COLOR CONVERSION ELEMENT FOR LEDS

Abstract

Color conversion element for LEDs, including: a color conversion section, formed as a flat plate, configured to change the color of light emitted by the LED as it passes through it; a light reflection section formed to cover the sides of the color conversion section and configured to reflect light traveling to the sides of the color conversion section; a light absorption section formed around the outer edge of the one light reflection section, which is configured to absorb light passing through the one light reflection section; wherein the color conversion section, the light reflection section and the light absorption section are formed in one piece as a flat plate with a light emission surface and the light reflection section reflects light that travels to the sides of the color conversion section, while the light absorption section removes laterally directed light, thereby improving the straightness of the emitted light, wherein the side surface of the color conversion section is formed at an incline; which has a layered shape and is formed to cover the inclined side surface of the color conversion section; the light absorption section is formed in a rectangular frame shape with an inclined inner side surface and an outer side surface parallel to the direction of light propagation; the entire structure is formed in the form of a rectangular flat plate shape.

Description

STATE OF THE ART 1. Field of the invention

[0001] The present disclosure relates to a color conversion element for an LED. More specifically, the present disclosure relates to a color conversion element for an LED that is installed in front of an LED chip and changes the wavelength of light emitted by the LED. 2. Discussion of the state of the art

[0002] Applications where multiple small LEDs are arranged and controlled to switch on and off independently, such as multi-beam LEDs for car headlights, have become more widespread. Since each small LED illuminates independently, it is important to improve the directness and light quality of each individual LED.

[0003] Japanese Patent No. JP 7 117 127 B2 discloses a light-emitting device comprising a substrate, a light-emitting element implemented on the substrate, and a wavelength conversion element (17) arranged on the light-emitting element, wherein a lower surface covers the entire upper surface of the light-emitting element and an upper surface is smaller than the lower surface. The wavelength conversion element has side surfaces whose width decreases from bottom to top. Additionally, a first cover element (19) covers the side surface of the wavelength conversion element, while a second cover element (21) covers the entire side surface of the light-emitting element and extends from the perimeter of the lower surface of the wavelength conversion element to the upper surface.The first and second cover elements have different light absorption rates, with the first cover element filling the space between the second cover element and the wavelength conversion element. The inner surface of the second cover element extends vertically from the perimeter of the lower surface of the wavelength conversion element towards the upper surface, thus providing a light-emitting device with improved optical performance.

[0004] From DE 20 2014 011 392 U1, an LED housing is known, comprising an LED unit and an opaque unit that covers at least one side surface of the LED unit. Furthermore, a vehicle light with such an LED housing is known from DE 20 2014 011 392 U1.

[0005] From DE 20 2024 101 556 U1 a device is known which uses a combination of laser diode excitation sources based on gallium and nitrogen-containing materials and a light-emitting source based on phosphorus materials.

[0006] From DE 10 2008 012 316 A1 a semiconductor light source with a primary radiation source and a luminescence conversion module is known.

[0007] From DE 10 2018 105 908 A1, an optoelectronic component is known which has an optoelectronic semiconductor chip with an emission side and a metal layer that is reflective or absorbing for radiation generated by the optoelectronic component. SUMMARY OF THE INVENTION

[0008] The present disclosure is aimed at providing a color conversion element for LEDs with high light linearity, a smooth surface and a compact size without cracks or chipping, thereby improving the light quality of LEDs.

[0009] The color conversion element for LEDs according to one embodiment of the present invention comprises: a color conversion section formed in a plate shape, which converts and transmits the color of light emitted by the LED; a light reflection section formed to cover the side of the color conversion section and to reflect light traveling to that side; and a light absorption section formed around the outer edge of the light reflection section to cover it and to absorb light traveling through the light reflection section. The color conversion section, the light reflection section, and the light absorption section are integrally formed in a plate shape with a flat, light-emitting surface.

[0010] The light reflection section reflects light that travels towards the side of the color conversion section, and the light absorption section eliminates light traveling laterally, thus improving the straightness of the emitted light.

[0011] The side of the color conversion section is formed with an inclined surface, a light reflection section is shaped as a layer to cover the inclined side of the color conversion section, and the light absorption section is formed in a rectangular frame shape, with its inner surface inclined and its outer surface parallel to the direction of light. Thus, the overall structure can have a rectangular, flat plate shape.

[0012] The side of the color conversion section is inclined to a certain depth, while the remaining section is parallel to the direction of light propagation. The light reflection section is plate-shaped and covers the side of the color conversion section; similarly, part of it is inclined to the direction of light propagation, while another part is parallel. The light absorption section is formed in a rectangular frame shape, with part of the inner surface inclined and the remaining part oriented parallel to the direction of light propagation, while the outer surface is parallel to the direction of light propagation, allowing the entire structure to assume a rectangular, flat plate shape.

[0013] The light reflection section can be made of a material selected from aluminium, silver, gold, copper, chromium, titanium dioxide or cerium oxide, and it can be attached to the color conversion section by a deposition process, forming a thin layer.

[0014] The light absorption section can be a mixture of glass and carbon powder, created by mixing liquid glass with carbon powder and subsequent hardening.

[0015] The light absorption section can be chromium oxide or a nickel-chromium alloy applied to the outside of the light reflection section. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other items, features and advantages of the present disclosure will be better understood by those skilled in the field by a detailed description of exemplary embodiments with reference to the accompanying drawings, in which: Fig. 1 a cross-sectional view of a color conversion element for LEDs according to an embodiment of the present invention; Fig. 2, Fig. 3, Fig. 4 to Fig. 5. Show the direction of light propagation and the light quality when using a color conversion element for LEDs according to a comparative example of the present invention; Fig. 6 is a diagram showing the method for manufacturing a color conversion element for LEDs according to an embodiment of the present invention; Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14 to Fig. 15 show the results of processes in the method for manufacturing a color conversion element for LEDs of the present invention; Fig. 16 a perspective view of a color conversion element for LEDs according to an embodiment of the present invention; Fig. 17 is a cross-sectional view of a color conversion element for LEDs according to another embodiment of the present invention. DETAILED DESCRIPTION OF EXEMPLARY EXECUTION FORMS

[0017] Embodiments of the present disclosure are described below with reference to the accompanying drawings. The accompanying drawings show exemplary embodiments of the present disclosure, which are provided only to further describe the present disclosure, and the technical scope of the present disclosure is not limited thereto.

[0018] In addition, regardless of the reference symbols, identical or corresponding components are given the same reference symbols, overlapping descriptions are omitted, and to simplify the description, the sizes and shapes of the individual components shown may be exaggerated or reduced.

[0019] In the meantime, terms with ordinal numbers, such as first, second, etc., can be used to describe different components, but the components are not limited by the terms, and the terms are only used for the purpose of distinguishing one component from another.

[0020] The color conversion element for LEDs 10 according to an embodiment of the present invention, as shown in Fig. 1, can be formed in a flat plate shape. In the middle part, a color conversion section 1 is formed, surrounded by a light reflection section 3. A light absorption section 5 can be formed around the perimeter of the light reflection section 3.

[0021] The color conversion section 1 is shaped as a rectangular plate with beveled sides. The light reflection section 3 can be formed on the outside of these beveled sides. The light reflection section 3 can be in contact with the sides of the color conversion section 1, with its outer surface parallel to the inner surface. The light reflection section 3 can be configured to cover the entire side of the color conversion section 1.

[0022] The light absorption section 5 can be formed to adhere to the outer surface of one of the light reflection sections 3. The inner surface of the light absorption section 5 can be shaped with the same inclination as the outer surface of the light reflection section 3. The outer surface of the light absorption section 5 can be oriented perpendicular to the upper and lower surfaces of the color conversion section 1. The light absorption section 5 can have a rectangular frame shape that covers the side of the light reflection section 3. In the combined state, the color conversion section 1, a light reflection section 3, and the light absorption section 5 form the color conversion element 10, which can be shaped as a flat rectangular plate.

[0023] The color conversion section 1 can be produced by mixing fluorescent material powder, glass powder, and a binder, followed by sintering. The light reflection section 3 can be a thin plate, layer, or film made of a metal such as aluminum, silver, gold, copper, chromium, titanium dioxide, or cerium oxide. The light absorption section 5 can be created by mixing carbon powder with a silicone or epoxy resin. Liquid glass can also be used instead of silicone resin, which may offer advantages over silicone resin in terms of strength, durability, and adhesion. As light passes through the color conversion section 1, its color is modified; when it enters the light reflection section 3, it is reflected; and when it enters the light absorption section 5, it is absorbed.

[0024] As shown in Fig. 2, a color conversion element 23 can be attached to the emission surface of an LED chip 20, forming a light-emitting module. The LED chip 20 emits blue light, which, upon passing through the color conversion element 23, is converted into white light and then emitted. In a comparative example where the color conversion element 23 consists only of a color conversion section 1, the light does not travel in a straight line during the color conversion process. In particular, the light does not travel perpendicular to the surface of the color conversion element 23, but spreads out laterally, as shown in Fig. Figure 2 shows that by arranging multiple light-emitting modules and independently controlling their on / off states, the light can be directed to shine only in the desired directions. However, if the straightness of each light-emitting module is reduced, it becomes impossible to direct the light only in the intended direction. Fig. 2. The light emitted by neighboring light-emitting modules can overlap and interfere with each other, potentially reducing the resolution.

[0025] As shown in Fig. 3. A light reflection section 25 can be formed in a thin plate, film, or layer around the side of the color conversion element 23. However, even in this case, the light does not necessarily travel in a straight line, as some of the reflected light travels in the opposite direction due to the light reflection section 25. In such cases, the straightness of the light can decrease even further. While some of the light emitted by the LED chip 20 travels in a straight line, another part may travel towards the side of the color conversion element 23, requiring correction to ensure that the laterally directed light also travels in a straight line. As shown in Fig. 3. Not all light reaching the light reflection section 25 is reflected; some light may pass through the light reflection section 25. Theoretically, the light reflection section 3 should reflect all light; in practice, however, a significant portion of the light is reflected, but some light may pass through the light reflection section 25 and move laterally. This can lead to reduced rectilinearity and contrast.

[0026] As shown in Fig. 4 and Fig. In the embodiment of the present invention, the color conversion element 10 is configured such that the area of ​​the color conversion section 1 gradually increases along the direction of light propagation. Similarly, the light reflection section 3, which covers the side of the color conversion section 1, is designed to extend its inner area along the direction of light propagation. By configuring the reflection surface to widen in the direction of light propagation, light traveling toward the side of the color conversion element 10 is reflected by the light reflection section 3 toward the center, thereby improving straightness. Since all the light passing through the light reflection section 3 is absorbed by the light absorption section 5, only light traveling in a straight line is converted and emitted.The direction of light propagation refers to the direction orthogonal to the surface of the LED chip 20 and represents the ideal direction to which all light components are aligned with optimal straightness.

[0027] Accordingly, as shown in Fig. 5, the radiation pattern of light according to the embodiment of the present invention is formed with a smaller width compared to the radiation pattern of light in the comparative example. Such a light-emitting module with good straightness is useful when several light-emitting modules are arranged to face different positions and are controlled to emit light only at desired locations.

[0028] The color conversion element for LEDs 10 integrates a single light reflection section 3 and a light absorption section 5 within itself. A light-emitting module can also be configured by attaching a color conversion element 23 with only one color conversion section 1 to the LED chip 20 and separately installing a light reflection or light absorption component on its side. However, in applications with strong vibrations, such as in automotive headlights, gaps can form or components can detach if the light reflection or light absorption components are not firmly adhered to the color conversion element 23. Because the light reflection section 3 and the light absorption section 5 are integrally formed within the color conversion element 10 itself, optical straightness can be maintained over extended periods, even under harsh conditions.Furthermore, since it is not necessary to construct a separate light-absorbing wall for the color conversion element 10, design freedom is increased and material consumption is minimized. In addition to vibrations, temperature also affects the service life of the light-emitting module. Due to the high power output during headlight operation, the internal temperature of the light-emitting module can rise to 200 °C, while it can drop to -40 °C when parked in winter. In such cases, thermal expansion and contraction of the various components can lead to cracks if gaps exist between them. These cracks degrade the optical quality of the light-emitting module. The color conversion element 10 according to the present invention, with its integrated and firmly bonded light reflection section 3 and light absorption section 5, prevents quality degradation caused by temperature fluctuations and vibrations.

[0029] The color conversion element for LEDs 10 according to an embodiment of the present invention can be achieved by the Fig. The process shown in section 6 is used. As shown in Fig. 7. First, a wafer 31 is prepared, which is divided into individual color conversion elements for LEDs 10. The wafer 31 can be produced in a circular or square shape. It is more efficient to produce a large wafer 31 and divide it into small, chip-sized color conversion elements for LEDs 10 than to produce small color conversion elements for LEDs 10 in the actual product size from the outset. This approach is used because the size of the color conversion elements for the commonly used LEDs 10 is relatively small for manual or machine processing. The wafer 31 can be obtained by mixing powdered phosphor with glass crystals or silicone resin and subsequently sintering, pressing, and drying.

[0030] Since this wafer 31 is not the size required for use in actual products, it must be separated into smaller color conversion elements for LEDs 10. Because the surface may be rough or curved, an additional planarization process is required.

[0031] As shown in Fig. 6, will be in process The top surface of wafer 31 was ground. The manufactured wafer 31 is shown in Fig. Figure 7 has a flat bottom B, but its top T may be uneven or sloping. Typically, the center is thin and the outer edges are thick, giving the top T a curved shape. In process The top surface T is smoothed with a grinding machine. If slight irregularities remain on the top surface T, i.e., if the surface roughness has not reached the desired level, a fine grinding process can be repeated to smooth it further.

[0032] The grinding process can be carried out using a surface grinding machine, which removes material from the surface of the wafer 31 by rotating a wide, disc-shaped wheel. Grinding gradually and uniformly reduces the thickness of the wafer 31. A grinding system can include mechanical equipment with a carrier that can move the grinding machine, a carrier bed for holding the wafer 31, and a control unit.

[0033] Next in the process Singulation trenches 33 are formed in the wafer 31. Using a singulation knife, several singulation lines are formed at regular intervals in straight lines, followed by perpendicular singulation lines to create a grid pattern. By cutting only to a partial depth without completely dividing the wafer 31, the singulation trenches 33 can be formed. Between the singulation trenches 33, the wafer 31 remains raised, forming sections that later become individual color conversion elements 10 for LEDs.

[0034] A slanted singulation knife can be used, the width of which tapers towards the outside. As shown in Fig. 8, the width of the singulation trench 33 also increases towards the outside. Then the bottom surface of the singulation trench 33 is cut again. This time, a planar singulation knife without a beveled edge is used, as opposed to a beveled singulation knife with beveled sides. In the first cutting process, the beveled singulation knife has its smallest width at the outermost edge relative to its pivot point. For the second cut, a singulation knife with the same or a slightly greater width can be used. As shown in Fig. 9, the isolation trench 33 will be completed after the first and second cuts.

[0035] The separation trench 33 is formed by the first cut down to a certain depth d1, and the next depth d2 is formed by the second cut. The bottom surface of the separation trench 33 is separated from the ground surface by a specified thickness d3. The section formed by the first cut is inclined and gradually narrows, while the section formed by the second cut below it has a constant width.

[0036] As shown in Fig. 9. When the singulation trench 33 is formed, breakout areas 34 also form. During processing of the wafer 31 with the singulation knife, the surface of the wafer can break out, resulting in a rough surface. The wafer 31 is created by combining various particles, so when the surface is cut with the singulation knife, the materials that make up the wafer 31 chip away and form the singulation trench 33, while simultaneously causing breakout. This breakout phenomenon frequently occurs at the edges of the singulation trench 33, especially at the outermost edges. A breakout area 34 can form at the widest outer edge of the top of the singulation trench 33. It is recommended to remove this to achieve a smooth surface.

[0037] With reference to Fig. 6, Fig. 9 and Fig. 10 will be in process <c>The upper surface T of the wafer 31, on which the singulation trenches 33 are formed, is ground using a surface grinder. This process ensures that the thickness of the wafer 31 is reduced uniformly. Grinding removes any breakout areas 34. Since the grinding aims to remove the breakout areas 34, it is only performed to a specified depth d4 on the surface to avoid completely removing the sloped surface formed during the first cut. After completion of the process <c>Wafer 31 will be as shown in Fig. 10 and Fig. 11 with projections 32 in decahedral form, arranged in a matrix pattern on the surface. The upper side faces of the projections 32 are oblique, while the lower side faces are formed perpendicularly.

[0038] As shown in Fig. 6 and Fig. 12, will be in process <d>A reflective layer 37 is formed on the surface of the wafer 31. The reflective layer 37 can be created in a layer shape that covers the surface of the color conversion element 10. The reflective layer 37 can be formed by a layer deposition process. In this process, the wafer 31 is fixed in a vacuum chamber so that the surface with the singulation grooves 33 faces downwards. The underlying metal is vaporized and condenses on the surface of the wafer 31 until a predetermined thickness is reached. By depositing the reflective layer 37 onto the surface of the wafer 31 on which the singulation grooves 33 are formed, as shown in Fig. 12, the reflective layer 37 extends into the interior of separation trenches 33. This reflective layer 37 ultimately forms the light reflection section 3 of the finished color conversion element 10.

[0039] As shown in Fig. 6 and Fig. 13, will be in process <e>A light-absorbing material 39 is applied to the surface T of the wafer 31, where the singulation grooves 33 are formed. By mixing carbon powder with silicone or epoxy resin, a liquid light-absorbing material 39 can be produced, which can cover the entire surface of the wafer 31, including the inner surfaces of the singulation grooves 33. This application can then be dried at room temperature or by heat drying so that the light-absorbing material 39 adheres to the outer surface of the reflective layer 37. The light-absorbing material 39 ultimately forms the light-absorbing section 5 of the finished color-conversion element 10. After application of the light-absorbing material 39, it can be leveled with a scraper and then dried. This allows the light-absorbing material 39 to be uniformly filled into the singulation grooves 33.

[0040] One method for applying the light-absorbing material 39 could involve injecting a mixture of carbon and silicone resin or liquid glass into the singulation trenches 33; however, other methods for applying the light-absorbing material 39 may also be used. Similar to the formation of the reflective layer 37 by deposition, the light-absorbing material 39 can also be applied or deposited onto the wafer 31. In this case, the light-absorbing material 39 used can be chromium oxide or a nickel-chromium alloy.

[0041] As shown in Fig. 6 and Fig. 14, will be in process <f>The surface of the wafer 31, to which the light-absorbing material 39 is attached, is ground. This results in the light-absorbing material 39 being ground to a uniform thickness on the surface of the wafer 31. As shown in Fig. 14. Grinding can continue until the top surfaces of the protrusions 32 of the wafer 31 are exposed. There is no need to grind too deeply to reach the deeper regions of the singulation trenches 33. This grinding process exposes the top surface of the wafer 31, and the singulation trenches 33 are filled with the reflective layer 37 and the light-absorbing material 39. Instead of applying the reflective layer 37 or the light-absorbing material 39 to the sides after fabrication of the color conversion element 10, the reflective layer 37 and the light-absorbing material 39 are integrated into the wafer 31 by filling the singulation trenches 33. This allows the wafer 31, the reflective layer 37, and the light-absorbing material 39 to be tightly bonded together.

[0042] Although it is possible to in Fig. To achieve the condition shown in 14 by filling only the isolation trenches 33 with light-absorbing material 39, it is preferable to do so as shown in Fig. 13, the light-absorbing material 39 is applied to both the upper surface of the wafer 31 and the singulation trenches 33 and then ground down. This is because it is practically impossible to fill only the singulation trenches 33 cleanly, precisely, and uniformly with light-absorbing material 39. Likewise, it is challenging to precisely deposit a reflective layer 37 only within the singulation trenches 33. Therefore, the reflective layer 37 and the light-absorbing material 39 are applied uniformly to the entire surface of the wafer 31, including the areas with the singulation trenches 33, and then ground down to expose the areas outside the singulation trenches 33. This procedure ensures that the reflective layer 37 and the light-absorbing material 39 adhere securely to the wafer 31 and uniformly fill the entire structure of the singulation trench 33.

[0043] As shown in Fig. 6 and Fig. 15, will be in process <g>Additional singulation trenches 38 are formed on the surface of the wafer 31, into which light-absorbing material 39 and the reflective layer 37 are filled. This process is similar to the process , in which the separation trenches 38 are created using a separation knife. As shown in Fig. 15. The new singulation trenches 38 are formed at the location where the original singulation trenches 33 were filled with the reflective layer 37 and the light-absorbing material 39. Secondary singulation trenches 38 are formed along the same singulation lines as the first singulation trenches 33. A very thin singulation knife is used, resulting in the formation of very narrow singulation trenches 38. The singulation trenches 38 are positioned to cut through the light-absorbing material 39 in the middle and divide it in the center, but due to the small width of the singulation trenches, the sides of the reflective layer 37 are not reached. The width of the singulation trenches 38 can be narrower than the shortest distance between the sides of adjacent reflective layers 37.The side walls of the isolation trenches 38 consist of light-absorbing material 39, in which the reflective layer 37 and the color conversion section 1 are located.

[0044] The depth of the secondary singulation trenches 38 can be greater than that of the primary singulation trenches 33. However, it is not deep enough to completely cut through the wafer 31. In process <g>Therefore, wafer 31 is not completely decomposed into individual color conversion elements 10. The complete separation of wafer 31 into color conversion elements 10 takes place in process <h>It is possible to cut during the process. <g>to finish with the singulation knife. However, this can result in uneven or slanted sides of the color conversion element 10, since the rotational force of the high-speed singulation knife can cause unintended movement or ejection of the color conversion elements 10. In the worst case, parts of the light absorption material 39 can break off or the reflective layer 37 can be damaged. To obtain a clean and smooth color conversion element 10, the following steps are taken in the process. <g>only the isolation trenches 38 were formed, and the wafer 31 is finally put into process <h>separated into several color conversion elements 10.

[0045] In this embodiment, the method describes a process execution <g>after process <f>Alternatively, it is also possible to process first. <g>and then process <f>to carry out. This would mean that first the isolation trenches 38 are formed and then the grinding is carried out.

[0046] In process <h>The wafer 31 with the formed secondary singulation grooves 38 is turned over so that the surface faces downwards, and the opposite side is ground. The grinding process uniformly reduces the thickness of the wafer 31. As previously described, decahedral projections 32 are arranged on the wafer 31, with the spaces between the projections 32 being filled with the reflective layer 37 and the light-absorbing material 39. The sides of the decahedral projections 32 include sections parallel to the direction of light propagation and oblique sections. By reducing the thickness of the wafer 31 until the grinding machine reaches the oblique sides of the projections 32, it is possible to obtain the color-changing element 10, as shown in Fig. 1 and Fig. 16. Since the grinding machine exerts uniform pressure on the wafer 31, the color conversion elements 10 do not deviate from their predetermined positions during the separation process. This results in a multitude of color conversion elements 10 with smooth surfaces and firmly integrated light reflection sections 3 and light absorption sections 5 along the sides.

[0047] Attaching this color conversion element 10 to the emission surface of the LED chip 20 enables an emission module with excellent light conductivity, as shown in Fig. 4. A high-conductivity emission module can be constructed using only the LED chip 20 and the color conversion element 10, without any additional components. This color conversion element 10 has a smooth surface on the color conversion section 1, a uniformly thick and smooth light reflection section 3, and a light absorption section 5 with a smooth surface that prevents light scattering. This structure further improves the light conductivity, as shown in Fig. 3. The light conductivity can decrease if the surface of the color conversion element 23 and the light reflection section 25 form a right angle or greater. As in Fig. As shown in Figure 4, the color conversion element 10 in this embodiment has an acute angle (d) between the light-emitting surface of the color conversion element 10 and the light-reflecting section 3. In other words, the light-reflecting section 3 gradually widens along the direction of light propagation, which increases light conductivity.

[0048] In process <h>This results in a thicker loop to a color conversion element 10 with the one in Fig. 1 cross-section shown, while a thinner loop incorporates a color conversion element 10 with the one shown in Fig. The cross-section shown in Figure 17 is obtained. In the latter case, grinding is only carried out to the extent that the underside of the light-reflecting layer 37 is removed, and not up to the inclined side of the projection 32. As a result, the side of the color conversion section 1, the light reflection section 3, and the light absorption section 5 can form a section 43 parallel to the direction of light propagation and a section 41 with an inclined shape. The light reflection section 3 near the LED chip 20 is inclined, which allows it to effectively collect light. The light reflection section 3 in areas farther from the LED chip 20, where fewer light components propagate laterally, is formed parallel to the direction of light propagation in order to guide the light in a straight path instead of actively collecting it.

[0049] Meanwhile, they illustrate Fig. 1, Fig. 16 and Fig. 17 Examples of a color conversion element 10 formed by injecting and fixing the light-absorbing material 39 in the singulation trench 33. When a light-absorbing material 39, such as chromium oxide or a nickel-chromium alloy, is applied or deposited onto the wafer 31, the light-absorbing material 39 may not completely fill the singulation trench 33. In such cases, the light-absorbing section 5 may also form a layer similar to the light-reflecting section 3. Therefore, when fabricated using the process described above, the side of the light-absorbing section 5 may not necessarily be perpendicular to the direction of light propagation, but rather inclined, like the light-reflecting section 3, as shown in Fig. 1. If the light-absorbing material 39 does not completely fill the singulation trench 33, the process may also <g>Omitted. If the layer of light absorption material 39 is thin, it may be possible to process the upper surface of the wafer 31. <f>to grind and then directly to process <h>to move on to separating wafer 31 into the color conversion element 10.

[0050] Although the above description focused on the inclined shape of the inner surface area of ​​the light reflection section 3, which gradually widens along the direction of light propagation, the color conversion element 10 can also be installed in the opposite direction to the LED chip 20. Even in this orientation, the straightness of the light can be improved compared to cases without the light reflection section 3 or the light absorption section 5.

[0051] Although embodiments of the present disclosure are described above, those skilled in the field may modify and alter the present disclosure in various ways by adding, changing or deleting components without departing from the spirit of the present disclosure as described in the attached claims which are included in the scope of the present disclosure.< / h> < / f> < / g> < / h> < / h> < / f> < / g> < / f> < / g> < / h> < / g> < / g> < / h> < / g> < / g> < / f> < / e> < / d> < / c> < / c>

Claims

Color conversion element for LEDs, comprising: a color conversion section formed as a flat plate configured to change the color of light emitted by the LED as it passes through it; a light reflection section formed to cover the sides of the color conversion section and configured to reflect light traveling to the sides of the color conversion section; a light absorption section formed around the outer edge of the light reflection section configured to absorb light traveling through the light reflection section;wherein the color conversion section, the light reflection section, and the light absorption section are formed integrally as a flat plate with a light-emitting surface, and the light reflection section reflects light that travels to the sides of the color conversion section, while the light absorption section removes laterally directed light, thereby improving the rectilinearity of the emitted light, wherein the side surface of the color conversion section is formed at an angle; the light reflection section has a layered shape and is formed to cover the inclined side surface of the color conversion section; the light absorption section is formed in a rectangular frame shape with an inclined inner side surface and an outer side surface parallel to the direction of light propagation; wherein the entire structure is formed in the form of a rectangular flat plate shape. Color conversion element for LEDs according to claim 1, wherein: the side surface of the color conversion section is inclined to a certain depth, the remaining section being formed parallel to the direction of light propagation; the light reflection section has a layered shape and covers the side surface of the color conversion section, wherein some sections are inclined in the direction of light propagation and other sections are parallel, similar to the color conversion section; the light absorption section is formed in a rectangular frame shape, wherein a portion of the inner side surface is inclined and the remainder is formed parallel to the direction of light propagation, and the outer side surface is formed parallel to the direction of light propagation; wherein the entire structure is formed in the form of a rectangular flat plate shape. Color conversion element for LEDs according to claim 1, wherein: the light reflection section is made of a material selected from the group consisting of aluminium, silver, gold, copper, chromium, titanium dioxide and cerium oxide, and is applied to the color conversion section in the form of a layer by a deposition process. Color conversion element for LEDs according to claim 1, wherein: the light absorption section is a mixture of glass and carbon powder formed by mixing liquid glass and carbon powder and hardening the mixture. Color conversion element for LEDs according to claim 1, wherein: the light absorption section is chromium oxide or a nickel-chromium alloy and is coated on the outside of the light reflection section by a deposition process.

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