Backlight module and display device

Abstract

The present disclosure provides a backlight module and a display device. The backlight module includes a plurality of light-emitting units, a first adhesive layer, at least one optical film, and a second adhesive layer. The first adhesive layer covers the plurality of light-emitting units. The at least one optical film is disposed on the plurality of light-emitting units. The second adhesive layer is disposed between the at least one optical film and the first adhesive layer.

Description

Technical Field

[0001] The present disclosure relates to an optical module and an electronic device, and more particularly to a backlight module and a display device. Background Art

[0002] Although the technology related to backlight modules has developed to a fairly mature level, there is still much room for improvement. For example, the optical film of a traditional backlight module needs to be supported by a substrate to increase stiffness, so the thickness of the backlight module is not easy to reduce. A single optical film is easily damaged by shaking or vibration during assembly or even transportation. The encapsulation glue of traditional chip-on-glass (COG) or chip-on-board (COB) packaging is only used for packaging and has no other added value (such as changing optical or electrical performance). Due to the large number of optical films, the assembly process of traditional backlight modules is complicated and the proportion of automated introduction is low. When the assembly process is mainly manual, the optical film is easily damaged by human beings. The assembly environment is an open environment, which is difficult to control environmental pollution, and the assemblers are also prone to contaminating the product during the assembly process. Summary of the Invention

[0003] The present disclosure provides a backlight module and a display device, which help to improve at least one problem encountered by traditional backlight modules.

[0004] According to an embodiment of the present disclosure, a backlight module includes a plurality of light-emitting units, a first adhesive layer, at least one optical film, and a second adhesive layer. The first adhesive layer covers the plurality of light-emitting units. The at least one optical film is disposed on the plurality of light-emitting units. The second adhesive layer is disposed between the at least one optical film and the first adhesive layer.

[0005] According to an embodiment of the present disclosure, a display device includes a backlight module and a display panel disposed on the backlight module. The backlight module includes a plurality of light-emitting units, a first adhesive layer, at least one optical film, and a second adhesive layer. The first adhesive layer covers the plurality of light-emitting units. The at least one optical film is disposed on the plurality of light-emitting units. The second adhesive layer is disposed between the at least one optical film and the first adhesive layer.

[0006] In order to make the above features and advantages of the present disclosure more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figures 1 to 6 are schematic cross-sectional views of backlight modules according to some embodiments of the present disclosure;

[0008] Figures 7 to 10 4 and 5 are cross-sectional schematic diagrams of display devices according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0009] The present disclosure will be understood by referring to the following detailed description in conjunction with the accompanying drawings. It should be noted that, for ease of understanding and for simplicity, many of the drawings in this disclosure depict only portions of electronic devices / displays, and certain components in the drawings are not drawn to scale. Furthermore, the number and dimensions of components in the drawings are for illustration only and are not intended to limit the scope of this disclosure. For example, the relative sizes, thicknesses, and positions of various layers, regions, or structures may be reduced or exaggerated for clarity.

[0010] Throughout this disclosure and the following claims, certain terms are used to refer to specific components. Those skilled in the art will appreciate that electronic device manufacturers may refer to the same components by different names. This document does not intend to distinguish between components that have the same function but are named differently. In the following description and claims, words such as "having" and "including" are open-ended and should be interpreted as meaning "including, but not limited to..."

[0011] Directional terms mentioned herein, such as "upper," "lower," "front," "backward," "left," "right," etc., are used only with reference to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrative purposes only and are not intended to limit the present disclosure. It should be understood that when an element or film layer is referred to as being "on" or "connected to" another element or film layer, the element or film layer may be directly on or directly connected to the other element or film layer, or there may be an intervening element or film layer between the two (indirect case). Conversely, when an element or film layer is referred to as being "directly on" or "directly connected to" another element or film layer, there may be no intervening element or film layer between the two.

[0012] The terms "approximately," "equal to," "equal to," "the same as," "substantially," or "approximately" mentioned herein generally represent falling within 10% of a given value or range, or falling within 5%, 3%, 2%, 1%, or 0.5% of a given value or range. In addition, the phrases "a given range is from a first value to a second value," and "a given range falls within the range from a first value to a second value" indicate that the given range includes the first value, the second value, and other values ​​therebetween.

[0013] In some embodiments of the present disclosure, terms such as "connected" and "interconnected," unless otherwise specified, may refer to two structures being in direct contact, or may refer to two structures not being in direct contact, with another structure positioned between them. Terms such as "connected" and "interconnected" may also include situations where both structures are movable or both structures are fixed. Furthermore, the terms "electrically connected" and "coupled" encompass any direct and indirect electrical connection means.

[0014] In some embodiments of the present disclosure, an optical microscope (OM), a scanning electron microscope (SEM), an α-step thin film thickness profilometer, an ellipsometer, or other suitable methods can be used to measure the area, width, thickness, or height of each device, or the distance or spacing between devices. Specifically, according to some embodiments, a scanning electron microscope can be used to obtain a cross-sectional structural image including the device to be measured, and the area, width, thickness, or height of each device, or the distance or spacing between devices, can be measured.

[0015] The electronic device disclosed herein may include a display device, an antenna device, a sensing device, a light-emitting device, or a splicing device, but is not limited thereto. The electronic device may include a bendable or flexible electronic device. The electronic device may, for example, include a liquid crystal layer or a light-emitting diode. The light-emitting diode may, for example, include an organic light-emitting diode (OLED), a sub-millimeter light-emitting diode (mini LED), a micro LED, or a quantum dot light-emitting diode (quantum dot LED, which may include QLED, QDLED), fluorescence, phosphor or other suitable materials, or a combination thereof, but is not limited thereto. The following text will use a display device as an electronic device to illustrate the contents of the present disclosure, but the present disclosure is not limited thereto.

[0016] The display device disclosed herein may be a non-self-luminous display device. A non-self-luminous display device may include, but is not limited to, a liquid crystal display device. A liquid crystal display device may include a backlight module and a liquid crystal display panel. The backlight module may provide illumination. The liquid crystal display panel is disposed on the backlight module and may convert the illumination light into display light with display information (e.g., grayscale or brightness).

[0017] Figures 1 to 6 2 are cross-sectional schematic diagrams of backlight modules according to some embodiments of the present disclosure. Figures 7 to 10are schematic cross-sectional views of display devices according to some embodiments of the present disclosure. Figures 1 to 10 Various implementations of the backlight module and display device disclosed herein are described.

[0018] exist Figures 1 to 10 In the embodiments, the same or similar elements will use the same or similar reference numerals, and their redundant description will be omitted. In addition, the features of different embodiments can be mixed and matched as needed as long as they do not violate the spirit of the invention or conflict with each other, and simple equivalent changes and modifications made in accordance with this specification or claims are still within the scope of this disclosure. In addition, the terms "first" and "second" mentioned in this specification or claims are only used to name different elements or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements, nor are they used to limit the manufacturing order or arrangement order of the elements.

[0019] Please refer to Figure 1 The backlight module 1 may include, but is not limited to, a plurality of light-emitting units 10, a first adhesive layer 11, at least one optical film (such as an optical film 12), and a second adhesive layer 13. The backlight module 1 may include, but is not limited to, one or more components or film layers based on different needs. For example, the backlight module 1 may further include, but is not limited to, a circuit board 14.

[0020] A plurality of light-emitting units 10 are disposed on a circuit board 14. For example, the circuit board 14 may include a printed circuit board, a glass substrate with a circuit disposed thereon, a semiconductor substrate or a flexible substrate, other suitable substrates or a combination thereof, but is not limited thereto. The plurality of light-emitting units 10 may be a plurality of light-emitting diode chips, such as a plurality of blue light-emitting diode chips, but is not limited thereto. In other embodiments, the plurality of light-emitting units 10 may also be a plurality of white light-emitting diode chips, but is not limited thereto. According to some embodiments, the light-emitting unit 10 may include an inorganic light-emitting diode (LED), such as a micro light-emitting diode (micro LED, mini LED), an organic light-emitting diode (OLED), an electroluminescence element (electroluminescence), other suitable light-emitting elements, or a combination thereof, but the present disclosure is not limited thereto. The plurality of light-emitting units 10 may be bonded and electrically connected to the circuit board 14 by flip-chip packaging technology (such as COG or COB), but is not limited thereto.

[0021] The first adhesive layer 11 covers the plurality of light emitting units 10. Figure 1As shown, a portion of the first adhesive layer 11 may be disposed between the plurality of light-emitting units 10, and another portion of the first adhesive layer 11 may be disposed on the plurality of light-emitting units 10. By making the thickness T11 of the first adhesive layer 11 (e.g., the maximum thickness of the first adhesive layer 11 in direction Z) greater than the thickness T10 of each of the plurality of light-emitting units 10 (e.g., the maximum thickness of the light-emitting unit 10 in direction Z), the first adhesive layer 11 may provide a flat bonding surface S11 to facilitate subsequent bonding of at least one optical film (e.g., the optical film 12) to the first adhesive layer 11, wherein the direction Z may be the normal direction of the circuit board 14.

[0022] According to some embodiments, the first adhesive layer 11 may be formed by curing a light-transmitting colloid. For example, the first adhesive layer 11 may include thermosetting glue, haze glue, transparent thermally conductive glue, adhesive film or other suitable adhesive materials, but is not limited thereto. Haze glue can provide a light diffusion effect, improve light uniformity or improve light mixing restrictions. Transparent thermally conductive glue can provide a heat dissipation effect without increasing the thickness of the module. According to some embodiments, the first adhesive layer 11 may include light-curing glue, light-thermal curing glue, moisture-curing glue, AB glue (acrylic, epoxy, polyurethane and other ingredients), other suitable materials or a combination of the foregoing, but is not limited thereto.

[0023] At least one optical film (such as optical film 12) is disposed on the plurality of light-emitting units 10. A second adhesive layer 13 is disposed between the at least one optical film (such as optical film 12) and the first adhesive layer 11. The optical film 12 can, for example, be attached to the bonding surface S11 of the first adhesive layer 11 via the second adhesive layer 13. For example, the at least one optical film (such as optical film 12) can include, but is not limited to, a blue light-transmitting film, a light wavelength conversion film, a brightness-enhancing film, or a composite film.

[0024] The blue light transmitting film allows blue light to pass through and reflects other light (such as red light or green light). The light wavelength conversion film can convert short wavelength light into long wavelength light, for example, converting blue light into red light, green light or a combination thereof. For example, the material of the light wavelength conversion film may include fluorescence, phosphor, quantum dots (QD), other suitable materials or a combination thereof, but is not limited thereto. The brightness enhancement film can provide the effect of concentrating and brightening light. For example, the brightness enhancement film may include a prism sheet, but is not limited thereto. The composite film can be an optical film that integrates multiple optical films using a roll to roll process. For example, the composite film may include a prism sheet, a reflective polarized brightness enhancement film (DualBrightness Enhancement Film, DBEF) and a diffuser, but is not limited thereto.

[0025] In this embodiment, the plurality of light emitting units 10 are, for example, a plurality of blue light emitting diode chips, and the optical film 12 is, for example, a wavelength conversion film capable of converting blue light into at least one of red light and green light, but the present invention is not limited thereto.

[0026] The second adhesive layer 13 is used to provide adhesion between the optical film 12 and the first adhesive layer 11. For example, the second adhesive layer 13 may include light-curing adhesive, heat-curing adhesive, tape, optically clear adhesive (OCA), optically clear resin (OCR), or other suitable adhesive materials, but is not limited thereto.

[0027] By covering the plurality of light-emitting units 10 with a first adhesive layer 11 to provide a flat bonding surface S11, and utilizing a second adhesive layer 13 to adhere at least one optical film (such as an optical film 12) to the bonding surface S11 of the first adhesive layer 11, it is possible to eliminate the need for an additional substrate (such as a plastic substrate) to increase the stiffness of the optical film, thereby helping to reduce the overall thickness of the backlight module 1. Furthermore, since the optical film 12 is tightly bonded to the underlying film layer, the number of interface reflections caused by air gaps can be reduced, reducing the loss of light generated by the light-emitting unit 10 and enabling more light to be output from the backlight module 1. Furthermore, by attaching the optical film 12 to the bonding surface S11 of the first adhesive layer 11, the manufacturing process at the module end can be simplified, enhancing the inline automated manufacturing capability, effectively improving the assembly yield, or reducing the chance of product contamination.

[0028] Please refer to Figure 2 The backlight module 1A further includes an optical film 15. The optical film 15 is, for example, a blue light-transmitting film that allows blue light to pass through. For example, the blue light-transmitting film (optical film 15) can be disposed above the plurality of light-emitting units 10 and below the wavelength conversion film (optical film 12). The blue light-transmitting film (optical film 15) allows the blue light from the plurality of light-emitting units 10 to pass through, enabling the wavelength conversion film to convert the blue light into red and green light.

[0029] In some embodiments, the optical film 15 and the optical film 12 can be integrated using a roll-to-roll process and then attached to the joining surface S11 of the first adhesive layer 11 via the second adhesive layer 13. In some embodiments, the optical film 15 can be attached to the joining surface S11 of the first adhesive layer 11 via the second adhesive layer 13, and the optical film 12 can be attached to the optical film 15 via another adhesive layer (not shown).

[0030] Please refer to Figure 3The backlight module 1B further includes an optical film 16. The optical film 16 is, for example, a composite film formed by integrating a prism sheet, a dual brightness enhancement film (DBEF), and a diffuser sheet, but is not limited thereto. In other embodiments, the optical film 16 may be a single optical film rather than a composite film.

[0031] In some embodiments, the optical film 16 and the optical film 12 can be integrated using a roll-to-roll process and then attached to the joining surface S11 of the first adhesive layer 11 via the second adhesive layer 13. In other embodiments, the optical film 12 can be attached to the joining surface S11 of the first adhesive layer 11 via the second adhesive layer 13, and the optical film 16 can be attached to the optical film 12 via another adhesive layer (not shown).

[0032] Please refer to Figure 4 , except for the backlight module 1C Figure 2 In addition to the backlight module 1A, the optical film 16 is also included. The description of the optical film 16 is referred to above and will not be repeated here. In some embodiments, the optical film 16, the optical film 12, and the optical film 15 can be integrated using a roll-to-roll process and then attached to the joint surface S11 of the first adhesive layer 11 via the second adhesive layer 13. In other embodiments, the optical film 15 can be attached to the joint surface S11 of the first adhesive layer 11 via the second adhesive layer 13, the optical film 12 can be attached to the optical film 15 via another adhesive layer (not shown), and the optical film 16 can be attached to the optical film 12 via yet another adhesive layer (not shown).

[0033] Please refer to Figure 5 The backlight module 1D further includes an optical film 16, but does not include the optical film 12. The optical film 16 is attached to the bonding surface S11 of the first adhesive layer 11 via the second adhesive layer 13. The optical film 16 is, for example, a composite film formed by integrating a prism sheet, a reflective brightness enhancement film, and a diffuser sheet, but is not limited thereto. In other embodiments, the optical film 16 may be a single optical film rather than a composite film.

[0034] The backlight module 1D further includes a plurality of packaging bodies 17. The plurality of packaging bodies 17 surround the plurality of light emitting units 10 respectively. Figure 5 As shown, each encapsulant 17 can cover the sidewall surface SS10 and light-emitting surface ST10 of a corresponding light-emitting unit 10. Furthermore, the first adhesive layer 11 also covers the multiple encapsulants 17 to provide a flat bonding surface S11. In other words, the thickness T11 of the first adhesive layer 11 (e.g., the maximum thickness of the first adhesive layer 11 in direction Z) is greater than the thickness T17 of at least one of the multiple encapsulants 17 (e.g., the maximum thickness of the encapsulant 17 in direction Z).

[0035] The package 17 may be hemispherical, but is not limited thereto. Hemispherical refers to a non-complete sphere, not limited to half of a sphere. In some embodiments, the plurality of light-emitting units 10 may be a plurality of white light-emitting diode chips, and the material of the package 17 may include, but is not limited to, encapsulant. In other embodiments, the plurality of light-emitting units 10 may be a plurality of blue light-emitting diode chips, and the material of the package 17 may include, but is not limited to, encapsulant, a light wavelength conversion material, or other suitable materials, or a combination thereof.

[0036] Please refer to Figure 6 , except for the backlight module 1E Figure 5 The backlight module 1D further includes an optical film 12. In the present embodiment, the plurality of light-emitting units 10 may be a plurality of blue light-emitting diode chips, the material of the package body 17 may include packaging glue and a light wavelength conversion material, and the optical film 12 may be, for example, a light wavelength conversion film that can convert blue light into at least one of red light and green light. In some embodiments, the light wavelength conversion film (optical film 12) and the light wavelength conversion material may be different colors. For example, the optical film 12 may convert blue light into red light (or green light), and the light wavelength conversion material may convert blue light into green light (or red light). In some embodiments, the light wavelength conversion film (optical film 12) and the light wavelength conversion material may also be the same color. For example, the light wavelength conversion film (optical film 12) and the light wavelength conversion material may both convert blue light into red light and green light.

[0037] Please refer to Figure 7 The display device DD may include a backlight module 1C and a display panel DP disposed on the backlight module 1C. The description of the backlight module 1C is described above and will not be repeated here. In other embodiments not shown, the backlight module 1C may be replaced with any of the aforementioned backlight modules. The following embodiments may also be modified in the same manner and will not be repeated here. The display panel DP may include a non-self-luminous display panel, such as a liquid crystal display panel, but is not limited thereto.

[0038] The display device DD may include one or more components or layers as needed. For example, the display device DD may further include an adhesive layer AD, and the display panel DP may be attached to the backlight module 1C via the adhesive layer AD, but the present invention is not limited thereto. The adhesive layer AD may be formed by curing a light-transmitting colloid. For example, the adhesive layer AD may include a thermosetting adhesive, a haze adhesive, a transparent thermally conductive adhesive, an adhesive film, or other suitable adhesive material, but the present invention is not limited thereto. In other embodiments not shown, the display panel DP may also be fixed to the backlight module 1C via a mechanical component, thereby omitting the adhesive layer AD.

[0039] Please refer to Figure 8 , display device DDA except Figure 7The display device DD further includes a reflective layer R. The reflective layer R is disposed on the sidewall of the backlight module 1C to reflect light and improve light utilization. For example, the reflective layer R can be formed by curing white glue, but is not limited thereto.

[0040] Please refer to Figure 9 In the display device DDB, the backlight module 1D is replaced Figure 7 In other embodiments not shown, the backlight module 1D may also be replaced with any of the aforementioned backlight modules, and the following embodiments may be similarly modified, which will not be repeated below.

[0041] Please refer to Figure 10 , display device DDC except Figure 9 The display device DDB further includes a reflective layer R. For the description of the reflective layer R, please refer to the above description and will not be repeated here.

[0042] In summary, in the embodiments disclosed herein, a first adhesive layer is used to provide a flat bonding surface to facilitate the subsequent bonding of at least one optical film to the first adhesive layer, thereby helping to improve the problem of difficulty in attaching an optical film to the flip chip package. By attaching at least one optical film to the first adhesive layer through a second adhesive layer, it is possible to avoid the need for an additional substrate (such as a plastic substrate) to increase the stiffness of the optical film, thereby helping to reduce the overall thickness of the backlight module. In addition, since the optical film is tightly bonded to the film layer below it, the number of interface reflections caused by air gaps can be reduced, allowing more light to be output from the backlight module. In addition, by attaching the optical film to the first adhesive layer, the process steps at the module end can be simplified, the proportion of online automated processes can be increased, and the assembly yield can be effectively improved or the chance of product contamination can be reduced. In some embodiments, the material of the first adhesive layer can be appropriately selected to further improve light uniformity, improve light mixing restrictions, or provide heat dissipation without increasing the thickness of the module. In some embodiments, the optical film can be appropriately selected to provide light wavelength conversion, concentrated brightness, improved light uniformity, or improved light utilization. In some embodiments, a reflective layer may be disposed on the sidewalls of the backlight module to improve light utilization efficiency.

[0043] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

[0044] Although the embodiments and advantages of the present disclosure have been disclosed above, it should be understood that anyone with ordinary knowledge in the art can make changes, substitutions and modifications without departing from the spirit and scope of the present disclosure, and the features between the embodiments can be arbitrarily mixed and replaced with each other to form other new embodiments. In addition, the scope of protection of the present disclosure is not limited to the processes, machines, manufacturing, material compositions, devices, methods and steps in the specific embodiments described in the specification. Any person skilled in the art can understand from the content of the present disclosure that the processes, machines, manufacturing, material compositions, devices, methods and steps currently or in the future developed can be used according to the present disclosure as long as they can implement substantially the same functions or obtain substantially the same results in the embodiments described herein. Therefore, the scope of protection of the present disclosure includes the above-mentioned processes, machines, manufacturing, material compositions, devices, methods and steps. In addition, each claim constitutes a separate embodiment, and the scope of protection of the present disclosure also includes the combination of each claim and embodiment. The scope of protection of the present disclosure shall be determined by the appended claims.

Claims

1. A backlight module, characterized in that: include: a plurality of light-emitting units; a first adhesive layer covering the plurality of light-emitting units and comprising a transparent thermally conductive adhesive; At least one optical film is disposed on the plurality of light-emitting units, wherein the at least one optical film comprises a light wavelength conversion film and is layered with the transparent thermally conductive adhesive; a plurality of packages, each of which is hemispherical and surrounds the plurality of light-emitting units, wherein the thickness of the first adhesive layer is greater than the thickness of at least one package among the plurality of packages, and the plurality of packages include a light wavelength conversion material; as well as a second adhesive layer disposed between the at least one optical film and the first adhesive layer; The color converted by the light wavelength conversion material is the same as the color converted by the light wavelength conversion film, and the light wavelength conversion film is located on a side of the second adhesive layer away from the first adhesive layer.

2. The backlight module according to claim 1, wherein: The plurality of light emitting units are a plurality of light emitting diode chips.

3. The backlight module according to claim 1, wherein: Part of the first adhesive layer is disposed between the plurality of light emitting units.

4. The backlight module according to claim 1, wherein: The first adhesive layer further comprises thermosetting adhesive, haze adhesive or adhesive film.

5. The backlight module according to claim 1, wherein: The at least one optical film further comprises a blue light transmitting film, a brightness enhancing film or a composite film.

6. A display device, characterized in that: include: Backlight module, including: a plurality of light-emitting units; a first adhesive layer covering the plurality of light-emitting units and comprising a transparent thermally conductive adhesive; At least one optical film is disposed on the plurality of light-emitting units, wherein the at least one optical film comprises a light wavelength conversion film and is layered with the transparent thermally conductive adhesive; a plurality of packages, each of which is hemispherical and surrounds the plurality of light-emitting units, wherein the thickness of the first adhesive layer is greater than the thickness of at least one package among the plurality of packages, and the plurality of packages include a light wavelength conversion material; and a second adhesive layer disposed between the at least one optical film and the first adhesive layer, wherein the color converted by the wavelength conversion material is the same as the color converted by the wavelength conversion film, and the wavelength conversion film is located on a side of the second adhesive layer away from the first adhesive layer; and The display panel is arranged on the backlight module.

7. The display device according to claim 6, wherein: The plurality of light emitting units are a plurality of light emitting diode chips.

8. The display device according to claim 6, wherein: Part of the first adhesive layer is disposed between the plurality of light emitting units.

9. The display device according to claim 6, wherein: The first adhesive layer further comprises thermosetting adhesive, haze adhesive or adhesive film.

10. The display device according to claim 6, wherein The at least one optical film further comprises a blue light transmitting film, a brightness enhancing film or a composite film.

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