm, which is not limited in this embodiment.

[0073] In summary, the above-mentioned packaging structure sequentially arranges the first solder resist ink layer 400 and the second solder resist ink layer 500 on the substrate 300 by secondary printing and secondary development, which increases the thickness of the solder resist ink, is beneficial to improve the reflectivity of the PCB, and thus improves the brightness of the backlight module.

[0074] Among them, the first solder resist ink layer 400 forms a first window 410 adapted to the LED chip 200 through the first development, so that the LED chip 200 is connected to the pad 310 exposed in the first window 410, and the solder resist ink is retained between the encapsulation glue layer 100 and the substrate 300, which can reduce the brightness loss of the backlight module. In addition, the second solder resist ink layer 500 forms a second window 510 adapted to the encapsulation glue layer 100 through the second development, so as to avoid the encapsulation glue layer 100 being placed on the second solder resist ink layer 500, thereby avoiding the LED chip 200 being lifted by the solder resist ink with increased thickness, resulting in a cold solder joint of the electrode 220, and ensuring a stable connection between the LED chip 200 and the pad 310.

[0075] At the same time, since the PCB solder mask window positions are staggered, the edge of the first window 410 is not aligned with the edge of the second window 510, so the side erosion of the window edge worsened by the increase in solder mask ink thickness can be improved.

[0076] In addition, the second window 510 can also serve as a positioning reference for the encapsulation adhesive layer 100 and the LED chip 200, so as to facilitate the identification of CSP lamp bead offset and the like during the SMT (Surface Mounted Technology) process.

[0077] This embodiment also provides a backlight module, including the above packaging structure.

[0078] Exemplarily, the backlight module may be a light bar or a light board, etc.

[0079] This embodiment further provides a display device, including the above-mentioned packaging structure or the above-mentioned backlight module.

[0080] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0081] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0082] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A packaging structure, characterized in that: include: Encapsulation glue layer; The LED chip is embedded in the packaging glue layer and exposed on the surface of the packaging glue layer; Base material; A first solder resist ink layer is disposed on the substrate, wherein the first solder resist ink layer is provided with a first window, and the first window is adapted to the LED chip; as well as A second solder resist ink layer, disposed on the first solder resist ink layer, the second solder resist ink layer being provided with a second window, the second window being adapted to the packaging adhesive layer; Wherein, a solder pad is arranged on the substrate, the solder pad is exposed in the first window, and is connected to the LED chip.

2. The packaging structure according to claim 1, characterized in that: The packaging adhesive layer has a packaging surface facing the substrate, the LED chip has a welding surface facing the substrate, the welding surface is exposed on the packaging surface, and the welding surface is flush with the packaging surface.

3. The packaging structure according to claim 2, characterized in that: An electrode is arranged on the welding surface, and the electrode is connected to the welding pad.

4. The packaging structure according to claim 2, characterized in that: The packaging surface is in contact with the first solder resist ink layer.

5. The packaging structure according to any one of claims 1 to 4, characterized in that: The sum of the thickness of the first solder resist ink layer and the second solder resist ink layer is H, and 40 μm≤H≤50 μm.

6. The packaging structure according to any one of claims 1 to 4, characterized in that: The thickness of the first solder resist ink layer is h1, h1≤30 μm; The thickness of the second solder resist ink layer is h2, where h2≤30 μm.

7. The packaging structure according to claim 6, characterized in that: The thickness of the first solder resist ink layer is 20 μm.

8. The packaging structure according to claim 6, characterized in that: 25μm≤h2≤30μm.

9. A backlight module, characterized in that: The invention comprises the packaging structure described in any one of claims 1 to 8.

10. A display device, characterized in that: The invention comprises the packaging structure described in any one of claims 1 to 8 or the backlight module described in claim 9.

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