TWI824713B - Wavelength conversion element and backlight module - Google Patents

Abstract

A wavelength conversion element including a substrate, a blocking wall structure layer and a wavelength conversion layer is provided. The blocking wall structure layer is disposed on a surface of the substrate, and defines a plurality of microgrooves. The reflectivity of the blocking wall structure layer is in a range of 1% to 99%. The wavelength conversion layer is disposed in the microgrooves, and includes a plurality of wavelength conversion particles. A height of the blocking wall structure layer along a normal direction of the surface of the substrate is greater than a height of the wavelength conversion layer along the normal direction of the surface of the substrate. A backlight module adopting the wavelength conversion element is also provided.

Description

Wavelength conversion components and backlight modules

The present invention relates to a light source technology, and in particular, to a wavelength conversion element and a backlight module.

Since liquid crystal itself does not have the ability to emit light, the display panel must rely on a backlight module to provide backlight to display images. Therefore, improving the color quality of backlight is one of the goals of strengthening liquid crystal display technology, and quantum dot technology just meets the basic concept of this requirement. In detail, quantum dot technology uses a blue light-emitting diode light source to illuminate green quantum dots and red quantum dots with different diameters to excite red light and green light respectively to achieve the red light, green light and blue light required for full-color display. Three primary colors. Moreover, it decomposes light with a high degree of efficiency, thereby achieving high chromaticity reproducibility, greatly increasing its color gamut, and making the colors of the liquid crystal display more vivid.

In the existing technical architecture, due to the energy level coordination design relationship of quantum dots in the structure, a sandwich structure must be used to encapsulate the quantum dot material in a water and oxygen barrier film to stabilize the brightness and chromaticity of the light converted by the quantum dot material. Since the light converted by the quantum dot material does not have a specific direction, but is scattered in all directions, the subsequent light pattern is difficult to adjust through the optical film and is prone to light leakage.

The "prior art" paragraph is only used to help understand the content of the present invention. Therefore, the content disclosed in the "prior art" paragraph may contain some conventional technologies that do not constitute common knowledge to those with ordinary knowledge in the technical field. The content disclosed in the "Prior Art" paragraph does not mean that the content or the problems to be solved by one or more embodiments of the present invention have been known or recognized by those with ordinary knowledge in the technical field before the application of the present invention.

The present invention provides a wavelength conversion element with better conversion efficiency and higher forward light output of the converted light beam.

The invention provides a backlight module with high assembly yield and thin overall thickness.

Other objects and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

In order to achieve one, part or all of the above objects or other objects, an embodiment of the present invention provides a wavelength conversion element. The wavelength conversion element includes a substrate, a barrier structure layer and a wavelength conversion layer. The retaining wall structural layer is disposed on the surface of the substrate and defines a plurality of micro-grooves. The reflectivity of the retaining wall structural layer ranges from 1% to 90%. Wavelength converting layers are disposed within these microgrooves. The wavelength conversion layer includes a plurality of wavelength conversion particles. The height of the barrier structure layer along the normal direction of the surface of the substrate is greater than the height of the wavelength conversion layer along the normal direction of the surface of the substrate.

In an embodiment of the present invention, the barrier structure layer of the wavelength conversion element has a first surface and a second surface that are away from each other along the normal direction of the surface of the substrate. The first surface and the second surface respectively have a first width and a second width along a direction. The second width is less than or equal to the first width, and both the first width and the second width are less than 0.4 mm.

In an embodiment of the present invention, the material of the barrier structure layer of the wavelength conversion element includes titanium dioxide, polymethylmethacrylate, polycarbonate or polystyrene.

In an embodiment of the present invention, the above-mentioned wavelength conversion element further includes a hard coating layer covering the surface of the wavelength conversion layer facing away from the substrate.

In an embodiment of the present invention, the wavelength conversion layer of the wavelength conversion element has a surface facing away from the substrate, and the surface of the wavelength conversion layer is exposed to the air.

In an embodiment of the present invention, the barrier structure layer of the wavelength conversion element has a first part and a second part defining each micro-groove. The first part and the second part respectively have a first height and a second height along the normal direction of the surface of the substrate, and the first height is different from the second height.

In an embodiment of the present invention, the wavelength conversion layer of the above-mentioned wavelength conversion element is a plurality of wavelength conversion patterns. These wavelength conversion patterns are respectively filled in multiple micro-grooves of the retaining wall structural layer. The difference in thickness of any two of these wavelength conversion patterns along the normal direction of the surface of the substrate is less than or equal to 0.5 microns.

In an embodiment of the present invention, the wavelength conversion layer of the above-mentioned wavelength conversion element is a plurality of wavelength conversion patterns. These wavelength conversion patterns are respectively filled in multiple micro-grooves of the retaining wall structural layer. Each wavelength conversion pattern is adapted to absorb the excitation beam and emit a converted beam. The chromaticity difference of the chromaticity coordinate x of the multiple converted light beams emitted by these wavelength conversion patterns in the CIE1931 color space is less than 0.01, and the chromaticity difference of the chromaticity coordinate y of these converted light beams in the CIE1931 color space is less than 0.01.

In an embodiment of the present invention, the barrier structural layer of the wavelength conversion element includes a first structural layer and a second structural layer. The second structural layer is stacked on the first structural layer in a normal direction of the surface of the substrate. The first structural layer has a first surface and a second surface that are away from each other along the normal direction of the surface of the substrate. The second surface connects the second structural layer. The second structural layer has a third surface facing away from the second surface. The third surface has a first width, a second width and a third width respectively along one direction. The second width is less than or equal to the first width, the third width is less than the second width, and the first width, the second width and the third width are all less than 0.4 mm.

In an embodiment of the present invention, the height of the barrier structure layer of the wavelength conversion element along the normal direction of the surface of the substrate is less than 1 mm.

In an embodiment of the present invention, the barrier structure layer of the wavelength conversion element has a first side and a second side defining adjacent two of the plurality of micro-grooves, and the first side and the second side are Flat, folded, curved, or a combination of the above.

In an embodiment of the present invention, each wavelength conversion particle of the above-mentioned wavelength conversion element includes a core layer, a shell layer and a plurality of hydrophobic functional groups. The shell covers the core. These hydrophobic functional groups are provided on the surface of the shell layer facing away from the core layer.

In an embodiment of the present invention, each hydrophobic functional group of the above-mentioned wavelength conversion element is a polysilane polymer.

In one embodiment of the present invention, the wavelength conversion layer of the above-mentioned wavelength conversion element further includes a hydrophobic base material, and a plurality of wavelength conversion particles are dispersedly provided in the hydrophobic base material.

In an embodiment of the present invention, the barrier structure layer of the above-mentioned wavelength conversion element includes a plurality of barrier structures. These structures are arranged adjacent to each other and define multiple micro-grooves. The wavelength conversion layer is filled into the micro grooves and forms a plurality of wavelength conversion patterns, and the cross-sectional profiles of these wavelength conversion patterns are triangular.

In order to achieve one, part or all of the above objects or other objects, an embodiment of the present invention provides a backlight module. The backlight module includes a light source and a wavelength conversion component. The light source is adapted to provide an excitation beam. The wavelength conversion element is arranged on the transmission path of the excitation beam, and includes a substrate, a barrier structure layer and a wavelength conversion layer. The retaining wall structural layer is disposed on the surface of the substrate and defines a plurality of micro-grooves. The reflectivity of the retaining wall structural layer ranges from 1% to 90%. The wavelength conversion layer is disposed within the micro-grooves and includes a plurality of wavelength conversion particles. The height of the barrier structure layer along the normal direction of the surface of the substrate is greater than the height of the wavelength conversion layer along the normal direction of the surface of the substrate.

In an embodiment of the present invention, each wavelength conversion particle of the above-mentioned backlight module includes a core layer, a shell layer and a plurality of hydrophobic functional groups. The shell covers the core. These hydrophobic functional groups are provided on the surface of the shell layer facing away from the core layer.

In an embodiment of the present invention, the above-mentioned backlight module further includes a light guide plate. The light guide plate has a light incident surface and a light exit surface connected to the light incident surface. The light source is arranged on one side of the light incident surface of the light guide plate. The wavelength conversion element is arranged on one side of the light exit surface of the light guide plate.

Based on the above, in the wavelength conversion element and the backlight module according to an embodiment of the present invention, the wavelength conversion layer is provided in the plurality of micro-grooves of the barrier structure layer, and the filling height of the wavelength conversion layer is lower than that of the barrier structure layer. the height of. Since the reflectivity of the retaining wall structural layer ranges from 1% to 90%, in addition to increasing the conversion efficiency of the excitation beam, it can also limit the scattering angle of the converted beam, increasing the amount of forward light. On the other hand, the setting of the retaining wall structural layer can also improve the stiffness of the wavelength conversion element. In addition to meeting the need for overall thickness thinning, it can also avoid the problem of reduced assembly yield of the backlight module caused by thinning.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, embodiments are given below and described in detail with reference to the accompanying drawings.

The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the drawings. Directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only for reference to the directions in the attached drawings. Accordingly, the directional terms used are illustrative and not limiting of the invention.

FIG. 1 is a schematic cross-sectional view of a backlight module according to an embodiment of the present invention. FIG. 2 is an enlarged schematic diagram of the wavelength conversion element of FIG. 1 . FIG. 3 is a schematic top view of the wavelength conversion element of FIG. 2 . FIG. 4 is a schematic top view of the wavelength conversion element of another modified embodiment of FIG. 3 . FIG. 5 is an enlarged schematic diagram of the wavelength conversion particles of FIG. 2 . FIG. 6 is an enlarged schematic view of the retaining wall structural layer of another embodiment of FIG. 2 . 7A to 7G are schematic cross-sectional views of retaining wall structural layers in other modified embodiments of FIG. 6 .

Referring to FIG. 1 , the backlight module 10 includes a light guide plate 100 , a light source 110 and a wavelength conversion element 120 . The light guide plate 100 has a light incident surface 100is and a light exit surface 100es connected to the light incident surface 100is. The light source 110 is disposed on one side of the light incident surface 100is of the light guide plate 100 . The wavelength conversion element 120 is disposed on one side of the light exit surface 100es of the light guide plate 100 . More specifically, the backlight module 10 of this embodiment is an edge-type backlight module, but it is not limited to this.

In this embodiment, the light source 110 is adapted to provide the excitation beam EB toward the light incident surface 100is of the light guide plate 100 , and the excitation beam EB passes through the transverse direction of the light guide plate 100 and then leaves the light guide plate 100 and is incident on the light exit surface 100es of the light guide plate 100 Wavelength conversion element 120. The wavelength conversion element 120 is disposed on the transmission path of the excitation beam EB, and is adapted to receive the excitation beam EB from the light guide plate 100 and emit the conversion beam CB.

Referring to FIGS. 2 and 3 , the wavelength conversion element 120 includes a substrate SUB, a barrier structure layer 123 and a wavelength conversion layer 125 . The retaining wall structure layer 123 is disposed on the surface SUBs of the substrate SUB, and defines a plurality of micro-grooves MG. The wavelength conversion layer 125 is disposed within these micro-grooves MG. In this embodiment, the retaining wall structural layer 123 may be formed by a plurality of first retaining walls 123BW1 and a plurality of second retaining walls 123BW2 arranged in a crosswise manner.

For example, the arrangement direction of the plurality of first blocking walls 123BW1 may be perpendicular to the arrangement direction of the plurality of second blocking walls 123BW2, and the extending direction of the first blocking walls 123BW1 may be perpendicular to the extending direction of the second blocking walls 123BW2. That is, the retaining wall structure layer 123 of this embodiment exhibits a mesh-arranged structure in the normal direction of the surface SUBs of the substrate SUB. In this embodiment, the plurality of micro-grooves MG defined by the retaining wall structural layer 123 may be arranged along the arrangement direction of the plurality of first retaining walls 123BW1 or the plurality of second retaining walls 123BW2. That is, these micro-grooves MG are arranged at intervals on the substrate SUB in a two-dimensional array, and the wavelength conversion layer 125 provided in these micro-grooves MG is divided by the barrier structure layer 123 into spaced apart and square shapes. A plurality of wavelength conversion patterns in the shape of 125P.

However, the present invention is not limited to this. Please refer to FIG. 4 . In another embodiment, the barrier wall structure layer 123 ″ of the wavelength conversion element 120A may also be composed of multiple barrier walls 123BW with a single extension direction, spaced along a single direction (for example, the horizontal direction of FIG. 4 ). are arranged. Therefore, the plurality of micro-grooves MG-A defined by the barrier structure layer 123″ are also arranged at intervals along the single direction, and the wavelength conversion layer 125A provided in these micro-grooves MG-A can It is divided into a plurality of wavelength conversion patterns arranged at intervals along the single direction and in the shape of strips. In another embodiment not shown, the plurality of micro-grooves defined by the retaining wall structural layer can also be arranged in a honeycomb manner.

Please refer to FIG. 2 . Please note that the height H of the barrier structure layer 123 along the normal direction of the surface SUBs of the substrate SUB is greater than the height H of the wavelength conversion layer 125 along the normal direction of the surface SUBs of the substrate SUB ( That is, the thickness t1 of the wavelength conversion pattern 125P1 or the thickness t2 of the wavelength conversion pattern 125P2), and the reflectivity of the barrier structure layer 123 is in a range between 1% and 90%. Accordingly, the excitation beam EB can be reflected back to the wavelength conversion layer 125 in the micro-groove MG through the barrier structure layer 123. In addition to increasing the conversion efficiency of the excitation beam EB, it can also limit the scattering angle of the conversion beam CB, making it The amount of light emitted in the forward direction increases. In this embodiment, the material of the retaining wall structural layer 123 includes a base material (such as acrylic resin) and a high reflectivity material (such as titanium dioxide, polymethylmethacrylate, polycarbonate or polystyrene), wherein high The reflectivity material is evenly mixed into the substrate. Preferably, the height H of the barrier structure layer 123 along the normal direction of the surface SUBs of the substrate SUB can be less than 1 mm to improve the process yield and ensure the light extraction quality of the backlight module 10 .

On the other hand, in this embodiment, the retaining wall structure layer 123 has a first surface SF1 and a second surface SF2 that are away from each other along the normal direction of the surface SUBs of the substrate SUB. The first surface SF1 and the second surface SF2 respectively have a first width W1 along a direction (for example, a direction parallel to the surface SUBs of the substrate SUB, or the horizontal direction in FIG. 2 or perpendicular to the extension direction of the retaining wall structure layer 123 ). and a second width W2. Specifically, the second width W2 of the retaining wall structural layer 123 is less than or equal to the first width W1, and these widths are all less than 0.4 mm. In this way, the visibility of the barrier structure layer 123 in the normal direction of the surface SUBs of the substrate SUB can be greatly reduced to ensure the display quality of the display using the backlight module 10 .

Furthermore, the wavelength conversion layer 125 may include a plurality of wavelength conversion particles WCP. In this embodiment, two types of wavelength conversion particles WCP are exemplarily explained, such as wavelength conversion particles WCP1 and wavelength conversion particles WCP2, but are not limited thereto. In other embodiments, the type of wavelength conversion particles WCP included in the wavelength conversion layer can be adjusted according to actual application requirements.

For example, in this embodiment, the wavelength conversion particle WCP1 is suitable for absorbing the incident excitation beam EB (as shown in Figure 1) and then emits red light, while the wavelength conversion particle WCP2 is suitable for absorbing the incident excitation beam EB and then emitting green light. Light, where the excitation beam EB is, for example, blue light, but is not limited thereto. For example, the excitation beam EB can also be ultraviolet light with a wavelength between 200 nanometers and 450 nanometers.

Please refer to Figures 2 and 5. The wavelength conversion particle WCP includes a core layer CL, a shell layer SL and multiple hydrophobic functional groups HFG, as shown in Figure 5. The shell layer SL covers the core layer CL. These hydrophobic functional groups HFG are provided on the surfaces SLs of the shell layer SL facing away from the core layer CL. In detail, the core layer CL of the wavelength conversion particle WCP is a luminescent core, and its material includes, for example, cadmium selenide (CdSe), cadmium sulfide (Cdmium Sulfide, CdS) or zinc selenide (Zinc Selenide, ZnSe), But it is not limited to this. In order to prevent the core layer CL from failing due to the intrusion of water vapor and oxygen, the shell layer SL covering the core layer CL can be used as a protective layer, and its material includes, for example, silicon dioxide (SiO2), cadmium sulfide or zinc selenide. etc., but not limited to this. In this embodiment, the total particle diameter Da of the core layer CL and the shell layer SL of the wavelength conversion particle WCP may be between 22 nanometers and 25 nanometers.

The surface SLs of the shell SL can have multiple ligands LG. The aforementioned plurality of hydrophobic functional groups HFG can be coordinated on the surface SLs of the shell layer SL through these ligands LG, and form a hydrophobic film layer. In this embodiment, the hydrophobic functional group HFG is, for example, polysilane polymer. By coating with this hydrophobic film layer, the water and oxygen blocking ability of the wavelength conversion particles WCP can be further improved. Therefore, in this embodiment, there is no need to provide an additional protective layer, barrier layer or another substrate on the side surface 125s of the wavelength conversion layer 125 away from the substrate SUB to block water and oxygen, which contributes to the thinness of the wavelength conversion element 120. change. More specifically, the surface 125s of the wavelength conversion layer 125 may be exposed to air AIR.

In this embodiment, the wavelength conversion layer 125 may further include a hydrophobic base material HPM, and these wavelength conversion particles WCP are dispersedly provided in the hydrophobic base material HPM. The material of the hydrophobic substrate HPM includes, for example, epoxy silicon, silicone rubber or acrylic. Accordingly, the water and oxygen blocking ability of the wavelength conversion layer 125 can be further improved. However, the present invention is not limited to this. In other embodiments, the base material of the wavelength conversion layer may also include a non-hydrophobic base material.

In particular, through the arrangement of the retaining wall structure layer 123, the stiffness of the thinned wavelength conversion element 120 can be further increased, so that the selected thickness of the substrate SUB can be reduced to between 12 microns and 50 microns. The overall thickness of the wavelength conversion element 120 can be less than 100 microns. That is to say, the thinned wavelength conversion element 120 can have sufficient stiffness through the support of the barrier structure layer 123 to avoid a decrease in the assembly yield of the backlight module 10 .

On the other hand, the provision of the barrier structure layer 123 can also increase the film thickness uniformity of the wavelength conversion layer 125 . For example, the thickness difference between any two of the plurality of wavelength conversion patterns 125P respectively filled in the plurality of micro-grooves MG along the normal direction of the surface SUBs of the substrate SUB (for example, the wavelength conversion pattern 125P1 and the wavelength conversion pattern 125P1 in FIG. 2 The thickness difference t2-t1 of the conversion pattern 125P2 may be less than or equal to 0.5 microns.

From another point of view, since the plurality of wavelength conversion patterns 125P filled in the plurality of micro-grooves MG of the barrier structure layer 123 have better film thickness uniformity, these wavelength conversion patterns 125P each absorb the excitation beam EB. The chromaticity difference of the chromaticity coordinate x in the CIE1931 color space of the emitted converted light beam CB can be less than 0.01, and the chromaticity difference of the chromaticity coordinate y in the CIE1931 color space can be less than 0.01. That is to say, the converted light beams CB emitted by the wavelength conversion patterns 125P respectively disposed in the plurality of micro-grooves MG may have better chromaticity uniformity. Preferably, the chromaticity difference of the chromaticity coordinate x and the chromaticity coordinate y of these converted light beams CB in the CIE1931 color space are both less than 0.005.

Please refer to Figures 2 and 6. Different from the barrier structure layer 123 of Figure 2, in another embodiment, the barrier structure layer 123' may include a first structure stacked in the normal direction of the surface SUBs of the substrate SUB. layer 123L1 and the second structural layer 123L2. The first structural layer 123L1 has a first surface SF1 and a second surface SF2 that are away from each other along the normal direction of the surface SUBs of the substrate SUB. The second surface SF2 of the first structural layer 123L1 is connected to the second structural layer 123L2. The second structural layer 123L2 has a third surface SF3 facing away from the second surface SF2. The first surface SF1 , the second surface SF2 and the third surface SF3 are respectively along a direction (for example, a direction parallel to the surface SUBs of the substrate SUB, or the horizontal direction in FIG. 6 or perpendicular to the extension direction of the retaining wall structure layer 123 ). It has a first width W1, a second width W2 and a third width W3.

It is particularly noted that the second width W2 of the retaining wall structural layer 123 is less than or equal to the first width W1, the third width W3 is less than the second width W2, and these widths are all less than 0.4 mm. In this way, the visibility of the barrier structure layer 123 in the normal direction of the surface SUBs of the substrate SUB can be greatly reduced to ensure the display quality of the display using the backlight module 10 .

However, the present invention is not limited to this. In other modified embodiments, the first side and the second side of the retaining wall structural layer may also be folded surfaces (for example, the first side 123ss1-A and the second side 123ss2-A of the retaining wall structural layer 123A in Figure 7A and the first side 123ss1-E and the second side 123ss2-E of the retaining wall structural layer 123E in Figure 7E), curved surfaces (such as the first side 123ss1-C and the second side 123ss2-C of the retaining wall structural layer 123C in Figure 7C and the first side 123ss1-G and the second side 123ss2-G of the retaining wall structural layer 123G of Figure 7G) or a plane (such as the first side 123ss1 and the second side 123ss2 of the retaining wall structural layer 123 of Figure 6 and the first side 123ss2 of Figure 7D The combination of the first side 123ss1-D and the second side 123ss2-D of the retaining wall structural layer 123D) and the curved surface (for example, the first side 123ss1-B and the second side 123ss2-B of the retaining wall structural layer 123B in Figure 7B and Figure 7B The first side 123ss1-F and the second side 123ss2-F of the retaining wall structural layer 123F of 7F).

It is particularly important to note that in the retaining wall structural layer 123A in FIG. 7A , the first side 123ss1-A and the second side 123ss2-A may be arranged asymmetrically. In the retaining wall structural layer 123D, the retaining wall structural layer 123E, the retaining wall structural layer 123F and the retaining wall structural layer 123G of Figures 7D to 7G, the third surfaces SF3-D, SF3- of these retaining wall structural layers E. The third surface SF3-F and the third surface SF3-G are not the third surface SF3 in Figure 6, the third surface SF3-A in Figure 7A, the third surface SF3-B in Figure 7B and the third surface in Figure 7C. Surface SF3-C is flat.

For example, in the retaining wall structural layer 123D in Figure 7D, its first side 123ss1-D and its second side 123ss2-D intersect and form a vertex angle. Similarly, in the retaining wall structure layer 123E of Figure 7E, its first side 123ss1-E and the second side 123ss2-E intersect and form a vertex angle. In the retaining wall structural layer 123F of FIG. 7F and the retaining wall structural layer 123G of FIG. 7G, both the third surface SF3-F and the third surface SF3-G are curved surfaces.

Other embodiments will be enumerated below to describe the present disclosure in detail, in which the same components will be marked with the same symbols, and the description of the same technical content will be omitted. Please refer to the previous embodiments for the omitted parts, which will not be described again below.

FIG. 8 is a schematic cross-sectional view of a wavelength conversion element according to another embodiment of the present invention. Please refer to FIG. 8 . The main difference between the wavelength conversion element 120B of this embodiment and the wavelength conversion element 120 of FIG. 2 lies in the thickness diversity of the retaining wall structural layer. Specifically, the barrier structure layer 123H of the wavelength conversion element 120B has two parts that define any micro-groove, for example: the first part 123P1 and the second part 123P2 that define the micro-groove MG1-B and the micro-groove MG2- The second part of B 123P2 and the third part 123P3.

It is particularly noted that the heights of the portions of the retaining wall structural layer 123H may be different. In this embodiment, the first part 123P1, the second part 123P2 and the third part 123P3 of the retaining wall structural layer 123H have a first height H1, a second height H2 and a third height respectively along the normal direction of the surface SUBs of the substrate SUB. Height H3, and these three heights are all different. For example, the first height H1 may be greater than the second height H2, and the third height H3 may be greater than the first height H1, but is not limited thereto. Through the above-mentioned height difference of the barrier structure layer 123H, the adsorption phenomenon between the wavelength conversion element 120B and other optical films can be avoided.

Figure 9 is a schematic cross-sectional view of a wavelength conversion element according to yet another embodiment of the present invention. Referring to FIG. 9 , unlike the wavelength conversion element 120 of FIG. 2 , the wavelength conversion element 120C of this embodiment may also optionally include a hard coating HCL. The hard coating HCL may cover the surface 125s of the wavelength conversion layer 125 facing away from the substrate SUB. That is, the wavelength conversion layer 125 of this embodiment is not exposed to the air AIR like the wavelength conversion layer 125 of FIG. 2 .

For example, in this embodiment, the water vapor transmission rate of the hard coating HCL can be greater than 10g/m2∙day, and the oxygen transmission rate of the hard coating HCL can be greater than 10cm3/m2∙day∙atm. That is to say, in this embodiment, due to the use of the hard coating HCL with high water vapor/oxygen resistance ability, the wavelength conversion particles WCP of the wavelength conversion layer 125 can also be used without hydrophobic functional groups HFG (as shown in Figure 5 shown) are replaced by wavelength converting particles.

FIG. 10 is a schematic cross-sectional view of a wavelength conversion element according to yet another embodiment of the present invention. Please refer to Figure 10. The difference between the wavelength conversion element 120D of this embodiment and the wavelength conversion element 120 of Figure 2 is that the configuration of the retaining wall structural layer is different. Specifically, in this embodiment, the retaining wall structural layer 123I is composed of, for example, multiple ridge structures. These ridge structures are arranged side by side along the horizontal direction of FIG. 10 , for example, and define multiple micro-grooves MG- C.

In this embodiment, the wavelength conversion layer 125B is filled in a plurality of micro-grooves MG-C between these structures (ie, the retaining wall structure layer 123I), and is cut into spaced apart arrangements and cross-sections (ie, FIG. 10 The figure) has a plurality of wavelength conversion patterns 125P" with a triangular outline. In particular, since the plurality of wavelength conversion patterns 125P in this embodiment are arranged close to each other, the transmittance of the retaining wall structure layer 123I is higher than that of the previous embodiments. The retaining wall structure of the example is high.

FIG. 11 is a schematic cross-sectional view of a backlight module according to another embodiment of the present invention. Please refer to FIG. 11 . Different from the backlight module 10 in FIG. 1 which is an edge-type backlight module, the backlight module 20 of this embodiment is a direct-type backlight module. For example, in this embodiment, the backlight module 20 may include a circuit board CBD and a plurality of light sources 110A. These light sources 110A are dispersedly arranged on the circuit board CBD and are electrically connected to the circuit board CBD. The wavelength conversion element 120 is arranged to overlap the light exit surfaces of these light sources 110A, and is suitable for absorbing the excitation beam EB emitted by each light source 110A and then emitting the converted beam CB.

Since the wavelength conversion element 120 of this embodiment is similar to the wavelength conversion element 120 of FIG. 1 , please refer to the relevant paragraphs of the foregoing embodiments for detailed description, and will not be described again here. On the other hand, the wavelength conversion element of each of the foregoing embodiments can be used to replace the wavelength conversion element 120 of this embodiment to meet different application designs or process requirements.

To sum up, in the wavelength conversion element and the backlight module according to one embodiment of the present invention, the wavelength conversion layer is provided in the plurality of micro-grooves of the barrier structure layer, and the filling height of the wavelength conversion layer is lower than the barrier wall The height of the structural layer. Since the reflectivity of the retaining wall structural layer ranges from 1% to 90%, in addition to increasing the conversion efficiency of the excitation beam, it can also limit the scattering angle of the converted beam, increasing the amount of forward light. On the other hand, the setting of the retaining wall structural layer can also improve the stiffness of the wavelength conversion element. In addition to meeting the need for overall thickness thinning, it can also avoid the problem of reduced assembly yield of the backlight module caused by thinning.

10, 20: Backlight module 100:Light guide plate 100es: light-emitting surface 100is: light incident surface 110, 110A: light source 120, 120A, 120B, 120C, 120D: wavelength conversion element 123, 123’, 123”, 123A~123H, 123I: retaining wall structural layer 123BW: retaining wall 123BW1: The first retaining wall 123BW2:Second retaining wall 123L1: First structural layer 123L2: Second structural layer 123P1~123P3: Part 1~Part 3 123ss1, 123ss1-A~123ss1-G: first side 123ss2, 123ss2-A~123ss2-G: second side 125, 125A, 125B: Wavelength conversion layer 125P, 125P1, 125P2, 125P”: wavelength conversion pattern 125s, SLs, SUBs: surface AIR: air CB: Conversion beam CBD: circuit board CL: nuclear layer Da: particle size EB: excitation beam H, H1, H2, H3: height HCL: hard coating HFG: hydrophobic functional group HPM: hydrophobic substrate LG: ligand MG, MG-A, MG1-B, MG2-B, MG-C: micro grooves SF1: first surface SF2: Second surface SF3, SF3-A~SF3-G: third surface SL: Shell SUB:Substrate t1, t2: thickness W1~W3: first width~third width WCP, WCP1, WCP2: wavelength conversion particles

FIG. 1 is a schematic cross-sectional view of a backlight module according to an embodiment of the present invention. FIG. 2 is an enlarged schematic diagram of the wavelength conversion element of FIG. 1 . FIG. 3 is a schematic top view of the wavelength conversion element of FIG. 2 . FIG. 4 is a schematic top view of the wavelength conversion element of another modified embodiment of FIG. 3 . FIG. 5 is an enlarged schematic diagram of the wavelength conversion particles of FIG. 2 . FIG. 6 is an enlarged schematic view of the retaining wall structural layer of another embodiment of FIG. 2 . 7A to 7G are schematic cross-sectional views of retaining wall structural layers in other modified embodiments of FIG. 6 . FIG. 8 is a schematic cross-sectional view of a wavelength conversion element according to another embodiment of the present invention. Figure 9 is a schematic cross-sectional view of a wavelength conversion element according to yet another embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of a wavelength conversion element according to yet another embodiment of the present invention. FIG. 11 is a schematic cross-sectional view of a backlight module according to another embodiment of the present invention.

120:Wavelength conversion element

123:Retaining wall structural layer

123ss1: first side

123ss2:Second side

125: Wavelength conversion layer

125P1, 125P2: Wavelength conversion pattern

125s, SUBs: Surface

AIR: air

H: height

HPM: hydrophobic substrate

MG: micro groove

SF1: first surface

SF2: Second surface

SUB:Substrate

t1, t2: thickness

WCP, WCP1, WCP2: wavelength conversion particles

W1: first width

W2: second width

Claims (18)

A wavelength conversion element, suitable for receiving an excitation beam, and includes: a substrate; a retaining wall structural layer, which is disposed on a surface of the substrate and defines a plurality of micro-grooves. The reflectivity of the retaining wall structural layer A range between 1% and 90%; and a wavelength conversion layer disposed in the micro-grooves, the wavelength conversion layer including a plurality of wavelength conversion particles, wherein the barrier structure layer is along the surface of the substrate The height in the normal direction of the wavelength conversion layer is greater than the height of the wavelength conversion layer in the normal direction along the surface of the substrate, the excitation beam penetrates the substrate and is transmitted to the wavelength conversion layer, and the excitation beam is converted in the wavelength The layer is converted into a converted beam. The wavelength conversion element of claim 1, wherein the barrier structure layer has a first surface and a second surface that are away from each other along the normal direction of the surface of the substrate, and the first surface and the The second surface respectively has a first width and a second width along a direction, the second width is less than or equal to the first width, and both the first width and the second width are less than 0.4 mm. The wavelength conversion element according to claim 1, wherein the material of the retaining wall structural layer includes titanium dioxide, polymethylmethacrylate, polycarbonate or polystyrene. The wavelength conversion element according to claim 1, further comprising: a hard coating covering a surface of the wavelength conversion layer facing away from the substrate. The wavelength conversion element of claim 1, wherein the wavelength conversion layer has a surface facing away from the substrate, and the surface of the wavelength conversion layer is exposed to the air. The wavelength conversion element of claim 1, wherein the barrier structure layer has a first part and a second part defining each of the micro-grooves, the first part and the second part along the surface of the substrate The normal directions of have a first height and a second height respectively, and the first height is different from the second height. The wavelength conversion element according to claim 1, wherein the wavelength conversion layer is a plurality of wavelength conversion patterns, and the wavelength conversion patterns are respectively filled in the micro grooves of the barrier structure layer, and any of the wavelength conversion patterns The thickness difference between the two along the normal direction of the surface of the substrate is less than or equal to 0.5 micron. The wavelength conversion element according to claim 1, wherein the wavelength conversion layer is a plurality of wavelength conversion patterns, and the wavelength conversion patterns are respectively filled in the micro grooves of the barrier structure layer, and each of the wavelength conversion patterns is suitable for After absorbing the excitation beam and emitting the conversion beam, the chromaticity difference of the chromaticity coordinates The chromaticity difference of the chromaticity coordinate y in is less than 0.01. The wavelength conversion element according to claim 1, wherein the barrier structural layer includes a first structural layer and a second structural layer, and the second structural layer is stacked on the first structural layer in the normal direction of the surface of the substrate. On a structural layer, the first structural layer has a first surface and a second surface that are away from each other along the normal direction of the surface of the substrate, and the second surface is connected to the second structural layer. The two structural layers have a third surface facing away from the second surface, and the first surface, the second surface and the third surface respectively have a first width, a second width and a third width along a direction, The second width is less than or equal to the first width, the third width is less than the second width, and the first width, the second width and the third width are all less than 0.4 mm. The wavelength conversion element according to claim 1, wherein the height of the barrier structure layer along the normal direction of the surface of the substrate is less than 1 mm. The wavelength conversion element according to claim 1, wherein the barrier structure layer has a first side and a second side defining two adjacent ones of the micro-grooves, and the first side and the second side It can be a flat surface, a folded surface, a curved surface, or a combination of the above. The wavelength conversion element according to claim 1, wherein each of the wavelength conversion particles includes: a core layer; a shell layer covering the core layer; and a plurality of hydrophobic functional groups disposed on the shell layer away from the core layer on the surface. The wavelength conversion element according to claim 12, wherein each of the hydrophobic functional groups is a polysilane polymer. The wavelength conversion element according to claim 12, wherein the wavelength conversion layer further includes a hydrophobic substrate, and the wavelength conversion particles are dispersedly provided in the hydrophobic substrate. The wavelength conversion element of claim 1, wherein the barrier structure layer includes a plurality of ridge structures, the ridge structures are arranged adjacent to each other and define the micro-grooves, and the wavelength conversion layer fills the micro-grooves. A plurality of wavelength conversion patterns are formed in the groove, and the cross-sectional profiles of these wavelength conversion patterns are triangular. A backlight module includes: a light source suitable for providing an excitation beam; and a wavelength conversion element disposed on the transmission path of the excitation beam, and includes: a substrate; and a blocking wall structure layer disposed on the substrate On a surface, and defining a plurality of micro-grooves, the reflectivity of the retaining wall structural layer ranges from 1% to 90%; and a wavelength conversion layer is provided in the micro-grooves, the wavelength conversion layer The layer includes a plurality of wavelength conversion particles, wherein the height of the barrier structure layer along the normal direction of the surface of the substrate is greater than the height of the wavelength conversion layer along the normal direction of the surface of the substrate, and the excitation The light beam penetrates the substrate and is transmitted to the wavelength conversion layer, and the excitation light beam is converted into a conversion light beam at the wavelength conversion layer. The backlight module of claim 16, wherein each of the wavelength conversion particles includes: a core layer; a shell layer covering the core layer; and a plurality of hydrophobic functional groups disposed on the shell layer away from the core layer on the surface. The backlight module of claim 16, further comprising: a light guide plate having a light incident surface and a light exit surface connected to the light incident surface, wherein the light source is disposed on one side of the light incident surface of the light guide plate , the wavelength conversion element is disposed on one side of the light exit surface of the light guide plate.

Images