Circuit board and electronic equipment

Abstract

The utility model provides a circuit board and electronic equipment, and the circuit board comprises a substrate which comprises a first substrate and a conductive layer disposed on the first substrate, and the substrate comprises at least one first region and a second region located at the periphery of the first region; the first distributed Bragg reflection structure is arranged on the substrate and covers the second area; and the at least one light-emitting chip is located on the side, away from the substrate, of the first distributed Bragg reflection structure, and the light-emitting chip is arranged corresponding to the first area and electrically connected with the conductive layer. According to the circuit board and the electronic equipment provided by the invention, the light utilization rate can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor devices, in particular to a circuit board and electronic equipment. Background Art

[0002] COB (Chip on Board) is a technology used to package electronic components. Light sources using COB technology can be used in LED (Light Emitting Diode) lighting and display products such as projection systems. COB technology directly packages multiple chips onto a printed circuit board and electrically connects them via wires or other connections. However, light sources using COB technology in related technologies suffer from low luminous efficiency and brightness. Utility Model Content

[0003] Embodiments of the present disclosure provide a circuit board and an electronic device, which can improve light utilization efficiency.

[0004] The technical solutions provided by the embodiments of the present disclosure are as follows:

[0005] In a first aspect, an embodiment of the present disclosure provides a circuit board, comprising:

[0006] A substrate, comprising a first substrate and a conductive layer provided on the first substrate, wherein the substrate comprises at least one first region and a second region located outside the first region;

[0007] a first distributed Bragg reflection structure, wherein the first distributed Bragg reflection structure is disposed on the substrate and covers the second area; and

[0008] At least one light-emitting chip is located on a side of the first distributed Bragg reflector structure away from the substrate, and the light-emitting chip is disposed corresponding to the first area and is electrically connected to the conductive layer.

[0009] Exemplarily, the circuit board further includes: a flat layer, which is arranged on the substrate; a side of the flat layer facing away from the substrate is a flat surface at least at a position corresponding to the second area, and the first distributed Bragg reflection structure is arranged on the flat surface.

[0010] Exemplarily, the planar layer has a hollow structure at a position corresponding to the first region, the hollow structure exposes a portion of the conductive layer, and the light-emitting chip is electrically connected to the conductive layer exposed by the hollow structure.

[0011] Illustratively, the flat layer directly covers the substrate; or, the flat layer and the substrate are connected via an adhesive layer.

[0012] Exemplarily, the first distributed Bragg reflection structure entirely covers other areas on the substrate except the first area, and the other areas include the second area; or, the substrate further includes a third area in addition to the first area and the second area, and the first distributed Bragg reflection structure does not cover at least the third area.

[0013] Exemplarily, the substrate includes at least two first areas, the circuit board includes at least two light-emitting chips, one light-emitting chip is arranged corresponding to one first area, and one second area is arranged corresponding to the periphery of each first area;

[0014] There is a gap between the second regions corresponding to at least two adjacent light-emitting chips; and / or the second regions corresponding to at least two adjacent light-emitting chips are connected to each other.

[0015] Exemplarily, the circuit board includes a plurality of the light-emitting chips distributed in an array, and the periphery of each light-emitting chip corresponds to one second area;

[0016] The area of ​​the second region close to the center of the array of the light-emitting chips is greater than or equal to the area of ​​the second region close to the edge of the array of the light-emitting chips.

[0017] Exemplarily, the thickness of the first distributed Bragg reflection structure in a direction perpendicular to the substrate is 20 to 100 micrometers.

[0018] Exemplarily, the first distributed Bragg reflection structure includes at least two material layers with different refractive indices, and the at least two material layers are alternately stacked in sequence.

[0019] Exemplarily, the film layer farthest from the substrate in the first distributed Bragg reflection structure is the starting layer;

[0020] Wherein, the at least two material layers include a silicon oxide layer and a titanium oxide layer, the silicon oxide layer and the titanium oxide layer are alternately stacked in sequence, and the starting layer is the silicon oxide layer or the titanium oxide layer;

[0021] Alternatively, the at least two material layers include a silicon oxide layer, a niobium oxide layer, and a magnesium fluoride layer stacked alternately in sequence, the niobium oxide layer is located between the magnesium fluoride layer and the silicon oxide layer, and the starting layer is the magnesium fluoride layer.

[0022] In a second aspect, an embodiment of the present disclosure further provides an electronic device, comprising the circuit board as described above.

[0023] The beneficial effects brought about by the embodiments of the present disclosure are as follows:

[0024] In the above scheme, by setting a first distributed Bragg reflection structure in the area located on the periphery of the light-emitting chip on the substrate of the circuit board, and using the first distributed Bragg reflection structure to reflect the light of the light-emitting chip, the light reflectivity can be improved, thereby increasing the light rate and improving the brightness of the electronic device using the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A front view of a circuit board in some embodiments of the present disclosure is shown;

[0026] Figure 2 In some embodiments Figure 1 A cross-sectional view taken along the E-E' direction;

[0027] Figure 3 In some other embodiments Figure 1 A cross-sectional view taken along the E-E' direction;

[0028] Figure 4 A schematic diagram showing the reflection path of light by the first distributed Bragg reflection structure in the circuit board in some embodiments of the present disclosure;

[0029] Figure 5 One of the structural schematic diagrams of the circuit board in the embodiment of the present disclosure is shown;

[0030] Figure 6 A second structural diagram showing a circuit board in an embodiment of the present disclosure;

[0031] Figure 7 A third structural diagram showing a circuit board in an embodiment of the present disclosure;

[0032] Figure 8 A fourth structural diagram showing a circuit board in an embodiment of the present disclosure;

[0033] Figure 9 A fifth structural diagram showing a circuit board in an embodiment of the present disclosure;

[0034] Figure 10 One of the schematic diagrams showing the stacking structure of the first distributed Bragg reflector structure;

[0035] Figure 11 A second schematic diagram showing the stacking structure of the first distributed Bragg reflector structure;

[0036] Figure 12 A third schematic diagram showing the stacking structure of the first distributed Bragg reflector structure;

[0037] Figure 13 Schematic diagram showing the stacking structure of light-emitting chips. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0039] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0040] As used in the embodiments of the present disclosure, the terms "parallel," "perpendicular," and "identical" include the strict sense of "parallel," "perpendicular," and "identical," as well as "approximately parallel," "approximately perpendicular," and "approximately identical" with respect to a certain tolerance, which, taking into account the tolerances associated with the measurement of a particular quantity (e.g., limitations of the measurement system), means within an acceptable range of deviation for a particular value as determined by one of ordinary skill in the art. For example, "approximately" can mean within one or more standard deviations, or within 3% or 5% of the stated value.

[0041] In addition, in this document, unless otherwise defined, the terms "substantially," "essentially," "approximately," and "about" are used to describe and explain small variations. When used in connection with an event or circumstance, these terms can encompass situations where the event or circumstance occurs exactly, as well as situations where the event or circumstance occurs approximately. For example, when used in connection with a numerical value, these terms can include a range of variation of less than or equal to 10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, less than or equal to ±0.05%. The term "substantially coplanar" can refer to two surfaces being aligned along the same plane within the micrometer range, for example, within 40 μm, 30 μm, 20 μm, 10 μm, or 1 μm.

[0042] It should be understood that in the exemplary embodiments of the present disclosure, when a layer or element is referred to as being on another layer or substrate, the layer or element may be directly on the other layer or substrate, or an intervening layer may exist between the layer or element and the other layer or substrate. "A and B are disposed on the same layer" means that A and B are formed using the same film-forming process to form a film layer for forming a specific pattern, and then the layer structure is formed using the same mask through a single patterning process.

[0043] Before describing in detail the circuit board and electronic device provided by the embodiments of the present disclosure, the following description of related technologies is given:

[0044] COB (Chip on Board) is a technology used to package electronic components. Light sources using COB technology can be used in LED (Light Emitting Diode) lighting and display products such as projection systems. COB technology directly packages multiple chips onto a printed circuit board and electrically connects them via wires or other connections. However, light sources using COB technology in related technologies suffer from low luminous efficiency and brightness.

[0045] The inventors of this application have found through research that one of the reasons for the above problems is:

[0046] In related technologies, light sources using COB technology solder chips onto printed circuit boards (PCBs). The light emitted by the chips is reflected by white oil applied to the PCB. However, white oil has a low reflectivity, resulting in significant light loss and wasted light.

[0047] In order to improve the above problems, embodiments of the present disclosure provide a circuit board and an electronic device, which can improve light utilization efficiency.

[0048] like Figures 1 to 3As shown, an embodiment of the present disclosure provides a circuit board, including: a substrate 100 , a first distributed Bragg reflector (DBR) 200 , and at least one light-emitting chip 300 .

[0049] The substrate 100 includes a first substrate 110 and a conductive layer 120 disposed on the first substrate 110. The substrate 100 may be a PCB (printed circuit board) substrate, and the conductive layer 120 may include circuitry on the PCB substrate. The substrate 100 includes a first region A and a second region B. The first region A may be an area for soldering the light-emitting chip 300.

[0050] The substrate 100 may include at least one first region A. For example, one first region A may be soldered to one light-emitting chip 300. The second region B is located outside the first region A. The second region B may be an area on the substrate 100 other than the first region A, or may be a portion surrounding the first region A.

[0051] The light-emitting chip 300 is located on a side of the first distributed Bragg reflector structure 200 away from the substrate 100. The light-emitting chip 300 is disposed corresponding to the first region A and is electrically connected to the conductive layer 120. The first distributed Bragg reflector structure 200 is disposed on the substrate 100 and covers the second region B. In other words, the first distributed Bragg reflector structure 200 is disposed on the substrate 100 and is located around the light-emitting chip 300.

[0052] The basic principle of a distributed Bragg reflector structure (DBR) is to utilize the interference effect of material layers with different refractive indices to reflect light of a specific wavelength. Structurally, a DBR structure can include at least two material layers with different refractive indices, alternately stacked in sequence. For example, a DBR structure can consist of multiple alternating layers of high and low refractive indices. The thickness of each layer can be 1 / 4 of the wavelength of the incident light, which achieves phase matching and enhances reflection.

[0053] When light waves are incident on a distributed Bragg reflector structure, the different refractive indices of the layers cause reflection and transmission of the light waves. Through the multi-layer design, light of a specific wavelength is reflected multiple times within the structure, creating strong interference and effectively reflecting the light back. The distributed Bragg reflector structure can achieve high reflectivity, especially within the specific wavelength range of the design. The reflectivity of a distributed Bragg reflector structure can reach over 99%. By adjusting the parameters of the distributed Bragg reflector structure, such as the film material and thickness of each layer, precise control and selection of specific wavelengths of light can be achieved.

[0054] In the embodiment of the present disclosure, the first distributed Bragg reflection structure 200 is applied to the substrate 100 of the circuit board. The first distributed Bragg reflection structure 200 is arranged in the peripheral area of ​​the light emitting chip 300 on the substrate 100. Figure 4 As shown, the first distributed Bragg reflection structure 200 can be used to reflect the light of the light-emitting chip 300. Compared with the solution of applying white oil on the circuit board to reflect light in the related art, the reflectivity of white oil is 70-80%, while the reflectivity of the first distributed Bragg reflection structure 200 can be increased to more than 99%. Therefore, in the embodiment of the present disclosure, by arranging the first distributed Bragg reflection structure 200 around the light-emitting chip 300, the reflectivity can be improved, the light utilization rate can be improved, and the brightness of the electronic device using the circuit board can be improved.

[0055] The light emitting chip 300 may include but is not limited to an LED chip.

[0056] In order to further improve the optical efficiency, in some embodiments, such as Figure 13 As shown, not only is a first distributed Bragg reflection structure 200 provided on the substrate 100, but a second distributed Bragg reflection structure 310 is also provided in the light-emitting chip 300. The second distributed Bragg reflection structure 310 in the light-emitting chip 300 is used to reflect the light emitted by the light source to improve the reflectivity of the bottom layer of the light-emitting chip 300 and increase the brightness of the light-emitting chip 300.

[0057] Specifically, Figure 13 As shown in the figure as an example, the light-emitting chip 300 may include a first electrode layer 320, a second substrate 330, a buffer layer 340, a second distributed Bragg reflector structure 310, a first semiconductor layer 350, a light-emitting layer 360, a second semiconductor layer 370, a window layer 380, a current spreading layer 390, and a second electrode layer 301, which are stacked in sequence. It should be understood that the structure of the light-emitting chip 300 is merely an example and is not intended to be limiting.

[0058] In some exemplary embodiments of the present disclosure, the circuit board may be a printed circuit board using COB technology, such as Figure 2 As shown, the circuit board may further include a packaging layer 400 . The packaging layer 400 may at least cover the light emitting chip 300 and the first distributed Bragg reflector structure 200 , so as to package the light emitting chip 300 onto the substrate 100 .

[0059] In addition, each material layer of the first distributed Bragg reflection structure 200 can be formed by using processes such as chemical vapor deposition (CVD), physical vapor deposition (PVD), laser induced deposition (PLD), and electron beam evaporation (EBE).

[0060] For the first distributed Bragg reflector structure 200, its process requires that the material layer needs to be grown on a flat surface, but the substrate 100 has a circuit and an uneven surface, making it difficult to directly form the first distributed Bragg reflector structure 200. Therefore, in some exemplary embodiments, such as Figure 2 As shown, the circuit board further includes a flat layer 500 disposed on the substrate 100. A side of the flat layer 500 facing away from the substrate 100 is a flat surface 501 at least at a location corresponding to the second region B. The first distributed Bragg reflector structure 200 is disposed on the flat surface 501. Thus, the flat layer 500 provides a flat surface for processing the first distributed Bragg reflector structure 200, thereby enabling the fabrication of the first distributed Bragg reflector structure 200.

[0061] Since the light-emitting chip is located on the side of the first distributed Bragg reflection structure 200 facing away from the substrate 100, the flat layer 500 is located between the first distributed Bragg reflection structure 200 and the substrate 100, and the first distributed Bragg reflection structure 200 is located around the light-emitting chip 300, the light-emitting chip needs to pass through the flat layer 500 and then be electrically connected to the conductive layer 120 on the substrate 100.

[0062] In order to achieve electrical connection between the light-emitting chip and the conductive layer 120, in some embodiments, the planar layer 500 has a hollow structure at a position corresponding to the first area A, and the hollow structure exposes a portion of the conductive layer 120, and the light-emitting chip 300 is electrically connected to the conductive layer 120 exposed by the hollow structure.

[0063] In some exemplary embodiments, Figure 2As shown, the flat layer 500 can be directly covered on the substrate 100. When manufacturing the circuit board, the flat layer 500 can be first formed on the substrate 100, and then the first distributed Bragg reflector structure 200 can be formed on the flat layer 500. The flat layer 500 can be an insulating layer, for example, a white oil layer, which can further reflect light.

[0064] In other embodiments, Figure 3 As shown, the flattening layer 500 is connected to the substrate 100 via an adhesive layer 600. When preparing the circuit board, a base substrate can be provided as the flattening layer 500. The first distributed Bragg reflector structure 200 is prepared on the flattening layer 500, and the flattening layer 500 is then attached to the substrate 100 via an adhesive. The flattening layer 500 can be a metal plate, for example, a steel plate. Using a metal plate for the flattening layer 500 has the following advantages: first, the process of preparing the first distributed Bragg reflector structure 200 on a metal plate is easier to implement, and the structure is flatter, further improving the incremental effect; second, the metal plate can further reflect light.

[0065] It should be noted that in the above embodiment, when the flat layer 500 is formed directly on the substrate 100, the side of the flat layer 500 facing away from the substrate 100 must be flat, which places high demands on the process. However, when the first distributed Bragg reflector structure 200 is formed on the flat layer 500 and then bonded to the substrate 100, the process is easier to implement, but this will increase the cost of materials such as steel plates for the flat layer 500. In actual applications, the specific structure of the flat layer 500 can be selected based on actual needs.

[0066] In addition, as an exemplary embodiment, Figure 1 As shown, the first distributed Bragg reflector structure 200 entirely covers areas other than the first area A on the substrate 100, including the second area B. In other words, the first distributed Bragg reflector structure 200 may be entirely formed in areas other than the first area A. In this case, the first distributed Bragg reflector structure 200 necessarily surrounds the periphery of the first area A and reflects light not only from the area where the light source of the light-emitting chip is located and from the edges around the light source, but also from other locations on the substrate 100 as much as possible, thereby improving light utilization.

[0067] In other exemplary embodiments, Figure 6As shown, the substrate 100 further includes a third area C in addition to the first area A and the second area B, and the first distributed Bragg reflector structure 200 does not at least cover the third area C. In other words, the first distributed Bragg reflector structure 200 may also only cover the area around the light emitting chip 300, without covering other areas.

[0068] The third area C may be an area occupied by other electronic components soldered on the circuit board, or an area that has little effect on improving the light reflectivity of the light-emitting chip 300. In practical applications, the coverage area of ​​the first distributed Bragg reflection structure 200 may be reasonably designed according to different usage scenarios.

[0069] The size of the coverage area of ​​the first distributed Bragg reflection structure 200 can be based on the area of ​​the substrate 100 to cover the entire surface, or can be based on the actual use of the area. Figure 5 As shown, the circuit board 10 can serve as a light source for a projection display device. The light emitted by the light source generally needs to be concentrated by the light guide sleeve 20. The coverage area of ​​the first distributed Bragg reflector structure 200 can surround the light-emitting chip 300, and its shape can be adapted to the shape of the light guide sleeve 20. In this way, the coverage area of ​​the first distributed Bragg reflector structure 200 can be arranged according to the actual contact area of ​​the light guide sleeve 20.

[0070] For example, Figure 1 In the illustrated embodiment, the coverage area of ​​the first distributed Bragg reflector structure 200 on the substrate 100 can be approximately a 46*32 mil rectangular area. Compared to the second distributed Bragg reflector structure 310 in the light-emitting chip 300, which has a size of approximately 30*20 mil, the first distributed Bragg reflector structure 200 disposed on the substrate 100 can be designed to be larger. It should be understood that the coverage area size of the first distributed Bragg reflector structure 200 is not limited to this.

[0071] In addition, for the distributed Bragg reflection structure, the thickness of the second distributed Bragg reflection structure 310 in the light-emitting chip 300 is affected by the overall thickness of the light-emitting chip 300 and can be 20 to 60 μm, while the thickness of the first distributed Bragg reflection structure 200 covered on the substrate 100 can be 20 to 60 microns. For example, the thickness of the first distributed Bragg reflection structure 200 on the substrate 100 can be 100 microns to achieve a better reflection effect.

[0072] It should also be noted that, in some embodiments, when a first distributed Bragg reflection structure is provided in the light-emitting chip 300, the sum of the coverage areas of the second distributed Bragg reflection structure 310 in the light-emitting chip 300 and the first distributed Bragg reflection structure 200 covered on the substrate 100 is greater than the area occupied by the light-emitting chip 300. In addition to reflecting the light in the area occupied by the light source of the light-emitting chip 300, the light around the edges of the light-emitting chip 300 can be reflected as much as possible.

[0073] It should be noted that, for the first distributed Bragg reflector structure 200 on the substrate 100, the patterning of each material layer can be achieved by providing a shielding member, the shielding member forming an opening pattern, and utilizing the opening pattern to obtain the desired shape of each material layer in the first distributed Bragg reflector structure 200. The shielding member can be a removable tape or a mask.

[0074] Taking the shielding member as tape as an example, the tape can be first covered on the substrate 100, and then the first distributed Bragg reflection structure 200 can be covered on the entire surface of the substrate 100 by evaporation or other methods, and then the tape can be torn off. The process is simple and low-cost.

[0075] In addition, the substrate 100 may include one or more light-emitting chips 300 .

[0076] In some embodiments, as Figure 6 As shown, at least two light-emitting chips 300 may be provided on the substrate 100, and the substrate 100 includes at least two first areas A, one light-emitting chip 300 is provided corresponding to one first area A, and one second area B is provided corresponding to the periphery of each first area A; wherein, a gap is retained between the second areas B corresponding to at least two adjacent light-emitting chips 300.

[0077] Specifically, Figure 6 As shown in the example, the circuit board includes a plurality of the light-emitting chips 300 distributed in an array, and the periphery of each of the light-emitting chips 300 corresponds to a second area B, and a gap is reserved between the second areas B corresponding to the adjacent light-emitting chips 300, so that the first distributed Bragg reflection structures 200 outside each of the light-emitting chips 300 are arranged independently of each other.

[0078] In other embodiments, Figure 8As shown, at least two light-emitting chips 300 may be provided on the substrate 100, and the substrate 100 includes at least two first areas A, one light-emitting chip 300 is provided corresponding to one first area A, and one second area B is provided corresponding to the periphery of each first area A; wherein, the second areas B corresponding to at least two adjacent light-emitting chips 300 are connected to each other.

[0079] Specifically, Figure 8 As shown in the example, the circuit board includes a plurality of the light-emitting chips 300 distributed in an array, and the periphery of each of the light-emitting chips 300 corresponds to a second region B, and the second regions B corresponding to all the light-emitting chips 300 are connected to each other, so that the first distributed Bragg reflection structures 200 around each of the light-emitting chips 300 are connected to each other.

[0080] In addition, in other embodiments, Figure 7 As shown, the first distributed Bragg reflector structures 200 outside some of the adjacent light emitting chips 300 may be spaced apart, and the first distributed Bragg reflector structures 200 outside some of the adjacent light emitting chips 300 may be connected to each other.

[0081] In the above solution, the circuit board with multiple light-emitting chips 300 can be used as an array light source, and its application scenarios may include but are not limited to lighting products. By setting a first distributed Bragg reflection structure 200 around each light-emitting chip 300, a brightening effect can be achieved.

[0082] In addition, for an array-type light source, the light at the center of the light emitting chip 300 array is brighter than that at the edge, resulting in a problem of uneven light.

[0083] In order to solve the above problems, in some exemplary embodiments, Figure 9 As shown, the circuit board includes a plurality of light-emitting chips 300 distributed in an array, and the periphery of each light-emitting chip 300 corresponds to a second region B. The area of ​​the second region B near the center of the array of light-emitting chips 300 is larger than the area of ​​the second region B near the edge of the array of light-emitting chips 300. Thus, by designing the area of ​​the first distributed Bragg reflector 200 at the edge of the array of light-emitting chips 300 to be larger than the area of ​​the first distributed Bragg reflector 200 at the center of the array of light-emitting chips 300, the light uniformity of the array light source can be improved.

[0084] The first distributed Bragg reflection structure 200 comprises at least two material layers with different refractive indices, which are alternately stacked in sequence. The material layers can be made of semiconductor materials, dielectric materials, metal materials, polymer materials or other optical materials.

[0085] Semiconductor materials include gallium nitride (GaN), gallium arsenide (GaAs), InP (indium phosphide), etc.; dielectric materials include silicon dioxide (SiO2), magnesium fluoride (MgF2), calcium fluoride (CaF2), silicon nitride (Si3N4), etc.; metal materials include gold and silver, etc.; polymer materials include polymethyl methacrylate (PMMA), polyimide (PI) and other polymer materials; and so on.

[0086] As an exemplary embodiment, Figure 10 As shown, the film layer farthest from the substrate 100 in the first distributed Bragg reflection structure 200 is the starting layer 210; wherein, at least two material layers include silicon oxide 201 and titanium oxide layer 202, the silicon oxide 201 and titanium oxide layer 202 are alternately stacked in sequence, and the starting layer 210 is the silicon oxide 201.

[0087] As another exemplary embodiment, Figure 11 As shown, the film layer farthest from the substrate 100 in the first distributed Bragg reflection structure 200 is the starting layer 210; wherein, at least two material layers include silicon oxide 201 and titanium oxide layer 202, the silicon oxide 201 and titanium oxide layer 202 are alternately stacked in sequence, and the starting layer 210 is the titanium oxide layer 202.

[0088] In addition, in order to enhance the utilization rate of blue light, in some embodiments, the titanium oxide layer 202 may be replaced with a niobium oxide layer and doped with a magnesium fluoride layer to improve the reflection efficiency of blue light. Figure 12 As shown, the at least two material layers include silicon oxide 201, niobium oxide layer 203, and magnesium fluoride layer 204, which are alternately stacked in sequence, and the niobium oxide layer 203 is located between the magnesium fluoride layer 204 and the silicon oxide 201. The starting layer 210 can be the magnesium fluoride layer 204, which can further improve the reflection efficiency.

[0089] It should be understood that the above is merely an exemplary description of the material layers in the first distributed Bragg reflector structure 200, but is not intended to be limiting. For example, in other embodiments, the at least two material layers in the first distributed Bragg reflector structure 200 may include gallium arsenide layers and indium phosphide layers stacked alternately in sequence.

[0090] In addition, an embodiment of the present disclosure further provides an electronic device, including the circuit board provided by the embodiment of the present disclosure. The electronic device may include but is not limited to a display device, and the display device includes but is not limited to a projection device, a smart phone, a display, a laptop computer, a tablet computer, an electronic photo frame, a driving recorder, a smart wearable device and other devices with a display function. Other essential components of the display device (such as a driver chip) should be understood by those of ordinary skill in the art, and will not be described in detail here, nor should they be used as a limitation to the present disclosure. Since the principle of solving the problem by the electronic device is similar to the principle of solving the problem by the above-mentioned circuit board, the embodiment of the electronic device provided by the embodiment of the present disclosure can refer to the embodiment of the above-mentioned circuit board provided by the embodiment of the present disclosure, and will not be described in detail here.

[0091] There are a few points to note:

[0092] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure. Other structures may refer to conventional designs.

[0093] (2) For the sake of clarity, the thickness of layers or regions in the drawings used to describe the embodiments of the present disclosure are exaggerated or reduced, i.e., these drawings are not drawn to scale. It is understood that when an element such as a layer, film, region, or substrate 100 is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element, or intervening elements may be present.

[0094] (3) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to form new embodiments.

[0095] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. The protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A circuit board, characterized in that: include: A substrate, comprising a first substrate and a conductive layer provided on the first substrate, wherein the substrate comprises at least one first region and a second region located outside the first region; a first distributed Bragg reflection structure, wherein the first distributed Bragg reflection structure is provided on the substrate and covers the second area; and At least one light-emitting chip is located on a side of the first distributed Bragg reflector structure away from the substrate, and the light-emitting chip is disposed corresponding to the first area and is electrically connected to the conductive layer.

2. The circuit board according to claim 1, wherein: The circuit board further includes: a flat layer, which is arranged on the substrate; a side of the flat layer facing away from the substrate is a flat surface at least at a position corresponding to the second area, and the first distributed Bragg reflection structure is arranged on the flat surface.

3. The circuit board according to claim 2, wherein: The planar layer has a hollow structure at a position corresponding to the first region, the hollow structure exposes a portion of the conductive layer, and the light-emitting chip is electrically connected to the conductive layer exposed by the hollow structure.

4. The circuit board according to claim 2, wherein: The flat layer directly covers the substrate; or the flat layer and the substrate are connected via an adhesive layer.

5. The circuit board according to claim 1, wherein: The first distributed Bragg reflection structure entirely covers other areas on the substrate except the first area, and the other areas include the second area; or the substrate further includes a third area in addition to the first area and the second area, and the first distributed Bragg reflection structure at least does not cover the third area.

6. The circuit board according to claim 1, wherein: The substrate includes at least two first areas, the circuit board includes at least two light-emitting chips, one light-emitting chip is arranged corresponding to one first area, and one second area is arranged corresponding to the periphery of each first area; There is a gap between the second regions corresponding to at least two adjacent light-emitting chips; and / or the second regions corresponding to at least two adjacent light-emitting chips are connected to each other.

7. The circuit board according to claim 6, wherein: The circuit board includes a plurality of the light-emitting chips distributed in an array, and the periphery of each light-emitting chip corresponds to one second area; The area of ​​the second region close to the center of the array of the light-emitting chips is greater than or equal to the area of ​​the second region close to the edge of the array of the light-emitting chips.

8. The circuit board according to claim 1, wherein: The thickness of the first distributed Bragg reflection structure in a direction perpendicular to the substrate is 20 to 100 micrometers.

9. The circuit board according to claim 1, wherein: The first distributed Bragg reflection structure includes at least two material layers with different refractive indices, and the at least two material layers are alternately stacked in sequence.

10. The circuit board according to claim 9, wherein: The film layer farthest from the substrate in the first distributed Bragg reflection structure is a starting layer; Wherein, the at least two material layers include a silicon oxide layer and a titanium oxide layer, the silicon oxide layer and the titanium oxide layer are alternately stacked in sequence, and the starting layer is the silicon oxide layer or the titanium oxide layer; Alternatively, the at least two material layers include a silicon oxide layer, a niobium oxide layer, and a magnesium fluoride layer stacked alternately in sequence, the niobium oxide layer is located between the magnesium fluoride layer and the silicon oxide layer, and the starting layer is the magnesium fluoride layer.

11. An electronic device, characterized in that: Comprising the circuit board according to any one of claims 1 to 10.

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