CN115128862A

CN115128862A - Backlight module and display device

Info

Publication number: CN115128862A
Application number: CN202110325546.4A
Authority: CN
Inventors: 余轩宇; 陈嘉伦; 黄士展; 陈志昌; 朱明辉
Original assignee: Innolux Display Corp
Current assignee: Innolux Corp
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2022-09-30
Also published as: TW202238239A

Abstract

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

Description

Backlight module and display device

Technical Field

The present disclosure relates to optical modules and electronic devices, and more particularly, to a backlight module and a display device.

Background

Although the related art of backlight modules has been developed to be quite mature, there is still much room for improvement. For example, the optical film of the conventional backlight module needs to be supported by a substrate to increase stiffness, so the thickness of the backlight module is not easily reduced. In the process of assembling and transporting the single optical film, the single optical film is easily damaged by shaking or vibration. The packaging glue of the conventional Chip On Glass (COG) or Chip On Board (COB) package is only used for packaging, and has no other added value (such as changing optical or electrical performance). Because the number of the optical films is large, the assembly process of the traditional backlight module is complicated, and the automatic lead-in ratio is low. In the case where the assembly process is mainly performed by manpower, the optical film is easily damaged by human. The assembly environment is an open environment, the environmental pollution is not easy to control, and the assembly personnel can easily pollute the product in the assembly process.

Disclosure of Invention

The present disclosure provides a backlight module and a display device, which help to solve at least one problem encountered by the conventional backlight module.

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. At least one optical film is arranged on the plurality of light-emitting units. The second adhesive layer is arranged between the at least one optical film and the first adhesive layer.

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 comprises a plurality of light emitting units, a first adhesion layer, at least one optical film and a second adhesion layer. The first adhesive layer covers the plurality of light emitting units. At least one optical film is arranged on the plurality of light-emitting units. The second adhesive layer is arranged between the at least one optical film and the first adhesive layer.

In order to make the aforementioned and other features and advantages of the disclosure more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 to 6 are schematic cross-sectional views of a backlight module according to some embodiments of the present disclosure;

fig. 7-10 are each a cross-sectional schematic view of a display device according to some embodiments of the present disclosure.

Detailed Description

The present disclosure may be understood by reference to the following detailed description taken in conjunction with the accompanying drawings. It should be noted that in order to facilitate the understanding of the reader and the simplicity of the drawings, the various drawings in the present disclosure depict only a portion of an electronic device/display device and certain elements of the drawings are not necessarily drawn to scale. In addition, the number and size of the elements in the figures are merely illustrative and are not intended to limit the scope of the present disclosure. For example, the relative sizes, thicknesses, and locations of various layers, regions, or structures may be reduced or exaggerated for clarity.

Certain terms are used throughout the description and following claims to refer to particular elements. 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 differ in function but not name. In the following description and claims, the words "having" and "including" are open-ended words that should be interpreted as meaning "including, but not limited to …".

Directional phrases used herein include, for example: "upper", "lower", "front", "rear", "left", "right", etc., refer only to the orientation of the figures. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting. It will be understood that when an element or layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or connected to the other element or layer or intervening elements or layers may be present (not directly). In contrast, when an element or layer is referred to as being "directly on" or "directly connected to" another element or layer, there are no intervening elements or layers present therebetween.

The terms "about," "equal," "identical," "substantially," or "substantially," as referred to herein generally represent falling within 10% of a given value or range, or represent falling within 5%, 3%, 2%, 1%, or 0.5% of the given value or range. Further, the phrase "a given range is from a first value to a second value," and "a given range is within a range from a first value to a second value" means that the given range includes the first value, the second value, and other values therebetween.

In some embodiments of the present disclosure, terms such as "connected," "interconnected," and the like, with respect to bonding, connecting, and the like, may refer to two structures being in direct contact, or may also refer to two structures not being in direct contact, unless otherwise specified, with respect to the structure between which they are disposed. The terms coupled and connected should also be construed to include both structures being movable or both structures being fixed. Furthermore, the terms "electrically connected" and "coupled" encompass any direct and indirect electrical connection.

In some embodiments of the present disclosure, the area, width, thickness or height of each element, or the distance or spacing between elements may be measured using an Optical Microscope (OM), a Scanning Electron Microscope (SEM), a thin film thickness profile (α -step), an ellipsometer, or other suitable methods. In detail, according to some embodiments, a scanning electron microscope may be used to obtain an image of a cross-sectional structure including elements to be measured, and measure the area, width, thickness or height of each element, or the distance or spacing between elements.

The electronic device of the present disclosure may include, but is not limited to, a display device, an antenna device, a sensing device, a light-emitting device, or a splicing device. The electronic device may include a bendable or flexible electronic device. The electronic device may for example comprise a liquid crystal (liquid crystal) layer or a light emitting diode. The light emitting diode may include, for example, an Organic Light Emitting Diode (OLED), a submillimeter light emitting diode (mini LED), a micro light emitting diode (micro LED), or a quantum dot light emitting diode (quantum dot LED, which may include QLED, QDLED), a fluorescent (fluorescent), a phosphorescent (phosphor), or other suitable material, or a combination thereof, but is not limited thereto. The disclosure will be described below with reference to a display device as an electronic device, but the disclosure is not limited thereto.

The display device of the present disclosure may be a non-self-emissive display device. The non-self-luminous display device may include a liquid crystal display device, but is not limited thereto. The liquid crystal display device can comprise a backlight module and a liquid crystal display panel. The backlight module can be used for providing illumination light. The liquid crystal display panel is arranged on the backlight module and can convert the illumination light into display light with display information (such as gray scale or brightness).

Fig. 1 to 6 are schematic cross-sectional views of a backlight module according to some embodiments of the present disclosure. Fig. 7-10 are each a cross-sectional schematic view of a display device according to some embodiments of the present disclosure. Various embodiments of the backlight module and the display device of the present disclosure will be described with reference to fig. 1 to 10.

In the embodiments of fig. 1 to 10, the same or similar elements will be denoted by the same or similar reference numerals, and the description thereof will be omitted. Furthermore, the features of the various embodiments may be combined in any suitable manner without departing from the spirit or conflict of the invention, and all such modifications and equivalents as may be within the spirit and scope of the disclosure are deemed to be within the ambit and scope of the disclosure. In addition, the terms "first", "second", and the like in the description and the claims are only used for naming different elements or distinguishing different embodiments or ranges, and are not used for limiting the upper limit or the lower limit of the number of the elements, and are not used for limiting the manufacturing order or the arrangement order of the elements.

Referring to fig. 1, the backlight module 1 may include a plurality of light emitting units 10, a first adhesive layer 11, at least one optical film (e.g., an optical film 12), and a second adhesive layer 13, but not limited thereto. The backlight module 1 may have one or more elements or film layers added or removed according to different requirements. For example, the backlight module 1 may further include a circuit board 14, but not limited thereto.

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

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

According to some embodiments, the first adhesive layer 11 may be formed by curing a light-transmissive colloid. For example, the first adhesive layer 11 may include a thermosetting adhesive, a haze adhesive, a transparent heat conductive adhesive, an adhesive film, or other suitable adhesive materials, but not limited thereto. The haze glue can provide a light diffusion effect, improve light emitting uniformity or improve light mixing limitation. The transparent heat-conducting glue can provide a heat dissipation effect and does not increase the thickness of the module. According to some embodiments, the first adhesive layer 11 may include a photo-curable adhesive, a moisture-curable adhesive, an AB adhesive (acrylic, epoxy, polyurethane, etc.), other suitable materials, or a combination thereof, but is not limited thereto.

At least one optical film (e.g., optical film 12) is disposed on the plurality of light-emitting units 10. The second adhesive layer 13 is disposed between at least one optical film (e.g., optical film 12) and the first adhesive layer 11. The optical film 12 may be attached to the bonding surface S11 of the first adhesive layer 11, for example, via the second adhesive layer 13. For example, the at least one optical film (e.g., optical film 12) may include, but is not limited to, a blue light transmissive film, a light wavelength conversion film, a brightness enhancement film, or a composite film.

The blue light-transmitting film transmits blue light and reflects other light (e.g., red light or green light). The light wavelength conversion film can convert short wavelength light into long wavelength light, such as blue light into red light, green light, or a combination thereof. For example, the material of the light wavelength conversion film may include fluorescence (fluorescence), phosphorescence (phosphorescence), Quantum Dot (QD), other suitable materials, or a combination thereof, but is not limited thereto. Brightness enhancing films can provide a concentrated brightness enhancement of light. For example, the brightness enhancement film may include a prism sheet, but not limited thereto. The composite film may be an optical film in which a plurality of optical films are integrated by a roll-to-roll process. For example, the composite Film may include a prism sheet, a reflective Brightness Enhancement Film (DBEF), and a diffusion sheet, but is not limited thereto.

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

The second adhesive layer 13 is used for providing adhesion for bonding the optical film 12 and the first adhesive layer 11. For example, the second Adhesive layer 13 may include a light-curing Adhesive, a heat-curing Adhesive, a tape, an Optically Clear Adhesive (OCA), an Optically Clear Resin (OCR), or other suitable Adhesive material, but is not limited thereto.

The first adhesive layer 11 covers the light-emitting units 10 to provide a flat joint surface S11, and the second adhesive layer 13 is used to attach at least one optical film (such as the optical film 12) to the joint surface S11 of the first adhesive layer 11, so that a substrate (such as a plastic substrate) is not required to be additionally arranged to increase the stiffness of the optical film, thereby contributing to reducing the overall thickness of the backlight module 1. In addition, since the optical film 12 is closely attached to the lower film layer, the number of interface reflections caused by air gaps can be reduced, the loss of light generated by the light emitting unit 10 can be reduced, and more light can be output from the backlight module 1. In addition, the optical film 12 is attached to the bonding surface S11 of the first adhesive layer 11, so that the process of the module end can be simplified, the on-line (inline) automatic process capability can be improved, the assembly yield can be effectively improved, and the chance of contamination of the product can be reduced.

Referring to fig. 2, the backlight module 1A further includes an optical film 15. The optical film 15 is, for example, a blue light-transmitting film that transmits blue light. For example, the blue light transmissive film (optical film 15) may be disposed above the plurality of light emitting cells 10 and below the light wavelength conversion film (optical film 12). The blue light-transmitting film (optical film 15) can transmit the blue light from the plurality of light-emitting units 10, so that the light wavelength conversion film can convert the blue light into red light and green light.

In some embodiments, the optical film 15 and the optical film 12 may be integrated by a roll-to-roll process, and then the second adhesive layer 13 is attached to the bonding surface S11 of the first adhesive layer 11. In some embodiments, the optical film 15 may be attached to the bonding surface S11 of the first adhesive layer 11 through the second adhesive layer 13, and the optical film 12 may be attached to the optical film 15 through another adhesive layer (not shown).

Referring to fig. 3, the 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 reflective brightness enhancement film (DBEF) and a diffusion sheet, but not limited thereto. In other embodiments, optical film 16 may also be a single optical film, rather than a composite film.

In some embodiments, the optical film 16 and the optical film 12 may be integrated by a roll-to-roll process, and then the second adhesive layer 13 is attached to the bonding surface S11 of the first adhesive layer 11. In other embodiments, the optical film 12 may be attached to the bonding surface S11 of the first adhesive layer 11 through the second adhesive layer 13, and the optical film 16 may be attached to the optical film 12 through another adhesive layer (not shown).

Referring to fig. 4, the backlight module 1C further includes an optical film 16 in addition to the backlight module 1A of fig. 2. For the description of the optical film 16, reference is made to the above description, which is not repeated here. In some embodiments, the optical film 16, the optical film 12, and the optical film 15 may be integrated by a roll-to-roll process, and then attached to the bonding surface S11 of the first adhesive layer 11 by the second adhesive layer 13. In other embodiments, the optical film 15 may be attached to the bonding surface S11 of the first adhesive layer 11 through the second adhesive layer 13, the optical film 12 may be attached to the optical film 15 through another adhesive layer (not shown), and the optical film 16 may be attached to the optical film 12 through another adhesive layer (not shown).

Referring to fig. 5, the backlight module 1D further includes the 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 diffusion sheet, but not limited thereto. In other embodiments, optical film 16 may also be a single optical film, rather than a composite film.

The backlight module 1D further includes a plurality of packages 17. The plurality of packages 17 surround the plurality of light emitting units 10, respectively. As shown in fig. 5, each of the packages 17 may cover the side wall surface SS10 and the light emitting surface ST10 of a corresponding light emitting unit 10. In addition, the first adhesive layer 11 also covers the plurality of packages 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 the direction Z) is greater than the thickness T17 of at least one package 17 of the plurality of packages 17 (e.g., the maximum thickness of the package 17 in the direction Z).

The package 17 may have a hemispherical shape, but is not limited thereto. Hemispherical refers to a non-perfect sphere and is not limited to one half of a sphere. In some embodiments, the light emitting units 10 may be white light emitting diode chips, and the material of the package 17 may include package glue, but is not limited thereto. In other embodiments, the light emitting units 10 may be blue light emitting diode chips, and the material of the package 17 may include, but is not limited to, an encapsulant, a light wavelength conversion material, or other suitable materials or combinations thereof.

Referring to fig. 6, the backlight module 1E further includes an optical film 12 in addition to the backlight module 1D of fig. 5. In the present embodiment, the light emitting units 10 may be blue light emitting diode chips, the material of the package 17 may include a package adhesive and a light wavelength conversion material, and the optical film 12 is, for example, a light wavelength conversion film capable of converting blue light into at least one of red light and green light. In some embodiments, the light wavelength converting film (optical film 12) and the light wavelength converting material may be different colors. For example, the optical film 12 converts blue light into red light (or green light), and the light wavelength conversion material converts blue light into green light (or red light). In some embodiments, the light wavelength converting film (optical film 12) and the light wavelength converting material may also be the same color. For example, the light wavelength conversion film (optical film 12) and the light wavelength conversion material can convert blue light into red light and green light.

Referring to fig. 7, the display device DD may include a backlight module 1C and a display panel DP disposed on the backlight module 1C. For the related description of the backlight module 1C, please refer to the foregoing description, which is not repeated herein. In other embodiments, not shown, the backlight module 1C can be replaced by any of the above-mentioned backlight modules, and the following embodiments can be modified accordingly, so that the description thereof will not be repeated. The display panel DP may include a non-self-luminous display panel, such as a liquid crystal display panel, but is not limited thereto.

The display device DD may have one or more elements or film layers added or subtracted as desired. 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 through the adhesive layer AD, but not limited thereto. The adhesive layer AD may be formed by curing a light-transmitting colloid. For example, the adhesion layer AD may include a thermosetting adhesive, a haze adhesive, a transparent heat conductive adhesive, an adhesive film, or other suitable adhesive materials, but not limited thereto. In other embodiments, not shown, the display panel DP may be fixed to the backlight module 1C by mechanical members to omit the adhesive layer AD.

Referring to fig. 8, a display device DDA includes a reflective layer R in addition to the display device DD of fig. 7. The reflective layer R is disposed on the sidewall of the backlight module 1C to reflect light, thereby improving light utilization. For example, the reflective layer R may be formed by curing a white glue, but not limited thereto.

Referring to fig. 9, in the display device DDB, the backlight module 1D replaces the backlight module 1C of fig. 7. In other embodiments not shown, the backlight module 1D can be replaced by any of the above backlight modules, and the following embodiments can be modified in the same way, so that the description thereof will not be repeated.

Referring to fig. 10, the display DDC further includes a reflective layer R in addition to the display DDB of fig. 9. For the description of the reflective layer R, please refer to the above description, and will not be repeated herein.

In summary, in the embodiments of the disclosure, the first adhesive layer is used to provide a flat bonding surface for bonding at least one optical film to the first adhesive layer, which is helpful to improve the problem that the optical film is not easily attached to the flip chip package. The at least one optical film is attached to the first adhesive layer through the second adhesive layer, so that the stiffness of the optical film can be increased without additionally arranging a base material (such as a plastic substrate), and the reduction of the overall thickness of the backlight module is facilitated. In addition, because the optical film is closely connected with the lower film layer, the times of interface reflection caused by air gaps can be reduced, and more light can be output from the backlight module. In addition, the optical film is attached to the first adhesive layer, so that the process procedure of the module end can be simplified, the on-line automatic process proportion is improved, and the assembly yield can be effectively improved or the pollution probability of products is reduced. In some embodiments, the material of the first adhesive layer may be selected appropriately to further improve light-emitting uniformity, improve light mixing limitation, or provide heat dissipation without increasing the thickness of the module. In some embodiments, the optical film may be selected to provide wavelength conversion, concentrated brightness enhancement, improved uniformity of light extraction, or improved light utilization. In some embodiments, a reflective layer may be disposed on the sidewalls of the backlight module to improve light utilization.

The above embodiments are only used for illustrating the technical solutions of the present disclosure, and not for limiting the same; while the present disclosure has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present disclosure.

Although the embodiments of the present disclosure and their advantages have been described above, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure by those skilled in the art, and that the features of the various embodiments may be arbitrarily mixed and substituted with one another to form new embodiments. Moreover, the scope of the present disclosure is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification, but rather, the present disclosure will suggest themselves to those skilled in the art having the benefit of this disclosure, and is intended to cover such modifications as may incorporate those features or methods into the practice of the present disclosure, as well as the equivalents of such processes, machines, manufacture, composition of matter, means, methods and steps, or any materials, which perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein. Accordingly, the scope of the present disclosure includes the processes, machines, manufacture, compositions of matter, means, methods, and steps described above. In addition, each claim constitutes a separate embodiment, and the scope of the present disclosure also includes combinations of the respective claims and embodiments. The scope of the present disclosure is to be determined by the claims appended hereto.

Claims

1. A backlight module, comprising:

a plurality of light emitting units;

a first adhesive layer covering the plurality of light emitting cells;

at least one optical film disposed on the plurality of light emitting units; and

a second adhesive layer disposed between the at least one optical film and the first adhesive layer.

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

3. The backlight module of claim 1, wherein a portion of the first adhesive layer is disposed between the plurality of light emitting units.

4. The backlight module of claim 1, wherein the first adhesive layer comprises a thermosetting adhesive, a haze adhesive, a transparent heat-conducting adhesive or an adhesive film.

5. The backlight module of claim 1, wherein the at least one optical film comprises a blue light transmissive film, a light wavelength converting film, a brightness enhancing film, or a composite film.

6. A display device, comprising:

a backlight module, comprising:

a plurality of light emitting units;

a first adhesive layer covering the plurality of light emitting cells;

a second adhesive layer disposed between the at least one optical film and the first adhesive layer; and

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 provided between the plurality of light emitting cells.

9. The display device according to claim 6, wherein the first adhesive layer comprises a thermosetting adhesive, a haze adhesive, a transparent heat-conducting adhesive or an adhesive film.

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